這是自己初期學習java  mvc模式時整理的jdbc連線資料庫的程式碼，資料庫為mysql

ConnDB是基礎類，封裝了連線資料庫需要的一些資訊。

package com.hsp.model;
import java.sql.*;
public class ConnDB {
    private Connection ct=null;
    public Connection getConn(){
    
     try{
     
      Class.forName("com.mysql.jdbc.Driver");
     
      ct=DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/test","root","czcat");
     }catch(Exception ex){
      ex.printStackTrace();
     }
    return ct;
    }
 }
 

增加操作

public boolean addUser(String username,String password,int date,int grade){
       boolean b=false;
    try {
        ct=new ConnDB().getConn();
    sm=ct.createStatement();
    int a=sm.executeUpdate("insert into xs(username,password,date,grade) values('"+username+"','"+password+"','"+date+"','"+grade+"')");
             if(a==1){  
              b=true;
             }
    } catch (Exception e) {
   e.printStackTrace();
  }finally{
   this.close();
  }
  return b;
   }
 

刪改操作

public boolean delUserById(String id){
    boolean b=false;
    try {
        ct=new ConnDB().getConn();
     sm=ct.createStatement();
    int a=sm.executeUpdate("delete from xs where userid='"+id+"'");
             if(a==1){  
              b=true;
             }
    } catch (Exception e) {
   e.printStackTrace();
  }finally{
   this.close();
  }
  return b;
   }
 

修改操作

public boolea update(int userid,String username,String password,int date,int grade){
    boolean b=false;
    try {
  ct=new ConnDB().getConn();
  sm=ct.createStatement();
  int a=sm.executeUpdate("update xs SET username='"+username+"',password='"+password+"',date='"+date+"',grade='"+grade+"' where userid='"+userid+"'");
 if(a==1){
  b=true;
 }
    } catch (Exception e) {
  e.printStackTrace();
 }finally{
  this.close();
 }
    return b;
   }

查詢操作 

public boolean checkUser(String u,String p){
     boolean b=false;
    try {
     
       ct=new ConnDB().getConn();
       sm=ct.createStatement();
       rs=sm.executeQuery("select password from xs where username='"+u
        +"'");
        if(rs.next())
        {
              if(rs.getString(1).equals(p)){
              b=true;
           }
        }
 } catch (Exception e) {
  e.printStackTrace();
 }finally{
  this.close();
 }
   
    return b;
    }
}

 關閉流

public void close(){
  try {
   if(rs!=null){
    rs.close();
    rs=null;
   }
   if(sm!=null){
    sm.close();
    sm=null;
   }
   if(ct!=null){
    ct.close();
    ct=null;
   }
  } catch (Exception e2) {
   e2.printStackTrace();
  }
 }