HttpClient is a sub-project under Apache Jakarta Common that can be used to provide efficient, up-to-date, feature-rich client programming toolkits that support the HTTP protocol, and it supports the latest HTTP protocol. Version and recommendations.
Currently the latest version of HttpClient is HttpClient 4.0.1 (GA), download page: [url]http://hc.apache.org/downloads.cgi[/url]
The following test survey examples assume that the user has logged in:
Example: Query information by mobile phone number ([url]http://www.ip138.com:8080/search.asp?[/url])
Webpage code
FORM action="" method="get" name="mobileform" onsubmit="return checkMobile();">
<TR bgColor=#eff1f3class=tdc>
<TD align=middle width=130 noswap>Mobile number (segment) </TD>
[color=blue]<TD align=middle width=*><INPUT class=tdc name="mobile" maxLength="11">[/color][color=red]<!--Find the input box name from the url Can also be seen -->[/color]
<INPUT name="action" type="hidden" value=mobile> <INPUT class=bdtj name=B1 type=submit value="Query"></TD>
</TR>
</FORM>
<TR class=tdc bgcolor=#EFF1F3>
<TD width="130" align="center" noswap>Mobile number segment you are querying</TD>
<TD width=* align="center" class=tdc2>13601695</TD>
</TR>
<TR class=tdc bgcolor=#EFF1F3>
<TD width="130" align="center" noswap> card number attribution</TD>
<TD width=* align="center" class=tdc2>Shanghai Shanghai</TD>
</TR>
<TR class=tdc bgcolor=#EFF1F3>
<TD width="130" align="center" noswap> card type </TD>[color=red]<!--display data, the common point for class is tdc2, which can be filtered in the process of analyzing html Standard -->[/color]
[color=blue]<TD width=* align="center" class=tdc2>Mobile Global Card</TD>[/color]
</TR>
<TR class=tdc bgcolor=#EFF1F3>
<TD align="center">Area code</TD>
[color=blue]<TD align="center" class=tdc2>021</TD>[/color]
</TR>
<TR class=tdc bgcolor=#EFF1F3>
<TD align="center">Postcode</TD>
<[color=blue]TD align="center" class=tdc2>200000</TD>[/color]
The above analysis, the necessary conditions for using HttpClient: url, parameters, and htmlparser filter conditions
Using the HttpClient query, in order to analyze the extracted html content, we use the htmlparser package, its home page: http://htmlparser.sourceforge.net/
Create a Telephone class in Eclipse, in addition to main (), including 2 methods:
Call HttpClient, get the responseString from the specified url and return.
Call HtmlParser to parse the html file:

public static String getPostString(String mobile) throws HttpException, IOException
{ 
	HttpClient hc=new HttpClient(); 
	PostMethod pm=new PostMethod("http://www.ip138.com:8080/search.asp"); /*Search page url*/
	hc.getParams().setContentCharset("gb2312"); 
	pm.addParameter("mobile",mobile); /*Retrieve the parameters of the page 1*/
	pm.addParameter("action","mobile"); /*Retrieve the parameters of the page 2*/
	hc.executeMethod(pm); 
	System.out.println("GET POST STRING: "+pm.getResponseBodyAsString());
	return pm.getResponseBodyAsString(); 
} 
public static void getMobileInfor(String poststring) throws ParserException 
{ 
	Parser parser=new Parser(poststring); 
	NodeList nodelist=null; 
	NodeFilter filter=new HasAttributeFilter("class","tdc2"); /*Filters the content of the page and extracts the content of class tdc2*/
	nodelist=parser.extractAllNodesThatMatch(filter); 
	for(int i=0;i<nodelist.size();i++) 
	{ 
		System.out.println("data"+i+ ":"+nodelist.elementAt(i).toPlainTextString().replace(" ","")); 
	} 
}

View the results of the operation as follows
Recommend a good place to learn HttpClient [url]http://htmlparser.com.cn/post/20090816119.html[/url]