httpClient如何接收格式错误的响应头部信息
使用 httpClient 从服务器端读取数据，出现异常 ：
Caused by: org.apache.http.ProtocolException: The server failed to respond with a valid HTTP response
执行的代码如下：
- Java code
public static String getResultByHttpGet() throws ClientProtocolException, IOException { String result = ""; String url="http://192.168.1.83/imonitorint.html?op=r&33032=0"; HttpGet httpGet = new HttpGet(url); //执行这行代码时出错 HttpResponse response = new DefaultHttpClient().execute(httpGet); if (response.getStatusLine().getStatusCode() == 200) { HttpEntity entity = response.getEntity(); result = EntityUtils.toString(entity, "GB2312"); } return result; }String url="http://192.168.1.83/imonitorint.html?op=r&33032=0";
这个url在浏览器中直接打开是有返回结果的，但是在代码中执行就会出错
通过ie浏览器插件httpwatch，查看服务器端返回的response的全部内容，发现返回的header为空。
如下图 ：
如何使HttpClient接受格式错误的响应头部信息,博客网上有人介绍，但是不够详细：
http://www.cnblogs.com/loveyakamoz/archive/2011/07/21/2113251.html
之前发帖讨论过这个问题，但是没有解决：
http://topic.csdn.net/u/20120816/16/f1092599-6b75-4216-aa24-b5f3f95fde6d.html?seed=814375011&r=79432055#r_79432055
全部的错误信息 ：
org.apache.http.client.ClientProtocolException
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:822)
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:754)
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:732)
at com.osee.yws.httpAgreement.HttpAgreement.getResultByHttpGet(HttpAgreement.java:50)
at com.osee.yws.bll.LCDOptionBll.readLcdOption(LCDOptionBll.java:104)
at com.osee.yws.bll.LCDOptionBll.readInput(LCDOptionBll.java:73)
at com.osee.yws.gui.SetDeviceOptionLCD$1.windowOpened(SetDeviceOptionLCD.java:74)
at java.awt.AWTEventMulticaster.windowOpened(Unknown Source)
at java.awt.AWTEventMulticaster.windowOpened(Unknown Source)
at java.awt.Window.processWindowEvent(Unknown Source)
at javax.swing.JDialog.processWindowEvent(Unknown Source)
at java.awt.Window.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$000(Unknown Source)
at java.awt.EventQueue$1.run(Unknown Source)
at java.awt.EventQueue$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$2.run(Unknown Source)
at java.awt.EventQueue$2.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
Caused by: org.apache.http.ProtocolException: The server failed to respond with a valid HTTP response
at org.apache.http.impl.conn.DefaultResponseParser.parseHead(DefaultResponseParser.java:109)
at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:252)
at org.apache.http.impl.AbstractHttpClientConnection.receiveResponseHeader(AbstractHttpClientConnection.java:281)
at org.apache.http.impl.conn.DefaultClientConnection.receiveResponseHeader(DefaultClientConnection.java:247)
at org.apache.http.impl.conn.AbstractClientConnAdapter.receiveResponseHeader(AbstractClientConnAdapter.java:219)
at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:298)
at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:125)
at org.apache.http.impl.client.DefaultRequestDirector.tryExecute(DefaultRequestDirector.java:645)
at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:464)
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:820)
... 33 more
[解决办法]
以下是我的观点：
光屏蔽解析head的代码错误应该是没有用的。
对于内容的读取，返回head的内容至关重要。
httpclient组件获取返回内容，需要head里面的至少这几个项目
1) HTTP/1.1 200 OK 状态码
2) Content-Length: 56008 长度
当然也可以是非固定长度的内容
2) Transfer-Encoding: chunked
3) Content-Type: text/html; charset=utf-8 标记内容格式
我们想想，连最起码的状态码/长度/格式都没提交给httpclient。它怎么去解析response。
当然也许存在可能跳过这些，得到原始的response stream。没仔细去分析httpclient的代码不好下结论。
[解决办法]