读 Beginning Android Games 2nd Edition (一) 创建读取文件IO的工具类

书中第三章列出了一个游戏开发的基本框架所要实现的接口

package com.badlogic.androidgames.framework;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public interface FileIO {
    public InputStream readAsset(String fileName) throws IOException;
    public InputStream readFile(String fileName) throws IOException;
    public OutputStream writeFile(String fileName) throws IOException;
}

这个类可以读取手机内存文件,Asset目录文件,SD卡文件,及ShardPreferences

package com.badlogic.androidgames.framework.impl;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import android.content.Context;
import android.content.SharedPreferences;
import android.content.res.AssetManager;
import android.os.Environment;
import android.preference.PreferenceManager;
import com.badlogic.androidgames.framework.FileIO;
public class AndroidFileIO implements FileIO {
    Context context;
    AssetManager assets;
    String externalStoragePath;
    public AndroidFileIO(Context context) {
        this.context = context;
        this.assets = context.getAssets();
        this.externalStoragePath = Environment.getExternalStorageDirectory()
        .getAbsolutePath() + File.separator;
    }
    public InputStream readAsset(String fileName) throws IOException {
        return assets.open(fileName);
    }
    public InputStream readFile(String fileName) throws IOException {
        return new FileInputStream(externalStoragePath + fileName);
    }
    public OutputStream writeFile(String fileName) throws IOException {
        return new FileOutputStream(externalStoragePath + fileName);
    }
    public SharedPreferences getPreferences() {
        return PreferenceManager.getDefaultSharedPreferences(context);
    }
}