Spring中的SQL存储过程



SimpleJdbcCall类可用于调用具有输入和输出参数的存储过程。在使用Apache Derby、DB2、MySQL、Microsoft SQL Server、Oracle和Sybase等任何RDBMS时,都可以使用此方法。

为了理解这种方法,让我们以Student表为例,它可以用以下DDL在MySQL TEST数据库中创建:

CREATE TABLE Student(
   ID   INT NOT NULL AUTO_INCREMENT,
   NAME VARCHAR(20) NOT NULL,
   AGE  INT NOT NULL,
   PRIMARY KEY (ID)
);

接下来,考虑以下MySQL存储过程,它接收学生ID并使用OUT参数返回相应学生的姓名和年龄。因此,让我们使用MySQL命令提示符在您的TEST数据库中创建此存储过程:

DELIMITER $$

DROP PROCEDURE IF EXISTS `TEST`.`getRecord` $$
CREATE PROCEDURE `TEST`.`getRecord` (
IN in_id INTEGER,
OUT out_name VARCHAR(20),
OUT out_age  INTEGER)
BEGIN
   SELECT name, age
   INTO out_name, out_age
   FROM Student where id = in_id;
END $$

DELIMITER ;

现在让我们编写Spring JDBC应用程序,它将在我们的Student表上实现简单的创建和读取操作。让我们准备好一个可运行的Eclipse IDE,并按照以下步骤创建一个Spring应用程序:

步骤 描述
1 创建一个名为SpringExample的项目,并在创建的项目中的src文件夹下创建一个com.tutorialspoint包。
2 Spring HelloWorld示例章节所述,使用添加外部JAR选项添加所需的Spring库。
3 在项目中添加Spring JDBC特定的最新库mysql-connector-java.jarorg.springframework.jdbc.jarorg.springframework.transaction.jar。如果您还没有这些库,可以下载所需的库。
4 创建DAO接口StudentDAO并列出所有所需的方法。虽然这不是必需的,您可以直接编写StudentJDBCTemplate类,但作为最佳实践,让我们这样做。
5 com.tutorialspoint包下创建其他所需的Java类StudentStudentMapperStudentJDBCTemplateMainApp
6 确保您已在TEST数据库中创建了Student表。还要确保您的MySQL服务器运行正常,并且您可以使用给定的用户名和密码访问数据库的读/写权限。
7 src文件夹下创建Beans配置文件Beans.xml
8 最后一步是创建所有Java文件和Bean配置文件的内容,并按如下所述运行应用程序。

以下是数据访问对象接口文件StudentDAO.java的内容

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 create
      * a record in the Student table.
   */
   public void create(String name, Integer 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(Integer id);
   
   /** 
      * This is the method to be used to list down
      * all the records from the Student table.
   */
   public List<Student> listStudents();
}

以下是Student.java文件的内容

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StudentMapper.java文件的内容

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;
   }
}

以下是为已定义的DAO接口StudentDAO编写的实现类文件StudentJDBCTemplate.java

package com.tutorialspoint;

import java.util.Map;

import javax.sql.DataSource;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.namedparam.MapSqlParameterSource;
import org.springframework.jdbc.core.namedparam.SqlParameterSource;
import org.springframework.jdbc.core.simple.SimpleJdbcCall;

public class StudentJDBCTemplate implements StudentDAO {
   private DataSource dataSource;
   private SimpleJdbcCall jdbcCall;

   public void setDataSource(DataSource dataSource) {
      this.dataSource = dataSource;
      this.jdbcCall =  new SimpleJdbcCall(dataSource).withProcedureName("getRecord");
   }
   public void create(String name, Integer age) {
      JdbcTemplate jdbcTemplateObject = new JdbcTemplate(dataSource);
      String SQL = "insert into Student (name, age) values (?, ?)";

      jdbcTemplateObject.update( SQL, name, age);
      System.out.println("Created Record Name = " + name + " Age = " + age);
      return;
   }
   public Student getStudent(Integer id) {
      SqlParameterSource in = new MapSqlParameterSource().addValue("in_id", id);
      Map<String, Object> out = jdbcCall.execute(in);

      Student student = new Student();
      student.setId(id);
      student.setName((String) out.get("out_name"));
      student.setAge((Integer) out.get("out_age"));
      return student;
   }
   public List<Student> listStudents() {
      String SQL = "select * from Student";
      List <Student> students = jdbcTemplateObject.query(SQL, new StudentMapper());
      return students;
   }
}

关于上述程序的一些说明:您为执行调用编写的代码涉及创建包含输入参数的SqlParameterSource。重要的是将为输入值提供的名称与存储过程中声明的参数名称相匹配。execute方法获取输入参数并返回一个Map,其中包含任何以存储过程中指定的名称为键的输出参数。现在让我们继续使用主应用程序文件MainApp.java,如下所示:

package com.tutorialspoint;

import java.util.List;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.tutorialspoint.StudentJDBCTemplate;

public class MainApp {
   public static void main(String[] args) {
      ApplicationContext context = new ClassPathXmlApplicationContext("Beans.xml");
      StudentJDBCTemplate studentJDBCTemplate = 
         (StudentJDBCTemplate)context.getBean("studentJDBCTemplate");
      
      System.out.println("------Records Creation--------" );
      studentJDBCTemplate.create("Zara", 11);
      studentJDBCTemplate.create("Nuha", 2);
      studentJDBCTemplate.create("Ayan", 15);

      System.out.println("------Listing Multiple Records--------" );
      List<Student> students = studentJDBCTemplate.listStudents();
      
      for (Student record : students) {
         System.out.print("ID : " + record.getId() );
         System.out.print(", Name : " + record.getName() );
         System.out.println(", Age : " + record.getAge());
      }
      System.out.println("----Listing Record with ID = 2 -----" );
      Student student = studentJDBCTemplate.getStudent(2);
      System.out.print("ID : " + student.getId() );
      System.out.print(", Name : " + student.getName() );
      System.out.println(", Age : " + student.getAge());
   }
}

以下是配置文件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.jdbc.Driver"/>
      <property name = "url" value = "jdbc:mysql://127.0.0.1:3306/TEST"/>
      <property name = "username" value = "root"/>
      <property name = "password" value = "password"/>
   </bean>

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

创建源文件和bean配置文件后,让我们运行应用程序。如果您的应用程序一切正常,它将打印以下消息:

------Records Creation--------
Created Record Name = Zara Age = 11
Created Record Name = Nuha Age = 2
Created Record Name = Ayan Age = 15
------Listing Multiple Records--------
ID : 1, Name : Zara, Age : 11
ID : 2, Name : Nuha, Age : 2
ID : 3, Name : Ayan, Age : 15
----Listing Record with ID = 2 -----
ID : 2, Name : Nuha, Age : 2
spring_jdbc_framework.htm
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