以下示例將演示如何使用spring jdbc進(jìn)行批量更新。我們將在單次批次操作中更新student
表中的記錄。
student
表的結(jié)果如下 -
CREATE TABLE student(
id INT NOT NULL AUTO_INCREMENT,
name VARCHAR(20) NOT NULL,
age INT NOT NULL,
PRIMARY KEY (id)
);
語(yǔ)法:
String SQL = "update Student set age = ? where id = ?";
int[] updateCounts = jdbcTemplateObject.batchUpdate(SQL,
new BatchPreparedStatementSetter() {
public void setValues(PreparedStatement ps, int i) throws SQLException {
ps.setInt(1, students.get(i).getAge());
ps.setInt(2, students.get(i).getId());
}
public int getBatchSize() {
return students.size();
}
});
在上面語(yǔ)法中 -
SQL
- 更新語(yǔ)句以更新學(xué)生的年齡。BatchPreparedStatementSetter
- 批量執(zhí)行者,在PerparedStatement
對(duì)象中設(shè)置每個(gè)項(xiàng)目的值,由學(xué)生對(duì)象和索引i
列出。 getBatchSize()
返回批處理的數(shù)量。jdbcTemplateObject
- NamedParameterJdbcTemplate
對(duì)象來(lái)更新數(shù)據(jù)庫(kù)中的學(xué)生對(duì)象。updateCounts
- int
數(shù)組包含每個(gè)更新查詢(xún)更新的行計(jì)數(shù)(數(shù)量)。要了解上面提到的Spring JDBC相關(guān)的概念,這里創(chuàng)建一個(gè)項(xiàng)目用來(lái)演示如何執(zhí)行批量更新。打開(kāi)Eclipse IDE,并按照以下步驟創(chuàng)建一個(gè)名稱(chēng)為:BatchOperation 的Spring應(yīng)用程序項(xiàng)目。
步驟說(shuō)明
完整的項(xiàng)目結(jié)構(gòu)如下所示 -
文件 : pom.xml 的內(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>BatchOperation</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>BatchOperation</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(fǎng)問(wèn)對(duì)象接口文件:StudentDAO.java的代碼內(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 list down all the records from the
* Student table.
*/
public List<Student> listStudents();
public void create(String name, Integer age);
public void batchUpdate(final List<Student> students);
}
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;
}
}
以下是文件:StudentJDBCTemplate.java的代碼內(nèi)容:
package com.yiibai;
import java.sql.PreparedStatement;
import java.util.List;
import javax.sql.DataSource;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.BatchPreparedStatementSetter;
import java.sql.SQLException;
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 List<Student> listStudents() {
String SQL = "select * from Student";
List<Student> students = jdbcTemplateObject.query(SQL, new StudentMapper());
return students;
}
public void batchUpdate(final List<Student> students) {
String SQL = "update Student set age = ? where id = ?";
int[] updateCounts = jdbcTemplateObject.batchUpdate(SQL, new BatchPreparedStatementSetter() {
public void setValues(PreparedStatement ps, int i) throws SQLException {
ps.setInt(1, students.get(i).getAge());
ps.setInt(2, students.get(i).getId());
}
public int getBatchSize() {
return students.size();
}
});
System.out.println("Records updated!");
}
public void create(String name, Integer age) {
// TODO Auto-generated method stub
String insertQuery = "insert into student (name, age) values (?, ?)";
jdbcTemplateObject.update( insertQuery, name, age);
System.out.println("Created Record Name = " + name + " Age = " + age);
return;
}
}
以下是程序執(zhí)行入口文件: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("Weiwei", 25);
List<Student> initialStudents = studentJDBCTemplate.listStudents();
System.out.println("Initial Students");
for (Student student2 : initialStudents) {
System.out.print("ID : " + student2.getId());
System.out.println(", Age : " + student2.getAge());
}
Student student = new Student();
student.setId(1);
student.setAge(25);
Student student1 = new Student();
student1.setId(3);
student1.setAge(25);
List<Student> students = new ArrayList<Student>();
students.add(student);
students.add(student1);
studentJDBCTemplate.batchUpdate(students);
List<Student> updatedStudents = studentJDBCTemplate.listStudents();
System.out.println("Updated Students");
for (Student student3 : updatedStudents) {
System.out.print("ID : " + student3.getId());
System.out.println(", Age : " + student3.getAge());
}
}
}
以下是Bean和數(shù)據(jù)庫(kù)配置文件: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(chēng)(BatchOperation)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,這將打印以下消息:
------Records Creation--------
Created Record Name = Maxsu Age = 21
Created Record Name = Curry Age = 22
Created Record Name = Weiwei Age = 25
Initial Students
ID : 1, Age : 21
ID : 2, Age : 22
ID : 3, Age : 25
Records updated!
Updated Students
ID : 1, Age : 25
ID : 2, Age : 22
ID : 3, Age : 25
數(shù)據(jù)庫(kù)中的student
表中的數(shù)據(jù)被修改為:
mysql> select * from student;
+----+--------+-----+
| id | name | age |
+----+--------+-----+
| 1 | Maxsu | 25 |
| 2 | Curry | 22 |
| 3 | Weiwei | 25 |
+----+--------+-----+
3 rows in set
mysql>