Springjdbc 简明教程

Spring JDBC - SimpleJdbcCall Class

org.springframework.jdbc.core.SimpleJdbcCall 类是一个多线程、可重复使用的对象，表示对存储过程或存储功能的调用。它提供元数据处理，以简化访问基本存储过程/功能所需的代码。

The org.springframework.jdbc.core.SimpleJdbcCall class is a multi-threaded, reusable object representing a call to a stored procedure or a stored function. It provides meta data processing to simplify the code needed to access basic stored procedures/functions.

在执行调用时，您需要提供的仅是过程/功能的名称和包含参数的映射。提供的参数的名称将与创建存储过程时声明的输入和输出参数匹配。

All you need to provide is the name of the procedure/function and a map containing the parameters when you execute the call. The names of the supplied parameters will be matched up with in and out parameters declared when the stored procedure was created.

Class Declaration

以下是 org.springframework.jdbc.core.SimpleJdbcCall 类的声明 -

Following is the declaration for org.springframework.jdbc.core.SimpleJdbcCall class −

public class SimpleJdbcCall
   extends AbstractJdbcCall
      implements SimpleJdbcCallOperations

以下示例将演示如何使用 Spring SimpleJdbcCall 调用存储过程。我们将通过调用一个存储过程来读取学生表中可用的一个记录。我们将传递一个 ID 并接收一个学生记录。

Following example will demonstrate how to call a stored procedure using Spring SimpleJdbcCall. We’ll read one of the available records in Student Table by calling a stored procedure. We’ll pass an id and receive a student record.

Syntax

SimpleJdbcCall jdbcCall = new SimpleJdbcCall(dataSource).withProcedureName("getRecord");
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"));

其中，

Where,

  1. jdbcCall − SimpleJdbcCall object to represent a stored procedure.

  2. in − SqlParameterSource object to pass a parameter to a stored procedure.

  3. student − Student object.

  4. out − Map object to represent output of stored procedure call result.

为了理解与 Spring JDBC 相关的上述概念，让我们编写一个调用存储过程的示例。为了编写我们的示例，让我们有一个可用的 Eclipse IDE 和使用以下步骤来创建一个 Spring 应用程序。

To understand the above-mentioned concepts related to Spring JDBC, let us write an example which will call a stored procedure. 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
      * a record from the Student table corresponding
      * to a passed student id.
   */
   public Student getStudent(Integer id);
}

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.util.List;
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 JdbcTemplate jdbcTemplateObject;

   public void setDataSource(DataSource dataSource) {
      this.dataSource = dataSource;
      this.jdbcTemplateObject = new JdbcTemplate(dataSource);
   }
   public Student getStudent(Integer id) {
      SimpleJdbcCall jdbcCall = new SimpleJdbcCall(dataSource).withProcedureName("getRecord");

      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;
   }
}

您为执行调用编写的代码涉及创建包含 IN 参数的 SqlParameterSource。将为输入值提供的名称与存储过程中声明的参数名称进行匹配非常重要。execute 方法获取 IN 参数并返回一个包含以存储过程中指定的名称为键值的任何输出参数的 Map。

The code you write for the execution of the call involves creating an SqlParameterSource containing the IN parameter. It’s important to match the name provided for the input value with that of the parameter name declared in the stored procedure. The execute method takes the IN parameters and returns a Map containing any out parameters keyed by the name as specified in the stored procedure.

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.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");
      Student student = studentJDBCTemplate.getStudent(1);
      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 。

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.

ID : 1, Name : Zara, Age : 11