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();
     }
 }

MySqlForMember

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