Android基于开源项目xutils3实现下载

 import android.app.Activity; import android.content.pm.PackageManager; import android.support.v4.app.ActivityCompat; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.EditText; import android.widget.ProgressBar; import android.widget.Toast; import org.xutils.common.Callback; import org.xutils.http.RequestParams; import org.xutils.x; import java.io.File; public class MainActivity extends AppCompatActivity { private EditText et_path; private ProgressBar pb; //动态获取权限 private static final int REQUEST_EXTERNAL_STORAGE = 1; private static String[] PERMISSIONS_STORAGE = { "android.permission.READ_EXTERNAL_STORAGE", "android.permission.WRITE_EXTERNAL_STORAGE" }; private String fileName; private String appName; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //动态获取权限 verifyStoragePermissions(this); x.view().inject(this); et_path = findViewById(R.id.et_path); pb = findViewById(R.id.progressBar); } //点击按钮下载（断点续传） public void click(View view) { //拿到路径 String path = et_path.getText().toString().trim(); fileName = getFileName(path); RequestParams params = new RequestParams(path); params.setSaveFilePath(fileName); params.setAutoRename(true); x.http().get(params, new Callback.ProgressCallback() { @Override public void onWaiting() { } @Override public void onStarted() { } @Override public void onLoading(long total, long current, boolean isDownloading) { //totle代表总进度，current代表当前进度 pb.setMax((int) total); pb.setProgress((int) current); System.out.println("测试1"); } @Override public void onSuccess(File result) { System.out.println("下载完成"); Toast.makeText(getApplicationContext(), "下载成功", Toast.LENGTH_SHORT).show(); } @Override public void onError(Throwable ex, boolean isOnCallback) { System.out.println("测试2"); } @Override public void onCancelled(CancelledException cex) { System.out.println("测试3"); } @Override public void onFinished() { System.out.println("测试4"); } }); } //动态获取权限 public static void verifyStoragePermissions(Activity activity) { try { //检测是否有写的权限 int permission = ActivityCompat.checkSelfPermission(activity, "android.permission.WRITE_EXTERNAL_STORAGE"); if (permission != PackageManager.PERMISSION_GRANTED) { // 没有写的权限，去申请写的权限，会弹出对话框 ActivityCompat.requestPermissions(activity, PERMISSIONS_STORAGE,REQUEST_EXTERNAL_STORAGE); } } catch (Exception e) { e.printStackTrace(); } } //获取文件名-->"http://10.173.29.234/test.exe" public String getFileName(String path) { int start = path.lastIndexOf("/") + 1; appName = path.substring(start); //    String fileName = Environment.getExternalStorageDirectory().getPath()+"/"+subString; String fileName = "/sdcard/file/"+ appName; return fileName; } }