HttpClient的超时用法小记

http://guoliangqi.iteye.com/blog/646609

HttpClient的超时用法小记

博客分类：
java

LinuxJavaApacheWindows.net

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 {

Java代码


/**
* @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

Java代码


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 {

Java代码


/**
* @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

Java代码


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

Java代码


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。