冲刺四

今天是冲刺的第四天，主要在安卓方面写了一些sql语句以及图片的获取和bitmap转化为字符串。

遇到的困难：不知道如何获取imageView的图片，图片储存到数据库加载资源过慢的情况。

解决思路：获取安卓中已经加载好的图片：Bitmap bitmap = ((BitmapDrawable)imageView.getDrawable()).getBitmap();

明天计划完成的任务：页面实现下拉刷新

附上编写的代码：

DBOpenHelper.java

package com.itheima.cloudnotes.db;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class DBOpenHelper
{
    private static String driver = "com.mysql.jdbc.Driver";//MySQL 驱动
    private static String url = "jdbc:mysql://39.101.190.190:3306/test";//MYSQL数据库连接Url
    private static String user = "root";//用户名
    private static String password = "123";//密码

    /**
     * 连接数据库
     * */

    public static Connection getConn(){
        Connection conn = null;
        try {
            Class.forName(driver);//获取MYSQL驱动
            conn = (Connection) DriverManager.getConnection(url, user, password);//获取连接
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return conn;
    }

    /**
     * 增删改关闭数据库
     * */

    public static void closeAll(Connection conn, PreparedStatement ps){
        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (ps != null) {
            try {
                ps.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

    }

    /**
     * 查询关闭数据库
     * */

    public static void closeAll(Connection conn, PreparedStatement ps, ResultSet rs){
        if (conn != null) {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (ps != null) {
            try {
                ps.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (rs != null) {
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }


}

DBService.java

package com.itheima.cloudnotes.db;

import com.itheima.cloudnotes.enity.Note;
import com.itheima.cloudnotes.enity.User;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

public class DBService
{
    private StringAndBitmap sab;
    private Connection conn=null; //打开数据库对象
    private PreparedStatement ps=null;//操作整合sql语句的对象
    private ResultSet rs=null;//查询结果的集合

    //DBService 对象
    public static  DBService dbService=null;

    //构造方法 私有化

    private  DBService(){

    }

    //获取操作数据库单例类对象
    public static DBService getDbService(){
        if(dbService==null){
            dbService=new DBService();
        }
        return dbService;
    }


    //判断用户是否已经注册过
    public boolean judgeUserExist(User user)
    {
        boolean flag=true;
        String sql="select * from user where user.account=?";
        //获取数据库连接对象
        conn=DBOpenHelper.getConn();
        try{
            if(conn!=null&&(!conn.isClosed())){
                ps=conn.prepareStatement(sql);
                if(ps!=null){
                    ps.setString(1,user.getAccount());
                    rs=ps.executeQuery();
                    if(rs.next()==false){
                        flag=true;
                    }else {
                        flag=false;
                    }
                }
            }
        }catch (SQLException e){
            e.printStackTrace();
        }
        DBOpenHelper.closeAll(conn,ps,rs); //关闭相关操作
        return flag;
    }

    //判断用户是否已经注册过
    public boolean judgeUserLegal(User user)
    {
        boolean flag=false;
        String sql="select * from user where user.account=? and user.password=?";
        //获取数据库连接对象
        conn=DBOpenHelper.getConn();
        try{
            if(conn!=null&&(!conn.isClosed())){
                ps=conn.prepareStatement(sql);
                if(ps!=null){
                    ps.setString(1,user.getAccount());
                    ps.setString(2,user.getPassword());
                    rs=ps.executeQuery();
                    if(rs.next()){
                        flag=true;
                    }else {
                        flag=false;
                    }
                }
            }
        }catch (SQLException e){
            e.printStackTrace();
        }
        DBOpenHelper.closeAll(conn,ps,rs); //关闭相关操作
        return flag;
    }

    //用户注册：添加用户相关信息
    public int insertUserData(User user,String bitToString){
        int result=-1;
        if(user!=null){
            conn=DBOpenHelper.getConn();
            String sql="insert into user (pickname,account,password,grade,user_icon) values (?,?,?,?,?)";
            try{
                boolean closed=conn.isClosed();
                if((conn!=null)&&(!closed)){
                    ps=conn.prepareStatement(sql);
                    String pickname=user.getPickname();
                    String account=user.getAccount();
                    String password=user.getPassword();
                    String grade="大一";
                    if(ps!=null){
                        ps.setString(1,pickname);
                        ps.setString(2,account);
                        ps.setString(3,password);
                        ps.setString(4,grade);
                        ps.setString(5,bitToString);
                        result=ps.executeUpdate();//返回1 执行成功
                    }
                }
            } catch (SQLException e) {
                e.printStackTrace( );
            }
        }
        DBOpenHelper.closeAll(conn,ps);
        return result;
    }

    public List<Note> getNotes()
    {
        List<Note> list=new ArrayList<>();
        String sql="select * from note";
        conn=DBOpenHelper.getConn();
        try{
            if(conn!=null&&(!conn.isClosed())){
                ps=conn.prepareStatement(sql);
                if(ps!=null)
                {
                    if(sab==null)
                    {
                        sab=new StringAndBitmap();
                    }
                    rs=ps.executeQuery();
                    while (rs.next())
                    {
                        Note note=new Note();
                        note.setId(rs.getInt("id"));
                        note.setIcon(sab.stringToBitmap(rs.getString("icon")));
                        note.setWriter_name(rs.getNString("writer_name"));
                        note.setCourse(rs.getString("course"));
                        note.setTitle(rs.getString("title"));
                        note.setDate(rs.getString("date"));
                        list.add(note);
                    }
                }
            }
        }catch (SQLException e){
            e.printStackTrace();
        }
        DBOpenHelper.closeAll(conn,ps,rs); //关闭相关操作
        return list;
    }

    public int getUserId(String account)
    {
        int userId=0;
        String sql="select id from user where account=?";
        conn=DBOpenHelper.getConn();
        try{
            if(conn!=null&&(!conn.isClosed())){
                ps=conn.prepareStatement(sql);
                if(ps!=null)
                {
                    ps.setString(1,account);
                    rs=ps.executeQuery();
                    if(rs.next())
                    {
                       userId=rs.getInt("id");
                    }
                }
            }
        }catch (SQLException e){
            e.printStackTrace();
        }
        DBOpenHelper.closeAll(conn,ps,rs); //关闭相关操作
        return userId;
    }

    public int insertCollect(int user_id,int note_id)
    {
            int result=-1;
            conn=DBOpenHelper.getConn();
            String sql="insert into collect(user_id,note_id) values (?,?)";
            try{
                boolean closed=conn.isClosed();
                if((conn!=null)&&(!closed)){
                    ps=conn.prepareStatement(sql);
                    if(ps!=null){
                        ps.setInt(1,user_id);
                        ps.setInt(2,note_id);
                        result=ps.executeUpdate();//返回1 执行成功
                    }
                }
            } catch (SQLException e) {
                e.printStackTrace( );
            }
        DBOpenHelper.closeAll(conn,ps);
            return result;
    }

    public List<Note> getCollectList(int user_id)
    {
        List<Note> list=new ArrayList<>();
        String sql="SELECT collect.user_id,note.id note_id,note.title,note.date FROM collect JOIN note ON collect.note_id=note.id WHERE collect.user_id=?";
        conn=DBOpenHelper.getConn();
        try{
            if(conn!=null&&(!conn.isClosed())){
                ps=conn.prepareStatement(sql);
                if(ps!=null)
                {
                    ps.setInt(1,user_id);
                    rs=ps.executeQuery();
                    while (rs.next())
                    {
                        Note note=new Note();
                        note.setId(rs.getInt("note_id"));
                        note.setTitle(rs.getString("title"));
                        note.setDate(rs.getString("date"));
                        list.add(note);
                    }
                }
            }
        }catch (SQLException e){
            e.printStackTrace();
        }
        DBOpenHelper.closeAll(conn,ps,rs); //关闭相关操作
        return list;
    }

    public Note getDetailNote(int note_id)
    {
        Note note=new Note();
        String sql="SELECT icon,writer_name,title,date,content from note where id=?";
        conn=DBOpenHelper.getConn();
        try{
            if(conn!=null&&(!conn.isClosed())){
                ps=conn.prepareStatement(sql);
                if(ps!=null)
                {
                    ps.setInt(1,note_id);
                    rs=ps.executeQuery();
                    if(rs.next())
                    {
                        if(sab==null)
                        {
                            sab=new StringAndBitmap();
                        }
                        note.setIcon(sab.stringToBitmap(rs.getString("icon")));
                        note.setWriter_name(rs.getString("writer_name"));
                        note.setTitle(rs.getString("title"));
                        note.setDate(rs.getString("date"));
                        note.setContent(rs.getString("content"));
                    }
                }
            }
        }catch (SQLException e){
            e.printStackTrace();
        }
        DBOpenHelper.closeAll(conn,ps,rs); //关闭相关操作
        return note;
    }

    public int deleteCollect(int user_id,int note_id)
    {
        int result=-1;
        conn=DBOpenHelper.getConn();
        String sql="delete from collect where user_id=? and note_id=?";
        try{
            boolean closed=conn.isClosed();
            if((conn!=null)&&(!closed)){
                ps=conn.prepareStatement(sql);
                if(ps!=null){
                    ps.setInt(1,user_id);
                    ps.setInt(2,note_id);
                    result=ps.executeUpdate();//返回1 执行成功
                }
            }
        } catch (SQLException e) {
            e.printStackTrace( );
        }
        DBOpenHelper.closeAll(conn,ps);
        return result;
    }

}