JAVA通过HTTP访问：Post+Get方式

public class TestGetPost {
	/**
	 * 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
	 */

	public static String sendGet(String url, String param) {
		String result = "";
		BufferedReader in = null;
		try {
			String urlName = url + "?" + param;
			URL realUrl = new URL(urlName);
			//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)");
			//建立实际的连接
			conn.connect();
			//获取所有响应头字段
			Map < String, List < String >> map = conn.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(conn.getInputStream()));
			String line;
			while ((line = in .readLine()) != null) {
				result += "/n" + 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 (IOException ex) {
				ex.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 URL所代表远程资源的响应
	 */
	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
			in = new BufferedReader(
				new InputStreamReader(conn.getInputStream()));
			String line;
			while ((line = in .readLine()) != null) {
				result += "/n" + 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;
	}


	//提供主方法，测试发送GET请求和POST请求
	public static void main(String args[]) {
		//发送GET请求
		String s = TestGetPost.sendGet("http://localhost:8888/abc/login.jsp", null);
		System.out.println(s);
		//发送POST请求
		String s1 = TestGetPost.sendPost(http: //localhost:8888/abc/a.jsp ,
			"user=李刚&pass=abc");
		System.out.println(s1);
	}
}