xutils的来实现断点续传

1.引入xutils的jar包 xUtils-2.6.14.jar2.如果是android 6.0还需要添加aphace httpclient的jar包 org.apache.http.legacy.jar

public class MainActivity extends Activity {

    private TextView tv;
    private ProgressBar pb;
    private TextView tvProgress;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        tv = (TextView) findViewById(R.id.tv_failure);

        pb = (ProgressBar) findViewById(R.id.pb);

        tvProgress = (TextView) findViewById(R.id.tv_progress);
    }

    public void startDown(View v) {
        HttpUtils http = new HttpUtils();
        String fileName = "pdf.exe";
        String path = "http://192.168.1.103:8080/android/" + fileName;

        HttpHandler handler = http.download(path, // 下载地址
                Environment.getExternalStorageDirectory() + File.separator + fileName, // 保存路径
                true, // 是否支持断点续传
                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 onLoading(long total, long current,
                            boolean isUploading) {
                        super.onLoading(total, current, isUploading);
                        pb.setMax((int) total);
                        pb.setProgress((int) current);
                        tvProgress.setText((current * 100 / total ) + "%");
                    }

                    @Override
                    public void onSuccess(ResponseInfo<File> responseInfo) {
                        File file = (File) responseInfo.result;
                        Toast.makeText(MainActivity.this, file.getPath(), 0)
                                .show();
                    }

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

布局文件

<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="com.example.multidown.MainActivity" >

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="startDown"
        android:text="开始下载" />

    <TextView
        android:id="@+id/tv_failure"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <ProgressBar
        android:id="@+id/pb"
        style="@android:style/Widget.ProgressBar.Horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/tv_progress"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>  

效果图:
[图片上传中。。。（1）]