用 java 檢測主機連網(wǎng)狀態(tài)

昵稱11462324 2013-01-14

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用 java 檢測主機連網(wǎng)狀態(tài)

通過幾天努力終于把那個問題給解決了,就是用java 檢測本機的連網(wǎng)狀態(tài),當網(wǎng)絡(luò)中斷時讓檢測網(wǎng)絡(luò),如果連接上網(wǎng)絡(luò),便又繼續(xù)下面的工作.以下是我寫的一個類,朋友們可以參考一下清單一:URLAvailability.java

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package xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.UnknownHostException;
import java.text.DateFormat;
import java.util.Date;
import org.apache.log4j.Logger;
/**
*
* 項目名稱： xxxxxxxxxx*
* 功能模塊名稱：
*
* 文件名稱為：URLAvailability.java
*
* 文件功能簡述： xxxxxxxxxxxxxxxxxxxxxxxxxx *
* 文件創(chuàng)建人：ChenTao
* @author ChenTao
* @version v1.0
* @time 2008-5-31上午10:00:35
* @copyright xxxxxxxxxxxxx */
@SuppressWarnings("unused")
public class URLAvailability {
private static Logger logger = Logger.getLogger(URLAvailability.class);
private static URL urlStr;
private static HttpURLConnection connection;
private static int state = -1;
private static String succ;
private static boolean isCon = false;
private String url;
private String closeTime = null;
private int status = 0;
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public static String getSucc() {
return succ;
}
public static void setSucc(String succ) {
URLAvailability.succ = succ;
}
/**
* 功能描述 : 檢查URL是否可用
*
* @param url
* 指定檢查的網(wǎng)絡(luò)地址
*
* @return String
*/
public synchronized static String isConnect(String url) {
state = -1;
succ = null;
if (url == null || url.length() <= 0) {
return succ;
}
new URLAvailability().connectState(url);
return succ;
}
/**
* 功能描述 : 檢測當前網(wǎng)絡(luò)是否斷開或 URL是否可連接,
* 如果網(wǎng)絡(luò)沒斷開,最多連接網(wǎng)絡(luò) 5 次, 如果 5 次都不成功說明該地址不存在或視為無效地址.
*
* @param url
* 指定URL網(wǎng)絡(luò)地址
*
* @return void
*/
private synchronized void connectState(String url) {
this.url = url;
int counts = 0;
while (counts < 5) {
try {
urlStr = new URL(this.getUrl());
connection = (HttpURLConnection) urlStr.openConnection();
state = connection.getResponseCode();
if (state == 200) {
succ = connection.getURL().toString();
}
break;
} catch (UnknownHostException ex) {
if(this.closeTime == null){
DateFormat df = DateFormat.getDateTimeInstance();
closeTime = df.format(new Date());
logger.error("網(wǎng)絡(luò)連接狀態(tài)已斷開,請檢查網(wǎng)絡(luò)連接設(shè)備");
logger.info("斷開時間 : " + this.closeTime);
logger.error("程序開始執(zhí)行每三分鐘檢測一次網(wǎng)絡(luò)");
}
try {
status ++;
logger.info("開始第" + status + " 次檢測網(wǎng)絡(luò)狀態(tài)是否可連接");
Thread.sleep(180000);
} catch (InterruptedException e) {
}
this.connectState(this.getUrl());
} catch (Exception ex) {
counts++;
continue;
}
if(status != 0){
DateFormat df = DateFormat.getDateTimeInstance();
closeTime = df.format(new Date());
logger.info("網(wǎng)絡(luò)成功連接");
}
}
}
}
大家看到上面我 cache 了UnknownHostException 異常,這個意思是在調(diào)用遠程主機發(fā)生的異常,我們只需要 cache 這個異常就搞定了,不信可試試把網(wǎng)線斷開后看看會發(fā)生什么