Today, i’ll do a simple example on how to simulate a http post request using Apache Common Http Components. This is a usefull utility, because i use it heavily on many projects, specially to do a simple messaging between desktop clients and the server side. Very simple, very lightweight and also very reliable.
Okay, first i start with the server version of the application. I create a new WebProject on Netbeans, create a simple servlet and deploy it on tomcat. This is a very simple servlet to print on netbeans console and give response whether 0 if failed, or 1 if succeed.
package com.edw.servlet;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.log4j.Logger;
public class LoginServlet extends HttpServlet {
private Logger logger = Logger.getLogger(LoginServlet.class);
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
try {
String username = request.getParameter("username");
String password = request.getParameter("password");
logger.debug("receiving post " + username + " and " + password);
response.getWriter().write("1");
} catch (Exception e) {
logger.error(e,e);
response.getWriter().write("0");
}
}
}
As usual, i register my servlet on web.xml.
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<servlet>
<servlet-name>loginServlet</servlet-name>
<servlet-class>com.edw.servlet.LoginServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>loginServlet</servlet-name>
<url-pattern>/loginServlet</url-pattern>
</servlet-mapping>
<session-config>
<session-timeout>
30
</session-timeout>
</session-config>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>
And now is my client’s side Java application.
package com.edw.postsimulator;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.Consts;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
public class PostSimulator {
// this is your target url
private static String url = "http://localhost:8084/WebTestPost/loginServlet";
public static void main(String[] args) throws Exception {
HttpClient httpclient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
// set the parameters
List <NameValuePair> nvps = new ArrayList<NameValuePair>();
nvps.add(new BasicNameValuePair("username", "edwin"));
nvps.add(new BasicNameValuePair("password", "dodol"));
// set the encoding
httpPost.setEntity(new UrlEncodedFormEntity(nvps, Consts.UTF_8));
// send the http request and get the http response
HttpResponse response = httpclient.execute(httpPost);
HttpEntity resEntity = response.getEntity();
// read the server's response contents
System.out.println(EntityUtils.toString(resEntity));
}
}
These are what is written on my Netbean’s console,
And this is my Netbean’s project configurations
Hope it helped others, Cheers 
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