Java的家庭记账本程序（B）

日期：2019.2.3

博客期：029

星期日

　　看看今天想先完成jsp的连接操作，所以首先意识到自己的程序中，管理员可以对成员进行冻结、解封操作，所以先回去补了一下数据库的内容！成员的内容里多了一项isfrozen用于判定当前人物是否被冻结，之后又去改了JavaBean属性、DOC层、servlet，这几项改动确实挺累人的，一改就都要改！唉~难受！好在现在改好了！今天就这样吧！

　　

package sql.mysql;

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

import basic.people.Member;

public class MySqlForMembers {
    //=======================================================================================【数据区】
    //JDBC 驱动名
    private final String JDBC_DRIVER = "com.mysql.jdbc.Driver";  
    //数据库 URL
    private final String DB_URL = "jdbc:mysql://localhost:3306/familycash?useSSL=false";
    //用户名
    private final String USER = "root";
    //密码
    private final String PASS = "123456";
    //构造器
    private Connection conn = null;
    private Statement stmt = null;
    private PreparedStatement pstmt = null;
    private ResultSet rs = null;
    //=======================================================================================【方法区】
    //-------《返回是否存在名称为name的数据》
    public boolean exist(String name){
        ReSetResult("SELECT name from member");
        try {
            while(rs.next())
            {
                String t = rs.getString("name");
                if(name.compareTo(t)==0)
                    return true;
            }
        } catch (SQLException e) {
            System.out.println("爷爷！你的数据库连接出现问题啦！");
        }
        return false;
    }
    //-------《返回是否存在型号为n的数据》
    public boolean exist(int code){
        ReSetResult("SELECT code from member");
        try {
            while(rs.next())
            {
                String t = rs.getString("code");
                if(code==Integer.parseInt(t))
                    return true;
            }
        } catch (SQLException e) {
            System.out.println("爷爷！你的数据库连接出现问题啦！");
        }
        return false;
    }
    //-------《重设rs》
    public void ReSetResult(String sql){
        try {
            stmt = conn.createStatement();
            rs = stmt.executeQuery(sql);
        } catch (SQLException e) {
            System.out.println("爷爷！你的数据库连接出现问题啦！");
        }
    }
    //-------《增删改查》
    //添加一个用户的数据
    public void Add(Member x){
        try {
            pstmt = (PreparedStatement) conn.prepareStatement("insert into member values (?,?,?,?,?)");
            pstmt.setInt(1, x.getCode());
            pstmt.setString(2, x.getName());
            pstmt.setString(3, x.getPassword());
            pstmt.setString(4, x.getCreatdate());
            pstmt.setInt(5, x.getIsFrozen());
            pstmt.executeUpdate();
            pstmt.close();
            } catch (SQLException e) {
                System.out.println("爷爷！你的数据库连接出现问题啦！");    
        }
    }
    //删除一个用户的数据
    public void Delete(String Name){
        try {
            pstmt = (PreparedStatement) conn.prepareStatement("delete from member where name=?");
            pstmt.setString(1,Name);
            pstmt.executeUpdate();
        } catch (SQLException e) {
            System.out.println("爷爷！你的数据库连接出现问题啦！");
        }
    }
    public void Delete(int code){
        try {
            pstmt = (PreparedStatement) conn.prepareStatement("delete from member where code=?");
            pstmt.setInt(1,code);
            pstmt.executeUpdate();
        } catch (SQLException e) {
            System.out.println("爷爷！你的数据库连接出现问题啦！");
        }
    }
    //更新一个用户的数据
    public void Renew(String Name,Member x){
        try {
            Class.forName(JDBC_DRIVER);
            conn = DriverManager.getConnection(DB_URL,USER,PASS);
            stmt = conn.createStatement();
            pstmt = (PreparedStatement) conn.prepareStatement("update member set code=?, name=?, password=?, creatdate=? , isfrozen=? where name=?");
            pstmt.setInt(1, x.getCode());
            pstmt.setString(2, x.getName());
            pstmt.setString(3, x.getPassword());
            pstmt.setString(4, x.getCreatdate());
            pstmt.setInt(5, x.getIsFrozen());
            pstmt.setString(6,Name);
            pstmt.executeUpdate();
            pstmt.close();
        } catch (SQLException e) {
            System.out.println("爷爷！你的数据库连接出现问题啦！");
        } catch (ClassNotFoundException e) {
            System.out.println("爷爷！你的Class驱动加载出现问题啦！");
        }
    }
    public void Renew(int code,Member x){
        try {
            Class.forName(JDBC_DRIVER);
            conn = DriverManager.getConnection(DB_URL,USER,PASS);
            stmt = conn.createStatement();
            pstmt = (PreparedStatement) conn.prepareStatement("update member set code=?, name=?, password=?, creatdate=? , isfrozen=? where code=?");
            pstmt.setInt(1, x.getCode());
            pstmt.setString(2, x.getName());
            pstmt.setString(3, x.getPassword());
            pstmt.setString(4, x.getCreatdate());
            pstmt.setInt(5, x.getIsFrozen());
            pstmt.setInt(6,code);
            pstmt.executeUpdate();
            pstmt.close();
        } catch (SQLException e) {
            System.out.println("爷爷！你的数据库连接出现问题啦！");
        } catch (ClassNotFoundException e) {
            System.out.println("爷爷！你的Class驱动加载出现问题啦！");
        }
    }
    //查询第几个用户的数据
    public Member GetFromSQL(int number){
        if(number <=0||number>Length())
            return null;
        ReSetResult("SELECT code, name, password, creatdate, isfrozen FROM member");
        try {
            int i = 1;
            while(rs.next()&&number>=i)
            {
                int Code = Integer.parseInt(rs.getString("code"));
                String Name = rs.getString("name");
                String Password = rs.getString("password");
                String Creatdate = rs.getString("creatdate");
                int IsFrozen = Integer.parseInt(rs.getString("isfrozen"));
                if(number==i)
                    return new Member(Code,Name,Password,Creatdate,IsFrozen);
                ++i;
            }
        } catch (SQLException e) {
            System.out.println("爷爷！你的数据库连接出现问题啦！");
        }
        return null;
    }
    //查询一个用户的数据
    public Member Refer(String name_s){
        ReSetResult("SELECT code, name, password, creatdate, isfrozen FROM member");
        Member s = null;
        try {
            while(rs.next())
            {
                int Code = Integer.parseInt(rs.getString("code"));
                String Name = rs.getString("name");
                String Password = rs.getString("password");
                String Creatdate = rs.getString("creatdate");
                int IsFrozen = Integer.parseInt(rs.getString("isfrozen"));
                if(name_s.compareTo(Name)==0)
                    return new Member(Code,Name,Password,Creatdate,IsFrozen);    
            }
        } catch (SQLException e) {
            System.out.println("爷爷！你的数据库连接出现问题啦！");
        }
        return s;
    }
    public Member Refer(int code_s){
        ReSetResult("SELECT code, name, password, creatdate, isfrozen FROM member");
        Member s = null;
        try {
            while(rs.next())
            {
                int Code = Integer.parseInt(rs.getString("code"));
                String Name = rs.getString("name");
                String Password = rs.getString("password");
                String Creatdate = rs.getString("creatdate");
                int IsFrozen = Integer.parseInt(rs.getString("isfrozen"));
                if(code_s==Code)
                    return new Member(Code,Name,Password,Creatdate,IsFrozen);    
            }
        } catch (SQLException e) {
            System.out.println("爷爷！你的数据库连接出现问题啦！");
        }
        return s;
    }
    //-------《数据数》
    public int Length(){
        ReSetResult("SELECT code, name, password, creatdate, isfrozen FROM member");
        int l = 0;
        try {
            while(rs.next())
            {
                ++l;
            }
        } catch (SQLException e) {
            System.out.println("爷爷！你的数据库连接出现问题啦！");
        }
        return l;
    }
    //-------《最大的编号值》
    public int MaxCode(){
        ReSetResult("SELECT code FROM member");
        int l = 0;
        try {
            while(rs.next())
            {
                int Code = Integer.parseInt(rs.getString("code"));
                if(l<Code)
                    l = Code;
            }
        } catch (SQLException e) {
            System.out.println("爷爷！你的数据库连接出现问题啦！");
        }
        return l;
    }
    //-------《释放》
    public void free(){
        try {
            if(pstmt!=null)
                pstmt.close();
            if(stmt!=null)
                stmt.close();
            if(conn!=null)
                conn.close();
        } catch (SQLException e) {
            System.out.println("爷爷！你的数据库连接出现问题啦！");
        }
    }
    //-------《构造方法》
    public MySqlForMembers(){
        try {
            Class.forName(JDBC_DRIVER);
            conn = DriverManager.getConnection(DB_URL,USER,PASS);
        } catch (ClassNotFoundException e1) {
            System.out.println("爷爷！你的Class驱动加载出现问题啦！");
        } catch (SQLException e) {
            System.out.println("爷爷！你的数据库连接出现问题啦！");
        }
    }
    //-------《主方法》
    public static void main(String[] args){
        MySqlForMembers m = new MySqlForMembers();
        System.out.println();
        for(int i=1;i<=m.Length();++i)
        {
            m.GetFromSQL(i).display();
        }
        m.free();
    }
}

 本代码由于涉及本人的部分个人信息——已于2019.6.20修改，代码仍然可用，请大家放心