java - 如何从内部存储或外部存储中读取文件并将文件存储在android中的arrayList中

Question

我的要求是最终用户必须能够将文件从内部或外部存储上传到应用程序，并最终在页面中显示文件名。

实际结果：现在我已从存储中获取文件名并在我的页面中显示该名称。

预期结果：最终用户必须能够将图像或视频文件从外部或内部存储加载到应用程序，并最终在页面中显示其名称。

但是不知道如何从存储中加载读取文件并将其存储在 arrayList 中。

获取文件名的代码

public class ServiceDetails extends AppCompatActivity {
    
    private Button next, attachment_one;
    private ImageButton attach_file;

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

        next = findViewById(R.id.submit);
        attachment_one = findViewById(R.id.attachmentOne);
        attach_file = findViewById(R.id.attachFile);

        next.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(ServiceDetails.this, ServiceAddress.class);
                startActivity(intent);
            }
        });

        attach_file.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                if(Build.VERSION.SDK_INT > Build.VERSION_CODES.M &&
                        checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
                    requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 10001);
                }
                new MaterialFilePicker()
                        .withActivity(ServiceDetails.this)
                        .withRequestCode(1)
                        .withFilter(Pattern.compile(".*\\.(mkv|wmv|avi|mpeg|swf|mov|mp4|jpg|jpeg)$"))
                        .withHiddenFiles(true) // Show hidden files and folders
                        .start();
            }
        });

        attachment_one.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                attachment_one.setVisibility(View.INVISIBLE);
            }
        });

    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        if (requestCode == 1 && resultCode == RESULT_OK) {
            String file_path = data.getStringExtra(FilePickerActivity.RESULT_FILE_PATH);
            String file_array[] = file_path.split("/");
            String file_name = file_array[file_array.length - 1];
            // Do anything with file

            if(attachment_one.getText().toString().isEmpty()) {
                attachment_one.setVisibility(View.VISIBLE);
                attachment_one.setText(file_name);
            } 
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        switch (requestCode) {
            case 10001: {
                if(grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    Toast.makeText(ServiceDetails.this, "Permission granted", Toast.LENGTH_LONG).show();
                }else {
                    Toast.makeText(ServiceDetails.this, "Permission not granted", Toast.LENGTH_LONG).show();
                    finish();
                }
            }
        }
    }
}

我是 android 新手，请帮我为这个答案提供解决方案。百万提前感谢！

显示文件附件选项的图像

标签： javaandroidarraylistandroid-permissionsandroid-file