检测tomcat服务状态，自动重启Tomcat

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检测tomcat服务状态，自动重启Tomcat

第一种方式：监控请求

原理很简单。 在机器上做一个测试的文件。如果我们的程序能够读取到这个文件，则证明运行正常，可简单实现Tomcat HA.

import java.net.URL;

import java.net.URLConnection;

import java.util.Date;

public class Detector {

private static void keepTomcatAlive() throws NullPointerException {

String s;

String t = new String("tomcat5.exe");

boolean isTomcatAlive = false;

java.io.BufferedReader in;

try {

URL url = new URL("http://localhost/heartbeat.htm");

URLConnection con = url.openConnection();

in = new java.io.BufferedReader(new java.io.InputStreamReader(con

.getInputStream()));

con.setConnectTimeout(1000);

con.setReadTimeout(4000);

while ((s = in.readLine()) != null) {

if (s.length() > 0) {

// 如果能够读取到页面则证明可用

return;

}

}

in.close();

} catch (Exception ex) {

}

try {

java.lang.Process p = java.lang.Runtime.getRuntime().exec(

"tasklist");

in = new java.io.BufferedReader(new java.io.InputStreamReader(p

.getInputStream()));

while ((s = in.readLine()) != null) {

if (s.startsWith(t)) {

isTomcatAlive = true;

break;

}

}

in.close();

} catch (Exception e) {

e.printStackTrace();

}

if (isTomcatAlive) {

System.out.println("<" + new Date()

+ "> Tomcat is alive but not response!");

stopTomcat();

}

startTomcat();

}

public static void stopTomcat() {

try {

java.lang.Process p = java.lang.Runtime.getRuntime().exec(

"net stop \"Apache Tomcat\"");

java.io.BufferedReader in = new java.io.BufferedReader(

new java.io.InputStreamReader(p.getInputStream()));

String s;

String t = "成功停止";

boolean restart = false;

while ((s = in.readLine()) != null) {

if (s.indexOf(t) != -1) {

restart = true;

  break;

}

}

System.out.println("<" + new Date() + "> Tomcat is stop "

+ (restart ? "OK" : "ERROR"));

} catch (Exception e) {

e.printStackTrace();

}

}

public static void startTomcat() {

try {

java.lang.Process p = java.lang.Runtime.getRuntime().exec(

"net stop \"Apache Tomcat\"");

} catch (Exception e) {

e.printStackTrace();

}

try {

java.lang.Process p = java.lang.Runtime.getRuntime().exec(

"net start \"Apache Tomcat\"");

java.io.BufferedReader in = new java.io.BufferedReader(

new java.io.InputStreamReader(p.getInputStream()));

String s;

String t = "启动成功";

boolean restart = false;

while ((s = in.readLine()) != null) {

if (s.indexOf(t) != -1) {

restart = true;

break;

}

}

System.out.println("<" + new Date() + "> Tomcat is start "

+ (restart ? "OK" : "ERROR"));

} catch (Exception e) {

e.printStackTrace();

}

}

public static void main(String[] args) {

while (true) {

try {

Detector.keepTomcatAlive();

Thread.sleep(30000);

} catch (Exception ex) {

}

}

}

}

第二种方式：监控日志
由于tomcat部署的应用，在客户使用的过程中，每过五六天总会吊死成僵尸进程，查看日志为无效的变元，搜遍网络，尝试了很多办法也没有解决此问题。同时不能更换web容器，因为会增加成本，只好用java写了个监控程序，目前正在测试中

import java.net.URL;

import java.net.URLConnection;

import java.text.SimpleDateFormat;

import java.util.Date;

import org.apache.log4j.Logger;

import org.apache.log4j.PropertyConfigurator;

import java.util.TimeZone;

/**

* NAME : tomcat.java

* FUNCTION : 监控服务器tomcat状态

* PROGRAMMED : TELSTAR/jlsu

* DATE(ORG) : 20090109

* PROJECT : TELSTAR

* OS : HP-UNIX

* HISTORY :

*/

public class TomcatDetector {</spa