HttpURLConnection 的使用

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 HttpInvoker
{
	public static final String GET_URL = "http://192.168.1.82:8082/xmbj/wordpdf";
	public static final String POST_URL = "http://192.168.1.82:8082/xmbj/wordpdf";
	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 + "?filePath="+URLEncoder.encode(URLEncoder.encode("F:/需求分析/海沧需求分析/2011-11-03海沧会议纪要.doc", "utf-8"),"utf-8");
//		String getURL = GET_URL + "?filePath=F:/需求分析/海沧需求分析/2011-11-03海沧会议纪要.doc";
		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"));
		String lines;
		while ((lines = reader.readLine()) != null)
		{
			System.out.println(lines);
		}
		reader.close();
		// 断开连接
		connection.disconnect();
	}

	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();
		// 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);
		connection.setDoInput(true);
		connection.setRequestMethod("POST");
		// Post 请求不能使用缓存
		connection.setUseCaches(false);
		//是static函数，作用于所有的URLConnection对象。
		// URLConnection.setInstanceFollowRedirects是成员函数，仅作用于当前函数
		connection.setInstanceFollowRedirects(true);
		// 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 = "name=" + URLEncoder.encode("中国人", "UTF-8");
		String content = "filePath=" + URLEncoder.encode(URLEncoder.encode("F:/需求分析/海沧需求分析/2011-11-03海沧会议纪要.doc", "utf-8"),"utf-8");
		String district = "&district=" + URLEncoder.encode("区域显示可", "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.writeBytes(district);
		out.flush();
		out.close(); // flush and close
		BufferedReader reader = new BufferedReader(new InputStreamReader(
		connection.getInputStream(), "UTF-8"));
		String line;
		System.out.println("=============================");
		System.out.println("Contents of post request");
		System.out.println("=============================");
		while ((line = reader.readLine()) != null)
		{
			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)
	{
		// TODO Auto-generated method stub
		try
		{
//		readContentFromGet();
		readContentFromPost();
		} catch (IOException e)
		{
		// TODO Auto-generated catch block
		e.printStackTrace();
		}
	}
}