(转)JAVA 检测网络是否为连通状态 ping
要用java检测网络资源是否可用，我们可以采用以下两种方法：
一种方法是调用ping命令，
如：
Process process= Runtime.getRuntime().exec("ping 192.168.0.5");
InputStreamReader return = new InputStreamReader(process.getInputStream());
LineNumberReader returnData = new LineNumberReader (return);
String line="";
while((line=returnData.readLine())!=null){
System.out.println(line);
}
通用对返回数据进行分析，来探测网络资源的可用性；
这种方法有一个缺点：就是许多网络资源是不允许被ping的，从而针对这类资源无法探测。
(2008-07-28记)
Dos中的ping 命令能很方便的检测网络是否为连通状态.但是在java中,一直没有找到好的方法检来测网络是否为连通状态.无奈之余,想出了如下方法:
package com.roadway.edserver.util;
import java.awt.Toolkit;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
/** *//**
* @Description:本类开启一个线程检测网络是否连通
* @Author : 惠万鹏
* @Time :2008-1-10
*/
public class NetworkManagement implements Runnable {
private int htmlCodeSize;
private int sleepMillisecond;
private int sleepMillisecondWhenNetWorkUnLinked;
private boolean isSpontaneousNotice;
private static boolean networkIsLinked;
private Thread thread = new Thread(this);
private Toolkit toolkit;
private String[] urls;
public NetworkManagement() {
this.urls = new String[]{"http://www.baidu.com", "http://www.google.cn"};
this.htmlCodeSize = 50;
this.sleepMillisecond = 5000;
this.sleepMillisecondWhenNetWorkUnLinked = 10000;
this.toolkit = Toolkit.getDefaultToolkit();
thread.start();
}
public void setURLs(String[] urls) {
if (urls != null && urls.length > 0) {
this.urls = urls;
}
}
public void setHtmlCodeSize(int htmlCodeSize) {
if (htmlCodeSize > 0) {
this.htmlCodeSize = htmlCodeSize;
}
}
public void isSpontaneousNotice(boolean isSpontaneousNotice) {
this.isSpontaneousNotice = isSpontaneousNotice;
}
public void setSleepMillisecont(int sleepMillisecont) {
if (sleepMillisecont > 100) {
this.sleepMillisecond = sleepMillisecont;
}
}
public void setSleepMillisecondWhenNetWorkUnLinked(int sleepMillisecont) {
if (sleepMillisecont > 100) {
this.sleepMillisecondWhenNetWorkUnLinked = sleepMillisecont;
}
}
public static boolean IsNetWordLinking() {
return NetworkManagement.networkIsLinked;
}
public void run() {
while (true) {
try {
this.isNetWorkLinked();
if (!NetworkManagement.networkIsLinked) {
this.isPrintMessage(this.isSpontaneousNotice);
Thread.sleep(this.sleepMillisecondWhenNetWorkUnLinked);
}
System.out.println(NetworkManagement.IsNetWordLinking());
Thread.sleep(this.sleepMillisecond);
} catch (Exception e) {
}
}
}
private boolean canGetHtmlCode(String httpUrl) {
String htmlCode = "";
try {
InputStream in;
URL url = new java.net.URL(httpUrl);
HttpURLConnection connection = (HttpURLConnection) url
.openConnection();
connection = (HttpURLConnection) url.openConnection();
connection.setRequestProperty("User-Agent", "Mozilla/4.0");
connection.connect();
in = connection.getInputStream();
byte[] buffer = new byte[this.htmlCodeSize];
in.read(buffer);
htmlCode = new String(buffer);
} catch (Exception e) {
}
if (htmlCode == null || htmlCode.equals("")) {
return false;
}
return true;
}
private void isNetWorkLinked() {
boolean tempIsNetWorkLinked = false;
for (int urlsCount = 0; urlsCount < this.urls.length; urlsCount++) {
if (this.canGetHtmlCode(this.urls[urlsCount])) {
tempIsNetWorkLinked = true;
break;
}
}
NetworkManagement.networkIsLinked = tempIsNetWorkLinked;
}
private void isPrintMessage(boolean isPrint) {
if (isPrint) {
toolkit.beep();
StringBuffer message = new StringBuffer();
message.append("------------->");
message.append("网络中断, ");
message.append(this.sleepMillisecondWhenNetWorkUnLinked);
message.append(" 毫秒后再次检测!<-------------");
System.out.println(message.toString());
}
}
public static void main(String[] args) {
NetworkManagement n = new NetworkManagement();
n.isSpontaneousNotice(true);
}
}
转自:http://hwpok.iteye.com/blog/615992
