HttpClient的超时用法小记

from：http://blog.163.com/xing_mu_1/blog/static/6614290201032084947978/

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。  

   测试版本为HttpClient——3.1

      一：连接超时：connectionTimeout

      1：指的是连接一个url的连接等待时间。

      2：设置方法为：

       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”

      4：超时时间3000ms过后，系统报出异常。

       org.apache.commons.httpclient.ConnectTimeoutException: The host did not accept the connection within timeout of 3000 ms

at org.apache.commons.httpclient.protocol.ReflectionSocketFactory.createSocket(ReflectionSocketFactory.java:155)
 at org.apache.commons.httpclient.protocol.DefaultProtocolSocketFactory.createSocket(DefaultProtocolSocketFactory.java:125)
 at org.apache.commons.httpclient.HttpConnection.open(HttpConnection.java:707)
 at org.apache.commons.httpclient.HttpMethodDirector.executeWithRetry(HttpMethodDirector.java:387)
 at org.apache.commons.httpclient.HttpMethodDirector.executeMethod(HttpMethodDirector.java:171)
 at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:397)

       二：读取数据超时：soTimeout

      1：指的是连接上一个url，获取response的返回等待时间

      2：设置方法

      public class TestHttpClientMain {

/**
  * @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(3000);
  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();
  }
 }
}

    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

      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。

       @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";
    }

      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：

        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)

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。