Spring 中 SQL 的存儲(chǔ)過程

Spring 中 SQL 的存儲(chǔ)過程

SimpleJdbcCall 類可以被用于調(diào)用一個(gè)包含 IN 和 OUT 參數(shù)的存儲(chǔ)過程。你可以在處理任何一個(gè) RDBMS 時(shí)使用這個(gè)方法，就像 Apache Derby， DB2， MySQL， Microsoft SQL Server， Oracle，和 Sybase。

為了了解這個(gè)方法，我們使用 Student 表，它可以在 MySQL TEST 數(shù)據(jù)庫(kù)中使用下面的 DDL 進(jìn)行創(chuàng)建：

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

下一步，考慮接下來的 MySQL 存儲(chǔ)過程，該過程使用 學(xué)生 Id 并且使用 OUT 參數(shù)返回相應(yīng)的學(xué)生的姓名和年齡。所以讓我們?cè)谀愕?TEST 數(shù)據(jù)庫(kù)中使用 MySQL 命令提示符創(chuàng)建這個(gè)存儲(chǔ)過程：

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 ;

現(xiàn)在，讓我們編寫我們的 Spring JDBC 應(yīng)用程序，它可以實(shí)現(xiàn)對(duì)我們的 Student 數(shù)據(jù)庫(kù)表的創(chuàng)建和讀取操作。讓我們使 Eclipse IDE 處于工作狀態(tài)，然后按照如下步驟創(chuàng)建一個(gè) Spring 應(yīng)用程序：

下面是數(shù)據(jù)訪問對(duì)象接口文件 StudentDAO.java 的內(nèi)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();
}

下面是 Student.java 文件的內(nèi)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;
   }
}

下面是 StudentMapper.java 文件的內(nèi)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;
   }
}

下面是實(shí)現(xiàn)類文件 StudentJDBCTemplate.java，定義了 DAO 接口 StudentDAO：

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;
   }
}

關(guān)于上述項(xiàng)目的幾句話：你編寫的課調(diào)用執(zhí)行的代碼涉及創(chuàng)建一個(gè)包含 IN 參數(shù)的 SqlParameterSource。名稱的匹配是很重要的，該名稱可以使用在存儲(chǔ)過程匯總聲明的參數(shù)名稱來提供輸入值。execute 方法利用 IN 參數(shù)返回一個(gè)包含在存儲(chǔ)過程中由名稱指定的任何外部參數(shù)鍵的映射?，F(xiàn)在讓我們移動(dòng)主應(yīng)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());      
   }
}

下面是配置文件 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://localhost: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>

一旦你已經(jīng)完成的創(chuàng)建了源文件和 bean 配置文件，讓我們運(yùn)行一下應(yīng)用程序。如果你的應(yīng)用程序一切都正常的話，這將會(huì)輸出以下消息：

------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