android 断点下载---XUtils

<uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

package com.bawei.myxutils;

import java.io.File;
import java.math.BigDecimal;

import android.app.Activity;
import android.os.Bundle;
import android.os.Environment;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;

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;

public class MainActivity extends Activity {

    private ProgressBar pb;
    private TextView text1;
    private TextView text2;
    private String path;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        pb = (ProgressBar) findViewById(R.id.progressBar1);// 进度条
        text1 = (TextView) findViewById(R.id.text1);// 显示当前下载了多少
        text2 = (TextView) findViewById(R.id.text2);// 显示下载总大小
        path = Environment.getExternalStorageDirectory().getPath();// 得到SD卡路径
        HttpUtils http = new HttpUtils();
        /**
         * url 下载的路径 target 下载文件保存的路径 autoResume 是否支持断点续传
         */
        HttpHandler handler = http.download(
                "http://101.200.142.201:8080/tqyb/dancer.avi", path
                        + "/dancer.avi", true /* 如果目标文件存在，接着未完成的部分继续下载。 */,
                true/* 如果从请求返回信息中获取到文件名，下载完成后自动重命名。 */,
                new RequestCallBack<File>() {
                    @Override
                    public void onStart() {
                        // TODO Auto-generated method stub
                        super.onStart();
                        Toast.makeText(MainActivity.this, "开始下载", 0).show();
                    }

                    /**
                     * 加载进度 pb为进度条，实现进度条进度加载 total 总得大小 current 当前的大小
                     */
                    @Override
                    public void onLoading(long total, long current,
                            boolean isUploading) {
                        // TODO Auto-generated method stub
                        pb.setMax((int) total);
                        pb.setProgress((int) current);
                        // 将字节转换成M
                        BigDecimal filesize = new BigDecimal(current);
                        BigDecimal megabyte = new BigDecimal(1024 * 1024);
                        float returnValue = filesize.divide(megabyte, 2,
                                BigDecimal.ROUND_UP).floatValue();
                        text1.setText(returnValue + "M");
                        // 将字节转换成M
                        BigDecimal filesize1 = new BigDecimal(total);
                        BigDecimal megabyte1 = new BigDecimal(1024 * 1024);
                        float returnValue1 = filesize1.divide(megabyte1, 2,
                                BigDecimal.ROUND_UP).floatValue();
                        text2.setText(returnValue1 + "M");

                    }

                    @Override
                    public void onSuccess(ResponseInfo<File> arg0) {
                        // TODO Auto-generated method stub
                        Toast.makeText(MainActivity.this, "下载成功", 0).show();
                    }

                    @Override
                    public void onFailure(HttpException arg0, String arg1) {
                        // TODO Auto-generated method stub
                        Toast.makeText(MainActivity.this, "下载失败", 0).show();
                    }
                });

    }

}