Spads 出品字符串高效提取数值方法 Shane 末日圣诞奉献

Spads 出品，作者 WangXP 与 Shane


目录
---------- ---------- ---------- ----------
1 【综述】
2 【程序】
3 【功能】
4 【性能】
5 【附录】



1 【综述】
---------- ---------- ---------- ----------
最近因为继续编写公式处理和 Json - Java 互转组件，所以专门制作、优化了字符串变成数值的工具方法，并在性能上取得了领先于阿帕奇工具和爪哇类库等方式的成就。本方法基本思路是逐字符扫描。目前关于将字符串转为数值，市面上常见的资料，我搜索总结了十几篇吧，大体是重复的，包括这么几种方法。我看过的资料网址收集在附录中。

1、通过 Java 系统提供的 Character#isDigit(char) 判断是否为数值，然后转换。
2、通过正则表达式判断是否为数值，然后转换。
3、直接转换，捕捉异常。
4、阿帕奇提供了 isNumeric(String) 和 isNumericSpace(String) 方法用以判断。如果是数值再转换。

目前我这边的需求是，需要支持整数、数字间的空格、空白头尾、小数以及直接小数点开头的小数。

JavaLib 的 isDigit(char) 只能判断数字，所以需要事先去除空格、首位负号和第一个小数点。
正则表达式在转换前需要去除空格
直接转换前也需要去除空格
阿帕奇工具方法能判断数字和空格，所以需要事先去除首位负号和第一个小数点。

Spads 编写程序是直接利用了字符特点，扫描字符串。也可以认为是一种结合了预处理与字符 ASCII 判断的方法。本方法会将能够解析成数值的字符串解析成数值，否则返回 null 。



2 【程序】
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Spads 直接编写了适用的程序，经过很长时间性能优化，达到了优于上述所有方法的效果。代码如下。

/** * <b>抽取字符串的数字值</b><br/> *  * 本方法用来将传入字符串的内容理解为十进制数值。如果传入字符串的内容无法理解为 * 数值，则返回 <code>null</code> 。数值字符串是指包括正、负的整数、浮点数；其中 * 允许出现分割用空格，允许直接使用小数点起头以表示 0.x 样的小数。<br/> * 方法使用示例如下。 * <pre> * StringTool.fetchNumberValue("15") = 15 (java.lang.Integer) * StringTool.fetchNumberValue("300 1500 1010") * = 30015001010 (java.lang.Long) * StringTool.fetchNumberValue("28 ") = 28 (java.lang.Integer) * StringTool.fetchNumberValue("3.8") = 3.8 (java.lang.Double) * StringTool.fetchNumberValue("-99") = -99 (java.lang.Integer) * StringTool.fetchNumberValue("+15") = null * StringTool.fetchNumberValue(".45") = 0.45 (java.lang.Double) * StringTool.fetchNumberValue("-.1") = -0.1 (java.lang.Double) * StringTool.fetchNumberValue("0x3AFF0") = null * StringTool.fetchNumberValue("042") = 42 (java.lang.Integer) * StringTool.fetchNumberValue("Spads") = null * StringTool.fetchNumberValue("") = null * StringTool.fetchNumberValue(null) = null * StringTool.fetchNumberValue("5 - 3") = null * StringTool.fetchNumberValue("3.1415926.5358") = null * StringTool.fetchNumberValue("13205972138597109830758190748937102794") * = 1.320597213859711E37 (java.lang.Double) * </pre> *  * 本方法不涉及正则表达式，同时未避免生成异常的巨大系统消耗，通过遍历字符串每 * 一个字符来判断其是否符合十进制数值格式，格式不符则直接返回 * <code>null</code> 。如果格式符合，浮点数按 {@link Double} 识别，整数按 * {@link Long} 识别。如果数值范围符合 {@link Integer} ，则转换。 *  * @seeStringTool#removeChar(String, char) * @param numStr准备提取数值的字符串 * @return传入字符串按十进制理解的数值对象，其类型有可能为 * <code>Long</code> 、 <code>Integer</code> 或者 <code>Double</code>。 * @exceptionNumberFormatException当字符串是整数但超过了 * {@link Long#MIN_VALUE} - {@link Long#MAX_VALUE} 范围同时其位数并不大于 20， * 或者字符串是浮点数 但超过了 * {@link Double#MIN_VALUE} - {@link Double#MAX_VALUE} 范围。 */static public Number parseNumber(String numStr){if (numStr == null || (numStr = numStr.trim()).length() == 0)return null;final StringBuilder numBuilder = new StringBuilder();boolean doubleFlag = false;final int length = numStr.length();char numChar;for (int index = 0; index != length; index++){numChar = numStr.charAt(index);if (numChar > 57) return null;switch (StringTool.charType[numChar]){// 在之前没有小数点的情况下出现小数点，记录，同时认为此字符串是浮点数case 3:if (doubleFlag || index == length - 1) return null;doubleFlag = true;// 此处通过// 如果是数字，认为此字符串还是数值，检查下一个字符case 4: numBuilder.append(numChar);// 此处通过// 如果是空格，直接检查下一个字符case 1: continue;// 如果是负号，又不是首位，则按非数值字符串进行返回case 2:if (index == 0){numBuilder.append(numChar);continue;}// 此处通过// 如果字符不符合数值格式，方法按非数值字符串进行返回case 0: return null;}}if (doubleFlag || length > 20)return Double.valueOf(numBuilder.toString());// 非浮点数情况，如果数值在整数范围内，则按整数返回。否则按长整数返回。final long num = Long.parseLong(numBuilder.toString());final int finalNum = (int) num;if (finalNum != num) return num;return finalNum;}/** * <b>字符类型数组</b><br/> * 为字符串抽取数值含义提供的字符类型获取器。通过将字符本身作为此数组下标获取对应 * 类型。类型用整数表示，含义如下。<br/> * 1 为空白间隔，对应 <code>' '</code> 和 <code>'\t'</code><br/> * 2 为负号，对应 <code>'-'</code><br/> * 3 为小数点，对应 <code>'.'</code><br/> * 4 为数字，对应 <code>'0', '1', '2', '3', '4', '5', '6', '7', '8', '9'</code> */static private int[] charType = {0,0,0,0,0, 0,0,0,0,1,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,1,0,0, 0,0,0,0,0,0,0,0,0,0, 2,3,0,4,4,4,4,4,4,4, 4,4,4};

经过测试，发现本方法可以完美地达到需要的处理效果。以下是测试报告。

Function test...---------- ---------- ---------- ----------String: 15In StringTool way, get: 15 (Integer)---------- ---------- ---------- ----------String: 28 In StringTool way, get: 28 (Integer)---------- ---------- ---------- ----------String: 3.8In StringTool way, get: 3.8 (Double)---------- ---------- ---------- ----------String: -99In StringTool way, get: -99 (Integer)---------- ---------- ---------- ----------String: .45In StringTool way, get: 0.45 (Double)---------- ---------- ---------- ----------String: -.1In StringTool way, get: -0.1 (Double)---------- ---------- ---------- ----------String: nullIn StringTool way, get: null (null)---------- ---------- ---------- ----------String: 0x3AFF0In StringTool way, get: null (null)---------- ---------- ---------- ----------String: 042In StringTool way, get: 42 (Integer)---------- ---------- ---------- ----------String: SpadsIn StringTool way, get: null (null)---------- ---------- ---------- ----------String: In StringTool way, get: null (null)---------- ---------- ---------- ----------String:       In StringTool way, get: null (null)---------- ---------- ---------- ----------String: 5 - 3In StringTool way, get: null (null)---------- ---------- ---------- ----------String: 三十八In StringTool way, get: null (null)---------- ---------- ---------- ----------String: 3.1415926.5358In StringTool way, get: null (null)---------- ---------- ---------- ----------String: 39501.50In StringTool way, get: 39501.5 (Double)---------- ---------- ---------- ----------String: 0.000385427In StringTool way, get: 3.85427E-4 (Double)---------- ---------- ---------- ----------String: .33796678In StringTool way, get: 0.33796678 (Double)---------- ---------- ---------- ----------String: 300011110000In StringTool way, get: 300011110000 (Long)---------- ---------- ---------- ----------String: 300 1500 1010In StringTool way, get: 30015001010 (Long)---------- ---------- ---------- ----------String: -570 0015 6726In StringTool way, get: -57000156726 (Long)---------- ---------- ---------- ----------String: -2378957832975In StringTool way, get: -2378957832975 (Long)---------- ---------- ---------- ----------String: 1370 0000In StringTool way, get: 13700000 (Integer)---------- ---------- ---------- ----------String: 2015773In StringTool way, get: 2015773 (Integer)---------- ---------- ---------- ----------String: 3850In StringTool way, get: 3850 (Integer)---------- ---------- ---------- ----------String: -80058In StringTool way, get: -80058 (Integer)---------- ---------- ---------- ----------String: -1 2853 2781In StringTool way, get: -128532781 (Integer)---------- ---------- ---------- ----------String: 3In StringTool way, get: 3 (Integer)---------- ---------- ---------- ----------String: 0In StringTool way, get: 0 (Integer)---------- ---------- ---------- ----------String: -597213859710830758190748937102794In StringTool way, get: -5.972138597108308E32 (Double)---------- ---------- ---------- ----------String: 78 9254 3253 2452 9572 8532In StringTool way, get: 7.892543253245296E21 (Double)---------- ---------- ---------- ----------String: 13205972138597109830758190748937102794In StringTool way, get: 1.320597213859711E37 (Double)---------- ---------- ---------- ----------

3 【功能】
---------- ---------- ---------- ----------
Spads 推出的 parseNumber(String) 方法能够完整地实现解读数值字符串的功能。那么其它几种方法表现如何呢？

其它方法的程序代码经过 Shane 认真处理，依然有 200 多行。我就不每行都贴出来了。这里简述一下各种方法所使用的方式。

A、简单爪哇类库方法 SimpleJavaLib
B、爪哇类库方法 JavaLib
核心判断方法

private boolean isNumericByJavaLib(CharSequence numSequence){for (int i = numSequence.length(); --i >= 0; )if (!Character.isDigit(numSequence.charAt(i))) return false;return true;}

SimpleJavaLib 将字符串直接传入此检测方法进行判断，如果检验通过则直接按 Long 类型转换。
JavaLib 方法首先给字符串去除空格、首位负号和第一个小数点，然后再传入此检测方法进行判断；如果检验通过则根据有无小数点决定用 Long 还是 Double ；如果是 Long ，得到结果之后会试图转换为 int ，已决定是否可以用整形。

C、简单正则表达式 SimpleRegex
用 \d* 来判断，然后按长整数转换。

D、完整正则表达式 WholeRegex
用 ^[-]?(((\s|\d)*\d(\s|\d)*(\.(\s|\d)*\d(\s|\d)*)?)|(\.(\s|\d)*[1-9](\s|\d)*)) 来判断。如果检验通过则根据有无小数点决定用 Long 还是 Double ；如果是 Long ，得到结果之后会试图转换为 int ，已决定是否可以用整形。

E、直接转换捕捉异常 Direct
根据字符串是否含有 '.' 字符，决定用 Double 转换还是用 Long 转换。如果转换发生异常，则返回 null 。如果是 Long ，得到结果之后会试图转换为 int ，已决定是否可以用整形。

F、直接判断字符 CharAscii

private Number fetchNumberByCharAscii(String numStr){for (int i = numStr.length(); --i >= 0; ){int chr = numStr.charAt(i);if (chr < 48 || chr > 57) return null;}return Long.valueOf(numStr);}

G、简单阿帕奇工具方法 SimpleApacheUtils
核心判断方法为 org.apache.commons.lang3.StringUtils.isNumeric(CharSequence)
其余部分与 A 类似

H、完整阿帕奇工具方法 WholeApacheUtils
核心判断方法为 org.apache.commons.lang3.StringUtils.isNumericSpace(CharSequence)
首先给字符串去除首位负号和第一个小数点，然后再传入此检测方法进行判断；如果检验通过则先消除空格，然后根据有无小数点决定用 Long 还是 Double ；如果是 Long ，得到结果之后会试图转换为 int ，已决定是否可以用整形。

我设计了这些测试用字符串，以检测各种方法的功能

private String[] numStrs = {"15", "\t28 ", "3.8", "-99", ".45", "-.1", null,"0x3AFF0", "042", "Spads", "", "      ", "5 - 3", "三十八","3.1415926.5358", "39501.50", "0.000385427", ".33796678","300011110000", "300 1500 1010", "-570 0015 6726", "-2378957832975","1370 0000", "2015773", "3850", "-80058", "-1 2853 2781", "3", "0","-597213859710830758190748937102794", "78 9254 3253 2452 9572 8532","13205972138597109830758190748937102794"};

检测结果如下。

Function test...---------- ---------- ---------- ----------String: 15In StringTool way, get: 15 (Integer)In SimpleJavaLib way, get: 15 (Long)In JavaLib way, get: 15 (Integer)In SimpleRegex way, get: 15 (Long)In WholeRegex way, get: 15 (Integer)In Direct way, get: 15 (Integer)In CharAscii way, get: 15 (Long)In SimpleApacheUtils way, get: 15 (Long)In WholeApacheUtils way, get: 15 (Integer)---------- ---------- ---------- ----------String: 28 In StringTool way, get: 28 (Integer)In SimpleJavaLib way, get: null (null)In JavaLib way, get: 28 (Integer)In SimpleRegex way, get: null (null)In WholeRegex way, get: 28 (Integer)In Direct way, get: 28 (Integer)In CharAscii way, get: null (null)In SimpleApacheUtils way, get: null (null)In WholeApacheUtils way, get: 28 (Integer)---------- ---------- ---------- ----------String: 3.8In StringTool way, get: 3.8 (Double)In SimpleJavaLib way, get: null (null)In JavaLib way, get: 3.8 (Double)In SimpleRegex way, get: null (null)In WholeRegex way, get: 3.8 (Double)In Direct way, get: 3.8 (Double)In CharAscii way, get: null (null)In SimpleApacheUtils way, get: null (null)In WholeApacheUtils way, get: 3.8 (Double)---------- ---------- ---------- ----------String: -99In StringTool way, get: -99 (Integer)In SimpleJavaLib way, get: null (null)In JavaLib way, get: -99 (Integer)In SimpleRegex way, get: null (null)In WholeRegex way, get: -99 (Integer)In Direct way, get: -99 (Integer)In CharAscii way, get: null (null)In SimpleApacheUtils way, get: null (null)In WholeApacheUtils way, get: -99 (Integer)---------- ---------- ---------- ----------String: .45In StringTool way, get: 0.45 (Double)In SimpleJavaLib way, get: null (null)In JavaLib way, get: 0.45 (Double)In SimpleRegex way, get: null (null)In WholeRegex way, get: 0.45 (Double)In Direct way, get: 0.45 (Double)In CharAscii way, get: null (null)In SimpleApacheUtils way, get: null (null)In WholeApacheUtils way, get: 0.45 (Double)---------- ---------- ---------- ----------String: -.1In StringTool way, get: -0.1 (Double)In SimpleJavaLib way, get: null (null)In JavaLib way, get: -0.1 (Double)In SimpleRegex way, get: null (null)In WholeRegex way, get: -0.1 (Double)In Direct way, get: -0.1 (Double)In CharAscii way, get: null (null)In SimpleApacheUtils way, get: null (null)In WholeApacheUtils way, get: -0.1 (Double)---------- ---------- ---------- ----------String: nullIn StringTool way, get: null (null)In SimpleJavaLib way, get EXCEPTION: java.lang.NullPointerExceptionIn JavaLib way, get: null (null)In SimpleRegex way, get: null (null)In WholeRegex way, get: null (null)In Direct way, get: null (null)In CharAscii way, get EXCEPTION: java.lang.NullPointerExceptionIn SimpleApacheUtils way, get: null (null)In WholeApacheUtils way, get: null (null)---------- ---------- ---------- ----------String: 0x3AFF0In StringTool way, get: null (null)In SimpleJavaLib way, get: null (null)In JavaLib way, get: null (null)In SimpleRegex way, get: null (null)In WholeRegex way, get: null (null)In Direct way, get: null (null)In CharAscii way, get: null (null)In SimpleApacheUtils way, get: null (null)In WholeApacheUtils way, get: null (null)---------- ---------- ---------- ----------String: 042In StringTool way, get: 42 (Integer)In SimpleJavaLib way, get: 42 (Long)In JavaLib way, get: 42 (Integer)In SimpleRegex way, get: 42 (Long)In WholeRegex way, get: 42 (Integer)In Direct way, get: 42 (Integer)In CharAscii way, get: 42 (Long)In SimpleApacheUtils way, get: 42 (Long)In WholeApacheUtils way, get: 42 (Integer)---------- ---------- ---------- ----------String: SpadsIn StringTool way, get: null (null)In SimpleJavaLib way, get: null (null)In JavaLib way, get: null (null)In SimpleRegex way, get: null (null)In WholeRegex way, get: null (null)In Direct way, get: null (null)In CharAscii way, get: null (null)In SimpleApacheUtils way, get: null (null)In WholeApacheUtils way, get: null (null)---------- ---------- ---------- ----------String: In StringTool way, get: null (null)In SimpleJavaLib way, get EXCEPTION: java.lang.NumberFormatException: For input string: ""In JavaLib way, get: null (null)In SimpleRegex way, get EXCEPTION: java.lang.NumberFormatException: For input string: ""In WholeRegex way, get: null (null)In Direct way, get: null (null)In CharAscii way, get EXCEPTION: java.lang.NumberFormatException: For input string: ""In SimpleApacheUtils way, get EXCEPTION: java.lang.NumberFormatException: For input string: ""In WholeApacheUtils way, get: null (null)---------- ---------- ---------- ----------String:       In StringTool way, get: null (null)In SimpleJavaLib way, get: null (null)In JavaLib way, get: null (null)In SimpleRegex way, get: null (null)In WholeRegex way, get: null (null)In Direct way, get: null (null)In CharAscii way, get: null (null)In SimpleApacheUtils way, get EXCEPTION: java.lang.NumberFormatException: For input string: "      "In WholeApacheUtils way, get: null (null)---------- ---------- ---------- ----------String: 5 - 3In StringTool way, get: null (null)In SimpleJavaLib way, get: null (null)In JavaLib way, get: null (null)In SimpleRegex way, get: null (null)In WholeRegex way, get: null (null)In Direct way, get: null (null)In CharAscii way, get: null (null)In SimpleApacheUtils way, get: null (null)In WholeApacheUtils way, get: null (null)---------- ---------- ---------- ----------String: 三十八In StringTool way, get: null (null)In SimpleJavaLib way, get: null (null)In JavaLib way, get: null (null)In SimpleRegex way, get: null (null)In WholeRegex way, get: null (null)In Direct way, get: null (null)In CharAscii way, get: null (null)In SimpleApacheUtils way, get: null (null)In WholeApacheUtils way, get: null (null)---------- ---------- ---------- ----------String: 3.1415926.5358In StringTool way, get: null (null)In SimpleJavaLib way, get: null (null)In JavaLib way, get: null (null)In SimpleRegex way, get: null (null)In WholeRegex way, get: null (null)In Direct way, get: null (null)In CharAscii way, get: null (null)In SimpleApacheUtils way, get: null (null)In WholeApacheUtils way, get: null (null)---------- ---------- ---------- ----------String: 39501.50In StringTool way, get: 39501.5 (Double)In SimpleJavaLib way, get: null (null)In JavaLib way, get: 39501.5 (Double)In SimpleRegex way, get: null (null)In WholeRegex way, get: 39501.5 (Double)In Direct way, get: 39501.5 (Double)In CharAscii way, get: null (null)In SimpleApacheUtils way, get: null (null)In WholeApacheUtils way, get: 39501.5 (Double)---------- ---------- ---------- ----------String: 0.000385427In StringTool way, get: 3.85427E-4 (Double)In SimpleJavaLib way, get: null (null)In JavaLib way, get: 3.85427E-4 (Double)In SimpleRegex way, get: null (null)In WholeRegex way, get: 3.85427E-4 (Double)In Direct way, get: 3.85427E-4 (Double)In CharAscii way, get: null (null)In SimpleApacheUtils way, get: null (null)In WholeApacheUtils way, get: 3.85427E-4 (Double)---------- ---------- ---------- ----------String: .33796678In StringTool way, get: 0.33796678 (Double)In SimpleJavaLib way, get: null (null)In JavaLib way, get: 0.33796678 (Double)In SimpleRegex way, get: null (null)In WholeRegex way, get: 0.33796678 (Double)In Direct way, get: 0.33796678 (Double)In CharAscii way, get: null (null)In SimpleApacheUtils way, get: null (null)In WholeApacheUtils way, get: 0.33796678 (Double)---------- ---------- ---------- ----------String: 300011110000In StringTool way, get: 300011110000 (Long)In SimpleJavaLib way, get: 300011110000 (Long)In JavaLib way, get: 300011110000 (Long)In SimpleRegex way, get: 300011110000 (Long)In WholeRegex way, get: 300011110000 (Long)In Direct way, get: 300011110000 (Long)In CharAscii way, get: 300011110000 (Long)In SimpleApacheUtils way, get: 300011110000 (Long)In WholeApacheUtils way, get: 300011110000 (Long)---------- ---------- ---------- ----------String: 300 1500 1010In StringTool way, get: 30015001010 (Long)In SimpleJavaLib way, get: null (null)In JavaLib way, get: 30015001010 (Long)In SimpleRegex way, get: null (null)In WholeRegex way, get: 30015001010 (Long)In Direct way, get: 30015001010 (Long)In CharAscii way, get: null (null)In SimpleApacheUtils way, get EXCEPTION: java.lang.NumberFormatException: For input string: "300 1500 1010"In WholeApacheUtils way, get: 30015001010 (Long)---------- ---------- ---------- ----------String: -570 0015 6726In StringTool way, get: -57000156726 (Long)In SimpleJavaLib way, get: null (null)In JavaLib way, get: -57000156726 (Long)In SimpleRegex way, get: null (null)In WholeRegex way, get: -57000156726 (Long)In Direct way, get: -57000156726 (Long)In CharAscii way, get: null (null)In SimpleApacheUtils way, get: null (null)In WholeApacheUtils way, get: -57000156726 (Long)---------- ---------- ---------- ----------String: -2378957832975In StringTool way, get: -2378957832975 (Long)In SimpleJavaLib way, get: null (null)In JavaLib way, get: -2378957832975 (Long)In SimpleRegex way, get: null (null)In WholeRegex way, get: -2378957832975 (Long)In Direct way, get: -2378957832975 (Long)In CharAscii way, get: null (null)In SimpleApacheUtils way, get: null (null)In WholeApacheUtils way, get: -2378957832975 (Long)---------- ---------- ---------- ----------String: 1370 0000In StringTool way, get: 13700000 (Integer)In SimpleJavaLib way, get: null (null)In JavaLib way, get: 13700000 (Integer)In SimpleRegex way, get: null (null)In WholeRegex way, get: 13700000 (Integer)In Direct way, get: 13700000 (Integer)In CharAscii way, get: null (null)In SimpleApacheUtils way, get EXCEPTION: java.lang.NumberFormatException: For input string: "1370 0000"In WholeApacheUtils way, get: 13700000 (Integer)---------- ---------- ---------- ----------String: 2015773In StringTool way, get: 2015773 (Integer)In SimpleJavaLib way, get: 2015773 (Long)In JavaLib way, get: 2015773 (Integer)In SimpleRegex way, get: 2015773 (Long)In WholeRegex way, get: 2015773 (Integer)In Direct way, get: 2015773 (Integer)In CharAscii way, get: 2015773 (Long)In SimpleApacheUtils way, get: 2015773 (Long)In WholeApacheUtils way, get: 2015773 (Integer)---------- ---------- ---------- ----------String: 3850In StringTool way, get: 3850 (Integer)In SimpleJavaLib way, get: 3850 (Long)In JavaLib way, get: 3850 (Integer)In SimpleRegex way, get: 3850 (Long)In WholeRegex way, get: 3850 (Integer)In Direct way, get: 3850 (Integer)In CharAscii way, get: 3850 (Long)In SimpleApacheUtils way, get: 3850 (Long)In WholeApacheUtils way, get: 3850 (Integer)---------- ---------- ---------- ----------String: -80058In StringTool way, get: -80058 (Integer)In SimpleJavaLib way, get: null (null)In JavaLib way, get: -80058 (Integer)In SimpleRegex way, get: null (null)In WholeRegex way, get: -80058 (Integer)In Direct way, get: -80058 (Integer)In CharAscii way, get: null (null)In SimpleApacheUtils way, get: null (null)In WholeApacheUtils way, get: -80058 (Integer)---------- ---------- ---------- ----------String: -1 2853 2781In StringTool way, get: -128532781 (Integer)In SimpleJavaLib way, get: null (null)In JavaLib way, get: -128532781 (Integer)In SimpleRegex way, get: null (null)In WholeRegex way, get: -128532781 (Integer)In Direct way, get: -128532781 (Integer)In CharAscii way, get: null (null)In SimpleApacheUtils way, get: null (null)In WholeApacheUtils way, get: -128532781 (Integer)---------- ---------- ---------- ----------String: 3In StringTool way, get: 3 (Integer)In SimpleJavaLib way, get: 3 (Long)In JavaLib way, get: 3 (Integer)In SimpleRegex way, get: 3 (Long)In WholeRegex way, get: 3 (Integer)In Direct way, get: 3 (Integer)In CharAscii way, get: 3 (Long)In SimpleApacheUtils way, get: 3 (Long)In WholeApacheUtils way, get: 3 (Integer)---------- ---------- ---------- ----------String: 0In StringTool way, get: 0 (Integer)In SimpleJavaLib way, get: 0 (Long)In JavaLib way, get: 0 (Integer)In SimpleRegex way, get: 0 (Long)In WholeRegex way, get: 0 (Integer)In Direct way, get: 0 (Integer)In CharAscii way, get: 0 (Long)In SimpleApacheUtils way, get: 0 (Long)In WholeApacheUtils way, get: 0 (Integer)---------- ---------- ---------- ----------String: -597213859710830758190748937102794In StringTool way, get: -5.972138597108308E32 (Double)In SimpleJavaLib way, get: null (null)In JavaLib way, get: -5.972138597108308E32 (Double)In SimpleRegex way, get: null (null)In WholeRegex way, get: -5.972138597108308E32 (Double)In Direct way, get: null (null)In CharAscii way, get: null (null)In SimpleApacheUtils way, get: null (null)In WholeApacheUtils way, get: -5.972138597108308E32 (Double)---------- ---------- ---------- ----------String: 78 9254 3253 2452 9572 8532In StringTool way, get: 7.892543253245296E21 (Double)In SimpleJavaLib way, get: null (null)In JavaLib way, get: 7.892543253245296E21 (Double)In SimpleRegex way, get: null (null)In WholeRegex way, get: 7.892543253245296E21 (Double)In Direct way, get: null (null)In CharAscii way, get: null (null)In SimpleApacheUtils way, get EXCEPTION: java.lang.NumberFormatException: For input string: "78 9254 3253 2452 9572 8532"In WholeApacheUtils way, get: 7.892543253245296E21 (Double)---------- ---------- ---------- ----------String: 13205972138597109830758190748937102794In StringTool way, get: 1.320597213859711E37 (Double)In SimpleJavaLib way, get EXCEPTION: java.lang.NumberFormatException: For input string: "13205972138597109830758190748937102794"In JavaLib way, get: 1.320597213859711E37 (Double)In SimpleRegex way, get EXCEPTION: java.lang.NumberFormatException: For input string: "13205972138597109830758190748937102794"In WholeRegex way, get: 1.320597213859711E37 (Double)In Direct way, get: null (null)In CharAscii way, get EXCEPTION: java.lang.NumberFormatException: For input string: "13205972138597109830758190748937102794"In SimpleApacheUtils way, get EXCEPTION: java.lang.NumberFormatException: For input string: "13205972138597109830758190748937102794"In WholeApacheUtils way, get: 1.320597213859711E37 (Double)---------- ---------- ---------- ----------

4 【性能】
---------- ---------- ---------- ----------
根据功能测试，我们可以看到，各种简易方法都不能满足需要。接下来对几种能够满足需要的“完整”方法来进行性能测评对比。测试程序通过多线程，每个线程执行一种方案若干次，来直观地表现各种方法的快慢。这种测试被重复了七轮，基本消除了线程调度起伏带来的影响。每轮执行的时间都收录并累加，作为最终评判各方法性能的依据。线程控制使用了原子操作类。测试代码如下。

public void testFetchNumberPerformance(){Runnable r;List<SortedMap<Long, String>> timeUsed =new ArrayList<SortedMap<Long, String>>(this.numStrs.length);System.out.println("Loop times = " + this.loopNum);System.out.println("---------- ---------- ---------- ----------");for (final String numStr: this.numStrs){final Map<String, Long> timeUsedCount =Collections.synchronizedMap(new HashMap<String, Long>());System.out.println("String: " + numStr);for (int loop = -1; ++loop != 7; ){final AtomicInteger runThreadNum = new AtomicInteger(0);// StringToolr = new Runnable(){public void run(){boolean hasEx = false;if (timeUsedCount.get("StringTool") == null)timeUsedCount.put("StringTool", 0L);long start = System.currentTimeMillis();for (int index = -1; ++index != FetchNumberTest.this.loopNum; ){try { StringTool.parseNumber(numStr); }catch (Exception ex) { hasEx = true; }}long use = System.currentTimeMillis() - start;System.out.print("\ttool:" + use + "ms" + (hasEx ? "(EX)" : "") + '.');use += timeUsedCount.get("StringTool");timeUsedCount.put("StringTool", use);runThreadNum.addAndGet(-1);Thread.yield();}};runThreadNum.addAndGet(1);new Thread(r).start();// JavaLibr = new Runnable(){public void run(){boolean hasEx = false;if (timeUsedCount.get("JavaLib") == null)timeUsedCount.put("JavaLib", 0L);long start = System.currentTimeMillis();for (int index = -1; ++index != FetchNumberTest.this.loopNum; ){try { FetchNumberTest.this.fetchNumberByJavaLib(numStr); }catch (Exception ex) { hasEx = true; }}long use = System.currentTimeMillis() - start;System.out.print("\tlib:" + use + "ms" + (hasEx ? "(EX)" : "") + '.');use += timeUsedCount.get("JavaLib");timeUsedCount.put("JavaLib", use);runThreadNum.addAndGet(-1);Thread.yield();}};runThreadNum.addAndGet(1);new Thread(r).start();// WholeRegexr = new Runnable(){public void run(){boolean hasEx = false;if (timeUsedCount.get("WholeRegex") == null)timeUsedCount.put("WholeRegex", 0L);long start = System.currentTimeMillis();for (int index = -1; ++index != FetchNumberTest.this.loopNum; ){try { FetchNumberTest.this.fetchNumberByRegex(numStr, false); }catch (Exception ex) { hasEx = true; }}long use = System.currentTimeMillis() - start;System.out.print("\treg:" + use + "ms" + (hasEx ? "(EX)" : "") + '.');use += timeUsedCount.get("WholeRegex");timeUsedCount.put("WholeRegex", use);runThreadNum.addAndGet(-1);Thread.yield();}};runThreadNum.addAndGet(1);new Thread(r).start();// Directr = new Runnable(){public void run(){boolean hasEx = false;if (timeUsedCount.get("Direct") == null)timeUsedCount.put("Direct", 0L);long start = System.currentTimeMillis();for (int index = -1; ++index != FetchNumberTest.this.loopNum; ){try { FetchNumberTest.this.fetchNumberByDirect(numStr); }catch (Exception ex) { hasEx = true; }}long use = System.currentTimeMillis() - start;System.out.print("\t--:" + use + "ms" + (hasEx ? "(EX)" : "") + '.');use += timeUsedCount.get("Direct");timeUsedCount.put("Direct", use);runThreadNum.addAndGet(-1);Thread.yield();}};runThreadNum.addAndGet(1);new Thread(r).start();// WholeApacheUtilsr = new Runnable(){public void run(){boolean hasEx = false;if (timeUsedCount.get("WholeApacheUtils") == null)timeUsedCount.put("WholeApacheUtils", 0L);long start = System.currentTimeMillis();for (int index = -1; ++index != FetchNumberTest.this.loopNum; ){try { FetchNumberTest.this.fetchNumberByApacheUtils(numStr); }catch (Exception ex) { hasEx = true; }}long use = System.currentTimeMillis() - start;System.out.print("\tap:" + use + "ms" + (hasEx ? "(EX)" : "") + '.');use += timeUsedCount.get("WholeApacheUtils");timeUsedCount.put("WholeApacheUtils", use);runThreadNum.addAndGet(-1);Thread.yield();}};runThreadNum.addAndGet(1);new Thread(r).start();while (runThreadNum.get() != 0){try { Thread.sleep(10); } catch (Exception ex) { }Thread.yield();}for (int index = -1; ++index != 3; ){try { Thread.sleep(100); } catch (Exception ex) { }Thread.yield();}System.out.println();}SortedMap<Long, String> thisNumStrTimeUsed =Collections.synchronizedSortedMap(new TreeMap<Long, String>());for (String name: timeUsedCount.keySet())thisNumStrTimeUsed.put(timeUsedCount.get(name), name);timeUsed.add(thisNumStrTimeUsed);for (Long time: thisNumStrTimeUsed.keySet())System.out.println(thisNumStrTimeUsed.get(time) + ": " + time + " ms.");System.out.println("---------- ---------- ---------- ----------");}}

每种方法循环量 loopNum 设为 12001000 ，各种情况性能表现如下。

Performance test...Loop times = 12001000---------- ---------- ---------- ----------String: 15tool:1201ms.--:1810ms.ap:2014ms.lib:3058ms.reg:5508ms.tool:982ms.--:1577ms.ap:1780ms.lib:2746ms.reg:5166ms.tool:967ms.--:1577ms.ap:1812ms.lib:2810ms.reg:5136ms.tool:983ms.--:1498ms.ap:1779ms.lib:2590ms.reg:5009ms.tool:920ms.--:1452ms.ap:1701ms.lib:2590ms.reg:5118ms.tool:998ms.--:1514ms.ap:1795ms.lib:2668ms.reg:5165ms.tool:998ms.--:1545ms.ap:1764ms.lib:2700ms.reg:5088ms.StringTool: 7049 ms.Direct: 10973 ms.WholeApacheUtils: 12645 ms.JavaLib: 19162 ms.WholeRegex: 36190 ms.---------- ---------- ---------- ----------String: 28 tool:1154ms.--:1654ms.ap:1966ms.lib:2684ms.reg:5353ms.tool:1123ms.--:1670ms.ap:1889ms.lib:2762ms.reg:5259ms.tool:1139ms.--:1764ms.ap:1889ms.lib:2747ms.reg:5460ms.tool:1168ms.--:1715ms.ap:1996ms.lib:2776ms.reg:5413ms.tool:1092ms.--:1842ms.ap:1842ms.lib:2794ms.reg:5447ms.tool:1170ms.--:1655ms.ap:1998ms.lib:2793ms.reg:5415ms.tool:1170ms.--:1671ms.ap:1858ms.lib:2685ms.reg:5338ms.StringTool: 8016 ms.Direct: 11971 ms.WholeApacheUtils: 13438 ms.JavaLib: 19241 ms.WholeRegex: 37685 ms.---------- ---------- ---------- ----------String: 3.8tool:2121ms.--:2793ms.ap:3885ms.lib:4775ms.reg:7942ms.tool:2075ms.--:2778ms.ap:3808ms.lib:4760ms.reg:7724ms.tool:2137ms.--:2840ms.ap:4135ms.lib:5230ms.reg:8803ms.tool:2044ms.--:2606ms.ap:3480ms.lib:4713ms.reg:7959ms.tool:2013ms.--:2451ms.ap:3620ms.lib:4760ms.reg:8193ms.tool:1856ms.--:2777ms.ap:4150ms.lib:5009ms.reg:8223ms.tool:1872ms.--:2403ms.ap:3729ms.lib:4887ms.reg:8382ms.StringTool: 14118 ms.Direct: 18648 ms.WholeApacheUtils: 26807 ms.JavaLib: 34134 ms.WholeRegex: 57226 ms.---------- ---------- ---------- ----------String: -99tool:1186ms.--:1780ms.ap:2248ms.lib:3325ms.reg:6649ms.tool:1108ms.--:1826ms.ap:2107ms.lib:2981ms.reg:6102ms.tool:1139ms.--:1717ms.ap:2170ms.lib:3247ms.reg:6446ms.tool:1154ms.--:1701ms.ap:1998ms.lib:3074ms.reg:6039ms.tool:1139ms.--:1686ms.ap:2029ms.lib:3199ms.reg:6508ms.tool:1123ms.--:1655ms.ap:1920ms.lib:2902ms.reg:5914ms.tool:1154ms.--:1748ms.ap:2123ms.lib:3215ms.reg:6773ms.StringTool: 8003 ms.Direct: 12113 ms.WholeApacheUtils: 14595 ms.JavaLib: 21943 ms.WholeRegex: 44431 ms.---------- ---------- ---------- ----------String: .45tool:1763ms.--:2435ms.ap:3777ms.lib:4651ms.reg:7662ms.tool:1888ms.--:2263ms.ap:3823ms.lib:4963ms.reg:8131ms.tool:2153ms.--:2965ms.ap:4182ms.lib:5321ms.reg:8271ms.tool:1903ms.--:2513ms.ap:3667ms.lib:4713ms.reg:8130ms.tool:2075ms.--:2684ms.ap:3948ms.lib:5041ms.reg:8396ms.tool:2231ms.--:2809ms.ap:3995ms.lib:5041ms.reg:8208ms.tool:2230ms.--:3183ms.ap:4197ms.lib:5306ms.reg:8193ms.StringTool: 14243 ms.Direct: 18852 ms.WholeApacheUtils: 27589 ms.JavaLib: 35036 ms.WholeRegex: 56991 ms.---------- ---------- ---------- ----------String: -.1tool:1825ms.--:2434ms.ap:4088ms.lib:4963ms.reg:7661ms.tool:2481ms.--:3028ms.ap:4525ms.lib:5665ms.reg:8084ms.tool:2153ms.--:2529ms.ap:4338ms.lib:5072ms.reg:7131ms.tool:2308ms.--:3292ms.ap:4322ms.lib:5446ms.reg:8224ms.tool:2543ms.--:2918ms.ap:4385ms.lib:5415ms.reg:8209ms.tool:2418ms.--:3012ms.ap:4213ms.lib:5446ms.reg:7959ms.tool:2247ms.--:2700ms.ap:3745ms.lib:4823ms.reg:7554ms.StringTool: 15975 ms.Direct: 19913 ms.WholeApacheUtils: 29616 ms.JavaLib: 36830 ms.WholeRegex: 54822 ms.---------- ---------- ---------- ----------String: null--:47ms.tool:125ms.lib:140ms.reg:156ms.ap:156ms.--:31ms.lib:94ms.tool:94ms.ap:78ms.reg:125ms.--:16ms.ap:95ms.tool:95ms.reg:126ms.lib:126ms.--:31ms.lib:94ms.tool:94ms.ap:94ms.reg:109ms.--:47ms.reg:94ms.lib:94ms.tool:94ms.ap:94ms.--:47ms.lib:94ms.reg:110ms.ap:63ms.tool:125ms.--:15ms.reg:78ms.tool:78ms.lib:110ms.ap:110ms.Direct: 234 ms.WholeApacheUtils: 690 ms.StringTool: 705 ms.JavaLib: 752 ms.WholeRegex: 798 ms.---------- ---------- ---------- ----------String: 0x3AFF0tool:406ms.ap:579ms.lib:1608ms.reg:4760ms.--:18146ms.tool:359ms.ap:578ms.lib:1763ms.reg:5180ms.--:17146ms.tool:328ms.ap:530ms.lib:1685ms.reg:4775ms.--:17303ms.tool:390ms.ap:562ms.lib:1607ms.reg:5009ms.--:15977ms.tool:359ms.ap:546ms.lib:1700ms.reg:4728ms.--:18519ms.tool:437ms.ap:702ms.lib:2107ms.reg:5494ms.--:16086ms.tool:374ms.ap:515ms.lib:1653ms.reg:5055ms.--:17224ms.StringTool: 2653 ms.WholeApacheUtils: 4012 ms.JavaLib: 12123 ms.WholeRegex: 35001 ms.Direct: 120401 ms.---------- ---------- ---------- ----------String: 042tool:1170ms.--:1795ms.ap:2014ms.lib:2934ms.reg:7100ms.tool:1482ms.--:2154ms.ap:2481ms.lib:3559ms.reg:7788ms.tool:1373ms.--:2029ms.ap:2154ms.lib:3261ms.reg:7381ms.tool:1279ms.--:1935ms.ap:2201ms.lib:3339ms.reg:7459ms.tool:1279ms.--:1936ms.ap:2294ms.lib:3450ms.reg:7507ms.tool:1373ms.--:1826ms.ap:2122ms.lib:3402ms.reg:7583ms.tool:1513ms.--:2356ms.ap:2529ms.lib:3668ms.reg:7912ms.StringTool: 9469 ms.Direct: 14031 ms.WholeApacheUtils: 15795 ms.JavaLib: 23613 ms.WholeRegex: 52730 ms.---------- ---------- ---------- ----------String: Spadstool:374ms.ap:577ms.lib:1825ms.reg:3480ms.--:15945ms.tool:281ms.ap:405ms.lib:1545ms.reg:3090ms.--:15930ms.tool:343ms.ap:655ms.lib:1716ms.reg:3324ms.--:16023ms.tool:265ms.ap:546ms.lib:1450ms.reg:3136ms.--:16148ms.tool:296ms.ap:452ms.lib:1482ms.reg:3012ms.--:18254ms.tool:297ms.ap:468ms.lib:1514ms.reg:2903ms.--:17131ms.tool:297ms.ap:484ms.lib:1482ms.reg:2981ms.--:15072ms.StringTool: 2153 ms.WholeApacheUtils: 3587 ms.JavaLib: 11014 ms.WholeRegex: 21926 ms.Direct: 114503 ms.---------- ---------- ---------- ----------String: tool:93ms.lib:125ms.ap:110ms.reg:2231ms.--:16334ms.tool:125ms.lib:156ms.ap:140ms.reg:2683ms.--:15539ms.tool:156ms.lib:172ms.ap:156ms.reg:2746ms.--:15570ms.tool:125ms.ap:140ms.lib:172ms.reg:2418ms.--:16272ms.tool:125ms.lib:125ms.ap:141ms.reg:2153ms.--:14431ms.lib:140ms.tool:140ms.ap:125ms.reg:2589ms.--:18627ms.tool:141ms.ap:156ms.lib:172ms.reg:2777ms.--:17909ms.StringTool: 905 ms.WholeApacheUtils: 968 ms.JavaLib: 1062 ms.WholeRegex: 17597 ms.Direct: 114682 ms.---------- ---------- ---------- ----------String:       lib:405ms.tool:421ms.ap:406ms.reg:2854ms.--:18175ms.tool:452ms.ap:468ms.lib:530ms.reg:3182ms.--:18833ms.lib:499ms.tool:499ms.ap:530ms.reg:2964ms.--:15086ms.lib:406ms.tool:421ms.ap:405ms.reg:2683ms.--:17005ms.ap:375ms.tool:421ms.lib:453ms.reg:3089ms.--:18752ms.tool:514ms.lib:500ms.ap:546ms.reg:3151ms.--:17254ms.lib:484ms.tool:484ms.ap:546ms.reg:3183ms.--:14962ms.StringTool: 3212 ms.WholeApacheUtils: 3276 ms.JavaLib: 3277 ms.WholeRegex: 21106 ms.Direct: 120067 ms.---------- ---------- ---------- ----------String: 5 - 3tool:530ms.ap:905ms.lib:1904ms.reg:8487ms.--:17490ms.tool:484ms.ap:733ms.lib:1483ms.reg:7583ms.--:18051ms.tool:514ms.ap:686ms.lib:1467ms.reg:7707ms.--:18285ms.tool:640ms.ap:905ms.lib:1904ms.reg:8519ms.--:17474ms.tool:437ms.ap:702ms.lib:1546ms.reg:7942ms.--:16881ms.tool:453ms.ap:702ms.lib:1546ms.reg:8332ms.--:18941ms.tool:593ms.ap:749ms.lib:1857ms.reg:8582ms.--:17335ms.StringTool: 3651 ms.WholeApacheUtils: 5382 ms.JavaLib: 11707 ms.WholeRegex: 57152 ms.Direct: 124457 ms.---------- ---------- ---------- ----------String: 三十八tool:328ms.ap:655ms.lib:1857ms.reg:3449ms.--:17537ms.tool:265ms.ap:483ms.lib:1466ms.reg:2731ms.--:18020ms.tool:265ms.ap:593ms.lib:1685ms.reg:3230ms.--:16101ms.tool:265ms.ap:468ms.lib:1420ms.reg:2981ms.--:17287ms.tool:328ms.ap:546ms.lib:1591ms.reg:3137ms.--:17318ms.tool:390ms.ap:624ms.lib:1685ms.reg:3012ms.--:17568ms.tool:265ms.ap:515ms.lib:1513ms.reg:2996ms.--:18005ms.StringTool: 2106 ms.WholeApacheUtils: 3884 ms.JavaLib: 11217 ms.WholeRegex: 21536 ms.Direct: 121836 ms.---------- ---------- ---------- ----------String: 3.1415926.5358tool:1248ms.ap:1951ms.lib:3558ms.--:21202ms.reg:46397ms.tool:1092ms.ap:1873ms.lib:3245ms.--:20578ms.reg:44931ms.tool:1310ms.ap:2247ms.lib:3963ms.--:22497ms.reg:46475ms.tool:1154ms.ap:2013ms.lib:3791ms.--:21280ms.reg:46428ms.tool:1186ms.ap:1951ms.lib:3371ms.--:22139ms.reg:49457ms.tool:1404ms.ap:2310ms.lib:3776ms.--:21233ms.reg:46881ms.tool:1108ms.ap:1889ms.lib:3277ms.--:20968ms.reg:43433ms.StringTool: 8502 ms.WholeApacheUtils: 14234 ms.JavaLib: 24981 ms.Direct: 149897 ms.WholeRegex: 324002 ms.---------- ---------- ---------- ----------String: 39501.50tool:3744ms.--:4088ms.ap:5929ms.lib:7318ms.reg:15728ms.tool:3728ms.--:4353ms.ap:5835ms.lib:7240ms.reg:14511ms.tool:3292ms.--:4104ms.ap:5914ms.lib:7225ms.reg:15166ms.tool:3198ms.--:3994ms.ap:5773ms.lib:6991ms.reg:15775ms.tool:3417ms.--:3698ms.ap:5633ms.lib:7038ms.reg:15198ms.tool:3260ms.--:4151ms.ap:6132ms.lib:7474ms.reg:15993ms.tool:3214ms.--:3620ms.ap:5399ms.lib:6788ms.reg:15603ms.StringTool: 23853 ms.Direct: 28008 ms.WholeApacheUtils: 40615 ms.JavaLib: 50074 ms.WholeRegex: 107974 ms.---------- ---------- ---------- ----------String: 0.000385427tool:4228ms.--:4603ms.ap:6444ms.lib:8177ms.reg:17944ms.tool:4087ms.--:4431ms.ap:6678ms.lib:8301ms.reg:17834ms.tool:3775ms.--:4306ms.ap:6241ms.lib:7849ms.reg:18801ms.tool:3994ms.--:4307ms.ap:6709ms.lib:7771ms.reg:19269ms.tool:3526ms.--:4307ms.ap:6053ms.lib:7693ms.reg:18177ms.tool:3884ms.--:4073ms.ap:6381ms.lib:7880ms.reg:19269ms.tool:3447ms.--:3760ms.ap:5711ms.lib:7225ms.reg:17959ms.StringTool: 26941 ms.Direct: 29787 ms.WholeApacheUtils: 44217 ms.JavaLib: 54896 ms.WholeRegex: 129253 ms.---------- ---------- ---------- ----------String: .33796678tool:3525ms.--:3916ms.ap:5648ms.lib:6928ms.reg:15712ms.tool:3292ms.--:3745ms.ap:5711ms.lib:7178ms.reg:15556ms.tool:3775ms.--:4119ms.ap:6007ms.lib:7287ms.reg:16071ms.tool:3463ms.--:3823ms.ap:5601ms.lib:7069ms.reg:14246ms.tool:3401ms.--:4026ms.ap:5991ms.lib:7162ms.reg:15884ms.tool:3806ms.--:4291ms.ap:5898ms.lib:7396ms.reg:15915ms.tool:3884ms.--:4088ms.ap:5960ms.lib:7553ms.reg:15946ms.StringTool: 25146 ms.Direct: 28008 ms.WholeApacheUtils: 40816 ms.JavaLib: 50573 ms.WholeRegex: 109330 ms.---------- ---------- ---------- ----------String: 300011110000tool:3213ms.--:4322ms.ap:4869ms.lib:6522ms.reg:16897ms.tool:3354ms.--:4010ms.ap:4899ms.lib:6647ms.reg:18614ms.tool:3260ms.--:3792ms.ap:4463ms.lib:6117ms.reg:17178ms.tool:3276ms.--:3776ms.ap:4696ms.lib:6444ms.reg:17678ms.tool:3057ms.--:3838ms.ap:4853ms.lib:6382ms.reg:17351ms.tool:3448ms.--:4197ms.ap:5040ms.lib:6492ms.reg:18489ms.tool:3588ms.--:4322ms.ap:5727ms.lib:7880ms.reg:20377ms.StringTool: 23196 ms.Direct: 28257 ms.WholeApacheUtils: 34547 ms.JavaLib: 46484 ms.WholeRegex: 126584 ms.---------- ---------- ---------- ----------String: 300 1500 1010tool:3432ms.--:3855ms.ap:5134ms.lib:6476ms.reg:18739ms.tool:3604ms.--:3963ms.ap:5055ms.lib:6367ms.reg:19409ms.tool:3432ms.--:3526ms.ap:4822ms.lib:5945ms.reg:18754ms.tool:2683ms.--:3371ms.ap:4712ms.lib:6258ms.reg:18239ms.tool:3198ms.--:3604ms.ap:4900ms.lib:6132ms.reg:19472ms.tool:3213ms.--:3620ms.ap:4790ms.lib:6133ms.reg:17444ms.tool:3135ms.--:3823ms.ap:5367ms.lib:6679ms.reg:18941ms.StringTool: 22697 ms.Direct: 25762 ms.WholeApacheUtils: 34780 ms.JavaLib: 43990 ms.WholeRegex: 130998 ms.---------- ---------- ---------- ----------String: -570 0015 6726tool:3323ms.--:3527ms.ap:5290ms.lib:6508ms.reg:18911ms.--:3588ms.tool:3667ms.ap:5273ms.lib:6554ms.reg:18224ms.tool:3588ms.--:4072ms.ap:5071ms.lib:6616ms.reg:18926ms.tool:3697ms.--:3948ms.ap:5196ms.lib:6304ms.reg:18910ms.tool:3698ms.--:4135ms.ap:5086ms.lib:6632ms.reg:17382ms.tool:3760ms.--:3932ms.ap:5445ms.lib:6726ms.reg:19612ms.tool:3448ms.--:3776ms.ap:5103ms.lib:6227ms.reg:18365ms.StringTool: 25181 ms.Direct: 26978 ms.WholeApacheUtils: 36464 ms.JavaLib: 45567 ms.WholeRegex: 130330 ms.---------- ---------- ---------- ----------String: -2378957832975tool:3354ms.--:4041ms.ap:5243ms.lib:6897ms.reg:18660ms.tool:3338ms.--:3886ms.ap:5086ms.lib:7068ms.reg:19347ms.tool:3978ms.--:3962ms.ap:5414ms.lib:7006ms.reg:18848ms.tool:3884ms.--:4525ms.ap:5352ms.lib:6928ms.reg:18551ms.tool:3962ms.--:4525ms.ap:5508ms.lib:6959ms.reg:19159ms.tool:4196ms.--:4306ms.ap:5164ms.lib:7161ms.reg:19018ms.tool:3931ms.--:3979ms.ap:5118ms.lib:6913ms.reg:17943ms.StringTool: 26643 ms.Direct: 29224 ms.WholeApacheUtils: 36885 ms.JavaLib: 48932 ms.WholeRegex: 131526 ms.---------- ---------- ---------- ----------String: 1370 0000tool:2262ms.--:2825ms.ap:3621ms.lib:5041ms.reg:13778ms.tool:2559ms.--:3184ms.ap:4010ms.lib:5213ms.reg:15432ms.tool:2434ms.--:3199ms.ap:4057ms.lib:5259ms.reg:14028ms.tool:2153ms.--:2778ms.ap:3964ms.lib:5228ms.reg:13778ms.tool:2480ms.--:2965ms.ap:3979ms.lib:4947ms.reg:15009ms.tool:2309ms.--:2918ms.ap:3761ms.lib:4916ms.reg:13872ms.tool:2465ms.--:2965ms.ap:3714ms.lib:5041ms.reg:14760ms.StringTool: 16662 ms.Direct: 20834 ms.WholeApacheUtils: 27106 ms.JavaLib: 35645 ms.WholeRegex: 100657 ms.---------- ---------- ---------- ----------String: 2015773tool:1872ms.--:2341ms.ap:3012ms.lib:4463ms.reg:11422ms.tool:2387ms.--:3449ms.ap:3466ms.lib:4854ms.reg:11641ms.tool:1919ms.--:2840ms.ap:3121ms.lib:4401ms.reg:12264ms.tool:1685ms.--:2325ms.ap:2934ms.lib:4635ms.reg:12030ms.tool:2012ms.--:2497ms.ap:3214ms.lib:4666ms.reg:11172ms.tool:2184ms.--:3043ms.ap:3495ms.lib:4854ms.reg:12780ms.tool:2496ms.--:3152ms.ap:3667ms.lib:4932ms.reg:13076ms.StringTool: 14555 ms.Direct: 19647 ms.WholeApacheUtils: 22909 ms.JavaLib: 32805 ms.WholeRegex: 84385 ms.---------- ---------- ---------- ----------String: 3850tool:1778ms.--:2653ms.ap:3137ms.lib:4401ms.reg:9878ms.tool:1669ms.--:2466ms.ap:2824ms.lib:4105ms.reg:8739ms.tool:1326ms.--:2107ms.ap:2513ms.lib:3621ms.reg:8817ms.tool:1794ms.--:2501ms.ap:2844ms.lib:4000ms.reg:8603ms.tool:1326ms.--:1904ms.ap:2326ms.lib:3527ms.reg:8957ms.tool:1731ms.--:2342ms.ap:2810ms.lib:4059ms.reg:9116ms.tool:1623ms.--:2560ms.ap:2746ms.lib:3840ms.reg:9364ms.StringTool: 11247 ms.Direct: 16533 ms.WholeApacheUtils: 19200 ms.JavaLib: 27553 ms.WholeRegex: 63474 ms.---------- ---------- ---------- ----------String: -80058tool:2199ms.--:2871ms.ap:3370ms.lib:4510ms.reg:9768ms.tool:1809ms.--:2232ms.ap:2809ms.lib:4337ms.reg:10516ms.tool:2200ms.--:2669ms.ap:3371ms.lib:4433ms.reg:10611ms.tool:1779ms.--:2326ms.ap:2684ms.lib:3761ms.reg:9643ms.tool:2106ms.--:2809ms.ap:3370ms.lib:4729ms.reg:10424ms.tool:1654ms.--:2326ms.ap:3215ms.lib:4651ms.reg:10362ms.tool:1716ms.--:1966ms.ap:2762ms.lib:4261ms.reg:10393ms.StringTool: 13463 ms.Direct: 17199 ms.WholeApacheUtils: 21581 ms.JavaLib: 30682 ms.WholeRegex: 71717 ms.---------- ---------- ---------- ----------String: -1 2853 2781tool:3073ms.--:3370ms.ap:4525ms.lib:5633ms.reg:17475ms.tool:2558ms.--:3027ms.ap:4634ms.lib:5556ms.reg:16101ms.tool:3292ms.--:3590ms.ap:4478ms.lib:5915ms.reg:16009ms.tool:2762ms.--:2918ms.ap:4728ms.lib:5821ms.reg:16727ms.tool:2730ms.--:2996ms.ap:4650ms.lib:5758ms.reg:16102ms.tool:2949ms.--:3386ms.ap:4354ms.lib:5743ms.reg:15447ms.tool:2762ms.--:3792ms.ap:5634ms.lib:6743ms.reg:16696ms.StringTool: 20126 ms.Direct: 23079 ms.WholeApacheUtils: 33003 ms.JavaLib: 41169 ms.WholeRegex: 114557 ms.---------- ---------- ---------- ----------String: 3tool:795ms.--:1483ms.ap:1935ms.lib:2810ms.reg:6179ms.tool:874ms.--:1733ms.ap:1810ms.lib:2638ms.reg:6102ms.tool:921ms.--:1733ms.ap:1810ms.lib:2903ms.reg:6476ms.tool:983ms.--:1717ms.ap:1858ms.lib:2716ms.reg:5978ms.tool:1030ms.--:1702ms.ap:1764ms.lib:2778ms.reg:6040ms.tool:842ms.--:1842ms.ap:1904ms.lib:2966ms.reg:6274ms.tool:858ms.--:1515ms.ap:1655ms.lib:2513ms.reg:5884ms.StringTool: 6303 ms.Direct: 11725 ms.WholeApacheUtils: 12736 ms.JavaLib: 19324 ms.WholeRegex: 42933 ms.---------- ---------- ---------- ----------String: 0tool:967ms.--:1795ms.ap:1966ms.lib:3043ms.reg:6226ms.tool:921ms.--:1733ms.ap:2014ms.lib:3029ms.reg:6212ms.tool:764ms.--:1452ms.ap:1608ms.lib:2357ms.reg:5883ms.tool:921ms.--:1515ms.ap:1701ms.lib:2575ms.reg:6040ms.tool:764ms.--:1499ms.ap:1576ms.lib:2762ms.reg:5980ms.tool:811ms.--:1452ms.ap:1671ms.lib:2466ms.reg:5696ms.tool:842ms.--:1576ms.ap:1733ms.lib:2747ms.reg:6070ms.StringTool: 5990 ms.Direct: 11022 ms.WholeApacheUtils: 12269 ms.JavaLib: 18979 ms.WholeRegex: 42107 ms.---------- ---------- ---------- ----------String: -597213859710830758190748937102794tool:24039ms.ap:26162ms.lib:28955ms.--:31283ms.reg:56618ms.tool:23681ms.ap:25897ms.lib:29876ms.--:31235ms.reg:56960ms.tool:25194ms.ap:26927ms.--:29237ms.lib:29441ms.reg:57038ms.tool:24367ms.ap:25367ms.lib:29034ms.--:31250ms.reg:55431ms.tool:26567ms.ap:28689ms.lib:30859ms.--:34152ms.reg:61110ms.tool:25225ms.ap:26085ms.lib:29657ms.--:31266ms.reg:58692ms.tool:25366ms.ap:27332ms.lib:29611ms.--:30813ms.reg:58005ms.StringTool: 174439 ms.WholeApacheUtils: 186459 ms.JavaLib: 207433 ms.Direct: 219236 ms.WholeRegex: 403854 ms.---------- ---------- ---------- ----------String: 78 9254 3253 2452 9572 8532tool:21731ms.ap:23136ms.lib:23949ms.--:28848ms.reg:47928ms.tool:20467ms.ap:22403ms.lib:23636ms.--:27942ms.reg:49237ms.tool:19625ms.ap:22964ms.lib:24385ms.--:27849ms.reg:48177ms.tool:21653ms.ap:23775ms.lib:24650ms.--:27614ms.reg:49236ms.tool:20795ms.ap:23073ms.lib:24088ms.--:29283ms.reg:48347ms.tool:21279ms.ap:23167ms.lib:23761ms.--:29143ms.reg:48925ms.tool:20795ms.ap:22247ms.lib:24619ms.--:27725ms.reg:48864ms.StringTool: 146345 ms.WholeApacheUtils: 160765 ms.JavaLib: 169088 ms.Direct: 198404 ms.WholeRegex: 340714 ms.---------- ---------- ---------- ----------String: 13205972138597109830758190748937102794--:29078ms.tool:47706ms.ap:49001ms.lib:49564ms.reg:80750ms.--:34102ms.tool:49079ms.ap:49392ms.lib:51841ms.reg:82761ms.--:28828ms.tool:45677ms.ap:47051ms.lib:49782ms.reg:81139ms.--:28407ms.tool:45553ms.ap:48003ms.lib:49829ms.reg:79642ms.--:27175ms.tool:46208ms.ap:47800ms.lib:48956ms.reg:79704ms.--:34757ms.tool:54679ms.ap:56864ms.lib:57816ms.reg:88221ms.--:28486ms.tool:47721ms.ap:48892ms.lib:49065ms.reg:81014ms.Direct: 210833 ms.StringTool: 336623 ms.WholeApacheUtils: 347003 ms.JavaLib: 356853 ms.WholeRegex: 573231 ms.---------- ---------- ---------- ----------

我们可以看到，除了 null 以及被转换数字太长的情况（30位数字以上）外，Spads 出品的 StringTool 都有非常明显的速度优势。 null 本身处理速度远远快于其它情况，即便是 StringTool ，也没有耽误多少执行时间。



5 【附录】
---------- ---------- ---------- ----------
Google 搜索 “Java 判断字符串是否为数值”
头条 http://www.blogjava.net/Javaphua/archive/2012/05/18/122131.html
显得方法最多 http://javapub.iteye.com/blog/666544
直转法 http://zhidao.baidu.com/question/38323159
无新意 http://www.ideagrace.com/html/doc/2006/04/28/00784.html
阿帕奇工具 http://blog.csdn.net/jojoy_828/article/details/2837784
比较全 http://blog.csdn.net/bluesuperman/article/details/1840952
无新意 http://www.cnblogs.com/ztf2008/archive/2009/02/19/1393744.html
无新意 http://wenwen.soso.com/z/q198258851.htm

Google 搜索 “Java 从字符串中提取数值”
头条 http://blog.csdn.net/wangjinyu501/article/details/7625636
无新意 http://bbs.csdn.net/topics/340240275
复数，但我这边需求不涉及 http://www.bcw52.com/JAVA/2471.html

Google 搜索“Java 字符串转化为数值”
http://dongdong1314.blog.51cto.com/389953/79385

CSDN 搜索 “Java 从字符串中提取数值”
对于判断为数值后的转换有详细描述 http://blog.csdn.net/wowwow_cai/article/details/4590553
同 Google http://blog.csdn.net/wangjinyu501/article/details/7625636


本文还发表在我的其它技术日志
ITeye ： http://surmounting.iteye.com/blog/1754323
中国开源社区： http://my.oschina.net/shane1984/blog/98088
51CTO ：
【综述】 http://shanelooli.blog.51cto.com/5523233/1100063
【程序】 http://shanelooli.blog.51cto.com/5523233/1100074
【功能】 http://shanelooli.blog.51cto.com/5523233/1100356
【性能】甲 http://shanelooli.blog.51cto.com/5523233/1100417
【性能】乙 http://shanelooli.blog.51cto.com/5523233/1100418