java编写Http服务器下载工具

import java.net.URL;
import java.net.URLConnection;
import java.io.File;
import java.io.InputStream;
import java.io.FileOutputStream;
import java.io.FileNotFoundException;
import java.io.IOException;

import org.apache.commons.io.FileUtils;

public class HttpUtil{
  private String httppath = "";

  public void setHttpPath(String httppath){
    this.httppath = httppath;
  }

  public String getHttpPath(){
    return this.httppath;
  }

  public HttpUtil(String httppath){
    this.httppath = httppath;
  }

  public InputStream getStream(String url){
    InputStream inStream = null;
    try{
      URL httpurl = new URL(url);
      URLConnection cOnn= httpurl.openConnection();
      inStream = conn.getInputStream();
    }catch (Exception e){
      e.printStackTrace();
      return null;
    }
    return inStream;
  }

  public int downLoad(String url,String localName ,int lines) throws FileNotFoundException, IOException{
    FileOutputStream fos = null;
    InputStream inStream = null;
    int ret = 0;
    try{
      URL httpurl = new URL(url);
      URLConnection cOnn= httpurl.openConnection();
      inStream = conn.getInputStream();
      fos = new FileOutputStream(localName);
      byte[] b = new byte[102400];
      int j = 0;
      while(inStream.read(b) != -1 && lines > 0){
        for(int i = j; i