发送http请求

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;

public class Http_post {
	public static final String GET_URL = "http://59.46.172.178:30011/port30017/p2p/ShengCaiWS/getUsedProject";

//	public static final String POST_URL = "http://59.46.172.178:30011/port30017/p2p/ShengCaiWS/getUsedProject";
	public static final String POST_URL = "http://59.46.172.178:30011/port30017/p2p/ShengCaiWS/getInvestRecord?projectId=4028814e4e098a40014e0a9f68d4000c";
	
	public static void readContentFromGet() throws IOException {
		// 拼凑get请求的URL字串，使用URLEncoder.encode对特殊和不可见字符进行编码
		String getURL = GET_URL + "?&activatecode="
				+ URLEncoder.encode("呵呵", "utf-8");
		URL getUrl = new URL(getURL);
		// 根据拼凑的URL，打开连接，URL.openConnection函数会根据URL的类型，
		// 返回不同的URLConnection子类的对象，这里URL是一个http，因此实际返回的是HttpURLConnection
		HttpURLConnection connection = (HttpURLConnection) getUrl
				.openConnection();
		// 进行连接，但是实际上get request要在下一句的connection.getInputStream()函数中才会真正发到
		// 服务器
		connection.connect();
		// 取得输入流，并使用Reader读取
		BufferedReader reader = new BufferedReader(new InputStreamReader(
				connection.getInputStream(), "utf-8"));// 设置编码,否则中文乱码
		System.out.println("=============================");
		System.out.println("Contents of get request");
		System.out.println("=============================");
		System.out.println("返回码:" + connection.getResponseCode());
		System.out.println("=============================");
		String lines;
		while ((lines = reader.readLine()) != null) {
			// lines = new String(lines.getBytes(), "utf-8");
			System.out.println(lines);
		}
		reader.close();
		// 断开连接
		connection.disconnect();
		System.out.println("=============================");
		System.out.println("Contents of get request ends");
		System.out.println("=============================");
	}

	public static void readContentFromPost() throws IOException {
		// Post请求的url，与get不同的是不需要带参数
		URL postUrl = new URL(POST_URL);
		// 打开连接
		HttpURLConnection connection = (HttpURLConnection) postUrl
				.openConnection();
		// Output to the connection. Default is
		// false, set to true because post
		// method must write something to the
		// connection
		// 设置是否向connection输出，因为这个是post请求，参数要放在
		// http正文内，因此需要设为true
		connection.setDoOutput(true);
		// Read from the connection. Default is true.
		connection.setDoInput(true);
		// Set the post method. Default is GET
		connection.setRequestMethod("POST");
		// Post cannot use caches
		// Post 请求不能使用缓存
		connection.setUseCaches(false);
		// This method takes effects to
		// every instances of this class.
		// URLConnection.setFollowRedirects是static函数，作用于所有的URLConnection对象。
		// connection.setFollowRedirects(true);

		// This methods only
		// takes effacts to this
		// instance.
		// URLConnection.setInstanceFollowRedirects是成员函数，仅作用于当前函数
		connection.setInstanceFollowRedirects(true);
		// Set the content type to urlencoded,
		// because we will write
		// some URL-encoded content to the
		// connection. Settings above must be set before connect!
		// 配置本次连接的Content-type，配置为application/x-www-form-urlencoded的
		// 意思是正文是urlencoded编码过的form参数，下面我们可以看到我们对正文内容使用URLEncoder.encode
		// 进行编码
		connection.setRequestProperty("Content-Type",
				"application/x-www-form-urlencoded");
		// 连接，从postUrl.openConnection()至此的配置必须要在connect之前完成，
		// 要注意的是connection.getOutputStream会隐含的进行connect。
		connection.connect();
		DataOutputStream out = new DataOutputStream(
				connection.getOutputStream());
		// The URL-encoded contend
		// 正文，正文内容其实跟get的URL中'?'后的参数字符串一致
		String content = "key=j0r53nmbbd78x7m1pqml06u2&type=1&toemail=[e-mail]"
				+ "&activatecode=" + URLEncoder.encode("哈哈", "utf-8");
		// DataOutputStream.writeBytes将字符串中的16位的unicode字符以8位的字符形式写道流里面
		out.writeBytes(content);
		out.flush();
		out.close(); // flush and close
		BufferedReader reader = new BufferedReader(new InputStreamReader(
				connection.getInputStream(), "utf-8"));// 设置编码,否则中文乱码
		String line = "";
		System.out.println("=============================");
		System.out.println("Contents of post request");
		System.out.println("=============================");
		System.out.println("返回码:" + connection.getResponseCode());
		System.out.println("=============================");
		while ((line = reader.readLine()) != null) {
			// line = new String(line.getBytes(), "utf-8");
			System.out.println(line);
		}
		System.out.println("=============================");
		System.out.println("Contents of post request ends");
		System.out.println("=============================");
		reader.close();
		connection.disconnect();
	}

	public static void main(String[] args) throws IOException {
		readContentFromPost();
		// readContentFromGet();
	}
}