我们轻松了，并不是生活越来越容易了，而是我们越来越强

import java.lang.annotation.ElementType;import java.lang.annotation.Retention;import java.lang.annotation.RetentionPolicy;import java.lang.annotation.Target;import java.lang.reflect.Field;...

信号量维护了一个许可集。如有必要，在许可可用前会阻塞每一个 acquire()，然后再获取该许可。每个 release() 添加一个许可，从而可能释放一个正在阻塞的获取者。[code="java"]package concurrent;import java.util.Collections;import java.util.HashSet;import java.util.S...

它允许一组线程互相等待，直到到达某个公共屏障点，barrier 在释放等待线程后可以重用，所以称它为循环 的 barrier。[code="java"]package concurrent;import java.util.concurrent.BrokenBarrierException;import java.util.concurrent.CyclicBarrier;...

[code="java"]package concurrent;import java.util.concurrent.Callable;import java.util.concurrent.ConcurrentHashMap;import java.util.concurrent.ExecutionException;import java.util.concurrent....

[code="java"]package concurrent;import java.util.Random;import java.util.concurrent.locks.ReentrantReadWriteLock;import java.util.concurrent.locks.ReentrantReadWriteLock.ReadLock;import java...

[code="java"]import java.util.concurrent.ArrayBlockingQueue;import java.util.concurrent.ThreadPoolExecutor;import java.util.concurrent.TimeUnit;public class ThreadLocalTest { public stat...

获取两时间间隔天、小时、分[code="java"] public static void main(String[] args){ Date _2days = toDate("2012-11-15 18:17:20", TIME_PATTERN); System.err.println(surplusUnitedTime(_2days)); ...

[code="java"] try{ Map paramMap = new HashMap(); String params = rundata.getRequest().getQueryString(); params = URLDecoder.decode(params,"UTF-8"); ...

[code="java"]public class GcTest { /** * [color=red]-Xloggc:d:\gc.log[/color] -Xms10m -Xmx10m * @param args * @throws InterruptedException */ public static void main(String[] args...

[code="java"]import java.io.File;import java.io.IOException;import java.io.RandomAccessFile;import java.nio.ByteBuffer;import java.nio.channels.FileChannel;public class TestNio { publi...

仅在计算完成时才能获取结果；如果计算尚未完成，则阻塞 get 方法。一旦计算完成，就不能再重新开始或取消计算.[code="java"]package concurrent;import java.util.concurrent.Callable;import java.util.concurrent.ExecutionException;import java.util....

在完成一组正在其他线程中执行的操作之前，它允许一个或多个线程一直等待，在某些场景下同CyclicBarrier类似。[code="java"]package concurrent;import java.util.concurrent.CountDownLatch;/** * 闭锁，要关注await,countDown的异常， * @author user *...

业务对象类[code="java"]import java.io.Serializable;public class Question implements Serializable { private static final long serialVersionUID = 1L; private String seq; private String q...

http://mgoann.iteye.com/blog/1409667

[code="java"]C:\Documents and Settings>jps -m6096 Jps -m2112 BTraceServer636C:\Documents and Settings>jps -1illegal argument: -1usage: jps [-help] jps [-q] [-mlvV] []Defini...

打印heap信息[code="java"]D:\>jmap -histo 4636 > d:log.log[/code]生成heap信息并生成二进制文件[code="java"]D:\>jmap -dump:live,format=b,file=d:\log.log 4636Dumping heap to D:\log.log ...Heap dump file...

[code="java"]D:\>jstack -l 6000[/code]参数：-F 强制返回-l 打印详细信息-h 帮助信息-help 帮助信息

[code="java"]package jmx;/** * 接口命名规则：xxxMBean * 实现类：xxx */public interface HelloMBean { public void setName(String name); public String getName(); public void print(); p...

废话少说直接上代码！[code="java"]import java.net.InetAddress;import java.util.HashMap;import java.util.List;import java.util.Map;import org.apache.zookeeper.CreateMode;import org.apache.zookeepe...

HttpClient新版本（新老版本没有做明确界定，Sorry!）[code="java"]package http;import java.util.ArrayList;import java.util.List;import org.apache.http.NameValuePair;import org.apache.http.client.HttpClien...

DSA DEMO

[code="java"]import java.util.ArrayList; import java.util.List; public class BinaryTest { public static List binaryNum(int targetNum) { List list = new ArrayList(); ...

压缩目标越大，压缩效果越明显！[code="java"]import java.io.ByteArrayInputStream;import java.io.ByteArrayOutputStream;import java.io.IOException;import java.util.zip.GZIPInputStream;import java.util.zip.GZ...