JAVA日报

app开发（dao2）

package dao;


import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.util.Log;

import java.util.ArrayList;
import java.util.List;

import bean.User;
import bean.User2;
import db.Sqlite;
import db.Sqlite2;

public class UserDao2 {
    private final Sqlite2 sqlite;
    private static UserDao2 userDao=null;
    private UserDao2(Context context){
        sqlite =new Sqlite2(context);
    }
    public static UserDao2 getInstance(Context context){
        if(userDao==null){
            userDao=new UserDao2(context);
        }
        return userDao;
    }
    //保存
    public void insert(User2 user){
        SQLiteDatabase db=sqlite.getWritableDatabase();
        ContentValues values=new ContentValues();
        values.put("num",user.getNum());
        values.put("name",user.getName());
        values.put("cl",user.getCl());
        values.put("phone",user.getPhone());
        db.insert("tex2",null,values);
        db.close();
    }
    //获取
    public boolean pkong(){
        boolean temp=false;
        SQLiteDatabase db=sqlite.getWritableDatabase();
        Cursor cursor=db.rawQuery("select *from tex2",null);
        if(cursor.getCount()!=0){
            temp=true;
        }
        return temp;
    }
    public List<User2> findAll(){
        SQLiteDatabase db=sqlite.getWritableDatabase();
        Cursor cursor=db.query("tex2",new String[]{"num","name","cl","phone"},null,null,null,null,null);
        List<User2> userList=new ArrayList<>();
        while(cursor.moveToNext()){
            User2 user2=new User2();
            user2.setNum(cursor.getString(0));
            user2.setName(cursor.getString(1));
            user2.setCl(cursor.getString(2));
            user2.setPhone(cursor.getString(3));
            //Log.e("sqliteshow",user.getName()+" "+user.getDate()+" "+user.getTime()+" "+user.getTem()+" "+user.getArea());
            userList.add(user2);
        }
        db.close();
        return userList;
    }
}