如何使用 java.net.URLConnection发出一个http请求呢？

实现步骤:
    使用统一资源定位器（java.net.URL）获取连接器（java.net.URLConnection）
    设置请求的参数
    发送请求
    以输入流的形式获取返回内容
    关闭输入流

package com.java265.other;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;

public class test {
	/*
	 * java265.com URLConnection发出URL请求的示例分享
	 */
	public static void main(String[] args) {
		try {
			String s1 = doGet();
			System.out.println(s1);

			String s2 = doPost();
			System.out.println(s2);

		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

	public static String doGet() throws Exception {
		URL localURL = new URL("http://java265.com");
		URLConnection connection = localURL.openConnection();
		HttpURLConnection httpURLConnection = (HttpURLConnection) connection;

		httpURLConnection.setRequestProperty("Accept-Charset", "utf-8");
		httpURLConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");

		InputStream inputStream = null;
		InputStreamReader inputStreamReader = null;
		BufferedReader reader = null;
		StringBuffer resultBuffer = new StringBuffer();
		String tempLine = null;

		if (httpURLConnection.getResponseCode() >= 300) {
			throw new Exception("HTTP Request is not success, Response code is " + httpURLConnection.getResponseCode());
		}

		try {
			inputStream = httpURLConnection.getInputStream();
			inputStreamReader = new InputStreamReader(inputStream);
			reader = new BufferedReader(inputStreamReader);

			while ((tempLine = reader.readLine()) != null) {
				resultBuffer.append(tempLine);
			}

		} finally {

			if (reader != null) {
				reader.close();
			}

			if (inputStreamReader != null) {
				inputStreamReader.close();
			}

			if (inputStream != null) {
				inputStream.close();
			}

		}

		return resultBuffer.toString();
	}

	public static String doPost() throws Exception {
		String parameterData = "paramter1=a¶mter2=java265.com";

		URL localURL = new URL("http://java265.com");
		URLConnection connection = localURL.openConnection();
		HttpURLConnection httpURLConnection = (HttpURLConnection) connection;

		httpURLConnection.setDoOutput(true);
		httpURLConnection.setRequestMethod("POST");
		httpURLConnection.setRequestProperty("Accept-Charset", "utf-8");
		httpURLConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
		httpURLConnection.setRequestProperty("Content-Length", String.valueOf(parameterData.length()));

		OutputStream outputStream = null;
		OutputStreamWriter outputStreamWriter = null;
		InputStream inputStream = null;
		InputStreamReader inputStreamReader = null;
		BufferedReader reader = null;
		StringBuffer resultBuffer = new StringBuffer();
		String tempLine = null;

		try {
			outputStream = httpURLConnection.getOutputStream();
			outputStreamWriter = new OutputStreamWriter(outputStream);

			outputStreamWriter.write(parameterData.toString());
			outputStreamWriter.flush();

			if (httpURLConnection.getResponseCode() >= 300) {
				throw new Exception(
						"HTTP Request is not success, Response code is " + httpURLConnection.getResponseCode());
			}

			inputStream = httpURLConnection.getInputStream();
			inputStreamReader = new InputStreamReader(inputStream);
			reader = new BufferedReader(inputStreamReader);

			while ((tempLine = reader.readLine()) != null) {
				resultBuffer.append(tempLine);
			}

		} finally {

			if (outputStreamWriter != null) {
				outputStreamWriter.close();
			}

			if (outputStream != null) {
				outputStream.close();
			}

			if (reader != null) {
				reader.close();
			}

			if (inputStreamReader != null) {
				inputStreamReader.close();
			}

			if (inputStream != null) {
				inputStream.close();
			}

		}

		return resultBuffer.toString();
	}

}