Android系统文件管理调用全攻略：开发指南与常见问题解决（含API示例）

// 1. 创建FileProvider实例
FileProvider fileProvider = new FileProvider(this, "com.example.fileprovider");

// 2. 获取目标文件Uri
Uri fileUri = fileProvider.getUriForFile(this, "com.example.fileprovider", new File("/sdcard/docs/report.pdf"));

// 3. 构建Intent
Intent intent = new Intent();
intent.setAction(Intent.ACTION_VIEW);
intent.setDataAndType(fileUri, "application/pdf");
intent.setFlags(Intent.FLAG_ACTIVITY_NO_HISTORY);

// 4. 添加权限请求
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
    requestPermissions(new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, REQUEST_CODE);
} else {
    startActivity(intent);
}

// 分片大小配置
int chunkSize = 1024 * 1024 * 5; // 5MB
FileRequest fileRequest = new FileRequest.Builder()
    .chunkSize(chunkSize)
    .build();

FileDownloadTask task = new FileDownloadTask(fileRequest);
task.setOnFileDownloadListener(new OnFileDownloadListener() {
    @Override
    public void onProgress(long progress, long total) {
        // 更新进度条
    }
});

// 设置缓存策略（Android 9+）
Request request = new Request.Builder()
    .header("Range", "bytes=0-1048576")
    .build();

// 动态Uri生成策略
Uri generateUri(File file) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
        return FileProvider.getUriForFile(this, "com.example.fileprovider", file);
    } else {
        return Uri.fromFile(file);
    }
}

// 动态权限请求模板
public void checkStoragePermissions() {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        if (checkSelfPermission(Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
            requestPermissions(new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, REQUEST_CODE);
        }
    }
}

ContentResolver resolver = getContentResolver();
Cursor cursor = resolver.query(
    MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
    new String[]{MediaStore.Audio.AudioColumns.TITLE},
    null,
    null
);

// 自定义Uri处理器
class CustomFileProvider extends FileProvider {
    @Override
    protected boolean verifyUri(String uri) {
        Uri parsedUri = Uri.parse(uri);
        if (parsedUri.getScheme().equals("file")) {
            String path = parsedUri.getPath();
            if (!path.startsWith("/sdcard/0/Android/data/com.example.fileprovider/")) {
                return false;
            }
        }
        return super.verifyUri(uri);
    }
}

// 存储权限分级控制
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
    if (checkSelfPermission(Manifest.permission.READ_MEDIA_IMAGES) != PackageManager.PERMISSION_GRANTED) {
        requestPermissions(new String[]{Manifest.permission.READ_MEDIA_IMAGES}, REQUEST_CODE);
    }
}

<application>
    <provider
        android:name="androidxrentent.FileProvider"
        android:authorities="com.example.fileprovider"
        android:exported="false"
        android:grantUriPermissions="true">
        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/file_paths" />
    </provider>
</application>

// 异常捕获示例
try {
    Uri fileUri = ...;
    Intent intent = ...;
    startActivity(intent);
} catch (NullPointerException e) {
    // 检查Uri合法性
    if (!fileUri.getScheme().equals("file")) {
        // 重新生成有效Uri
        fileUri = FileProvider.getUriForFile(this, "com.example.fileprovider", new File());
    }
}

// 创建系统文件管理界面
FileBrowserActivity activity = new FileBrowserActivity();
activity.setRootDirectory(new File("/sdcard"));
activity.setFileFilter(new FileFilter() {
    @Override
    public boolean accept(File file) {
        return file.isDirectory() || file.getName().endsWith(".doc");
    }
});
activity.start();

// 预加载远程文件
Request request = new Request.Builder()
    .header("Range", "bytes=0-1048576")
    .build();

FileRequestPreloader preloader = new FileRequestPreloader(request);
preloader.start(new OnFilePreloadedListener() {
    @Override
    public void onPreloaded(long progress, long total) {
        // 显示预加载进度
    }
});

// 实现文件操作沙箱
class SecureFileOperator {
    public Uri operateFile(File file, String operation) {
        // 生成临时容器文件
        File tempFile = File.createTempFile("temp", ".sand");
        // 执行操作
        performOperation(file, tempFile, operation);
        if (performSanitization(tempFile)) {
            return FileProvider.getUriForFile(this, "com.example secure provider", tempFile);
        }
        return null;
    }
}

// AES加密存储
File encryptedFile = new File("encrypted.bin");
try (FileOutputStream out = new FileOutputStream(encryptedFile)) {
    Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
    SecretKey secretKey = KeyGenerator.getInstance("AES").generateKey();
    cipher.init(Cipher.ENCRYPT_MODE, secretKey);
    out.write(cipher.doFinal(data));
}

Uri fileUri = ...;
Intent intent = new Intent(Intent.ACTION_VIEW, fileUri);
startActivity(intent);
// 错误：未处理PERMISSION DenIED

Uri fileUri = FileProvider.getUriForFile(this, "com.examplevider", new File());
Intent intent = new Intent(Intent.ACTION_VIEW, fileUri);
startActivity(intent);
// 错误：允许访问任意类型文件