在应用程序中创建CSV或TXT文件，并将其保存到下载文件夹- Android

import android.os.Environment;

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;

public class MainActivity extends AppCompatActivity {

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

        // 创建CSV文件
        File csvFile = new File(getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS), "data.csv");

        try {
            // 写入数据
            BufferedWriter writer = new BufferedWriter(new FileWriter(csvFile));
            writer.write("Name, Age, Email");
            writer.newLine();
            writer.write("John Doe, 25, john.doe@example.com");
            writer.newLine();
            writer.write("Jane Smith, 30, jane.smith@example.com");
            writer.close();

            // 文件保存成功
            Toast.makeText(this, "文件保存成功", Toast.LENGTH_SHORT).show();
        } catch (IOException e) {
            e.printStackTrace();
            // 文件保存失败
            Toast.makeText(this, "文件保存失败", Toast.LENGTH_SHORT).show();
        }
    }
}

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