[android] 保存文件到SD卡详解手机开发

package com.tsh.savefile.service; 
 
import java.io.BufferedReader; 
import java.io.File; 
import java.io.FileInputStream; 
import java.io.FileOutputStream; 
import java.io.InputStreamReader; 
import java.util.HashMap; 
import java.util.Map; 
 
import android.content.Context; 
import android.os.Environment; 
import android.widget.Toast; 
 
public class LoginService { 
    /** 
     * 保存用户名和方法的业务方法 
     * @param context 上下文 
     * @param username 用户名 
     * @param password 方法 
     * @return 
     */ 
    public static boolean saveUserInfo(Context context,String username,String password){ 
        if(!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){ 
            Toast.makeText(context, "sd卡不可用", Toast.LENGTH_SHORT).show(); 
            return false; 
        } 
        File file=new File(Environment.getExternalStorageDirectory(),"/info1.txt"); 
        try { 
            FileOutputStream fos=new FileOutputStream(file); 
            String info=username+"##"+password; 
            fos.write(info.getBytes()); 
            fos.close(); 
            return true; 
        } catch (Exception e) { 
            e.printStackTrace(); 
            return false; 
        } 
         
    } 
    /** 
     * 读取 
     * @return 
     */ 
    public static Map<String,String> getSavedUserInfo(Context context){ 
        File file=new File(Environment.getExternalStorageDirectory(),"/info1.txt"); 
        try { 
            FileInputStream fis=new FileInputStream(file); 
            BufferedReader br=new BufferedReader(new InputStreamReader(fis)); 
            String[] res=br.readLine().split("##"); 
            Map<String, String> map=new HashMap<String,String>(); 
            map.put("username", res[0]); 
            map.put("password", res[1]); 
            return map; 
        } catch (Exception e) { 
            e.printStackTrace(); 
            return null; 
        } 
         
    } 
}