java多线程发送URL请求

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.text.NumberFormat;
import java.text.SimpleDateFormat;
import java.util.Date;

/**
 * This Class to test the PrintNet processing the snapshot performance.
 * It's mainly to solve the out of memory issue.
 * 
 * @author yfan
 *
 */
public class PnSnapshotPerformanceTest extends Thread {
  
  //TODO threadNumber
  private static final int threadNumber = 50;//50
  
  private static final int perThreadCreatSnpNumber = 20;//20
  
  private static final String urlStr = "http://**************com:6080/pn_entry.jsp";
  
  private static final SimpleDateFormat dateFomat =
      new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:ms");
  
  public PnSnapshotPerformanceTest() {
    super();
  }

  public PnSnapshotPerformanceTest(String name) {
    super(name);
  }

  @Override
  public void run() {
    for (int i = 1; i <= perThreadCreatSnpNumber; i++) {
      long startTime = System.currentTimeMillis();
      System.out.println(getCurrDateStr() + " " + this.getName() + "_" + i + ": Start to handle the snapshot <<<<<<<<<<<<<<<<<<<<<<<<<<" + getCurrentMemoryInfo());
      
      try {
        doPost();// send post request
      } catch (Exception e) {
        e.printStackTrace();
      }
      
      long useTime = System.currentTimeMillis() - startTime;
      System.out.println(getCurrDateStr() + " " +this.getName() + "_" + i + ": Handle the snapshot end >>>>>>>>>>>>>>>>>>>>>>>>>>>>use time: " + useTime/60000 + ":" + useTime%60000/1000 + ":" + useTime%60000%1000);
    }
  }
  
  public void doPost() {
    HttpURLConnection conn = null;
    try {
      URL url = new URL(urlStr);
      conn = (HttpURLConnection) url.openConnection();
      conn.setInstanceFollowRedirects(false);
      conn.setDoOutput(true);
      conn.setRequestMethod("POST");
      //conn.setUseCaches(false);
    
      //TODO test
      String snapshotStr = readFile("C:/bill/HP/eclipse_workspace/DailyPractice/src/d20130304/snapshot.xml");
      //String snapshotStr = readFile("C:/bill/HP/eclipse_workspace/DailyPractice/src/d20130304/snapshot_2.xml");
      StringBuffer sb = new StringBuffer();
      addPair(sb, "XML_string", snapshotStr);
      String parametersStr = sb.substring(0, sb.length() - 1);
      //System.out.println("parametersStr: \n" + parametersStr.substring(0, 1000));
      
      OutputStreamWriter out = new OutputStreamWriter(conn.getOutputStream());
      out.write(parametersStr);
      out.flush();
      out.close();
      
      //conn.getInputStream();
      BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
      String line = null;
      sb = new StringBuffer();
      while ((line = reader.readLine()) != null) {
        sb.append(line);
      }
      
      line = sb.toString();
      System.out.println("return line: \n" + line);
      //System.out.println(">>>>>>>>>>>>>>>>>>>>>>>Send request end. ");
      
      System.out.println("conn.getResponseCode(): " + conn.getResponseCode());
    } catch (IOException e) {
      // handle e
      System.out.println(">>>>>>>>>>>>>>IOException: " + e);
    } finally {
      if (conn != null) {
        conn.disconnect();
        //System.out.println("Disconnect successfully. ");
      }
    }
  }
  
  private String readFile(String filePath) {
    FileReader fr = null;
    BufferedReader br = null;
    StringBuffer sBuffer = new StringBuffer();

    try {
      fr = new FileReader(filePath);// d20130304/snapshot.xml
    } catch (FileNotFoundException e) {
      e.printStackTrace();
    }

    br = new BufferedReader(fr);
    String tempLine;
    try {
      tempLine = br.readLine();
      while (tempLine != null) {
        sBuffer.append(tempLine);
        sBuffer.append("\n");
        tempLine = br.readLine();
      }
      //System.out.println("sBuffer: \n" + sBuffer);
    } catch (IOException e) {
      e.printStackTrace();
    } finally {
      try {
        if (br != null)
          br.close();
        if (fr != null)
          fr.close();
      } catch (IOException e) {
        e.printStackTrace();
      }
    }
    
    return sBuffer.toString().trim();
  }
  
  public static void addPair(StringBuffer sb, String name, String value)
      throws UnsupportedEncodingException {
    if (value == null) {
      return;
    }
    sb.append(name);
    sb.append("=");
    sb.append(java.net.URLEncoder.encode(value, "UTF-8"));
    sb.append("&");
  }
  
  public static String getCurrDateStr() {
    Date date = new Date();
    return dateFomat.format(date);
  }
  
  public String getCurrentMemoryInfo () {
    StringBuilder sb = new StringBuilder();
    try {
      Runtime runtime = Runtime.getRuntime();

      NumberFormat format = NumberFormat.getInstance();

      long maxMemory = runtime.maxMemory();
      long allocatedMemory = runtime.totalMemory();
      long freeMemory = runtime.freeMemory();

      sb.append("free memory: " + format.format(freeMemory / 1048576) + "; ");
      sb.append("allocated memory: " + format.format(allocatedMemory / 1048576)
          + "; ");
      sb.append("max memory: " + format.format(maxMemory / 1048576) + "; ");
      sb.append("total free memory: "
          + format.format((freeMemory + (maxMemory - allocatedMemory)) / 1048576)
          + "; ");

      return sb.toString();
    } catch (Exception e) {
      e.printStackTrace();
    }
    
    return sb.toString();
  }

  public static void main(String[] args) {
    for (int i = 1; i <= threadNumber; i++) {
      PnSnapshotPerformanceTest pspt = new PnSnapshotPerformanceTest("Thread_" + i);
      pspt.start();
    }
  }
  
}