URLConnection发送post和get请求

1、请求类例子

package com.until;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLConnection;
import java.util.List;
import java.util.Map;

/**
 * 发送http请求的公共类
 * @author Administrator
 */
public class HttpRequest {
	/**
	 * 向指定URL发送GET方法的请求
	 * @param url 发送请求的URL
	 * @param param 请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
	 * @return URL 所代表远程资源的响应结果
	 */
	public static String sendGet(String url, String param) {
		String result = "";
		BufferedReader in = null;
		try {
			String urlNameString = url + "?" + param;
			URL realUrl = new URL(urlNameString);
			//打开和URL之间的连接
			URLConnection connection = realUrl.openConnection();
			//设置通用的请求属性
			connection.setRequestProperty("accept", "*/*");
			connection.setRequestProperty("connection", "Keep-Alive");
			connection.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
			//建立实际的连接
			connection.connect();
			//获取所有响应头字段
			Map<String, List<String>> map = connection.getHeaderFields();
			//遍历所有的响应头字段
			for (String key : map.keySet()) {
				System.out.println(key + "--->" + map.get(key));
			}
			//定义 BufferedReader输入流来读取URL的响应
			in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
			String line;
			while ((line = in.readLine()) != null) {
				result += line;
			}
		} catch (Exception e) {
			System.out.println("发送GET请求出现异常！" + e);
			e.printStackTrace();
		}
		// 使用finally块来关闭输入流
		finally {
			try {
				if (in != null) {
					in.close();
				}
			} catch (Exception e2) {
				e2.printStackTrace();
			}
		}
		return result;
	}

	/**
	 * 向指定 URL 发送POST方法的请求
	 * @param url发送请求的 URL
	 * @param param 请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
	 * @return 所代表远程资源的响应结果
	 */
	public static String sendPost(String url, String param) {
		PrintWriter out = null;
		BufferedReader in = null;
		String result = "";
		try {
			URL realUrl = new URL(url);
			//打开和URL之间的连接
			URLConnection conn = realUrl.openConnection();
			//设置通用的请求属性
			conn.setRequestProperty("accept", "*/*");
			conn.setRequestProperty("connection", "Keep-Alive");
			conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
			//发送POST请求必须设置如下两行
			conn.setDoOutput(true);
			conn.setDoInput(true);
			// 获取URLConnection对象对应的输出流
			out = new PrintWriter(conn.getOutputStream());
			//发送请求参数
			out.print(param);
			//flush输出流的缓冲
			out.flush();
			//定义BufferedReader输入流来读取URL的响应,(处理乱码)
			in = new BufferedReader(new InputStreamReader(conn.getInputStream(),"utf-8"));
			
			String line;
			while ((line = in.readLine()) != null) {
				result += line;
			}
		} catch (Exception e) {
			System.out.println("发送 POST 请求出现异常！" + e);
			e.printStackTrace();
		}
		// 使用finally块来关闭输出流、输入流
		finally {
			try {
				if (out != null) {out.close();}
				if (in != null) {in.close();}
			} catch (IOException ex) {
				ex.printStackTrace();
			}
		}
		return result;
	}	
}

 

2、测试类例子

package com.test;

import com.until.HttpRequest;

public class HttpUtilTest {
	public static void main(String[] args) {
		 //发送 GET 请求
//        String s=HttpRequest.sendGet("http://localhost:6144/Home/RequestString", "key=123&v=456");
//        System.out.println(s);
        
        //发送 POST 请求
        String sr = HttpRequest.sendPost("http://php.weather.sina.com.cn/xml.php", "city=武汉&password=DJOYnieT8234jlsK&day=0");
        System.out.println(sr);
	}
}