安卓读取外部存储/storage/emulated/0/Download/函数

以下是一个示例代码，演示如何在安卓中读取外部存储的文件：

import android.os.Environment;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;

public class MainActivity extends AppCompatActivity {
    private static final String FILE_PATH = Environment.getExternalStorageDirectory().getPath() + "/Download/sample.txt";

    private String readFileFromExternalStorage() {
        StringBuilder stringBuilder = new StringBuilder();
        try {
            File file = new File(FILE_PATH);
            BufferedReader bufferedReader = new BufferedReader(new FileReader(file));
            String line;
            while ((line = bufferedReader.readLine()) != null) {
                stringBuilder.append(line);
            }
            bufferedReader.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return stringBuilder.toString();
    }

    // 在合适的地方调用该方法
    private void readExternalStorage() {
        if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
            String fileContent = readFileFromExternalStorage();
            // 处理文件内容
            // ...
        }
    }
}

请注意，为了能够读取外部存储的文件，你需要在AndroidManifest.xml文件中添加以下权限：

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />