Spring JDBC批次操作


以下範例將演示如何使用spring jdbc進行批次更新。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();
      }
   });

在上面語法中 -

  • SQL - 更新語句以更新學生的年齡。
  • BatchPreparedStatementSetter - 批次執行者,在PerparedStatement物件中設定每個專案的值,由學生物件和索引i列出。 getBatchSize()返回批次處理的數量。
  • jdbcTemplateObject - NamedParameterJdbcTemplate物件來更新資料庫中的學生物件。
  • updateCounts - int陣列包含每個更新查詢更新的行計數(數量)。

建立專案

要了解上面提到的Spring JDBC相關的概念,這裡建立一個專案用來演示如何執行批次更新。開啟Eclipse IDE,並按照以下步驟建立一個名稱為:BatchOperation 的Spring應用程式專案。

步驟說明

  1. 參考第一個Spring JDBC專案來建立一個Maven專案 - /20/235/8754.html
  2. 更新bean組態並執行應用程式。

完整的專案結構如下所示 -

檔案 : pom.xml 的內容 -

<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>

以下是資料存取物件介面檔案:StudentDAO.java的程式碼內容:

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);
}

以下是檔案:Student.java的程式碼內容:

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;
    }
}

以下是檔案:StudentMapper.java的程式碼內容:

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;
   }
}

以下是檔案:StudentJDBCTemplate.java的程式碼內容:

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;
    }
}

以下是程式執行入口檔案:MainApp.java的程式碼內容:

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和資料庫組態檔案:application-beans.xml的程式碼內容:

<?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 檔案的位置是:{workspace}/fistapp/src/main/java 目錄,如果放置錯了,程式可能會因為找不到此組態檔案而出錯。

完成建立原始碼和bean和資料庫連線資訊的檔案組態後,執行應用程式。這裡先簡單說明一下執行的步驟,在專案名稱(BatchOperation)上點選右鍵,在彈出的選單中選擇:【Run As】-> 【Maven test】

在執行測試成功後,應該會輸出類似以下內容(含有 BUILD SUCCESS 的資訊) 。
接下來,點選類檔案:MainApp.java 選擇【Run As】->【Java Application】,如果應用程式一切正常,這將列印以下訊息:

------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

資料庫中的student表中的資料被修改為:

mysql> select * from student;
+----+--------+-----+
| id | name   | age |
+----+--------+-----+
|  1 | Maxsu  |  25 |
|  2 | Curry  |  22 |
|  3 | Weiwei |  25 |
+----+--------+-----+
3 rows in set

mysql>