我正在尝试创建一个应用程序，我必须在其中上传任何不超过 16-20 MB 的文件。我正在使用 OkHttpClient3，但我的主要问题是它将使用简单名称的文件，例如 a.mp4、b.jpg 等，但它不能选择像 hello world 12.mp4 这样的文件，代码应该是什么放在 RequestBody file_body = RequestBody.create(MediaType.parse(content_type),f). 我的代码是。

public  void enable_button(){
        choosefile.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                new MaterialFilePicker()
                        .withActivity(ShowStudent.this)
                        .withRequestCode(10)
                        .start();
            }
        });
    }
    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        if(requestCode == 100 && (grantResults[0] == PackageManager.PERMISSION_GRANTED)){
            enable_button();
        }else {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                requestPermissions(new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},100);
            }
        }
    }
    @Override
    protected void onActivityResult(int requestCode, int resultCode, final Intent data) {
        if(requestCode == 10 && resultCode == RESULT_OK){
            progress = new ProgressDialog(ShowStudent.this);
            progress.setTitle("Uploading");
            progress.setMessage("Please wait...");
            progress.show();

            Thread t = new Thread(new Runnable() {
                @Override
                public void run() {
                    File f  = new File(data.getStringExtra(FilePickerActivity.RESULT_FILE_PATH));
                    String content_type  = getMimeType(f.getPath());
                    String file_path = f.getAbsolutePath();
                    OkHttpClient client = new OkHttpClient();
                    RequestBody file_body = RequestBody.create(MediaType.parse(content_type),f);
                    RequestBody request_body = new MultipartBody.Builder()
                            .setType(MultipartBody.FORM)
                            .addFormDataPart("type",content_type)
                            .addFormDataPart("uploaded_file",file_path.substring(file_path.lastIndexOf("/")+1), file_body)
                            .build();
                    Request request = new Request.Builder()
                            .url("http://onsitesupport.info/diary/uploadproject.php")
                            .post(request_body)
                            .build();
                    try {
                        Response response = client.newCall(request).execute();
                        if(!response.isSuccessful()){
                            throw new IOException("Error : "+response);
                        }
                        progress.dismiss();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            });
            t.start();
        }
    }
    private String getMimeType(String path) {
        String extension = MimeTypeMap.getFileExtensionFromUrl(path);
        return MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension);
    }

我得到了这个异常

E/AndroidRuntime: FATAL EXCEPTION: Thread-3122
              Process: com.kliff.studentteacherportal, PID: 29436
              java.lang.NullPointerException: Attempt to invoke interface    method 'int java.lang.CharSequence.length()' on a null object reference
                  at java.util.regex.Matcher.reset(Matcher.java:177)
                  at java.util.regex.Matcher.<init>(Matcher.java:90)
                  at java.util.regex.Pattern.matcher(Pattern.java:297)
                  at okhttp3.MediaType.parse(MediaType.java:51)
                  at com.kliff.studentteacherportal.ShowStudent$2.run(ShowStudent.java:100)
                  at java.lang.Thread.run(Thread.java:818)
E/WindowManager: android.view.WindowLeaked: Activity com.kliff.studentteacherportal.ShowStudent has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{26acab10 V.E..... R......D 0,0-684,322} that was originally added here
                 at android.view.ViewRootImpl.<init>(ViewRootImpl.java:458)
                 at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:278)
                 at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:85)
                 at android.app.Dialog.show(Dialog.java:311)
                 at com.kliff.studentteacherportal.ShowStudent.onActivityResult(ShowStudent.java:91)
                 at android.app.Activity.dispatchActivityResult(Activity.java:6294)
                 at android.app.ActivityThread.deliverResults(ActivityThread.java:3873)
                 at android.app.ActivityThread.handleSendResult(ActivityThread.java:3920)
                 at android.app.ActivityThread.access$1300(ActivityThread.java:182)
                 at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1523)
                 at android.os.Handler.dispatchMessage(Handler.java:111)
                 at android.os.Looper.loop(Looper.java:194)
                 at android.app.ActivityThread.main(ActivityThread.java:5706)
                 at java.lang.reflect.Method.invoke(Native Method)
                 at java.lang.reflect.Method.invoke(Method.java:372)
                 at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1033)
                 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:828)
W/MALI: glDrawArrays:714: [MALI] glDrawArrays takes more than 5ms here. Total elapse time(us): 5659

最佳答案

好的，我明白了，它不能选择带空格的文件，但我通过替换解决了我的问题

String mimeType= URLConnection.guessContentTypeFromName(f.getName()); 
RequestBody file_body = RequestBody.create(MediaType.parse(mimeType),f);`

关于android - 无法使用 OkHttp3 在文件管理器中选择文件，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/40480874/