java根据线程查询代码 java 多线程查询

java中线程编程代码怎么写啊

线程用到Thread或者Runnable接口(Thread也操作了Runnable接口）

创新互联是一家专注于网站建设、成都网站建设与策划设计,准格尔网站建设哪家好?创新互联做网站,专注于网站建设10年,网设计领域的专业建站公司;建站业务涵盖:准格尔等地区。准格尔做网站价格咨询:13518219792

继承了Thread类后需要重载其run方法，在方法里写你需要完成的事情，开始线程是调用其start方法。

操作Runnable接口必须实现其run方法，在方法里写你需要完成的事情，Runnable接口没有start方法，所以启动线程还是需要依靠Thread类 new Thread(Runnable runnable).start();

一般项目中多是操作接口，因为类只能单继承，接口可以操作多个。

java线程的经典代码

package threadgroup;

class ThreadDemo3 extends Thread {

private String name;

private int delay;

public ThreadDemo3(String sname, int i_delay) {

name = sname;

delay = i_delay;

}

public void run() {

try {

sleep(delay);

} catch (InterruptedException e) {

}

System.out.println("多线程测试！\n" + name + "\n" + delay);

}

}

public class testMyThread {

public static void main(String[] args) {

ThreadDemo3 th1,th2,th3;

th1 = new ThreadDemo3("线程1", (int) (Math.random() * 900));

th2 = new ThreadDemo3("线程2", (int) (Math.random() * 900));

th3 = new ThreadDemo3("线程3", (int) (Math.random() * 900));

th1.start();

th2.start();

th3.start();

}

}

package threadgroup;

public class threadDemo {

public static void main(String[] args) {

Thread t = Thread.currentThread();

t.setName("你好吗？");

System.out.println("正在进行的Thread是：" + t);

try {

for (int i = 0; i 5; i++) {

System.out.println("我不叫穆继超" + i);

Thread.sleep(3000);

}

} catch (Exception e) {

// TODO: handle exception

System.out.println("Thread has wrong" + e.getMessage());

}

}

}

package threadgroup;

public class threadDemo2 implements Runnable {

public threadDemo2() {

Thread t1 = Thread.currentThread();

t1.setName("第一个主进程");

System.out.println("正在运行" + t1);

Thread t2 = new Thread(this, "");

System.out.println("在创建一个进程");

t2.start();

try {

System.out.println("使他进入第一个睡眠状态");

Thread.sleep(2000);

} catch (InterruptedException e) {

System.out.println("Thread has wrong" + e.getMessage());

}

System.out.println("退出第一个进程");

}

public void run() {

try {

for (int i = 0; i 5; i++) {

System.out.println("进程" + i);

Thread.sleep(3000);

}

} catch (InterruptedException e) {

// TODO: handle exception

System.out.println("Thread has wrong" + e.getMessage());

}

System.out.println("退出第二个进程");

}

public static void main(String[] args) {

new threadDemo2();

}

}

求java多线程遍历目录的完整代码，能运行的那种

目录结构为树型结构，用多线程不大好做，线程最多在前几层进行分割，比如每个目录下有两个目录，共5层，那么root目录下就能启用2个线程分别进行遍历，所以第二层就启动了2个线程进行遍历，加上主线程共三个线程，虽然这样做是可以做，但是要更具实际情况进行线程的规划，否则容易线程过多导致cpu超负荷，或者假死，再提一点，遍历目录不建议用递归来写，因为目录较多容易栈溢出。

随手写了个，会有点bug就是关闭线程池的时候，还有就是有可能目录太多进入拒绝策略，这个东西 可以考虑使用令牌桶算法，或者计数器算法来做。这里提供个简单的例子。

public class TraverseUtil {

public static BlockingQueue blockingQueue = new LinkedBlockingQueue(100);

public static ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor(100,100,10, TimeUnit.SECONDS,blockingQueue);

public static void traverseFolder2(String path) {

File file = new File(path);

if (file.exists()) {

File[] files = file.listFiles();

if (null == files || files.length == 0) {

System.out.println("文件夹是空的!");

return;

} else {

for (File file2 : files) {

if (file2.isDirectory()) {

System.out.println("文件夹:" + file2.getAbsolutePath());

threadPoolExecutor.execute(new Runnable() {

@Override

public void run() {

traverseFolder2(file2.getAbsolutePath());

}

});

} else {

System.out.println("文件:" + file2.getAbsolutePath());

}

}

}

} else {

System.out.println("文件不存在!");

}

}

public static void main(String[] args) throws InterruptedException {

traverseFolder2("C:\\Users\\a8932\\Desktop\\md");

}

}

典型Java线程池的代码及其各部分功能介绍

（ ）根据xml文件来管理线程池的最大最小线程数（ ）对线程池通过Timer定期扫描以防止线程未激活 （ ）通过某一个变量（本程序中是freeThreadCount）来得到空闲线程的数目 一 配置xml（listen xml）是 ?xml version= encoding= UTF ?configConsumeThreadPoolminPools /minPools　! 线程池最小线程 maxPools /maxPools! 线程池最大线程 checkThreadPeriod /checkThreadPeriod　! 检查线程池中线程的周期 分钟 /ConsumeThreadPool/config 二 对于ConsumeThreadPoolPara的javabean: import java io *;public class ConsumeThreadPoolPara implements Serializable{private int minPools;private int maxPools;private int checkThreadPeriod;public int getMinPools(){return minPools;}public int getMaxPools(){return maxPools;}public int getCheckThreadPeriod(){return checkThreadPeriod;}public void setMinPools(int minPools){this minPools = minPools;}public void setMaxPools(int maxPools){this maxPools = maxPools;}public void setCheckThreadPeriod(int checkThreadPeriod){this checkThreadPeriod = checkThreadPeriod;}public String toString(){return minPools+ + maxPools+ +checkThreadPeriod;}public ConsumeThreadPoolPara() {}public static void main(String[] args) {ConsumeThreadPoolPara consumeThreadPool = new ConsumeThreadPoolPara();}} 三 解析xml程序代码（生成ConsumeThreadPoolPara） 使用jdom解析 import jdom *;import jdom input SAXBuilder;import java io *;import java util *;public class ParseConfig {static Hashtable Listens = null;static ConnPara connpara = null;static ConsumeThreadPoolPara consumeThreadPoolPara = null;private static String configxml = listen xml ;static{getConsumeThreadPoolPara();　//得到消费的线程池的参数}/*** 装载文档* @return 返回根结点* @throws JDOMException*/public static Element loadDocument() throws JDOMException{SAXBuilder parser = new SAXBuilder(); // 新建立构造器try {Document document = parser build(configxml);Element root = document getRootElement();return root;}catch(JDOMException e){logger error( listen xml文件格式非法！ );throw new JDOMException();}}public static ConsumeThreadPoolPara getConsumeThreadPoolPara(){if(consumeThreadPoolPara ==null){try {Element root = loadDocument();Element consumeThreadPool = root getChild( ConsumeThreadPool );if (consumeThreadPool != null) { //代表有数据库配置consumeThreadPoolPara = new ConsumeThreadPoolPara();Element minPools = consumeThreadPool getChild( minPools );consumeThreadPoolPara setMinPools(Integer parseInt(minPools getTextTrim()));Element maxPools = consumeThreadPool getChild( maxPools );consumeThreadPoolPara setMaxPools(Integer parseInt(maxPools getTextTrim()));Element checkThreadPeriod = consumeThreadPool getChild( checkThreadPeriod );consumeThreadPoolPara setCheckThreadPeriod(Integer parseInt(checkThreadPeriod getTextTrim()));}}catch (JDOMException e) {}}return consumeThreadPoolPara;}} 四 线程池源代码 import java util *;/*** pTitle: 线程池/p* pDescription: 采集消费模块/p* pCopyright: Copyright (c) /p* pCompany: /p* @author 张荣斌* @version */public class ThreadPool {private static int minPools = ; //最小连接池数目private static int maxPools = ; //最大连接池数目private static int checkThreadPeriod = ; //检查连接池的周期ArrayList m_ThreadList;　//工作线程列表LinkedList m_RunList = null;　//工作任务列表int totalThread = ;　//总线程数static int freeThreadCount = ;　//未被使用的线程数目private java util Timer timer = null;　//定时器static Object o = new Object();static{　//先初始化线程池的参数ConsumeThreadPoolPara consumeThreadPoolPara = ParseConfig getConsumeThreadPoolPara();if(consumeThreadPoolPara!=null){minPools = consumeThreadPoolPara getMinPools();maxPools = consumeThreadPoolPara getMaxPools();checkThreadPeriod = consumeThreadPoolPara getCheckThreadPeriod()* * ;}}public void setMinPools(int minPools){this minPools = minPools;}public void setMaxPools(int maxPools){this maxPools = maxPools;}public void setCheckThreadPeriod(int checkThreadPeriod){this checkThreadPeriod = checkThreadPeriod;}public ThreadPool() {m_ThreadList=new ArrayList();m_RunList=new LinkedList();for(int i= ;iminPools;i++){WorkerThread temp=new WorkerThread();totalThread = totalThread + ;m_ThreadList add(temp);temp start();try{Thread sleep( );}catch(Exception e){}}timer = new Timer(true);　//启动定时器timer schedule(new CheckThreadTask(this) checkThreadPeriod);}/*** 当有一个工作来的时候启动线程池的线程* 当空闲线程数为 的时候 看总线程是否小于最大线程池的数目 就new一个新的线程 否则sleep 直到有空闲线程为止;* 当空闲线程不为 则将任务丢给空闲线程去完成* @param work*/public synchronized void run(String work){if (freeThreadCount == ) {if(totalThreadmaxPools){WorkerThread temp = new WorkerThread();totalThread = totalThread + ;m_ThreadList add(temp);temp start();synchronized(m_RunList){m_RunList add(work);m_RunList notify();}}else{while (freeThreadCount == ) {try {Thread sleep( );}catch (InterruptedException e) {}}synchronized(m_RunList){m_RunList add(work);m_RunList notify();}}} else {synchronized(m_RunList){m_RunList add(work);m_RunList notify();}}}/*** 检查所有的线程的有效性*/public synchronized void checkAllThreads() {Iterator lThreadIterator = erator();while (lThreadIterator hasNext()) { //逐个遍厉WorkerThread lTestThread = (WorkerThread) lThreadIterator next();if (! (lTestThread isAlive())) { //如果处在非活动状态时lTestThread = new WorkerThread(); //重新生成个线程lTestThread start(); //启动}}}/*** 打印调试信息*/public void printDebugInfo(){System out println( totalThread= +totalThread);System out println( m_ThreadList size()= +m_ThreadList size());}/**** pTitle: 工作线程类/p* @author 张荣斌* @version */class WorkerThread extends Thread{boolean running = true;String work;public void run(){while(running){synchronized(o){freeThreadCount++;}synchronized(m_RunList){while(m_RunList size() == ){try{m_RunList wait();if(!running) return;}catch(InterruptedException e){} lishixinzhi/Article/program/Java/gj/201311/27379