環境Spring boot
1、JDBC（JdbcTemplate
）
pom.xml
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-jdbc</artifactId> </dependency>
Service
@Autowired private JdbcTemplate jdbcTemplate; public void jdbc(List<String> list){ int[] updatedCountArray=jdbcTemplate.batchUpdate("INSERT INTO customer (name) VALUES (?);", new BatchPreparedStatementSetter() { @Override public void setValues(PreparedStatement preparedStatement, int i) throws SQLException { preparedStatement.setString(1,list.get(i)); } @Override public int getBatchSize() { return list.size(); } }); }
2、網上最常見的JPA----entityManager批量操作方法
Entity
package net.xjdsz.model;import javax.persistence.*;/** * Created by dingshuo on 2017/6/23. */@Entity@Table(name = "customer", schema = "test", catalog = "")public class CustomerEntity { private int id; private String name; @Id @GeneratedValue(strategy = GenerationType.AUTO) @Column(name = "id", nullable = false) public int getId() { return id; } public void setId(int id) { this.id = id; } @Basic @Column(name = "name", nullable = true, length = 100) public String getName() { return name; } public void setName(String name) { this.name = name; } @Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; CustomerEntity that = (CustomerEntity) o; if (id != that.id) return false; if (name != null ? !name.equals(that.name) : that.name != null) return false; return true; } @Override public int hashCode() { int result = id; result = 31 * result + (name != null ? name.hashCode() : 0); return result; }}
Service
private EntityManager em; @PersistenceContext(name = "EntityManagerFactory") public void SetEntityManager(EntityManager em) { this.em = em; } @Transactional public void saveBatch(List<CustomerEntity> list) { for (int i = 0; i < 10000; i++) { em.persist(list.get(i)); if (i % 1000 == 0) { em.flush(); em.clear(); } } }
3、Jpa---Repository循環寫入
Repository
package net.xjdsz.dao;import net.xjdsz.model.CustomerEntity;import org.springframework.data.jpa.repository.JpaRepository;import org.springframework.stereotype.Repository;/** * Created by dingshuo on 2017/6/23. */@Repositorypublic interface CustomerRepository extends JpaRepository<CustomerEntity,Integer> {}
4、Jpa--
Repository批量寫入
Service
@Transactional public void saveBatchJpa(List<CustomerEntity> list) { repository.save(list); }
實驗代碼：
用的是Spring boot，所以開了一個RestController去做實驗
package net.xjdsz;import net.xjdsz.dao.CustomerRepository;import net.xjdsz.dao.TestService;import net.xjdsz.model.CustomerEntity;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.web.bind.annotation.GetMapping;import org.springframework.web.bind.annotation.RestController;import java.util.ArrayList;import java.util.List;/** * Created by dingshuo on 2017/6/23. */@RestControllerpublic class TestController { @Autowired TestService service;//測試用的Service類 @Autowired CustomerRepository repository; //實體Repository接口 @GetMapping(value = "/test") public void test(){ List<String> list=new ArrayList<>(); //給jdbctemplate用的集合 List<CustomerEntity> customerEntityList=new ArrayList<>();//給jpa用的集合 for(int i=0;i<10000;i++){ list.add("學生"+i); CustomerEntity customerEntity=new CustomerEntity(); customerEntity.setName("學生"+i); customerEntityList.add(customerEntity); } //1.jdbc long startTime=System.currentTimeMillis(); //獲取開始時間 service.jdbc(list); long endTime=System.currentTimeMillis(); //獲取結束時間 System.out.println("jdbc程序運行時間： "+(endTime-startTime)+"ms"); //2.jpa-em long startTime1=System.currentTimeMillis(); //獲取開始時間 service.saveBatch(customerEntityList); long endTime1=System.currentTimeMillis(); //獲取結束時間 System.out.println("JPA-EM程序運行時間： "+(endTime1-startTime1)+"ms"); //3.jpa-循環 long startTime2=System.currentTimeMillis(); //獲取開始時間 for(int i=0;i<customerEntityList.size();i++){ repository.save(customerEntityList.get(i)); } long endTime2=System.currentTimeMillis(); //獲取結束時間 System.out.println("JPA-循環程序運行時間： "+(endTime2-startTime2)+"ms"); //4.jpa-集合 long startTime3=System.currentTimeMillis(); //獲取開始時間 repository.save(customerEntityList); long endTime3=System.currentTimeMillis(); //獲取結束時間 System.out.println("JPA-集合程序運行時間： "+(endTime3-startTime3)+"ms"); }}
實驗結果
jdbc程序運行時間： 878msJPA-EM程序運行時間： 2018msJPA-循環程序運行時間： 21915msJPA-集合程序運行時間： 2373ms
結論就是如果追求極致的性能（批量操作速度），優選JDBC。EM和JPA直接操作集合沒有太大的性能區別，這對於新接觸Spring JPA（比如我）的人來說，不比糾結有時候沒法注入EM，直接使用JPA操作集合即可。
JPA的循環造作相當於對單條insert重復了10000遍，自然最慢，也不推薦了。
如下是JPA操作集合的代碼，可以看出起始內部也是用的em，所以可以放心大膽的用了。
@Transactional public <S extends T> List<S> save(Iterable<S> entities) { List<S> result = new ArrayList<S>(); if (entities == null) { return result; } for (S entity : entities) { result.add(save(entity)); } return result; }/* * (non-Javadoc) * @see org.springframework.data.repository.CrudRepository#save(java.lang.Object) */ @Transactional public <S extends T> S save(S entity) { if (entityInformation.isNew(entity)) { em.persist(entity); return entity; } else { return em.merge(entity); } }