Springjdbc 简明教程
Spring JDBC - StoredProcedure Class
org.springframework.jdbc.core.StoredProcedure 类是 RDBMS 存储过程的对象抽象的超类。此类是抽象的,其目的是子类提供一个委派到提供的 execute(java.lang.Object…) 方法的类型化调用方法。继承的 SQL 属性是 RDBMS 中存储过程的名称。
Class Declaration
以下是 org.springframework.jdbc.core.StoredProcedure 类的声明 −
public abstract class StoredProcedure
extends SqlCall
以下示例将演示如何使用 Spring StoredProcedure 调用存储过程。我们将通过调用存储过程读取学生表中可用记录之一。我们将传递一个 ID 并收到一个学生记录。
Syntax
class StudentProcedure extends StoredProcedure{
public StudentProcedure(DataSource dataSource, String procedureName){
super(dataSource,procedureName);
declareParameter(new SqlParameter("in_id", Types.INTEGER));
declareParameter(new SqlOutParameter("out_name", Types.VARCHAR));
declareParameter(new SqlOutParameter("out_age", Types.INTEGER));
compile();
}
public Student execute(Integer id){
Map<String, Object> out = super.execute(id);
Student student = new Student();
student.setId(id);
student.setName((String) out.get("out_name"));
student.setAge((Integer) out.get("out_age"));
return student;
}
}
其中,
-
StoredProcedure − 用于表示存储过程的 StoredProcedure 对象。
-
StudentProcedure − StudentProcedure 对象扩展 StoredProcedure 以声明输入、输出变量,并将结果映射到 Student 对象。
-
student − Student object.
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。
Step |
Description |
1 |
更新在第 Spring JDBC - First Application 章创建的 Student 项目。 |
2 |
更新 bean 配置并按如下说明运行应用程序。 |
以下是对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 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。
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。
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 。
package com.tutorialspoint;
import java.sql.Types;
import java.util.List;
import java.util.Map;
import javax.sql.DataSource;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.SqlOutParameter;
import org.springframework.jdbc.core.SqlParameter;
import org.springframework.jdbc.core.namedparam.MapSqlParameterSource;
import org.springframework.jdbc.core.namedparam.SqlParameterSource;
import org.springframework.jdbc.object.StoredProcedure;
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) {
StudentProcedure studentProcedure = new StudentProcedure(dataSource, "getRecord");
return studentProcedure.execute(id);
}
}
class StudentProcedure extends StoredProcedure {
public StudentProcedure(DataSource dataSource, String procedureName) {
super(dataSource,procedureName);
declareParameter(new SqlParameter("in_id", Types.INTEGER));
declareParameter(new SqlOutParameter("out_name", Types.VARCHAR));
declareParameter(new SqlOutParameter("out_age", Types.INTEGER));
compile();
}
public Student execute(Integer id){
Map<String, Object> out = super.execute(id);
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。
以下是 MainApp.java 文件的内容。
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.
<?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。
ID : 1, Name : Zara, Age : 10