在android中创建目录

import java.io.File;

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // 创建内部存储目录
        File internalDir = new File(getFilesDir(), "my_directory");
        if (!internalDir.exists()) {
            internalDir.mkdir();
        }

        // 创建外部存储目录
        File externalDir = new File(getExternalFilesDir(null), "my_directory");
        if (!externalDir.exists()) {
            externalDir.mkdir();
        }

        // 创建缓存目录
        File cacheDir = new File(getCacheDir(), "my_directory");
        if (!cacheDir.exists()) {
            cacheDir.mkdir();
        }

        // 创建SD卡目录
        File sdCardDir = new File(Environment.getExternalStorageDirectory(), "my_directory");
        if (!sdCardDir.exists()) {
            sdCardDir.mkdir();
        }
    }
}