结构化 数据库 代码

附：程序代码点击下载
1. 结构化数据库代码 程序结构：

User.java是bean类.
JdbcUtils.java是数据库工具类，包含数据库驱动加载，连接数据库，数据库资源释放。
db.properties是数据库的配置信息，包含数据库url，用户名和密码。将其分离出来，便于底层数据库的更改。
Demo3_insert.java包含数据库增删查改操作，将他们进行了封装。

2.具体代码：
db.properties

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/mytest
username=root
password=root

JdbcUtils.java

package com.hongwei.utils;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;


public class JdbcUtils {

    private static Properties config = new Properties();
    //静态代码块，只执行一次，类加载时执行
    static{ 
        try {
            config.load(JdbcUtils.class.getClassLoader().getResourceAsStream("db.properties")); 
            System.out.println(config.getProperty("driver"));
            Class.forName(config.getProperty("driver"));
        } catch (Exception e) {
            throw new ExceptionInInitializerError(e);
        }
    }

    public static Connection getConnection() throws SQLException{       
        return DriverManager.getConnection(config.getProperty("url"),config.getProperty("username"),config.getProperty("password"));
    }

    public static void release(ResultSet rs,Statement st,Connection conn){
        if(rs!=null){
            try{
                rs.close();
            }catch(Exception e){
                e.printStackTrace();
            }
            rs = null;
        }
        if(st!=null){
            try{
                st.close();
            }catch(Exception e){
                e.printStackTrace();
            }
            st = null;
        }
        if(conn!=null){
            try{
                conn.close();
            }catch(Exception e){
                e.printStackTrace();
            }
        }
    }
}

Demo3_insert.java

package com.hongwei.jdbc;

import com.hongwei.bean.User;
import com.hongwei.utils.JdbcUtils;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;

import org.junit.Test;

import com.hongwei.utils.JdbcUtils;

public class Demo3_insert {


    public void insert() throws SQLException{
        Connection conn = null;
        Statement st = null;
        ResultSet rs = null;
        try{
            conn = JdbcUtils.getConnection();
            st = conn.createStatement();
            String sql ="insert into users(id,name,password,email,birthday) values('4','zhouqiqi','123456','[email protected]','1992-10-14')";
            int num = st.executeUpdate(sql);
            if(num>0){
                System.out.println("插入成功！");
            }
        }finally{
            JdbcUtils.release(rs, st, conn);
        }
    }

    public void update() throws SQLException{
        Connection conn = null;
        Statement st = null;
        ResultSet rs = null;
        try{
            conn = JdbcUtils.getConnection();
            st = conn.createStatement();
            String sql = "update users set name='zhouxiaowei'";
            int num = st.executeUpdate(sql);
            if(num>0){
                System.out.println("修改成功！");
            }
        }finally{
            JdbcUtils.release(rs, st, conn);
        }
    }

    public void delete() throws SQLException{
        Connection conn = null;
        Statement st = null;
        ResultSet rs = null;
        try{
            conn = JdbcUtils.getConnection();
            st = conn.createStatement();
            String sql ="delete from users where id='1'";
            int num = st.executeUpdate(sql);
            if(num>0){
                System.out.println("删除成功！");
            }
        }finally{
            JdbcUtils.release(rs, st, conn);
        }
    }

    @Test
    public void getAll() throws SQLException{
        Connection conn = null;
        Statement st = null;
        ResultSet rs = null;
        try{
            conn = JdbcUtils.getConnection();
            st = conn.createStatement();
            String sql ="select * from users";
            rs = st.executeQuery(sql);
            ArrayList<User> list = new ArrayList<User>();
            while(rs.next()){
                User user = new User();
                user.setId(rs.getInt("id"));
                user.setName(rs.getString("name"));
                user.setPassword(rs.getString("password"));
                user.setEmail(rs.getString("email"));
                user.setDate(rs.getDate("birthday"));
                list.add(user);
            }
            System.out.println(list);
        }finally{
            JdbcUtils.release(rs, st, conn);
        }
    }
}

User.java

package com.hongwei.bean;

import java.sql.Date;

public class User {
    private int id;
    private String name;
    private String password;
    private String email;
    private Date date;


    public User(int id, String name, String password, String email, Date date) {
        super();
        this.id = id;
        this.name = name;
        this.password = password;
        this.email = email;
        this.date = date;
    }
    public User() {
        super();
        // TODO Auto-generated constructor stub
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public Date getDate() {
        return date;
    }
    public void setDate(Date date) {
        this.date = date;
    }
    @Override
    public String toString() {
        return "User [id=" + id + ", name=" + name + ", password=" + password
                + ", email=" + email + ", date=" + date + "]";
    }   
}

注：若要求改为oracle数据库，只需修改db.properties。此外，对应的sql语句可能也要修改。