JavaWeb 服務啓動時,在後臺啓動加載一個線程
JavaWeb 服務啓動時,在後臺啓動加載一個線程。
目前,我所掌握的一共有兩種方法,第一種是監聽(Listener),第二種是配置隨項目啓動而啓動的Servlet。
下面對這兩種方法做一簡單的介紹,(Mark一下,防止以後急用又忘記了):
監聽(Listener)
首先,我們創建一個監聽的類,繼承ServletContextListener,如下:
源碼複製打印
package com.wxp.thread;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
/**
* Listener的方式在後臺執行一線程
*
* @author Champion.Wong
*
*/
public class MyListener implements ServletContextListener {
private MyThread myThread;
public void contextDestroyed(ServletContextEvent e) {
if (myThread != null && myThread.isInterrupted()) {
myThread.interrupt();
}
}
public void contextInitialized(ServletContextEvent e) {
String str = null;
if (str == null && myThread == null) {
myThread = new MyThread();
myThread.start(); // servlet 上下文初始化時啓動 socket
}
}
}
/**
* 自定義一個 Class 線程類繼承自線程類,重寫 run() 方法,用於從後臺獲取並處理數據
*
* @author Champion.Wong
*
*/
class MyThread extends Thread {
public void run() {
while (!this.isInterrupted()) {// 線程未中斷執行循環
try {
Thread.sleep(2000); //每隔2000ms執行一次
} catch (InterruptedException e) {
e.printStackTrace();
}
// ------------------ 開始執行 ---------------------------
System.out.println("____FUCK TIME:" + System.currentTimeMillis());
}
}
}
然後,在web.xml中配置如下:
源碼複製打印
<listener$amp;>amp;$nbsp;
<listener-class>com.wxp.thread.MyListener</listener-class$amp;>amp;$nbsp;
</listener$amp;>amp;$nbsp;
OK!
2.使用Servlet,在項目啓動的時候啓動它。
首先,創建一個Servlet,繼承HttpServlet
package com.wxp.thread;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import comon.Constants;
public class MyServlet extends HttpServlet{
private static final long serialVersionUID = 1L;
private MyThread1 myThread1;
public MyServlet(){
}
public void init(){
String str = null;
if (str == null && myThread1 == null) {
myThread1 = new MyThread1();
myThread1.start(); // servlet 上下文初始化時啓動 socket
}
}
public void doGet(HttpServletRequest httpservletrequest, HttpServletResponse httpservletresponse)
throws ServletException, IOException{
}
public void destory(){
if (myThread1 != null && myThread1.isInterrupted()) {
myThread1.interrupt();
}
}
}
/**
* 自定義一個 Class 線程類繼承自線程類,重寫 run() 方法,用於從後臺獲取並處理數據
*
* @author Champion.Wong
*
*/
class MyThread1 extends Thread {
public void run() {
while (!this.isInterrupted()) {// 線程未中斷執行循環
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
// ------------------ 開始執行 ---------------------------
System.out.println("____FUCK TIME:" + System.currentTimeMillis());
}
}
}
然後,在web.xml中配置
<!-- LISTENER FOR THREAD -->
<servlet>
<servlet-name>MyListener</servlet-name>
<servlet-class>com.ite.wxp.MyServlet</servlet-class>
<load-on-startup>9</load-on-startup$amp;>amp;$lt;!-- 數字越小,啓動的優先級越高,必須大於0 -->
</servlet>
<servlet-mapping>
<servlet-name>MyListener</servlet-name>
<url-pattern>/test</url-pattern>
</servlet-mapping>
OK.啓動項目,預期效果!
目前,我所掌握的一共有兩種方法,第一種是監聽(Listener),第二種是配置隨項目啓動而啓動的Servlet。
下面對這兩種方法做一簡單的介紹,(Mark一下,防止以後急用又忘記了):
監聽(Listener)
首先,我們創建一個監聽的類,繼承ServletContextListener,如下:
源碼複製打印
package com.wxp.thread;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
/**
* Listener的方式在後臺執行一線程
*
* @author Champion.Wong
*
*/
public class MyListener implements ServletContextListener {
private MyThread myThread;
public void contextDestroyed(ServletContextEvent e) {
if (myThread != null && myThread.isInterrupted()) {
myThread.interrupt();
}
}
public void contextInitialized(ServletContextEvent e) {
String str = null;
if (str == null && myThread == null) {
myThread = new MyThread();
myThread.start(); // servlet 上下文初始化時啓動 socket
}
}
}
/**
* 自定義一個 Class 線程類繼承自線程類,重寫 run() 方法,用於從後臺獲取並處理數據
*
* @author Champion.Wong
*
*/
class MyThread extends Thread {
public void run() {
while (!this.isInterrupted()) {// 線程未中斷執行循環
try {
Thread.sleep(2000); //每隔2000ms執行一次
} catch (InterruptedException e) {
e.printStackTrace();
}
// ------------------ 開始執行 ---------------------------
System.out.println("____FUCK TIME:" + System.currentTimeMillis());
}
}
}
然後,在web.xml中配置如下:
源碼複製打印
<listener$amp;>amp;$nbsp;
<listener-class>com.wxp.thread.MyListener</listener-class$amp;>amp;$nbsp;
</listener$amp;>amp;$nbsp;
OK!
2.使用Servlet,在項目啓動的時候啓動它。
首先,創建一個Servlet,繼承HttpServlet
package com.wxp.thread;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import comon.Constants;
public class MyServlet extends HttpServlet{
private static final long serialVersionUID = 1L;
private MyThread1 myThread1;
public MyServlet(){
}
public void init(){
String str = null;
if (str == null && myThread1 == null) {
myThread1 = new MyThread1();
myThread1.start(); // servlet 上下文初始化時啓動 socket
}
}
public void doGet(HttpServletRequest httpservletrequest, HttpServletResponse httpservletresponse)
throws ServletException, IOException{
}
public void destory(){
if (myThread1 != null && myThread1.isInterrupted()) {
myThread1.interrupt();
}
}
}
/**
* 自定義一個 Class 線程類繼承自線程類,重寫 run() 方法,用於從後臺獲取並處理數據
*
* @author Champion.Wong
*
*/
class MyThread1 extends Thread {
public void run() {
while (!this.isInterrupted()) {// 線程未中斷執行循環
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
// ------------------ 開始執行 ---------------------------
System.out.println("____FUCK TIME:" + System.currentTimeMillis());
}
}
}
然後,在web.xml中配置
<!-- LISTENER FOR THREAD -->
<servlet>
<servlet-name>MyListener</servlet-name>
<servlet-class>com.ite.wxp.MyServlet</servlet-class>
<load-on-startup>9</load-on-startup$amp;>amp;$lt;!-- 數字越小,啓動的優先級越高,必須大於0 -->
</servlet>
<servlet-mapping>
<servlet-name>MyListener</servlet-name>
<url-pattern>/test</url-pattern>
</servlet-mapping>
OK.啓動項目,預期效果!
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