http://www.cnblogs.com/linjiqin/archive/2012/02/16/2353597.html

通過HttpURLConnection模拟post表單送出

package junit;

import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

import org.junit.Test;

import com.hrtx.util.StreamTool;

public class EsmTest {

    /**
     * 通過HttpURLConnection模拟post表單送出
     * @throws Exception
     */
    @Test
    public void sendEms() throws Exception {
        String wen = "MS2201828";
        String btnSearch = "EMS快遞查詢";
        URL url = new URL("http://www.kd185.com/ems.php");
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setRequestMethod("POST");// 送出模式
        // conn.setConnectTimeout(10000);//連接配接逾時 機關毫秒
        // conn.setReadTimeout(2000);//讀取逾時 機關毫秒
        conn.setDoOutput(true);// 是否輸入參數

        StringBuffer params = new StringBuffer();
        // 表單參數與get形式一樣
        params.append("wen").append("=").append(wen).append("&")
              .append("btnSearch").append("=").append(btnSearch);
        byte[] bypes = params.toString().getBytes();
        conn.getOutputStream().write(bypes);// 輸入參數
        InputStream inStream=conn.getInputStream();
        System.out.println(new String(StreamTool.readInputStream(inStream), "gbk"));

    }

}      

封裝後的代碼：

/**
     * 通過HttpURLConnection模拟post表單送出
     * 
     * @param path
     * @param params 例如"name=zhangsan&age=21"
     * @return
     * @throws Exception
     */
    public static byte[] sendPostRequestByForm(String path, String params) throws Exception{
        URL url = new URL(path);
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setRequestMethod("POST");// 送出模式
        // conn.setConnectTimeout(10000);//連接配接逾時 機關毫秒
        // conn.setReadTimeout(2000);//讀取逾時 機關毫秒
        conn.setDoOutput(true);// 是否輸入參數
        byte[] bypes = params.toString().getBytes();
        conn.getOutputStream().write(bypes);// 輸入參數
        InputStream inStream=conn.getInputStream();
        return StreamTool.readInputStream(inStream);
    }      

package com.hrtx.util;

import java.io.ByteArrayOutputStream;
import java.io.InputStream;

public class StreamTool {
    /**
     * 從輸入流中讀取資料
     * @param inStream
     * @return
     * @throws Exception
     */
    public static byte[] readInputStream(InputStream inStream) throws Exception{
        ByteArrayOutputStream outStream = new ByteArrayOutputStream();
        byte[] buffer = new byte[1024];
        int len = 0;
        while( (len = inStream.read(buffer)) !=-1 ){
            outStream.write(buffer, 0, len);
        }
        byte[] data = outStream.toByteArray();//網頁的二進制資料
        outStream.close();
        inStream.close();
        return data;
    }
}