SpringDataJpa整理_无法解析的成员访问表达式[ifoperator]-优快云博客

本文介绍了SpringDataJpa的基础知识，包括JPA规范、SpringDataJpa与Hibernate的关系，以及通过步骤演示如何搭建一个基础的SpringDataJpa Demo，涉及配置文件、对象映射、Repository接口和各种测试类。

首先什么是JPA？

JPA是一种ORM框架的规范

什么是SpringDataJpa？

其是Spring封装了JPA的规范，提供了在Repository层（接口层）的实现

Hibernate与SpringDataJpa的关系？

Hibernate是SpringDataJpa的服务提供者，最终SpringDataJpa调用服务提供者完成对数据库持久化的操作，服务提供者可以替换成其他

废话不多说，开始基础Demo的搭建

第一步，使用idea，新建一个maven工程，导入依赖，Pom.xml如下

    <properties>
        <spring.version>5.0.2.RELEASE</spring.version>
        <hibernate.version>5.0.7.Final</hibernate.version>
        <slf4j.version>1.6.6</slf4j.version>
        <log4j.version>1.2.12</log4j.version>
        <c3p0.version>0.9.1.2</c3p0.version>
        <mysql.version>5.1.6</mysql.version>
    </properties>
    <dependencies>
        <!-- junit鍗曞厓娴嬭瘯 -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>

        <!-- spring beg -->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.6.8</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <!-- spring瀵筼rm妗嗘灦鐨勬敮鎸佸寘-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <!-- spring end -->

        <!-- hibernate beg -->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>${hibernate.version}</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
            <version>${hibernate.version}</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-validator</artifactId>
            <version>5.2.1.Final</version>
        </dependency>
        <!-- hibernate end -->

        <!-- c3p0 beg -->
        <dependency>
            <groupId>c3p0</groupId>
            <artifactId>c3p0</artifactId>
            <version>${c3p0.version}</version>
        </dependency>
        <!-- c3p0 end -->

        <!-- log end -->
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>${log4j.version}</version>
        </dependency>

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>${slf4j.version}</version>
        </dependency>

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>${slf4j.version}</version>
        </dependency>
        <!-- log end -->


        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>${mysql.version}</version>
        </dependency>

        <!-- spring data jpa -->
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-jpa</artifactId>
            <version>1.9.0.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <!-- el beg spring data jpa -->
        <dependency>
            <groupId>javax.el</groupId>
            <artifactId>javax.el-api</artifactId>
            <version>2.2.4</version>
        </dependency>

        <dependency>
            <groupId>org.glassfish.web</groupId>
            <artifactId>javax.el</artifactId>
            <version>2.2.4</version>
        </dependency>
        <!-- el end -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.16.22</version>
        </dependency>
    </dependencies>

第二步，配置spring的核心配置文件applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:jpa="http://www.springframework.org/schema/data/jpa" xmlns:task="http://www.springframework.org/schema/task"
       xsi:schemaLocation="
		http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
		http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd
		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
		http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc.xsd
		http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd
		http://www.springframework.org/schema/data/jpa
		http://www.springframework.org/schema/data/jpa/spring-jpa.xsd">

    <!--1,配置数据库连接池-->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="com.mysql.jdbc.Driver" />
        <property name="jdbcUrl" value="jdbc:mysql://10.X.X.5:3306/ihrm?characterEncoding=UTF-8" />
        <property name="user" value="root" />
        <property name="password" value="root" />
    </bean>

    <!--配置entityManagerFactory-->
    <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="dataSource" ref="dataSource"></property>
        <property name="packagesToScan" value="com.bdcloud.entity"></property>
        <property name="persistenceProvider">
            <bean class="org.hibernate.jpa.HibernatePersistenceProvider"></bean>
        </property>
        <!--jpa的供应商适配器-->
        <property name="jpaVendorAdapter">
            <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
                <property name="generateDdl" value="false" />
                <property name="database" value="MYSQL" />
                <property name="databasePlatform" value="org.hibernate.dialect.MySQLDialect" />
                <property name="showSql" value="true" />
            </bean>
        </property>
        <property name="jpaDialect">
            <bean class="org.springframework.orm.jpa.vendor.HibernateJpaDialect"></bean>
        </property>
    </bean>

    <!--事务管理器-->
    <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
        <property name="entityManagerFactory" ref="entityManagerFactory"></property>
    </bean>

    <!--整合springdata jpa-->
    <jpa:repositories base-package="com.bdcloud.dao" transaction-manager-ref="transactionManager" entity-manager-factory-ref="entityManagerFactory"></jpa:repositories>

    <!--配置扫描包-->
    <context:component-scan base-package="com.bdcloud"></context:component-scan>
</beans>

第三步，配置对象与表的映射

package com.bdcloud.entity;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.ToString;

import javax.persistence.*;

/***
 * 作者类
 */
@Entity
@Table(name = "t_author")
@Data
@ToString
@NoArgsConstructor
@AllArgsConstructor
public class Author {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;

    private String name;

//    @Column(insertable=false,updatable=false)
//    private int b_id;

    @ManyToOne(targetEntity = Book.class,cascade = CascadeType.ALL)
    @JoinColumn(name = "b_id",referencedColumnName = "id")
    private Book book;

}

--------------------------
package com.bdcloud.entity;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.ToString;
import org.springframework.beans.factory.annotation.Autowired;

import javax.persistence.*;
import java.io.Serializable;
import java.util.HashSet;
import java.util.Set;

/***
 * 图书类，用于验证一对多的关系映射，一本书对应多个作者
 */
@Entity
@Table(name = "t_book")
@Data
@ToString
@NoArgsConstructor
@AllArgsConstructor
public class Book implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;

    private String name;

    private String author;

    private double price;

    @OneToMany(targetEntity = Author.class)
    @JoinColumn(name = "b_id",referencedColumnName = "id")
    private Set<Author> authors = new HashSet<Author>(0);

}

-------------------------
package com.bdcloud.entity;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.ToString;

import javax.jws.soap.SOAPBinding;
import javax.persistence.*;
import java.util.HashSet;
import java.util.Set;

/***
 * 角色类 用于映射用户-角色多对多的关系
 */
@Entity
@Table(name = "t_roles")
@Data
@ToString
@NoArgsConstructor
@AllArgsConstructor
public class Role {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "role_id")
    private int roleId;

    private String name;

    //Cascade：用于配置级联操作，谁配置代表该对象维护映射关系
    @ManyToMany(cascade = CascadeType.ALL)
    /***
     * joinTable ：用于配置中间表情况
     * joinColumns 配置该对象与中间表的映射关系，name字段配置建立关系时本表的关联值，referencedColumnName为配置中间表中对应的值
     * inverseJoinColumns 配置另一个关联对象与中间表的映射关系
     */
    @JoinTable(name = "user_role_rel",joinColumns = {@JoinColumn(name = "role_id",referencedColumnName = "role_id")},inverseJoinColumns = {@JoinColumn(name = "user_id",referencedColumnName = "user_id")})
    private Set<User> users = new HashSet<User>(0);

}

---------------------------------
package com.bdcloud.entity;


import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.ToString;

import javax.persistence.*;

/***
 * 用户类
 */
@Entity
@Table(name = "t_user")
@Data
@ToString
@AllArgsConstructor
@NoArgsConstructor
public class User {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "user_id")
    private int userId;

    private String name;

}

第四步，配置Dao层接口

package com.bdcloud.dao;

import com.bdcloud.entity.Author;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.JpaSpecificationExecutor;

/***
 * 作者Dao层
 */
public interface AuthorDao extends JpaRepository<Author,Integer>,JpaSpecificationExecutor<Author> {
}

------------------------------
package com.bdcloud.dao;

import com.bdcloud.entity.Book;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
import org.springframework.data.jpa.repository.Modifying;
import org.springframework.data.jpa.repository.Query;

import java.util.List;

/***
 * 图书Dao接口
 */
public interface BookDao extends JpaRepository<Book,Integer>,JpaSpecificationExecutor<Book> {

    public Book findBookByName(String name);

    @Query(value = "from Book where name = ?1")
    public Book findCustomer(String name);

    @Query(value = "from Book ")
    public List<Book> findAllBooks();

    @Query(value = "update Book set name = ?1 where id = ?2")
    @Modifying
    public void updateBook(String name,int id);


    @Query(value = "select * from t_book",nativeQuery = true)
    public List<Object[]> findBySql();
}

----------------------------
package com.bdcloud.dao;

import com.bdcloud.entity.Role;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.JpaSpecificationExecutor;

/***
 * 角色Dao
 * JpaRepository：该接口封装Jpa基本CURD操作
 * JpaSpecificationExecutor：该接口封装动态查询Specification的jpa操作
 */
public interface RoleDao extends JpaRepository<Role,Integer>,JpaSpecificationExecutor<Role> {
}

第五步，配置Spring的测试类-单表测试

package com.bdcloud;

import com.bdcloud.dao.BookDao;
import com.bdcloud.entity.Book;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath:applicationContext.xml")
public class BookDaoTest {

    @Autowired
    BookDao bookDao;

    @Test
    public void testSave(){
        Book book = new Book();
        book.setName("小可爱");
        book.setAuthor("lixiangfeng");
        book.setPrice(18.69d);
        bookDao.save(book);
    }
}

第五步，配置Spring的测试类-jpql测试

package com.bdcloud;

import com.bdcloud.dao.BookDao;
import com.bdcloud.entity.Book;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.annotation.Rollback;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.transaction.annotation.Transactional;

import java.util.Arrays;
import java.util.List;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath:applicationContext.xml")
public class BookJpqlTest {

    @Autowired
    BookDao bookDao;

    @Test
    public void testFind(){
        Book name = bookDao.findBookByName("小可爱");
//        Book name = bookDao.findCustomer("小可爱");
        System.out.println(name);
        
    }

    @Test
    public void testFindAll(){
        List<Book> allBooks = bookDao.findAllBooks();
        for (Book b:
             allBooks) {
            System.out.println(b);
        }
    }

    @Test
    @Transactional
    @Rollback(value = false)
    public void testUpdate(){
        bookDao.updateBook("哇哈哈",4);
    }

	/*
	** JPQL 测试
	**/
    @Test
    public void findBySql(){
        List<Object[]> bySql = bookDao.findBySql();
        for (Object[] a:
             bySql) {
            System.out.println(Arrays.toString(a));
        }
    }
}

第五步，配置Spring的测试类-动态查询条件测试

package com.bdcloud;

import com.bdcloud.dao.BookDao;
import com.bdcloud.entity.Book;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Pageable;
import org.springframework.data.jpa.domain.Specification;
import org.springframework.test.annotation.Rollback;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.transaction.annotation.Transactional;

import javax.persistence.criteria.*;
import java.util.Arrays;
import java.util.List;


/***
 * spring data jpa 动态查询
 */
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath:applicationContext.xml")
public class BookSpecificationsTest {

    @Autowired
    BookDao bookDao;

    /***
     * 动态查询-模糊查询
     */
    @Test
    public void testFind(){

        Specification<Book> specification = new Specification<Book>() {
            public Predicate toPredicate(Root<Book> root, CriteriaQuery<?> criteriaQuery, CriteriaBuilder criteriaBuilder) {
                return criteriaBuilder.like(root.<String>get("name").as(String.class),"小可爱%");
            }
        };

        List<Book> all = bookDao.findAll(specification);
        for (Book b:
             all) {
            System.out.println(b);
        }
    }

    /***
     * 测试动态查询
     */
    @Test
    public void testFindOne(){
        Specification<Book> sp = new Specification<Book>() {
            public Predicate toPredicate(Root<Book> root, CriteriaQuery<?> criteriaQuery, CriteriaBuilder criteriaBuilder) {
                Path<Object> name = root.get("name");
                Predicate predicate = criteriaBuilder.equal(name, "小可爱");
                return predicate;
            }
        };

        Book one = bookDao.findOne(sp);
        System.out.println(one);
    }

    /***
     * 使用动态查询完成分页
     */
    @Test
    public void testPageAble(){
        Pageable pageable = new PageRequest(0,2);
        Page<Book> all = bookDao.findAll(null, pageable);
        List<Book> content = all.getContent();
        for (Book b:
             content) {
            System.out.println(b);
        }
    }

}

第五步，配置Spring的测试类-多表映射测试查询

package com.bdcloud;

import com.bdcloud.dao.AuthorDao;
import com.bdcloud.dao.BookDao;
import com.bdcloud.entity.Author;
import com.bdcloud.entity.Book;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Pageable;
import org.springframework.data.jpa.domain.Specification;
import org.springframework.test.annotation.Rollback;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.transaction.annotation.Transactional;

import javax.persistence.criteria.*;
import java.util.List;


/***
 * spring data jpa 动态查询
 */
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath:applicationContext.xml")
public class BookMoreTableTest {

    @Autowired
    BookDao bookDao;

    @Autowired
    AuthorDao authorDao;


    /***
     * 一对多插入
     */
    @Test
    @Transactional
    @Rollback(value = false)
    public void testFind(){

        Book book = new Book();
        book.setName("钢铁是如何炼成的3");

        Author author = new Author();
        author.setName("契科夫斯基3");

        author.setBook(book);

        bookDao.save(book);
        authorDao.save(author);
    }

    /***
     * 测试级联操作
     *
     * CascadeType.ALL		包含所有
     * CascadeType.MERGE	级联更新
     * CascadeType.PERSIST	级联保存
     * CascadeType.REMOVE	级联删除：
     */
    @Test
    @Transactional
    @Rollback(value = false)
    public void testCasde(){

        Book book = new Book();
        book.setName("钢铁是如何炼成的5");

        Author author = new Author();
        author.setName("契科夫斯基5");

        author.setBook(book);

        authorDao.save(author);
    }
}

第五步，配置Spring的测试类-配置Many-to-Many

package com.bdcloud;

import com.bdcloud.dao.BookDao;
import com.bdcloud.dao.RoleDao;
import com.bdcloud.entity.Book;
import com.bdcloud.entity.Role;
import com.bdcloud.entity.User;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Pageable;
import org.springframework.data.jpa.domain.Specification;
import org.springframework.test.annotation.Rollback;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.transaction.annotation.Transactional;

import javax.persistence.criteria.*;
import java.util.List;


/***
 * spring data jpa 动态查询
 */
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath:applicationContext.xml")
public class UserAndRoleTest {

    @Autowired
    RoleDao roleDao;

    /***
     * 测试多对多
     */
    @Test
    @Transactional
    @Rollback(value = false)
    public void testFind(){

        User user = new User();
        user.setName("李项");

        Role role = new Role();
        role.setName("java工程师");

        role.getUsers().add(user);

        roleDao.save(role);
    }


}