以下示例将演示如何使用Spring JDBC更新查询.我们将更新学生表中的可用记录.
String updateQuery = "update Student set age = ? where id = ?"; jdbcTemplateObject.update(updateQuery, age, id);
其中,
updateQuery : 更新查询以使用占位符更新学生.
jdbcTemplateObject : StudentJDBCTemplate对象用于更新数据库中的student对象.
为了理解上述与Spring JDBC相关的概念,让我们编写一个例子这将更新查询.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 update * a record into the Student table. */ public void update(Integer id, 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); }
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; 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 void update(Integer id, Integer age){ String SQL = "update Student set age = ? where id = ?"; jdbcTemplateObject.update(SQL, age, id); System.out.println("Updated Record with ID = " + id ); return; } public Student getStudent(Integer id) { String SQL = "select * from Student where id = ?"; Student student = jdbcTemplateObject.queryForObject( SQL, new Object[]{id}, new StudentMapper()); return student; } }
以下是 MainApp.java 文件的内容.
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"); System.out.println("----Updating Record with ID = 2 -----" ); studentJDBCTemplate.update(2, 20); 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://localhost:3306/TEST"/> <property name = "username" value = "root"/> <property name = "password" value = "admin"/> </bean> <!-- Definition for studentJDBCTemplate bean --> <bean id = "studentJDBCTemplate" class = "com.it1352.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.如果您的应用程序一切正常,它将打印以下消息.
----Updating Record with ID = 2 ----- Updated Record with ID = 2 ----Listing Record with ID = 2 ----- ID : 2, Name : Nuha, Age : 20