Http请求超时的一种处理方法[通俗易懂]

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URLConnection类常见的超时处理就是调用其setConnectTimeout和setReadTimeout方法：

setConnectTimeout：设置连接主机超时（单位：毫秒）
setReadTimeout：设置从主机读取数据超时（单位：毫秒）

还有一种比较另类的就是利用java Object对象的wait()和notify()、notifyAll()方法，利用线程的等待和通知机制处理urlConnection的超时，下面直接贴代码：

public class HttpConnProcessThread implements Runnable { public boolean isStop = false; public boolean readOK = false; private HttpURLConnection reqConnection = null; public Thread readingThread; private int readLen; private String msg = null; private String reqMethod; private byte[] data; /** * ReadThread constructor comment. */ public HttpConnProcessThread(HttpURLConnection reqConnection, String msg, String reqMethod ) { super(); this.reqConnection = reqConnection; this.msg = msg; this.reqMethod = reqMethod; } public void run() { InputStream input = null; OutputStream output = null; try{ //reqConnection.connect(); output = reqConnection.getOutputStream(); if ("post".equalsIgnoreCase(reqMethod) && msg != null && msg.length() >0) { output.write(msg.getBytes()); output.close(); output = null; } // 处理HTTP响应的返回状态信息 int responseCode = reqConnection.getResponseCode();// 响应的代码if( responseCode != 200 ) System.out.println("connect failed! responseCode = " + responseCode + " msg=" + reqConnection.getResponseMessage()); input = reqConnection.getInputStream(); int len; byte[] buf = new byte[2048]; readLen = 0; ByteArrayOutputStream outStream = new ByteArrayOutputStream(); 　　　　　　　// 读取inputStream while (!isStop) { len = input.read(buf); if (len <= 0) { this.readOK = true; input.close(); data=outStream.toByteArray(); break; } outStream.write(buf, 0, len); readLen += len; } } catch( IOException ie) {} catch(Exception e) {} finally { try{ reqConnection.disconnect(); if( input != null ) input.close(); if( output != null ) output.close(); //唤醒线程，跳出等待  wakeUp(); }catch(Exception e) { } } } public String getMessage(){ if (!readOK) //超时  { return ""; } if (readLen <= 0) { return ""; } return new String(data, 0, readLen); } public void startUp() { this.readingThread = new Thread(this); readingThread.start(); } //唤醒线程，不再等待 private synchronized void wakeUp() { notifyAll(); } public synchronized void waitForData(int timeout) { try { //指定超时时间，等待connection响应  wait(timeout); } catch (Exception e) { } if (!readOK) { isStop = true; try{ //中断线程 if( readingThread.isAlive() ) readingThread.interrupt(); }catch(Exception e) { } } } public static main(String[] args){ String msg=""; URL reqUrl = new URL("http://127.0.0.1:8080/"); // 建立URLConnection连接 reqConnection = (HttpURLConnection) reqUrl.openConnection(); HttpConnProcessThread rec = new HttpConnProcessThread(reqConnection, msg, "post" ); rec.startUp();
　　 // 如果顺利连接到并读完数据，则跳出等待，否则等待超时 rec.waitForData(2000); String retMessage = rec.getMessage(); } }