JSon数据的解析

最近一个项目要对艺龙,携程等酒店预订网站进行价格信息采集.因为这两个网站都不是省油的灯啊,多次提交ajax表单,参数编码,获取特定的城市和酒店代码等等手段,可谓过五关斩六将,总算是把数据采集回来,但是又面临一个难题:采集回来的信息是json格式的,那就涉及到json数据转换成java对象了

首先要了解json数据的格式

[{"CityType":"hotel","TabList":[{"TabId":"1","Name":"\u70ED\u95E8","NameEn":"Hot","CityList":[{"ProvinceId":null,"CityId":"0101","CityCode":"0101","CityNameCn":"\u5317\u4EAC","CityNameEn":"Beijing","CityThreeSign":"","CityType":"hotel","OldEnglishName":"peking"},{"ProvinceId":null,"CityId":"0201","CityCode":"0201","CityNameCn":"\u4E0A\u6D77","CityNameEn":"Shanghai","CityThreeSign":"","CityType":"hotel","OldEnglishName":""},{"ProvinceId":null,"CityId":"2001","CityCode":"2001","CityNameCn":"\u5E7F\u5DDE","CityNameEn":"Guangzhou","CityThreeSign":"","CityType":"hotel","OldEnglishName":"canton"}]}]}];

jsonViewer是个好东西,不过HTTPAnalysis直接就集成了jsonViewer,不过还是前者比较轻巧:

json和java之间的互换可以使用json-lib, 基本的使用可以看文档就行.网上也有一些集成的类,我建议直接看它的源代码,了解他是如何通过反射和使用临时对象解析json数据,并封装成java对象.

这个json数据时list的嵌套,如果要对整个json文件解析,需要使用如下方法,需要构造跟json数据对应的Tab.class 和City.class,而且字段名称必须一致(骆驼首字母小写),提供默认构造方法,这样就可以将json数据作为一个完整的对象,想怎么干都行了.

 

HashMap<String,Class> map = new HashMap<String,Class>();map.put("tabList", Tab.class);map.put("cityList", City.class);          /**        * 从一个JSON数组得到一个java对象集合，其中对象中包含有集合属性        * @param object        * @param clazz        * @param map 集合属性的类型 (key : 集合属性名, value : 集合属性类型class) eg: ("beansList" : Bean.class)        * @return        */        public static List getDTOList(String jsonString, Class clazz, Map map){             setDataFormat2JAVA();             JSONArray array = JSONArray.fromObject(jsonString);             List list = new ArrayList();             for(Iterator iter = array.iterator(); iter.hasNext();){                 JSONObject jsonObject = (JSONObject)iter.next();                 list.add(JSONObject.toBean(jsonObject, clazz, map));             }             return list;         }     

由于我的需求只是需要重json数据中获取特定的信息对象,如上面的cityList,像tabList等对象我没必要去构造和获取,而且在实际使用过程中我发现

json数据中变量如果不是首字母小写,是无法转换成java对象的.这个确实很坑爹!!!!!

 

于是乎,我就写了个直接读取和解析一个片段json数据的类,有了这个类,加上对象映射,基本上没什么解析不了

package com.gxy.weixin.util;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.util.ArrayList;import java.util.Iterator;import java.util.LinkedList;import java.util.List;import java.util.regex.Matcher;import java.util.regex.Pattern;import net.sf.json.JSONArray;import net.sf.json.JSONObject;public class JSonStrUtils {/** * json 数据括号自动补全 * **/public static String autoComplete(String targetJson) {LinkedList<Character> stack = new LinkedList<Character>();String returnStr = "";char[] charArray = targetJson.toCharArray();for (int i = 0; i < charArray.length; i++) {if (charArray[i] == '[' || charArray[i] == '{') {// 入栈stack.addFirst(charArray[i]);} else if (charArray[i] == ']') {// 判断是否闭合char last = stack.peekFirst();if (last != '[') {// 不闭合,补 }returnStr += '}';} else// 闭合{stack.pollFirst();}} else if (charArray[i] == '}') {// 判断是否闭合char last = stack.peekFirst();if (last != '{') {// 不闭合,补 }returnStr += ']';} else// 闭合{stack.pollFirst();}}returnStr += charArray[i];}for (char c : stack) {System.out.println("left in stack:" + c);}return returnStr;}/*** * 用于处理json数据中出现变量名非首字母小写的情况,利用正则匹配变量,然后把首字母变成小写 * */public static String dealWithFirstChar(String jsonInput) {String originalInput = jsonInput;StringBuilder inputStr = new StringBuilder(jsonInput);String regex = "\"(\\w+)\":";Pattern p = Pattern.compile(regex, Pattern.CASE_INSENSITIVE);Matcher m = p.matcher(inputStr);List<String> result = new ArrayList<String>();while (m.find()) {String valueName = m.group(1);String newValueName = null;char[] words = valueName.toCharArray();if (Character.isUpperCase(words[0])) {// 首字母大写,不符合变量命名规范words[0] = Character.toLowerCase(words[0]);newValueName = new String(words);// System.out.println("orignal value:"+valueName+" new value :"+// newValueName);// String regexWord = "\""+valueName+"\":";String regx1 = "\"" + valueName + "\":";String replace = "\"" + newValueName + "\":";originalInput = originalInput.replaceAll(regx1, replace);}result.add(valueName);inputStr.delete(0, m.end(0));m = p.matcher(inputStr);}return originalInput;}/*** * 用户将unicode编码转换成汉字 * */public static String UnicodeToString(String str) {Pattern pattern = Pattern.compile("(\\\\u(\\p{XDigit}{4}))");Matcher matcher = pattern.matcher(str);char ch;while (matcher.find()) {ch = (char) Integer.parseInt(matcher.group(2), 16);str = str.replace(matcher.group(1), ch + "");}return str;}/*** * 用户将汉字转换成unicode编码 * */public static String toUNICODE(String s) {StringBuilder sb = new StringBuilder();for (int i = 0; i < s.length(); i++) {if (s.charAt(i) <= 256) {sb.append("\\u00");} else {sb.append("\\u");}sb.append(Integer.toHexString(s.charAt(i)).toUpperCase());}return sb.toString();}/** * 读取json文件,转换为字符串 * */public static String readJSonFile(String fileName) {InputStream in = null;String jsonStr = "";try {in = JSonStrUtils.class.getResourceAsStream(fileName);BufferedReader reader = new BufferedReader(new InputStreamReader(in));String temp = reader.readLine();while (temp != null) {jsonStr += temp;temp = reader.readLine();}in.close();} catch (IOException e) {e.printStackTrace();System.out.println("read json file failed :" + fileName);}return jsonStr;}/*** * 在指定的JSONObject 中寻找特定属性的第一个值 * */public static List<String> findTargetProperty(JSONObject object,String propertyName, boolean isRecursive) {List<String> values = new ArrayList<String>();for (Iterator entries = object.names().iterator(); entries.hasNext();) {String name = (String) entries.next();Object value = object.get(name);if (name.equals(propertyName)) {// 找到目标属性values.add(value.toString());} else if (isRecursive) {if (value instanceof JSONObject) {values.addAll(findTargetProperty((JSONObject) value,propertyName, isRecursive));} else if (value instanceof JSONArray) {JSONArray array = (JSONArray) value;for (Iterator iter = array.iterator(); iter.hasNext();) {JSONObject jsonObject = (JSONObject) iter.next();values.addAll(findTargetProperty(jsonObject,propertyName, isRecursive));}}}}return values;}/*** * 从指定的JSonArray中寻找指定名称的子json数组 * */public static List<JSONArray> findTargetJSonArray(JSONArray array,String targetName) {List<JSONArray> arrays = new ArrayList<JSONArray>();for (Iterator iter = array.iterator(); iter.hasNext();) {// 遍历数组中的JSONObjectJSONObject jsonObject = (JSONObject) iter.next();if (jsonObject == null || jsonObject.isNullObject()) {continue;}for (Iterator entries = jsonObject.names().iterator(); entries.hasNext();) {String name = (String) entries.next();Object value = jsonObject.get(name);if (value instanceof JSONArray) {// 属性为数组// 先判断是否目标数组if (name.equals(targetName)) {arrays.add((JSONArray) value);}// 递归查找arrays.addAll(findTargetJSonArray((JSONArray) value,targetName));}}}return arrays;}}

原文地址：http://xoknight.net/?cat=58