spring的增删改查

最新推荐文章于 2021-07-26 00:12:01 发布

原创最新推荐文章于 2021-07-26 00:12:01 发布 · 241 阅读

CC 4.0 BY-SA版权

本文介绍Spring框架的基本概念，包括其轻量级IoC和AOP特性，以及如何在Java应用中配置和使用Spring进行数据库操作。通过一个学生信息管理系统实例，详细展示了Spring的配置、实体类定义、DAO层、Service层的实现，以及测试类的编写。

Spring框架是由于软件开发的复杂性而创建的。Spring使用的是基本的JavaBean来完成以前只可能由EJB完成的事情。然而，Spring的用途不仅仅限于服务器端的开发。从简单性、可测试性和松耦合性角度而言，绝大部分Java应用都可以从Spring中受益。
Spring是一个轻量级控制反转(IoC)和面向切面(AOP)的容器框架。

一，引入架包

在这里插入图片描述

二，配置applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
        <!--1.提供注解支持-->
        <context:component-scan base-package="com.zr"/>

        <!--2.配置数据源-->
        <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
            <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
            <property name="url" value="jdbc:mysql://localhost:3306/java?useSSL=true&amp;character=utf-8"/>
            <property name="username" value="root"/>
            <property name="password" value="123456"/>
        </bean>
        <!--3.创建JDBCTemplate对象注入dataSource-->
        <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
            <property name="dataSource" ref="dataSource"/>
        </bean>
    

</beans>

三，定义实体类

public class Student {
    private  int id;
    private String name;
    private String sex;
    private int age;

    public Student(String name, String sex, int age,int id) {
        this.name = name;
        this.sex = sex;
        this.age = age;
        this.id = id;
    }

    public Student(String name, String sex, int age) {
        this.name = name;
        this.sex = sex;
        this.age = age;
    }

    public Student(int i, String 朱璐晨) {
    }

    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 getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "Student{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", sex='" + sex + '\'' +
                ", age=" + age +
                '}';
    }
}

四，Dao层

import com.zr.bean.Student;

import java.util.List;

public interface IStudentDao {
    //增加
    boolean addStu(Student student);
    //删除
    boolean delStu(int id);
    //修改
    boolean updStu(Student student);
    //单查询
    Student findById(int id);
    //全查
    List<Student> findAll();
}

五，Dao层实现类

@Repository
public class StudentDaoImpl implements IStudentDao {
    @Autowired
    private JdbcTemplate jdbcTemplate;

    //注入方法
    private void setJdbcTemplate(JdbcTemplate jdbcTemplate){
        this.jdbcTemplate = jdbcTemplate;
    }

    @Override
    public boolean addStu(Student student) {
        boolean flag = false;
        String sql = "insert into tb_student values(null,?,?,?)";
        int row = jdbcTemplate.update(sql, student.getName(), student.getSex(), student.getAge());
        if (row > 0){
            flag = true;
        }
        return flag;
    }

    @Override
    public boolean delStu(int id) {
        boolean flag = false;
        String sql = "delete from tb_student where id = ?";
        int row = jdbcTemplate.update(sql, id);
        if (row > 0){
            flag = true;
        }
        return flag;
    }

    @Override
    public boolean updStu(Student student) {
        boolean flag = false;
        String sql = "update tb_student set name=?,sex=?,age=? where id=?";
        int row = jdbcTemplate.update(sql,new Object[]{student.getName(),student.getSex(),student.getAge(),student.getId()});
        if (row > 0){
            flag=true;
        }
        return flag;
    }

    @Override
    public Student findById(int id) {
        String sql = "select * from tb_student where id = ?";
        BeanPropertyRowMapper<Student> rowMapper = new BeanPropertyRowMapper<>(Student.class);
        Student student = jdbcTemplate.queryForObject(sql, new Object[]{id}, rowMapper);

        return student;
    }

    @Override
    public List<Student> findAll() {
        String sql = "select * from tb_student";
        BeanPropertyRowMapper<Student> rowMapper = new BeanPropertyRowMapper<>(Student.class);
        List<Student> studentList = jdbcTemplate.query(sql, rowMapper);
        return studentList;
    }
}

六，ServiceDao类

public interface IStudentService {
    //增加
    boolean addStu(Student student);
    //删除
    boolean delStu(int id);
    //修改
    boolean updStu(Student student);
    //单查询
    Student findById(int id);
    //全查
    List<Student> findAll();
}

七，Service实现类

@Service
public class StudentServiceImpl implements IStudentService {

    @Autowired
    private IStudentDao dao;
    @Override
    public boolean addStu(Student student) {
        return dao.addStu(student);
    }

    @Override
    public boolean delStu(int id) {
        return dao.delStu(id);
    }

    @Override
    public boolean updStu(Student student) {
        return dao.updStu(student);
    }

    @Override
    public Student findById(int id) {
        return dao.findById(id);
    }

    @Override
    public List<Student> findAll() {
        return dao.findAll();
    }
}

测试类

public class Main {
    public static void main(String[] args) {
        TestString testString = new TestString();
        testString.test();
    }
}

package com.zr.test;

import com.zr.bean.Student;
import com.zr.service.impl.StudentServiceImpl;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.util.List;
import java.util.Scanner;

public class TestString {
    ApplicationContext ac = new ClassPathXmlApplicationContext("/applicationContext.xml");


    Scanner sc = new Scanner(System.in);
    @Test
    public void test(){
        Scanner sc = new Scanner(System.in);
        System.out.println("欢迎进入用户管理系统！");
        System.out.println("请选择：");
        System.out.println("1.查询全部学生信息");
        System.out.println("2.通过id查询学生信息");
        System.out.println("3.添加学生信息");
        System.out.println("4.修改学生信息");
        System.out.println("5.删除学生信息");
        System.out.println("0.退出");
        boolean flag = false;
        while (flag == false){
            switch (sc.nextInt()){
                case 1:
                    findAll();
                    break;
                case 2:
                    findById();
                    break;
                case 3:
                    addStu();
                    break;
                case 4:
                    update();
                    break;
                case 5:
                    delStu();
                    break;
                case 0:
                    System.out.println("退出");
                    return;
                default:
                    System.out.println("请输入正确的选项");
                    break;
            }
        }








    }

    public void addStu(){
        StudentServiceImpl ssi = (StudentServiceImpl) ac.getBean("studentServiceImpl");
        findAll();
        Student student = new Student(sc.next(),sc.next(),sc.nextInt());
        boolean b = ssi.addStu(student);
        if (b){
            System.out.println("学生添加成功！");
            findAll();
        }else {
            System.out.println("学生添加失败！");
        }

    }

    public Student findById(){
        StudentServiceImpl ssi = (StudentServiceImpl) ac.getBean("studentServiceImpl");
        System.out.println("请输入查询的学生id");
        Student by = ssi.findById(sc.nextInt());
        System.out.println("学生信息如下：");
        System.out.println(by);
        return by;
    }


    public void findAll(){
        StudentServiceImpl ssi = (StudentServiceImpl) ac.getBean("studentServiceImpl");
        List<Student> studentList = ssi.findAll();
        System.out.println("学生信息表如下：");
        for (Student stu:studentList) {
            System.out.println(stu);
        }
    }

    public void delStu(){
        StudentServiceImpl ssi = (StudentServiceImpl) ac.getBean("studentServiceImpl");
        findAll();
        System.out.println("请输入要删除的学生信息id");
        ssi.delStu(sc.nextInt());
        System.out.println("删除后学生信息表");
        findAll();
    }

    public void update(){
        StudentServiceImpl ssi = (StudentServiceImpl) ac.getBean("studentServiceImpl");
        findAll();
        Student s2 = findById();
        Student student = new Student(sc.next(),sc.next(),sc.nextInt(),s2.getId());
        boolean b = ssi.updStu(student);
        if (b){
            System.out.println("修改成功！");
            System.out.println("修改后的学生信息表：");
            findAll();
            test();
        }else {
            System.out.println("修改失败");
            test();
        }


    }
}