Brave and Moderate

String做字符串拼接的效率太低，要用StringBuffer StringBuffer sb = new StringBuffer(); sb.append("aaa").append("bb").append("cc"); String res = sb.toString();

mapA为HashMap Set entrySet = mapA.entrySet();int i=0; for(Iterator iter = entrySet.iterator(); iter.next); { i++; Map.Entry entry = iter.next(); System.out.println("the "+i+"th key is"en

一、实现java线程的两种方法： 1、  继承Thread类： package com.threads; public class FirstThread extends Thread { private int count; private int thread_no; public FirstThread(int thread_no) { this.thr

import java.net.MalformedURLException; import java.net.URL; import java.net.URLConnection; public class OpenConnection { public static void main(String[] args) { try { URL facebookUrl =

package com.biztool; import java.io.File; import java.io.FileOutputStream; import java.io.OutputStreamWriter; import java.io.Writer; import javax.xml.parsers.DocumentBuilder; import javax.