HttpClient的超时用法小记
? ? HttpClient在使用中有两个超时时间，是一直接触和使用的，由于上次工作中使用httpClient造成了系统悲剧的情况，特地对它的两个超时时间进行了小小的测试，在这里记录下。
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?? ? 测试版本为HttpClient——3.1
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?? ? 一：连接超时：connectionTimeout
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?? ? 1：指的是连接一个url的连接等待时间。
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?? ? 2：设置方法为：
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?? ??public class TestHttpClientMain {
/** * @param args */ public static void main(String[] args) { HttpClient client = new HttpClient(); HttpMethod method = new GetMethod( "http://test.com"); client.getHttpConnectionManager().getParams() .setConnectionTimeout(3000); client.getHttpConnectionManager().getParams().setSoTimeout(3000); try { int statusCode = client.executeMethod(method); System.out.println(statusCode); byte[] responseBody = null; responseBody = method.getResponseBody(); String result = new String(responseBody); System.out.println(result); } catch (HttpException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } ??
?? ? 3：测试的时候，将url改为一个不存在的url：“http://test.com”
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?? ? 4：超时时间3000ms过后，系统报出异常。
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?? ??org.apache.commons.httpclient.ConnectTimeoutException: The host did not accept the connection within timeout of 3000 ms
- /** * @param args */ public static void main(String[] args) { HttpClient client = new HttpClient(); HttpMethod method = new GetMethod( "http://localhost:8080/firstTest.htm?method=test"); client.getHttpConnectionManager().getParams() .setConnectionTimeout(4000); client.getHttpConnectionManager().getParams().setSoTimeout(2000); try { int statusCode = client.executeMethod(method); System.out.println(statusCode); byte[] responseBody = null; responseBody = method.getResponseBody(); String result = new String(responseBody); System.out.println(result); } catch (HttpException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } ??
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?? ? 3：测试的时候的连接url为我本地开启的一个url，http://localhost:8080/firstTest.htm?method=test
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?? ? 在我这个测试url里，当访问到这个链接时，线程sleep一段时间，来模拟返回response超时。
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?? ??@RequestMapping(params = "method=test") //<——②
public String testMethod(ModelMap model) { try { Thread.sleep(3000); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } System.out.println("call testMethod method."); model.addAttribute("name", "test method"); return "test"; } ??
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?? ? 4：将读取response返回超时时间设的时间比那个sleep时间短之后，运行程序给出异常：
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?? ? ?java.net.SocketTimeoutException: Read timed out
at java.net.SocketInputStream.socketRead0(Native Method) at java.net.SocketInputStream.read(Unknown Source) at java.io.BufferedInputStream.fill(Unknown Source) at java.io.BufferedInputStream.read(Unknown Source) at org.apache.commons.httpclient.HttpParser.readRawLine(HttpParser.java:78) at org.apache.commons.httpclient.HttpParser.readLine(HttpParser.java:106) at org.apache.commons.httpclient.HttpConnection.readLine(HttpConnection.java:1116) at org.apache.commons.httpclient.HttpMethodBase.readStatusLine(HttpMethodBase.java:1973) at org.apache.commons.httpclient.HttpMethodBase.readResponse(HttpMethodBase.java:1735) ??
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?? ? ok，以后再写httpClient这两个超时时间一定要加上，不加就很可能悲剧的了。