SpringData入门案列

springData基础

目录

1.创建项目，导入依赖：pom.xml

2.配置Spring核心配置文件：ApplicationContext.xml

3.创建实体：

4.Repository接口

5.Repository接口中方法定义约定

6.@Query注解自定义SQL

7.CrudRepository接口

8.PagingAndSortingRepository接口

---

1.创建项目，导入依赖：pom.xml

	4.0.0

	SpringDataJPA_Demo01
	SpringDataJPA_Demo01
	0.0.1-SNAPSHOT
	jar

	SpringDataJPA_Demo01
	http://maven.apache.org

	
		UTF-8
	

	
		
		
			junit
			junit
			4.10
			test
		
		
		
			mysql
			mysql-connector-java
			5.1.38
		
		
		
			org.springframework
			spring-context
			4.3.5.RELEASE
		
		
		
			org.springframework
			spring-jdbc
			4.3.5.RELEASE
		
		
		
			org.springframework.data
			spring-data-jpa
			1.8.0.RELEASE
		
		
			org.hibernate
			hibernate-entitymanager
			4.3.6.Final
		
	

2.配置Spring核心配置文件：ApplicationContext.xml

	
	
		
		
		
		
	

	
	
		
		
		
			
		
		
		
		
		
			
				
				org.hibernate.cfg.ImprovedNamingStrategy
				
				org.hibernate.dialect.MySQL5InnoDBDialect
				
				true
				
				true
				
				update
			
		
	

	
	
		
	

	
	

	
	

	
	

在mysql建表 

create database demodb;

use demodb;

 

3.创建实体：

添加注解——

@Entity   声明当前bean映射称为一个Entity实体，Entity实体会对应数据库中的表

 @Id      当前属性是当前实体的Id属性

@GeneratedValue   指定该属性自增

@Column  指定列的名字和长度

package com.lj.domain;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;

@Entity(name="stu")
public class Student {
	private int id;
	private String name;
	private int age;
	
	public Student() {
	}

	public Student(int id, String name, int age) {
		this.id = id;
		this.name = name;
		this.age = age;
	}

	@Id
	@GeneratedValue
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	@Column(name="username",length=20)
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	@Override
	public String toString() {
		return "Student [id=" + id + ", name=" + name + ", age=" + age + "]";
	}
}

4.Repository接口

SpringDataJPA的核心接口是Repository，可以通过自定义接口继承该接口，在其中定义方法实现对实体的管理

可以在该接口的实现类中定义方法来实现对实体的管理，这些方法的名称是基于约定而来的，按照约定定义方法，SpringData将会按照约定操作表。

package com.lj.repository;

import java.util.List;

import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.Repository;

import com.lj.domain.Student;

public interface StudentRepository extends Repository {
    //	可以通过将nativeQuery属性设置为true来表明之后的value中是原生的sql语句
	@Query(nativeQuery=true,value="select * from stu where id between ?1 and ?2")
	public List queryBetween2(int begin,int end);

	//可以通过?n的方式在JPA Query语句中引用方法中的参数
	@Query("select o from stu o where o.id between ?1 and ?2")
	public List queryBetween(int begin,int end);

	//此处注意，写的不是sql，而是JPA Query语句，操作的不是数据库中的表，而是实体，所以不要写表名，而是写实体名称
	@Query("select count(1) from stu o ")
	public Integer getCount();

	public List findByAgeBetweenAndNameLikeAndIdGreaterThan(int begin, int end, String nameLike, int id);

	public List findByAgeBetween(int begin, int end);

	public Student findByNameAndAge(String name, int age);

	public Student findByName(String name);

	public void exists(Integer id);

	public void delete(Integer id);

	public void save(Student student);

}

 

进行测试看：

package com.lj.test;

import java.util.List;

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.lj.domain.Student;
import com.lj.repository.StudentRepository;

public class Test01 {
	
	/**
	 * 查询
	 */
	@Test
	public void test11(){
		//1.初始化Spring容器
		ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
		//2.获取StudentRepository
		StudentRepository repository = context.getBean(StudentRepository.class);
		//3.调用方法
		List list = repository.queryBetween2(2, 4);
		System.out.println(list);
	}
	/**
	 * 查询
	 */
	@Test
	public void test10(){
		//1.初始化Spring容器
		ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
		//2.获取StudentRepository
		StudentRepository repository = context.getBean(StudentRepository.class);
		//3.调用方法
		List list = repository.queryBetween(2, 4);
		System.out.println(list);
	}
	@Test
	public void test09(){
		//1.初始化Spring容器
		ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
		//2.获取StudentRepository
		StudentRepository repository = context.getBean(StudentRepository.class);
		//3.调用方法
		int count = repository.getCount();
		System.out.println(count);
	}
	
	/**
	 * 查询
	 */
	@Test
	public void test08(){
		//1.初始化Spring容器
		ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
		//2.获取StudentRepository
		StudentRepository repository = context.getBean(StudentRepository.class);
		//3.调用方法
		List list = repository.findByAgeBetweenAndNameLikeAndIdGreaterThan(20, 30, "z%", 3);
		System.out.println(list);
	}
	
	/**
	 * 查询
	 */
	@Test
	public void test07(){
		//1.初始化Spring容器
		ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
		//2.获取StudentRepository
		StudentRepository repository = context.getBean(StudentRepository.class);
		//3.调用方法
		List list = repository.findByAgeBetween(20, 30);
		System.out.println(list);
	}
	
	/**
	 * 查询
	 */
	@Test
	public void test06(){
		//1.初始化Spring容器
		ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
		//2.获取StudentRepository
		StudentRepository repository = context.getBean(StudentRepository.class);
		//3.调用方法
		Student stu = repository.findByNameAndAge("zl",33);
		System.out.println(stu);
	}
	
	/**
	 * 查询
	 */
	@Test
	public void test05(){
		//1.初始化Spring容器
		ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
		//2.获取StudentRepository
		StudentRepository repository = context.getBean(StudentRepository.class);
		//3.调用方法
		Student stu = repository.findByName("ww");
		System.out.println(stu);
	}
	
	/**
	 * 删除
	 */
	@Test
	public void test04(){
		//1.初始化Spring容器
		ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
		//2.获取StudentRepository
		StudentRepository repository = context.getBean(StudentRepository.class);
		//3.调用方法
		repository.delete(1);
	}
	
	/**
	 * 修改
	 */
	@Test
	public void test03(){
		//1.初始化Spring容器
		ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
		//2.获取StudentRepository
		StudentRepository repository = context.getBean(StudentRepository.class);
		//3.调用方法
		Student stu = new Student(1,"zsf",29);
		repository.save(stu);
	}
	
	/**
	 * 新增
	 */
	@Test
	public void test02(){
		//1.初始化Spring容器
		ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
		//2.获取StudentRepository
		StudentRepository repository = context.getBean(StudentRepository.class);
		//3.调用方法
		Student stu = new Student(0,"zs",19);
		repository.save(stu);
	}
	
	/**
	 * 初始化容器时创建表
	 */
	@Test
	public void test01(){
		//1.初始化Spring容器
		ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
	}
}

5.Repository接口中方法定义约定

查询操作：查询以findBy开头，后跟查询条件，多个查询条件之间可以通过and或or连接

6.@Query注解自定义SQL

可以在Repository中的方法上使用@Query注解直接声明该方法要执行的操作语句，则此时调用该方法会直接执行指定SQL，而不参照默认方法名对应语句规则。

 

7.CrudRepository接口

自带了增删改查相关方法的Repository接口的子接口

public interface StudentRepository2 extends CrudRepository {

}

8.PagingAndSortingRepository接口

可以附带分页和排序效果的Repository接口的子接口

public interface StudentRepository3 extends PagingAndSortingRepository {

}