org.springframework.jdbc.core.SimpleJdbcCall 类是一个多线程,可重用的对象,表示对存储过程或存储函数的调用.它提供了元数据处理,以简化访问基本存储过程/函数所需的代码.
您需要提供的只是过程/函数的名称和包含参数的映射.执行呼叫.提供的参数的名称将与创建存储过程时声明的in和out参数匹配.
以下是声明 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.我们将通过调用存储过程来读取学生表中的一个可用记录.我们将传递一个id并收到学生记录.
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,
jdbcCall : SimpleJdbcCall对象表示存储过程.
in : 用于将参数传递给存储过程的SqlParameterSource对象.
学生 : 学生对象.
out : Map对象表示存储过程调用结果的输出.
要理解上面提到的与Spring JDBC相关的概念,让我们编写一个将调用存储过程的示例.要编写我们的示例,让我们使用一个可用的Eclipse IDE并使用以下步骤创建一个Spring应用程序.
Step | 描述 |
---|---|
1 | 更新在章节下创建的项目学生 Spring JDBC - First Application . |
2 | 更新bean配置并运行应用程序,如下所述. |
以下是数据访问对象接口文件的内容 StudentDAO.java .
package com.it1352; 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.it1352; 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.it1352; 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; } }
以下是定义的DAO接口StudentDAO的实现类文件 StudentJDBCTemplate.java .
package com.it1352; 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; } }
为执行调用而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的名称相匹配非常重要. execute方法接受IN参数并返回一个Map,其中包含由存储过程中指定的名称键入的任何out参数.
以下是 MainApp.java的内容 file.
package com.it1352; import java.util.List; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import com.it1352.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.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.IT屋.StudentJDBCTemplate"> <property name = "dataSource" ref = "dataSource" /> </bean> </beans>
完成源和bean配置文件的创建后,让我们运行应用程序.如果你的申请一切正常,它将打印以下信息.
ID : 1, Name : Zara, Age : 11