spring：一个简单实例之对DAO的支持

spring 对 DAO 的支持~~

1、在 MySQL 中创建 db_spring 数据库，新建 t_student 表

DROP TABLE IF EXISTS `t_student`;

CREATE TABLE `t_student` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(20) DEFAULT NULL,
  `age` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;

insert  into `t_student`(`id`,`name`,`age`) values (1,'张三',12),(2,'李四',12),(3,'王五',12),(4,'赵六',12),(5,'孙器',12),(6,'阙八',12);

2、创建 spring 项目

3、引入 jar 包

4、新建 student 实体类

package com.java.model;

public class Student {

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

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

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

	@Override
	public String toString() {
		return "Student [id=" + id + ", name=" + name + ", age=" + age + "]";
	}
		
}

5、创建 studentDao 和其实现类 studentDaoImpl

package com.java.dao;

import java.util.List;

import com.java.model.Student;

public interface StudentDao {

	public int addStudent(Student student);
	
	public int updateStudent(Student student);
	
	public int deleteStudent(int id);
	
	public List<Student> findStudents();
}

package com.java.dao.impl;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowCallbackHandler;

import com.java.dao.StudentDao;
import com.java.model.Student;

public class StudentDaoImpl implements StudentDao{

	private JdbcTemplate jdbcTemplate;
	
	public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
		this.jdbcTemplate = jdbcTemplate;
	}

	@Override
	public int addStudent(Student student) {
		String sql="insert into t_student values(null,?,?)";
		Object []params=new Object[]{student.getName(),student.getAge()};
		return jdbcTemplate.update(sql,params);
	}

	@Override
	public int updateStudent(Student student) {
		String sql="update t_student set name=?,age=? where id=?";
		Object []params=new Object[]{student.getName(),student.getAge(),student.getId()};
		return jdbcTemplate.update(sql,params);
	}

	@Override
	public int deleteStudent(int id) {
		String sql="delete from t_student where id=?";
		Object []params=new Object[]{id};
		return jdbcTemplate.update(sql,params);
	}

	@Override
	public List<Student> findStudents() {
		String sql="select * from t_student";
		final List<Student> studentList=new ArrayList<Student>();
		jdbcTemplate.query(sql, new RowCallbackHandler(){

			@Override
			public void processRow(ResultSet rs) throws SQLException {
				Student student=new Student();
				student.setId(rs.getInt("id"));
				student.setName(rs.getString("name"));
				student.setAge(rs.getInt("age"));
				studentList.add(student);
			}
			
		});
		return studentList;
	}

}

6、加入配置文件

<?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:aop="http://www.springframework.org/schema/aop"
    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/aop
        http://www.springframework.org/schema/aop/spring-aop.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd">
        
	<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
        <property name="driverClassName" value="${jdbc.driverClassName}"/>
        <property name="url" value="${jdbc.url}"/>
        <property name="username" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>
    
	<context:property-placeholder location="jdbc.properties"/>
    
    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
    	<property name="dataSource" ref="dataSource"></property>
    </bean>
	
	
	<bean id="studentDao" class="com.java.dao.impl.StudentDaoImpl">
		<property name="jdbcTemplate" ref="jdbcTemplate"></property>
	</bean> 
	
	<bean id="studentService" class="com.java.service.impl.StudentServiceImpl">
		<property name="studentDao" ref="studentDao"></property>
	</bean> 
	
</beans>

7、jdbc.properties

jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/db_spring
jdbc.username=root
jdbc.password=root

8、service 层

package com.java.service;

import java.util.List;

import com.java.model.Student;

public interface StudentService {

	public int addStudent(Student student);
	
	public int updateStudent(Student student);
	
	public int deleteStudent(int id);
	
	public List<Student> findStudents();
}

package com.java.service.impl;

import java.util.List;

import com.java.dao.StudentDao;
import com.java.model.Student;
import com.java.service.StudentService;

public class StudentServiceImpl implements StudentService{

	private StudentDao studentDao;
	
	public void setStudentDao(StudentDao studentDao) {
		this.studentDao = studentDao;
	}

	@Override
	public int addStudent(Student student) {
		return studentDao.addStudent(student);
	}

	@Override
	public int updateStudent(Student student) {
		return studentDao.updateStudent(student);
	}

	@Override
	public int deleteStudent(int id) {
		return studentDao.deleteStudent(id);
	}

	@Override
	public List<Student> findStudents() {
		return studentDao.findStudents();
	}

}

8、测试类

package com.java.test;

import java.util.List;

import org.junit.Before;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.java.model.Student;
import com.java.service.StudentService;


public class Test {

	private ApplicationContext ac;

	@Before
	public void setUp() throws Exception {
		ac=new ClassPathXmlApplicationContext("beans.xml");
	}

	@Test
	public void addStudent() {
		StudentService studentService=(StudentService)ac.getBean("studentService");
		int addNums=studentService.addStudent(new Student("王五", 1));
		if(addNums==1){
			System.out.println("添加成功");
		}
	}
	
	@Test
	public void updateStudent() {
		StudentService studentService=(StudentService)ac.getBean("studentService");
		int updateNums=studentService.updateStudent(new Student(8,"王五2", 2));
		if(updateNums==1){
			System.out.println("更新成功");
		}
	}
	
	@Test
	public void deleteStudent() {
		StudentService studentService=(StudentService)ac.getBean("studentService");
		int deleteNums=studentService.deleteStudent(8);
		if(deleteNums==1){
			System.out.println("删除成功");
		}
	}
	
	@Test
	public void findStudents() {
		StudentService studentService=(StudentService)ac.getBean("studentService");
		List<Student> studentList=studentService.findStudents();
		for(Student student:studentList){
			System.out.println(student);
		}
	}
}

到此结束啦~~

原文链接：https://blog.csdn.net/xingyun_yj/article/details/77871100

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