Spring JDBC 示例

Posted 2021-02-19 爱吃西瓜的番茄酱

准备工作

• 创建一个 Spring 应用程序

• 在项目中添加 Spring JDBC 指定的最新的库
  mysql-connector-java.jar，
  org.springframework.jdbc.jar
  org.springframework.transaction.jar。

• 创建 DAO 接口 StudentDAO 并列出所有必需的方法

• 创建其他的必需的 Java 类 Student，StudentMapper，StudentJDBCTemplate 和 MainApp

• 确保你已经在 TEST 数据库中创建了 Student 表。并确保你的 MySQL 服务器运行正常，且你可以使用给出的用户名和密码读/写访问数据库。

示例

以下是数据访问对象接口文件 StudentDAO.java 的内容：

package hello;
import java.util.List;
import javax.sql.DataSource;

public interface StudentDAO {
    /**
     * This is the method to be used to initialize
     * database resources ie. connection.
     */
    public void setDataSource(DataSource ds);
    /**
     * This is the method to be used to create
     * a record in the Student table.
     */
    public void create(String name, int age);
    /**
     * This is the method to be used to list down
     * a record from the Student table corresponding
     * to a passed student id.
     */
    public Student getStudent(int id);
    /**
     * This is the method to be used to list down
     * all the records from the Student table.
     */
    public List<Student> listStudents();
    /**
     * This is the method to be used to delete
     * a record from the Student table corresponding
     * to a passed student id.
     */
    public void delete(int id);
    /**
     * This is the method to be used to update
     * a record into the Student table.
     */
    public void update(int id, int age);
}

下面是 Student.java 文件的内容：

package hello;
//import org.springframework.beans.factory.annotation.Autowired;

public class Student {
    private int age;
    private String name;
    private int id;
    public void setAge(int age){
        this.age = age;
    }
    public int getAge(){
        //System.out.println("age:"+age);
        return age;
    }
    public void setName(String name){
        this.name = name;
    }
    public String getName(){
        //System.out.println("name:"+name);
        return name;
    }
   public void setId(int id){
        this.id = id;
   }
   public int getId(){
        return id;
   }
}

以下是 StudentMapper.java 文件的内容：

package hello;
import java.sql.ResultSet;
import java.sql.SQLException;
import org.springframework.jdbc.core.RowMapper;

public class StudentMapper implements RowMapper<Student> {
    public Student mapRow(ResultSet rs, int rowNum) throws SQLException{
        Student student = new Student();
        student.setId(rs.getInt("id"));
        student.setName(rs.getString("name"));
        student.setAge(rs.getInt("age"));
        return student;
    }
}

下面是为定义的 DAO 接口 StudentDAO 的实现类文件 StudentJDBCTemplate.java：

package hello;
import java.util.List;
import javax.sql.DataSource;
import org.springframework.jdbc.core.JdbcTemplate;

public class StudentJDBCTemplate implements StudentDAO {
    private DataSource dataSource;
    private JdbcTemplate jdbcTemplate;
    public void setDataSource(DataSource dataSource){
        this.dataSource = dataSource;
        this.jdbcTemplate = new JdbcTemplate(dataSource);
    }
    public void create(String name, int age){
        String SQL = "insert into Student(name, age) values(? ,?)";
        jdbcTemplate.update(SQL,name, age);
        System.out.println("Create Record Name = " + name + " Age = " + age);
        return;
    }
    public Student getStudent(int id){
        String SQL = "select * from Student where id =?";
        Student student = jdbcTemplate.queryForObject(SQL,
                new Object[]{id}, new StudentMapper());
        return student;
    }
    public List<Student> listStudents(){
        String SQL = "select * from Student";
        List<Student> students = jdbcTemplate.query(SQL,
                new StudentMapper());
        return students;
    }
    public void delete(int id){
        String SQL="delete from Student where id = ?";
        jdbcTemplate.update(SQL,id);
        System.out.println("Delete Record with ID = "+ id);
        return;
    }
    public void update(int id, int age){
        String SQL = "update Student set age = ? where id = ?";
        jdbcTemplate.update(SQL,age, id);
        System.out.println("Update Record with ID = "+ id);
        return;
    }
}

以下是 MainApp.java 文件的内容：

package hello;
import java.util.List;
import hello.StudentJDBCTemplate;
//import org.springframework.context.support.AbstractApplicationContext;
//import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
//import org.springframework.context.annotation.*;

@EnableAutoConfiguration(exclude={DataSourceAutoConfiguration.class})
public class MainApp {
    public static void main(String[] args) {
        ApplicationContext context =
                new ClassPathXmlApplicationContext("Beans.xml");
        StudentJDBCTemplate studentJDBCTemplate = (StudentJDBCTemplate)context.getBean("studentJDBCTemplate");
        System.out.println("=====Record Creation=====");
        studentJDBCTemplate.create("番茄",11);
        studentJDBCTemplate.create("鸡蛋", 2);
        studentJDBCTemplate.create("西瓜", 15);
        System.out.println("=====Listing Multiple Records=====");
        List<Student> students = studentJDBCTemplate.listStudents();
        for (Student record: students){
            System.out.println("ID: "+ record.getId());
            System.out.println("Name: "+ record.getName());
            System.out.println("Age: "+record.getAge());
        }
        System.out.println("====Updateing Record with ID = 2====");
        studentJDBCTemplate.update(2, 20);
        System.out.println("===Listing Record with ID = 2====");
        Student student = studentJDBCTemplate.getStudent(2);
        System.out.println("ID: "+ student.getId());
        System.out.println("Name: "+ student.getName());
        System.out.println("Age: "+ student.getAge());
    }
}

下述是配置文件 Beans.xml 的内容：

<?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">

    <!-- Initialization for data source -->
    <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/TEST?&amp;useSSL=false"/>
        <property name="username" value="root"/>
        <property name="password" value="123456"/>
    </bean>

    <!-- Definition for studentJDBCTemplate bean -->
    <bean id="studentJDBCTemplate"
          class="hello.StudentJDBCTemplate">
        <property name="dataSource" ref="dataSource"/>
    </bean>

</beans>

运行应用程序:

=====Record Creation=====
Create Record Name = 番茄 Age = 11
Create Record Name = 鸡蛋 Age = 2
Create Record Name = 西瓜 Age = 15
=====Listing Multiple Records=====
ID: 1
Name: 番茄
Age: 11
ID: 2
Name: 鸡蛋
Age: 20
ID: 3
Name: 西瓜
Age: 15
ID: 4
Name: 番茄
Age: 11
ID: 5
Name: 鸡蛋
Age: 2
ID: 6
Name: 西瓜
Age: 15
ID: 7
Name: 番茄
Age: 11
ID: 8
Name: 鸡蛋
Age: 2
ID: 9
Name: 西瓜
Age: 15
====Updateing Record with ID = 2====
Update Record with ID = 2
===Listing Record with ID = 2====
ID: 2
Name: 鸡蛋
Age: 20

Process finished with exit code 0

每天学习一点点，每天进步一点点。