音乐播放记录查询

mainactivity

import java.io.File;import java.io.FileFilter;import java.util.Random;import android.app.Activity;import android.content.ContentValues;import android.content.Intent;import android.database.Cursor;import android.media.MediaPlayer;import android.os.Bundle;import android.os.Environment;import android.util.Log;import android.view.Menu;import android.view.MenuItem;import android.view.View;//SQLiteDatabase//Cursor//SimpleCursorAdapter//SQliteOpenHelperpublic class MainActivity extends Activity {private Random random=new Random();private MusicSQLiteHelper mHelper;private File[] musics;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);loadSdcardMusics();    //通过此对象操作数据库    mHelper=new MusicSQLiteHelper(this,"media.db", null,2);}/**获取/mnt/sdcard/music目录下的音乐文件*/private void loadSdcardMusics(){File sdcard=Environment.    getExternalStoragePublicDirectory(Environment.DIRECTORY_MUSIC);musics=sdcard.listFiles(new FileFilter() {@Overridepublic boolean accept(File file) {return file.isFile()&&file.getName().endsWith(".mp3");}});}private MediaPlayer mPlayer;/**实现音乐的随机播放功能*/public void onMusicPlay(View v){//判断是否存在音乐if(musics==null||musics.length==0)return;//随机获取一个音乐文件File m=musics[random.nextInt(musics.length)];//获得音乐文件的路径String path=m.getPath();long time=System.currentTimeMillis();//播放音乐if(mPlayer==null){mPlayer=new MediaPlayer();}else{mPlayer.reset();//重置}try{mPlayer.setDataSource(path);//设置要播放的音乐路径mPlayer.prepare();//加载音乐mPlayer.start();//开始播放}catch(Exception e){e.printStackTrace();}//写或更新播放日志onWritePlayLog(path, time);}private void onWritePlayLog(String path, long time) {//判断此音乐在日志信息中是否已经存在String sql="select * from playhistory where data=?";Cursor c=mHelper.query(sql, new String[]{path});if(!c.moveToFirst()){        //存储音乐播放日志信息ContentValues values=new ContentValues();values.put("data", path);values.put("playdate",time);mHelper.insert("playhistory", values);Log.i("TAG", "log insert ok!");}else{sql="update playhistory set playdate=? where data=?";mHelper.update(sql, new String[]{String.valueOf(time),path});Log.i("TAG", "log update ok!");}c.close();}private boolean paused;private int currentPos;public void onMusicPause(View v){if(mPlayer!=null&&mPlayer.isPlaying()){mPlayer.pause();}}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {getMenuInflater().inflate(R.menu.main, menu);return true;}@Overridepublic boolean onOptionsItemSelected(MenuItem item) {if(item.getItemId()==R.id.historyId){startActivity(new Intent(this,PlayHistoryActivity.class));}return super.onOptionsItemSelected(item);}@Overrideprotected void onDestroy() {// TODO Auto-generated method stubsuper.onDestroy();if(mPlayer!=null){  //释放资源  mPlayer.release();  mPlayer=null;}}}

MusicSQLiteHelper

import android.content.ContentValues;import android.content.Context;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteDatabase.CursorFactory;import android.database.sqlite.SQLiteOpenHelper;import android.util.Log;/** * SQLiteOpenHelper 是一个可以操作SQLite数据系统 * 的一个工具类，它提供了一些方法可以直接获得 * SQLiteDatabase 对象，并通过此对象执行一些CRUD操作 * */public class MusicSQLiteHelper extends                          SQLiteOpenHelper{    public MusicSQLiteHelper(Context context, String name, CursorFactory factory, int version) {        super(context, name, factory, version);    }    /**借助此方法向表中写入数据*/    public long insert(String table,ContentValues values){        //创建或打开数据库        SQLiteDatabase sdb=        getWritableDatabase();        //向表中写入数据        long id=sdb.insert(table, null, values);        //释放资源        sdb.close();        return id;    }    /**查询数据*/    public Cursor query(String sql,String selectionArgs[]){        SQLiteDatabase sdb=        getReadableDatabase();        return sdb.rawQuery(sql, selectionArgs);    }    /**更新数据*/    public void update(String sql,String bindArgs[]){        SQLiteDatabase sdb=        getWritableDatabase();        sdb.execSQL(sql, bindArgs);        sdb.close();    }    /**创建数据库时执行，且只执行一次,一般会在     * 此方法中创建一些表*/    @Override    public void onCreate(SQLiteDatabase db) {        Log.i("TAG", "onCreate");        String sql="create table playhistory("        + "_id integer primary key autoincrement,"        + "data text not null,"        + "playdate long not null)";        db.execSQL(sql);        Log.i("TAG", "table create ok!");    }    /**数据库的版本升级时，此方法会自动执行*/    @Override    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {        Log.i("TAG", "onUpgrade");        /*String sql="drop table if exists playhistory";        db.execSQL(sql);        onCreate(db);*/    }}

PlayHistoryActivity

import java.text.SimpleDateFormat;import java.util.ArrayList;import java.util.Date;import java.util.HashMap;import java.util.List;import java.util.Map;import android.app.Activity;import android.database.Cursor;import android.os.Bundle;import android.widget.ListView;import android.widget.SimpleAdapter;public class PlayHistoryActivity extends Activity {@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_play_history);MusicSQLiteHelper mHelper=new MusicSQLiteHelper(this,"media.db", null, 2);Cursor cursor=mHelper.query("select * from playhistory order by playdate desc", null);List<Map<String,Object>> list=new ArrayList<Map<String,Object>>();SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");while(cursor.moveToNext()){Map<String,Object> map=new HashMap<String, Object>();String path=cursor.getString(cursor.getColumnIndex("data"));    long time=cursor.getLong(cursor.getColumnIndex("playdate"));String title=path.substring(path.lastIndexOf("/")+1,path.lastIndexOf("."));map.put("title",title);map.put("path", path);map.put("playdate",sdf.format(new Date(time)));    list.add(map);}cursor.close();ListView lsv=(ListView) findViewById(R.id.listHistoryId);SimpleAdapter adapter=new SimpleAdapter(this,list, android.R.layout.simple_list_item_2,new String[]{"title","playdate"},new int[]{android.R.id.text1,android.R.id.text2});lsv.setAdapter(adapter);}}

xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context=".MainActivity" >    <ImageButton        android:id="@+id/imageButton1"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignParentLeft="true"        android:layout_alignParentTop="true"        android:layout_marginLeft="32dp"        android:layout_marginTop="27dp"        android:src="@android:drawable/ic_media_play"         android:onClick="onMusicPlay"/>    <ImageButton        android:id="@+id/imageButton2"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignLeft="@+id/imageButton1"        android:layout_below="@+id/imageButton1"        android:layout_marginTop="29dp"        android:src="@android:drawable/ic_media_pause"        android:onClick="onMusicPause" /></RelativeLayout>

<ListView xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:id="@+id/listHistoryId"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context=".PlayHistoryActivity" ></ListView>