JAVA API 实例

from  http://blog.csdn.net/earbao/article/details/8236334

import java.io.BufferedInputStream;import java.io.BufferedOutputStream;import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.FileWriter;import java.io.IOException;import java.io.InputStreamReader;import java.io.PrintWriter;import java.io.RandomAccessFile;import java.lang.ref.SoftReference;import java.math.BigDecimal;import java.math.BigInteger;import java.net.FileNameMap;import java.text.SimpleDateFormat;import java.util.ArrayDeque;import java.util.ArrayList;import java.util.Arrays;import java.util.BitSet;import java.util.Calendar;import java.util.Collection;import java.util.Collections;import java.util.Date;import java.util.EnumSet;import java.util.Enumeration;import java.util.HashMap;import java.util.HashSet;import java.util.Hashtable;import java.util.IdentityHashMap;import java.util.Iterator;import java.util.LinkedHashMap;import java.util.LinkedHashSet;import java.util.LinkedList;import java.util.List;import java.util.Map;import java.util.PriorityQueue;import java.util.Queue;import java.util.Random;import java.util.Set;import java.util.Stack;import java.util.StringTokenizer;import java.util.TimeZone;import java.util.Timer;import java.util.TimerTask;import java.util.TreeMap;import java.util.TreeSet;import java.util.UUID;import java.util.Vector;import java.util.WeakHashMap;import java.util.concurrent.ConcurrentLinkedQueue;import java.util.zip.ZipEntry;import java.util.zip.ZipFile;import java.util.zip.ZipOutputStream;/** * 云守护 * 2012-11-28  * @author qq:542335496 * */public class TestAPI {enum Sex {MAN, WOMEN}@SuppressWarnings("unused")private class Person {private Integer id;private String name;public Person() {};public Person(Integer id, String name) {this.id = id;this.name = name;}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}}@SuppressWarnings("unchecked")public static void main(String[] args) throws Exception {/** 集合 */Collection<Integer> collection;{collection=new ArrayList<Integer>();collection.addAll(Arrays.asList(1,2,3,4,5,6,7,8,9));/** 中断程序的运行，测试用*/if(true){return ;}}/** 列表 */List<Integer> list;/** 数组列表 */ArrayList<Integer> arrayList;/** 链表 */LinkedList<Integer> linkedList;/** 链表实现的hashmap */LinkedHashMap<Integer, String> linkedHashMap;{arrayList=new ArrayList<Integer>();for(int i=0;i<15;i++){arrayList.add(i);}System.out.println(arrayList);linkedList=new LinkedList<Integer>();linkedList.addAll(arrayList);System.out.println(linkedList);linkedHashMap=new LinkedHashMap<Integer, String>();for(int i=0;i<15;i++){linkedHashMap.put(i, "value"+i);}System.out.println(linkedHashMap);System.out.println(arrayList.contains(14));System.out.println(linkedList.indexOf(11));System.out.println(linkedList.offer(100));System.out.println(linkedList.peekLast());System.out.println(linkedList.peek());System.out.println(linkedList.remove(2));System.out.println(linkedList);Set<Integer> set=linkedHashMap.keySet();Set<Map.Entry<Integer, String>> entrySet=linkedHashMap.entrySet();Iterator<Integer> iterator=set.iterator();while(iterator.hasNext()){Integer key=iterator.next();String value=linkedHashMap.get(key);System.out.print(" key="+key+" value="+value);}System.out.println();if(true){return ;}}/** 队列 */Queue<Integer> queue;/**双端队列 */ArrayDeque<Integer> arrayDeque;/**优先级队列 */PriorityQueue<Integer> priorityQueue;ConcurrentLinkedQueue<Integer> concurrentLinkedQueue;{priorityQueue = new PriorityQueue<Integer>();priorityQueue.addAll(Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));System.out.println(priorityQueue);arrayDeque=new ArrayDeque<Integer>();arrayDeque.addAll(priorityQueue);System.out.println(arrayDeque.pop());System.out.println(arrayDeque.poll());//入队列arrayDeque.push(500);arrayDeque.push(200);//出队列System.out.println(arrayDeque.remove());//入队列System.out.println(arrayDeque.add(99));System.err.println(arrayDeque);// 出队列,这里顺序乱了？//priorityQueue.poll();show(priorityQueue);Iterator<Integer>  iterator=priorityQueue.iterator();while(iterator.hasNext()){Integer data=iterator.next();System.out.print("\t"+data);}System.out.println();concurrentLinkedQueue=new ConcurrentLinkedQueue<Integer>();concurrentLinkedQueue.addAll(priorityQueue);System.out.println(concurrentLinkedQueue);if(true){return ;}}/** 栈 */Stack<Integer> stack;{stack = new Stack<Integer>();for (int i = 0; i < 10; i++) {stack.add(i);}show(stack);stack.addElement(111);// 容量不足时，增长一倍System.out.println(stack.capacity());System.out.println(stack.size());System.out.println(stack.indexOf(111));System.out.println(stack.remove(1));System.out.println(stack.retainAll(Arrays.asList(3, 4, 5, 6, 7, 8)));System.out.println(stack.search(3));System.out.println(stack.toString());System.out.println(stack.peek());stack.pop();stack.pop();stack.push(100);System.out.println(stack.subList(1, 4));show(stack);stack.removeAllElements();System.out.println(stack.isEmpty());}/** 向量 */Vector<Integer> vector;{vector = new Vector<Integer>();for (int i = 0; i < 20; i++) {vector.add(i);}show(vector);vector.addElement(1999);// 容量不足时，增大一倍System.out.println(vector.capacity());System.out.println(vector.contains(1));System.out.println(vector.containsAll(Arrays.asList(1, 2, 3, 4, 5,6)));System.out.println(vector.lastIndexOf(19));System.out.println(vector.remove(1));System.out.println(vector.removeAll(Arrays.asList(1, 2, 3, 4, 5, 6,7, 8, 9)));System.out.println(vector.retainAll(Arrays.asList(10, 11, 12, 13,14, 15, 60)));System.out.println(vector.size());System.out.println(vector.elementAt(2));System.out.println(vector.firstElement());System.out.println(vector.lastElement());System.out.println(vector.subList(1, 5));vector.ensureCapacity(52);System.out.println(vector.size());vector.removeAllElements();System.out.println(vector.isEmpty());show(vector);}System.out.println("========map=======");Map<Integer, String> map;Hashtable<Integer, String> hashtable;HashMap<Integer, String> hashMap;// EnumMap<Sex,Map> enumMap;/** 树实现的map */TreeMap<Integer, String> treeMap;// ConcurrentHashMap<Integer, String> concurrentHashMap;// ConcurrentMap<Integer, String> concurrentMap;WeakHashMap<Integer, String> weakHashMap;IdentityHashMap<Integer, String> identityHashMap;{hashMap = new HashMap<Integer, String>();hashtable = new Hashtable<Integer, String>();treeMap = new TreeMap<Integer, String>();weakHashMap = new WeakHashMap<Integer, String>();identityHashMap = new IdentityHashMap<Integer, String>();for (int i = 0; i < 20; i++) {hashMap.put(i, "云守护" + i);}show(hashMap);hashtable.putAll(hashMap);treeMap.putAll(hashMap);weakHashMap.putAll(hashMap);identityHashMap.putAll(hashMap);show(hashtable);show(treeMap);show(weakHashMap);show(identityHashMap);System.out.println(hashMap.containsKey(14));System.out.println(hashMap.containsValue("云守护5"));System.out.println(hashMap.values());System.out.println(hashtable.remove(1));System.out.println(hashtable.values());hashtable.clear();System.out.println(hashtable.isEmpty());}System.out.println("========set=======");// 集合Set的使用Set<Integer> set;BitSet bitSet;EnumSet enumSet;HashSet<Integer> hashSet;/** 树实现的set */TreeSet<Integer> treeSet;/** 链表实现的hashset */LinkedHashSet<Integer> linkedHashSet;Iterator<Integer> iterator;{enumSet = EnumSet.noneOf(Sex.class);hashSet = new HashSet<Integer>();treeSet = new TreeSet<Integer>();linkedHashSet = new LinkedHashSet<Integer>();// 自动排序？？for (int i = 15; i > 0; i--) {hashSet.add(i);}treeSet.addAll(hashSet);linkedHashSet.addAll(hashSet);enumSet.add(Sex.MAN);enumSet.add(Sex.WOMEN);show(hashSet);show(treeSet);show(linkedHashSet);show(enumSet);System.out.println(enumSet.size());enumSet.clear();System.out.println(enumSet.size());System.out.println(enumSet.isEmpty());System.out.println(hashSet.contains(10));System.out.println(linkedHashSet.containsAll(hashSet));linkedHashSet.remove(14);System.out.println(linkedHashSet.containsAll(hashSet));hashSet.removeAll(linkedHashSet);show(hashSet);Object[] objs = treeSet.toArray();show(objs);Integer[] strs = treeSet.toArray(new Integer[0]);show(strs);for (Iterator<Integer> iterator2 = treeSet.iterator(); iterator2.hasNext();) {Integer data = iterator2.next();System.out.print(data + "\t");}System.out.println();}// 要学习java.util.StringTokenizer stringTokenizer;{String[] temps = "1,2,3,4,5,6".split(",");show(temps);stringTokenizer = new StringTokenizer("1,2,3,4,5,6,7,8,9", ",");String[] datas = new String[stringTokenizer.countTokens()];int i = 0;while (stringTokenizer.hasMoreTokens()) {String str = stringTokenizer.nextToken();System.out.print(str + "\t");datas[i] = str;i++;}System.out.println();show(datas);}java.util.Calendar calendar;java.util.Date date;{calendar = Calendar.getInstance();int year = calendar.get(Calendar.YEAR);int month = calendar.get(Calendar.MONTH) + 1;int day = calendar.get(Calendar.DAY_OF_MONTH);int hours = calendar.get(Calendar.HOUR_OF_DAY);int minute = calendar.get(Calendar.MINUTE);int second = calendar.get(Calendar.SECOND);System.out.println(year + "-" + month + "-" + day + " " + hours+ ":" + minute + ":" + second);date = new Date();System.out.println(date.after(new Date(System.currentTimeMillis() + 1000)));System.out.println(date.compareTo(new Date(System.currentTimeMillis() - 1000)));SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");String str = dateFormat.format(date);System.out.println(str);}java.util.Random random;{random = new Random();System.out.println(random.nextBoolean());System.out.println(random.nextDouble());System.out.println(random.nextFloat());System.out.println(random.nextInt());System.out.println(random.nextInt(15));System.out.println(random.nextLong());byte[] datas = new byte[10];random.nextBytes(datas);System.out.println(datas);random.setSeed(10000);System.out.println(random.nextInt());System.out.println(random.nextInt());}java.util.Scanner scanner;java.util.Timer timer;java.util.TimerTask timerTask;{timer = new Timer();timerTask = new TimerTask() {@SuppressWarnings("deprecation")@Overridepublic void run() {System.out.println(new Date().toLocaleString());}};timer.schedule(timerTask, 1000, 1000);// timerTask.run();}java.util.TimeZone timeZone;{System.gc();System.out.println(UUID.randomUUID());timeZone = TimeZone.getDefault();System.out.println(timeZone.getDisplayName());/** * String[] strs=timeZone.getAvailableIDs(); for(String str:strs){ * System.out.println(str); } */}java.lang.Character character;{character = Character.valueOf('f');int data = Character.digit(character, 16);System.out.println(data);int data2 = Character.digit(5, 16);System.out.println(data2);System.out.println(Character.isDigit('b'));System.out.println(Character.reverseBytes('a'));}java.lang.Process process;{process = Runtime.getRuntime().exec("cmd /c dir", null,new File("."));BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(process.getInputStream(), "GBK"));String line;while ((line = bufferedReader.readLine()) != null) {System.out.println(line);}// ///////System.out.println("=======");ProcessBuilder builder = new ProcessBuilder("java");builder.directory(new File("C:\\Program Files\\Java\\jdk1.6.0_30\\bin"));Process process2 = builder.start();BufferedReader bufferedReader2 = new BufferedReader(new InputStreamReader(process2.getInputStream(), "GBK"));while ((line = bufferedReader2.readLine()) != null) {System.out.println(line);}}java.lang.Class<Integer> class1;java.lang.CharSequence charSequence;{java.lang.ClassLoader.getSystemResource("file.xml");charSequence = "wujianhua";System.out.println(charSequence.charAt(6));System.out.println(charSequence.length());System.out.println(charSequence.subSequence(2, 5));System.out.println(charSequence.hashCode());}java.lang.Number number;java.lang.Package package1;{/** * Package[] datas=Package.getPackages(); for(Package * package2:datas){ System.out.println(package2.getName()); } */package1 = Package.getPackage("java.lang");System.out.println(package1.getImplementationTitle());System.out.println(package1.getImplementationVendor());System.out.println(package1.getImplementationVersion());System.out.println(package1.getSpecificationTitle());System.out.println(package1.getSpecificationVendor());System.out.println(package1.getSpecificationVersion());System.out.println(package1.getDeclaredAnnotations());System.out.println(package1.isSealed());}java.lang.String string;{System.out.println("".isEmpty());}// 学习的接口java.util.Comparator<Integer> comparator;java.util.RandomAccess randomAccess;java.util.SortedMap<Integer, String> sortedMap;java.util.SortedSet<Integer> sortedSet;java.applet.Applet applet;java.io.File file;java.io.FileFilter fileFilter;java.io.PrintWriter printWriter;{try {printWriter = new PrintWriter(new BufferedWriter(new FileWriter("writer.txt")));printWriter.append("你好");printWriter.append(",");printWriter.append("云守护");printWriter.println();printWriter.print("呵呵");printWriter.write("测试");printWriter.println(new BigInteger("123456789"));printWriter.flush();printWriter = new PrintWriter(System.out);printWriter.println("问鼎天下");printWriter.write("顺手牵羊");printWriter.flush();printWriter.close();} catch (IOException e) {e.printStackTrace();}}java.io.RandomAccessFile randomAccessFile;{try {randomAccessFile = new RandomAccessFile("test.txt", "rw");randomAccessFile.write("雨无声".getBytes());randomAccessFile.writeUTF("男");randomAccessFile.write(22);// againrandomAccessFile.write("云守护".getBytes());randomAccessFile.writeUTF("女");randomAccessFile.write(21);randomAccessFile.close();RandomAccessFile randomAccessFile2 = new RandomAccessFile("test.txt", "rw");randomAccessFile2.skipBytes(6);System.out.println(randomAccessFile2.getFilePointer());System.out.println(randomAccessFile2.readUTF());randomAccessFile2.skipBytes(1);byte[] names = new byte[6];randomAccessFile2.read(names);System.out.println(new String(names));randomAccessFile2.seek(0);randomAccessFile2.read(names);System.out.println(new String(names));} catch (Exception e) {e.printStackTrace();}if (true) {return;}}/** 软引用 */java.lang.ref.SoftReference<Integer> softReference;{Integer data = 0;softReference = new SoftReference<Integer>(data);data = softReference.get();if (data == null) {data = softReference.get();}System.out.println(data);}java.math.BigDecimal bigDecimal = new BigDecimal("123456789");System.out.println("====bigInteger===");java.math.BigInteger bigInteger = new BigInteger("123456789");{System.out.println(bigInteger.abs() + "\t" + bigInteger.bitCount()+ "\t" + bigInteger.bitLength());System.out.println(bigInteger.doubleValue());System.out.println(bigInteger.floatValue());System.out.println(bigInteger.longValue());System.out.println(bigInteger.intValue());System.out.println(bigInteger.divide(new BigInteger("11111111")));// System.out.println(bigInteger);System.out.println(bigInteger.multiply(new BigInteger("2")));System.out.println(bigInteger.subtract(new BigInteger("111111111")));System.out.println(bigInteger.add(new BigInteger("111111111")));}java.net.HttpURLConnection httpURLConnection;java.net.Socket socket;java.net.URI uri;java.net.URLConnection urlConnection;java.net.FileNameMap fileNameMap = new FileNameMap() {@Overridepublic String getContentTypeFor(String fileName) {return "txt";}};System.out.println(fileNameMap.getContentTypeFor("d:\test.txt"));java.util.regex.Matcher matcher;java.util.regex.Pattern pattern;System.out.println("====zipFile===");java.util.zip.ZipFile zipFile;{File file2 = new File(".");System.out.println(file2.getAbsolutePath());try {zipFile("file.doc", "file.zip", "file.doc");unZip("file.zip", "d:/test/");} catch (Exception e) {e.printStackTrace();}}javax.crypto.Cipher cipher;System.out.println("====collections===");Collections collections;{List<Integer> list2 = new ArrayList<Integer>();Collections.addAll(list2, 12, 45, 62, 98, 32, 41, 15, 24, 3, 4);Collections.sort(list2);// 排序show(list2);int pos = 0;if ((pos = Collections.binarySearch(list2, 15)) != -1) {System.out.println("二分查找到的位置：" + pos);};// 初始化，让list3.size()>0,然后才可以进行深拷贝List<Integer> list3 = new ArrayList<Integer>(Arrays.asList(new Integer[list2.size()]));System.out.println(list3.size());Collections.copy(list3, list2);// 拷贝show(list3);System.out.println("最大值：" + Collections.max(list3));System.out.println("最小值:" + Collections.min(list3));// 枚举集合Enumeration<Integer> enumerations = Collections.enumeration(list2);show(enumerations);List<Integer> list4 = new ArrayList<Integer>();// 返回一个安全的集合list4 = Collections.synchronizedList(list3);show(list4);// 反转集合Collections.reverse(list3);show(list3);}}@SuppressWarnings("unchecked")private static void show(Queue queue) {for (Object obj : queue) {System.out.print("\t" + obj);}System.out.println();}private static void show(Map<Integer, String> maps) {Set<Integer> keySet = maps.keySet();// Set<Map.Entry<Integer, String>> entrySet=maps.entrySet();for (Iterator<Integer> iterator = keySet.iterator(); iterator.hasNext();) {Integer key = iterator.next();String value = maps.get(key);System.out.print("key=" + key + "\tvalue=" + value + "\t");}System.out.println();}private static void show(Object[] objs) {for (Object data : objs) {System.out.print(data + "\t");}System.out.println();}@SuppressWarnings("unchecked")private static void show(Set hashSet) {for (Object data : hashSet) {System.out.print(data + "\t");}System.out.println();}public static void show(List<Integer> datas) {for (Integer data : datas) {System.out.print(data + "\t");}System.out.println();}public static void show(Vector<Integer> datas) {for (Integer data : datas) {System.out.print(data + "\t");}System.out.println();}public static void show(Enumeration<Integer> datas) {for (Enumeration<Integer> e = datas; e.hasMoreElements();) {System.out.print(e.nextElement() + "\t");}System.out.println();}public static void show(String[] datas) {for (String data : datas) {System.out.print(data + "\t");}System.out.println();}/** 压缩 */public static void zipFile(String srcFilePath, String destZipFilePath,String fileName) throws Exception {File file = new File(destZipFilePath);int leng = 0;byte[] b = new byte[1024];// 压缩ZipOutputStream zos = new ZipOutputStream(new FileOutputStream(file));// 被压缩的文件FileInputStream fis = new FileInputStream(srcFilePath);// 在压缩包中的路径ZipEntry z1 = new ZipEntry(fileName);zos.putNextEntry(z1);while ((leng = fis.read(b)) != -1) {zos.write(b, 0, leng);}zos.close();fis.close();}@SuppressWarnings("unchecked")public static void unZip(String fileName, String unZipDir) throws Exception {// 先判断目标文件夹是否存在，如果不存在则新建，如果父目录不存在也新建File f = new File(unZipDir);if (!f.exists()) {f.mkdirs();}BufferedOutputStream dest = null;BufferedInputStream is = null;ZipEntry entry;ZipFile zipfile = new ZipFile(fileName);Enumeration e = zipfile.entries();while (e.hasMoreElements()) {entry = (ZipEntry) e.nextElement();// System.out.println("Extracting: " + entry);is = new BufferedInputStream(zipfile.getInputStream(entry));int count;byte data[] = new byte[1024];FileOutputStream fos = new FileOutputStream(unZipDir + "/"+ entry.getName());// System.out.println("entry.getName(): " + entry.getName());dest = new BufferedOutputStream(fos, 1024);while ((count = is.read(data, 0, 1024)) != -1) {dest.write(data, 0, count);}dest.flush();dest.close();is.close();}}public static boolean makeDir(String unZipDir) {boolean b = false;try {File f = new File(unZipDir);if (!f.exists()) {b = f.mkdirs();}} catch (Exception e) {e.printStackTrace();return b;}return b;}}