Springjdbc 简明教程

Spring JDBC - Multiple Batches Operation

以下示例将展示如何使用 Spring JDBC 在单个调用中执行多个批处理更新。我们将以批处理大小为 1 的多批处理操作更新 Student 表中可用的记录。

Following example will demonstrate how to make multiple batch updates in a single call using Spring JDBC. We’ll update the available records in Student table in a multiple batch operation where batch size is 1.

Syntax

String SQL = "update Student set age = ? where id = ?";
int[][] updateCounts = jdbcTemplateObject.batchUpdate(SQL,students,1,
   new ParameterizedPreparedStatementSetter<Student>() {

   public void setValues(PreparedStatement ps, Student student)
      throws SQLException {
      ps.setInt(1, student.getAge());
      ps.setInt(2, student.getId());
   }
});

其中，

Where,

  1. SQL − Update query to update student’s age.

  2. jdbcTemplateObject − StudentJDBCTemplate object to update student object in the database.

  3. ParameterizedPreparedStatementSetter − Batch executor, set values in PerparedStatement per item identified by the list of objects student.

  4. updateCounts − Int[][] array containing updated row count per update query per batch.

为了理解与 Spring JDBC 相关的上述概念，我们编写一个示例，该示例将更新多个批处理操作。要编写示例，让我们准备一个可用的 Eclipse IDE，并使用以下步骤创建一个 Spring 应用程序。

To understand the above-mentioned concepts related to Spring JDBC, let us write an example which will update multiple batch operation. To write our example, let us have a working Eclipse IDE in place and use the following steps to create a Spring application.

Step

Description

1

Update the project Student created under chapter Spring JDBC - First Application.

2

Update the bean configuration and run the application as explained below.

以下是对数据访问对象接口文件 StudentDAO.java 的内容。

Following is the content of the Data Access Object interface file StudentDAO.java.

package com.tutorialspoint;

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 list down
      * all the records from the Student table.
   */
   public List<Student> listStudents();
   public void batchUpdate(final List<Student> students);
}

以下是 Student.java 文件的内容。

Following is the content of the Student.java file.

package com.tutorialspoint;

public class Student {
   private Integer age;
   private String name;
   private Integer id;

   public void setAge(Integer age) {
      this.age = age;
   }
   public Integer getAge() {
      return age;
   }
   public void setName(String name) {
      this.name = name;
   }
   public String getName() {
      return name;
   }
   public void setId(Integer id) {
      this.id = id;
   }
   public Integer getId() {
      return id;
   }
}

以下是对 StudentMapper.java 文件的内容。

Following is the content of the StudentMapper.java file.

package com.tutorialspoint;

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;
   }
}

以下是对所定义的 DAO 接口 StudentDAO 实现的类文件 StudentJDBCTemplate.java 。

Following is the implementation class file StudentJDBCTemplate.java for the defined DAO interface StudentDAO.

package com.tutorialspoint;

import java.sql.PreparedStatement;
import java.util.List;
import javax.sql.DataSource;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.ParameterizedPreparedStatementSetter;
import java.sql.SQLException;

public class StudentJDBCTemplate implements StudentDAO {
   private DataSource dataSource;
   private JdbcTemplate jdbcTemplateObject;

   public void setDataSource(DataSource dataSource) {
      this.dataSource = dataSource;
      this.jdbcTemplateObject = new JdbcTemplate(dataSource);
   }
   public List<Student> listStudents() {
      String SQL = "select * from Student";
      List <Student> students = jdbcTemplateObject.query(SQL, new StudentMapper());
      return students;
   }
   public void batchUpdate(final List<Student> students){
      String SQL = "update Student set age = ? where id = ?";
      int[][] updateCounts = jdbcTemplateObject.batchUpdate(
         SQL,students,1,new ParameterizedPreparedStatementSetter<Student>() {
            public void setValues(PreparedStatement ps, Student student)
               throws SQLException {
               ps.setInt(1, student.getAge());
               ps.setInt(2, student.getId());
            }
         }
      );
      System.out.println("Records updated!");
   }
}

以下是 MainApp.java 文件的内容。

Following is the content of the MainApp.java file.

package com.tutorialspoint;

import java.util.ArrayList;
import java.util.List;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MainApp {
   public static void main(String[] args) {
      ApplicationContext context = new ClassPathXmlApplicationContext("Beans.xml");
      StudentJDBCTemplate studentJDBCTemplate = (StudentJDBCTemplate)context.getBean("studentJDBCTemplate");

      List<Student> initialStudents = studentJDBCTemplate.listStudents();
      System.out.println("Initial Students");

      for(Student student2: initialStudents){
         System.out.print("ID : " + student2.getId() );
         System.out.println(", Age : " + student2.getAge());
      }
      Student student = new Student();
      student.setId(1);
      student.setAge(17);

      Student student1 = new Student();
      student1.setId(3);
      student1.setAge(18);

      List<Student> students = new ArrayList<Student>();
      students.add(student);
      students.add(student1);
      studentJDBCTemplate.batchUpdate(students);

      List<Student> updatedStudents = studentJDBCTemplate.listStudents();
      System.out.println("Updated Students");

      for(Student student3: updatedStudents){
         System.out.print("ID : " + student3.getId() );
         System.out.println(", Age : " + student3.getAge());
      }
   }
}

以下是配置文件 Beans.xml 。

Following is the configuration file Beans.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"
   xsi:schemaLocation = "http://www.springframework.org/schema/beans
   http://www.springframework.org/schema/beans/spring-beans-3.0.xsd ">

   <!-- Initialization for data source -->
   <bean id = "dataSource"
      class = "org.springframework.jdbc.datasource.DriverManagerDataSource">
      <property name = "driverClassName" value = "com.mysql.cj.jdbc.Driver"/>
      <property name = "url" value = "jdbc:mysql://localhost:3306/TEST"/>
      <property name = "username" value = "root"/>
      <property name = "password" value = "admin"/>
   </bean>

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

一旦您完成创建源代码和 bean 配置文件，让我们运行此应用程序。如果应用程序一切正常，它将打印以下信息。

Once you are done creating the source and bean configuration files, let us run the application. If everything is fine with your application, it will print the following message.

Initial Students
ID : 1, Age : 15
ID : 3, Age : 16
records updated!
Updated Students
ID : 1, Age : 17
ID : 3, Age : 18