HttpClient使用

转自 xiazdong

HTTP GET核心代码：

(1)DefaultHttpClient client = new DefaultHttpClient();

(2)HttpGet get = new HttpGet(String url);//此处的URL为http://..../path?arg1=value&....argn=value

(3)HttpResponse response = client.execute(get); //模拟请求

(4)int code = response.getStatusLine().getStatusCode();//返回响应码

(5)InputStream in = response.getEntity().getContent();//服务器返回的数据

HTTP POST核心代码：

(1)DefaultHttpClient client = new DefaultHttpClient();

(2)BasicNameValuePair pair = new BasicNameValuePair(String name,String value);//创建一个请求头的字段，比如content-type,text/plain

(3)UrlEncodedFormEntity entity = new UrlEncodedFormEntity(List<NameValuePair> list,String encoding);//对自定义请求头进行URL编码

(4)HttpPost post = new HttpPost(String url);//此处的URL为http://..../path

(5)post.setEntity(entity);

(6)HttpResponse response = client.execute(post);

(7)int code = response.getStatusLine().getStatusCode();

(8)InputStream in = response.getEntity().getContent();//服务器返回的数据

服务器端代码和通过URLConnection发出请求的代码

package org.xiazdong.servlet;
import java.io.IOException;
import java.io.OutputStream;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;


@WebServlet("/Servlet1")
public class Servlet1 extends HttpServlet {


protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String nameParameter = request.getParameter("name");
String ageParameter = request.getParameter("age");
String name = new String(nameParameter.getBytes("ISO-8859-1"),"UTF-8");
String age = new String(ageParameter.getBytes("ISO-8859-1"),"UTF-8");
System.out.println("GET");
System.out.println("name="+name);
System.out.println("age="+age);
response.setCharacterEncoding("UTF-8");
OutputStream out = response.getOutputStream();//返回数据
out.write("GET请求成功!".getBytes("UTF-8"));
out.close();
}


protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");
String name = request.getParameter("name");
String age = request.getParameter("age");
System.out.println("POST");
System.out.println("name="+name);
System.out.println("age="+age);
response.setCharacterEncoding("UTF-8");
OutputStream out = response.getOutputStream();
out.write("POST请求成功!".getBytes("UTF-8"));
out.close();
}
}