1、数据库封装工具类

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class DBTools {
	public static void insert(Context context, DownloadInfoBean bean){
		DBHelper db = new DBHelper(context);
		db.open();
		db.insert(bean);
		db.close();
	}

	public static void delete(Context context){
		DBHelper db = new DBHelper(context);
		db.open();
		db.delete();
		db.close();
	}

	public static void update(Context context, DownloadInfoBean bean){
		DBHelper db = new DBHelper(context);
		db.open();
		db.update(bean);
		db.close();
	}

	public static DownloadInfoBean query(Context context){
		DownloadInfoBean bean = null;
		DBHelper db = new DBHelper(context);
		db.open();
		Cursor cursor = db.query();
		if(cursor != null){
			if(cursor.getCount() > 0){
				cursor.moveToFirst();
				bean = new DownloadInfoBean();
				bean.filesize = cursor.getInt(1);
				bean.complete = cursor.getInt(2);
			}
			cursor.close();
		}
		db.close();
		return bean;
	}

	public static final class DBHelper extends SQLiteOpenHelper{

	private final static String DB_NAME = "download_info.db";
	private final static int DB_VERSION = 1;
	private final String TB_DOWNLOAD_INFO = "tb_download_info";
	private static SQLiteDatabase sqlDb = null;
	private static Object lock = new Object();

	public DBHelper(Context context) {
		super(context, DB_NAME, null, DB_VERSION);
		// TODO Auto-generated constructor stub
	}

	public void open(){
		synchronized (lock) {
			sqlDb = this.getReadableDatabase();
		}
	}

	public void close(){
		synchronized (lock) {
			if(sqlDb != null){
				sqlDb.close();
			}
		}
	}

	public void insert(DownloadInfoBean bean){
		synchronized (lock) {
			ContentValues values = new ContentValues();
			values.put("filesize", bean.filesize);
			values.put("complete", bean.complete);
			sqlDb.insert(TB_DOWNLOAD_INFO, null, values);
		}
	}

	public void delete(){
		synchronized (lock) {
			sqlDb.delete(TB_DOWNLOAD_INFO, null, null);
		}
	}

	public void update(DownloadInfoBean bean){
		synchronized (lock) {
			ContentValues values = new ContentValues();
			values.put("complete", bean.complete);
			sqlDb.update(TB_DOWNLOAD_INFO, values, "filesize=?", new String[]{bean.filesize+""});
		}
	}

	public Cursor query(){
		synchronized (lock) {
			return sqlDb.query(TB_DOWNLOAD_INFO, null, null, null, null, null, null);
		}
	}

	@Override
	public void onCreate(SQLiteDatabase db) {
		// TODO Auto-generated method stub
		db.execSQL("CREATE TABLE IF NOT EXISTS "+
		TB_DOWNLOAD_INFO+"("+
		"id integer NOT NULL PRIMARY KEY AUTOINCREMENT,"+
		"filesize  integer NOT NULL default 0,"+//文件大小
		"complete integer NOT NULL default 0)");//下载完成大小
	}

	@Override
	public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
		// TODO Auto-generated method stub
		onCreate(db);
	}

	}
}

2、数据对象bean

public class DownloadInfoBean {
	public int filesize = 0;
	public int complete = 0;
}

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