#1.下载utils项目

https://github.com/wyouflf/xUtils

#2布局文件里实现UI

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <EditText
        android:id="@+id/tv_path"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="http://down.360safe.com/inst.exe" />
    <Button
        android:layout_marginTop="10dip"
        android:layout_width="match_parent"
        android:onClick="download"
        android:layout_height="wrap_content"
        android:text="下载"
         />
    <TextView
         android:id="@+id/tv_info"
          android:layout_width="match_parent"
          android:layout_marginTop="10dip"
      	  android:layout_height="wrap_content"
      	  android:text="提示信息"
         />

</LinearLayout>

#3.在mainactivity中实现代码功能

package com.wzw.downloaddemo;

import java.io.File;

import com.lidroid.xutils.HttpUtils;
import com.lidroid.xutils.exception.HttpException;
import com.lidroid.xutils.http.HttpHandler;
import com.lidroid.xutils.http.ResponseInfo;
import com.lidroid.xutils.http.callback.RequestCallBack;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends Activity {

	private EditText etPath;
	private TextView tvInfo;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		etPath=(EditText) findViewById(R.id.tv_path);
		tvInfo=(TextView) findViewById(R.id.tv_info);

	}
	public void download(View v){
		String path =etPath.getText().toString();
		HttpUtils http = new HttpUtils();
		http.download(path, "/sdcard/360.exe", true, true, new RequestCallBack<File>() {

	<span style="white-space:pre">	</span>@Override
	        public void onStart() {
	            tvInfo.setText("正在连接...");
	        }

			 @Override
		    public void onLoading(long total, long current, boolean isUploading) {
		           tvInfo.setText(current + "/" + total);
			 }

			 @Override
		     public void onFailure(HttpException error, String msg) {
		           tvInfo.setText(msg);
		      }

			@Override
			public void onSuccess(ResponseInfo<File> responseInfo) {
				// TODO Auto-generated method stub
				tvInfo.setText("downloaded:" + responseInfo.result.getPath());
			}
		});

	}

}

用Utils的话比用传统的方式要方便的多。