org.springframework.jdbc.object.SqlUpdate類(lèi)提供了表示SQL更新的可重用操作對(duì)象。
使用到的 Student 表的結(jié)構(gòu)如下 -
CREATE TABLE Student(
ID INT NOT NULL AUTO_INCREMENT,
NAME VARCHAR(20) NOT NULL,
AGE INT NOT NULL,
PRIMARY KEY (ID)
);
類(lèi)的聲明
以下是org.springframework.jdbc.object.SqlUpdate接口的聲明 -
public abstract class SqlUpdate<T>
extends SqlOperation
用法
JdbcTemplate對(duì)象。RowMapper接口的StudentMapper對(duì)象。JdbcTemplate對(duì)象方法在使用SqlUpdate對(duì)象時(shí)進(jìn)行數(shù)據(jù)庫(kù)操作。以下示例將演示如何使用SqlUpdate對(duì)象進(jìn)行數(shù)據(jù)更新操作。首先使用StudentMapper對(duì)象將讀取記錄從student表映射到Student對(duì)象。
語(yǔ)法
String SQL = "update Student set age = ? where id = ?";
SqlUpdate sqlUpdate = new SqlUpdate(dataSource,SQL);
sqlUpdate.declareParameter(new SqlParameter("age", Types.INTEGER));
sqlUpdate.declareParameter(new SqlParameter("id", Types.INTEGER));
sqlUpdate.compile();
sqlUpdate.update(age.intValue(),id.intValue());
在上代碼中，
StudentJDBCTemplate對(duì)象用于從數(shù)據(jù)庫(kù)中讀取學(xué)生記錄。StudentMapper對(duì)象將student表中記錄映射到Student對(duì)象。SqlUpdate對(duì)象用于更新學(xué)生記錄。要了解上述與Spring JDBC相關(guān)的概念，下面我們編寫(xiě)一個(gè)使用StudentMapper對(duì)象進(jìn)行讀取查詢和映射結(jié)果。打開(kāi)Eclipse IDE，并按照以下步驟創(chuàng)建一個(gè)Spring應(yīng)用程序，這里創(chuàng)建一個(gè)名稱為：SqlUpdate 的項(xiàng)目。
步驟說(shuō)明
完整的項(xiàng)目結(jié)構(gòu)如下所示 -
以下是Maven配置文件：pom.xml的代碼內(nèi)容：
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.yiibai</groupId>
<artifactId>SqlUpdate</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>SqlUpdate</name>
<url>http://maven.apache.org</url>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.40</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>4.1.0.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>4.1.4.RELEASE</version>
</dependency>
</dependencies>
</project>
以下是數(shù)據(jù)訪問(wèn)對(duì)象接口文件：StudentDAO.java的內(nèi)容：
package com.yiibai;
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 all the records from the
* Student table.
*/
public List<Student> listStudents();
/**
* This is the method to be used to update a record into the Student table.
*/
public void update(Integer id, Integer age);
}
以下是文件：Student.java的代碼內(nèi)容：
package com.yiibai;
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;
}
}
以下是文件：StudentMapper.java的代碼內(nèi)容：
package com.yiibai;
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;
}
}
實(shí)現(xiàn)類(lèi)StudentJDBCTemplate.java實(shí)現(xiàn)了定義的DAO接口 - StudentDAO.java，以下是文件：StudentJDBCTemplate.java的代碼內(nèi)容：
package com.yiibai;
import java.sql.Types;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.sql.DataSource;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.jdbc.core.SqlParameter;
import org.springframework.jdbc.core.namedparam.MapSqlParameterSource;
import org.springframework.jdbc.core.namedparam.SqlParameterSource;
import org.springframework.jdbc.core.simple.SimpleJdbcCall;
import org.springframework.jdbc.core.simple.SimpleJdbcInsert;
import org.springframework.jdbc.object.SqlQuery;
import org.springframework.jdbc.object.SqlUpdate;
public class StudentJDBCTemplate implements StudentDAO {
private DataSource dataSource;
private JdbcTemplate jdbcTemplateObject;
SimpleJdbcInsert jdbcInsert;
public void setDataSource(DataSource dataSource) {
this.dataSource = dataSource;
this.jdbcTemplateObject = new JdbcTemplate(dataSource);
this.jdbcInsert = new SimpleJdbcInsert(dataSource).withTableName("Student");
}
public void create(String name, Integer age) {
Map<String, Object> parameters = new HashMap<String, Object>();
parameters.put("name", name);
parameters.put("age", age);
jdbcInsert.execute(parameters);
System.out.println("Created Record Name = " + name + " Age = " + age);
return;
}
public List<Student> listStudents() {
String sql = "select * from Student";
SqlQuery<Student> sqlQuery = new SqlQuery<Student>() {
@Override
protected RowMapper<Student> newRowMapper(Object[] parameters, Map<?, ?> context) {
return new StudentMapper();
}
};
sqlQuery.setDataSource(dataSource);
sqlQuery.setSql(sql);
List<Student> students = sqlQuery.execute();
return students;
}
public void update(Integer id, Integer age) {
String SQL = "update Student set age = ? where id = ?";
SqlUpdate sqlUpdate = new SqlUpdate(dataSource, SQL);
sqlUpdate.declareParameter(new SqlParameter("age", Types.INTEGER));
sqlUpdate.declareParameter(new SqlParameter("id", Types.INTEGER));
sqlUpdate.compile();
sqlUpdate.update(age.intValue(), id.intValue());
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;
}
}
以下是文件：MainApp.java的代碼內(nèi)容：
package com.yiibai;
import java.util.ArrayList;
import java.util.List;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.yiibai.StudentJDBCTemplate;
public class MainApp {
public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("application-beans.xml");
StudentJDBCTemplate studentJDBCTemplate = (StudentJDBCTemplate) context.getBean("studentJDBCTemplate");
System.out.println("------Records Creation--------");
studentJDBCTemplate.create("Maxsu", 21);
studentJDBCTemplate.create("Curry", 22);
studentJDBCTemplate.create("Suzend", 23);
System.out.println("----Updating Record with ID = 1 -----");
studentJDBCTemplate.update(1, 10);
System.out.println("----Listing Record with ID = 1 -----");
Student student = studentJDBCTemplate.getStudent(1);
System.out.print("ID : " + student.getId());
System.out.print(", Name : " + student.getName());
System.out.println(", Age : " + student.getAge());
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());
}
}
}
以下是文件：application-beans.xml的代碼內(nèi)容：
<?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?characterEncoding=utf8&useSSL=true" />
<property name="username" value="root" />
<property name="password" value="123456" />
</bean>
<!-- Definition for studentJDBCTemplate bean -->
<bean id="studentJDBCTemplate" class="com.yiibai.StudentJDBCTemplate">
<property name="dataSource" ref="dataSource" />
</bean>
</beans>
注意： application-beans.xml 文件的位置是：{workspace}/fistapp/src/main/java 目錄，如果放置錯(cuò)了，程序可能會(huì)因?yàn)檎也坏酱伺渲梦募鲥e(cuò)。
完成創(chuàng)建源代碼和bean和數(shù)據(jù)庫(kù)連接信息的文件配置后，運(yùn)行應(yīng)用程序。這里先簡(jiǎn)單說(shuō)明一下運(yùn)行的步驟，在項(xiàng)目名稱(SqlUpdate)上點(diǎn)擊右鍵，在彈出的菜單中選擇：【Run As】-> 【Maven test】
在運(yùn)行測(cè)試成功后，應(yīng)該會(huì)輸出類(lèi)似以下內(nèi)容(含有 BUILD SUCCESS 的信息) 。
接下來(lái)，點(diǎn)擊類(lèi)文件：MainApp.java 選擇【Run As】->【Java Application】，如果應(yīng)用程序一切正常，這將打印以下結(jié)果：
------Records Creation--------
Created Record Name = Maxsu Age = 21
Created Record Name = Curry Age = 22
Created Record Name = Suzend Age = 23
----Updating Record with ID = 1 -----
Updated Record with ID = 1
----Listing Record with ID = 1 -----
ID : 1, Name : Maxsu, Age : 10
------Listing Multiple Records--------
ID : 1, Name : Maxsu, Age : 10
ID : 2, Name : Curry, Age : 22
ID : 3, Name : Suzend, Age : 23
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