解决Spring Data JPA延迟加载no session错误
来源:互联网 发布:iris数据集 编辑:程序博客网 时间:2024/05/21 18:32
项目采用spring boot构建,提供restful接口给PHP调用,接口类统一使用@RestController注解
实体关系
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "department_id")private Department department;
@OneToMany(mappedBy = "department", fetch = FetchType.LAZY)private Set<Employee> employees;
单元测试
@Testpublic void testGet() {Department dept = deptService.get(1L);Assert.assertEquals("IT", dept.getName());Set<Employee> employees = dept.getEmployees();Assert.assertEquals(2, employees.size());}
异常信息
org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: com.ai.demo.entity.Department.employees, could not initialize proxy - no Sessionat org.hibernate.collection.internal.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:587)at org.hibernate.collection.internal.AbstractPersistentCollection.withTemporarySessionIfNeeded(AbstractPersistentCollection.java:204)at org.hibernate.collection.internal.AbstractPersistentCollection.readSize(AbstractPersistentCollection.java:148)at org.hibernate.collection.internal.PersistentSet.size(PersistentSet.java:143)at com.ai.demo.service.DepartmentServiceTests.testGet(DepartmentServiceTests.java:37)at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)at java.lang.reflect.Method.invoke(Method.java:498)at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:75)at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:86)at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:84)at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:252)at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94)at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)at org.junit.runners.ParentRunner.run(ParentRunner.java:363)at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:191)at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:678)at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)
1.关闭LazyInitialization, 将fetch设成eager
2.在spring boot的配置文件application.properties添加spring.jpa.open-in-view=true
3.用spring 的OpenSessionInViewFilter
第一种方式显然不好,无法使用到延迟加载的特性,会带来性能问题
后面两种方式只能用在Servlet容器下,而当我们在spring boot环境下运行单元测试的时候是无法启用OpenSessionInViewFilter的
其实要解决这种情况下的问题也很简单,只需要在单元测试方法@Transactional注解即可解决
@Test@Transactionalpublic void testGet() {Department dept = deptService.get(1L);Assert.assertEquals("IT", dept.getName());Set<Employee> employees = dept.getEmployees();Assert.assertEquals(2, employees.size());}
0 0
- 解决Spring Data JPA延迟加载no session错误
- spring解决延迟加载问题--no session
- 解决spring+springMVC+Hibernate+spring-data-jpa懒加载No session问题
- 解决JPA延迟加载错误问题
- spring jpa 延迟加载
- Spring-data-jpa 集成Hibernate时延迟加载问题
- 使用clone解决hibernate+spring集成中的延迟加载问题及分析(no session or session was closed)
- 使用clone解决hibernate+spring集成中的延迟加载问题及分析(no session or session was closed)
- 延迟加载时发生no session错误的解决办法
- 使用Hibernate.initialize解决no session的延迟加载问题
- 使用Hibernate.initialize解决no session的延迟加载问题
- spring data jpa懒加载session失效:OpenEntityManagerInViewFilter 取代OpenSessionInViewFilter
- 解决spring hibernate,session延迟加载的配置文件
- Hibernate延迟加载 或 no session or session was closed 问题的解决(OpenSessionInViewFilter使用)
- Spring-data-jpa常见错误
- Spring-Data-JPA 错误总结
- 使用spring-data-jpa的时候出现 could not initialize proxy - no Session
- hibernate延迟加载导致no session
- macOS10.12下如何丝滑的使用appium?
- POJ 2996-Help Me with the Game(模拟-描述棋盘中KQRBNP的位置)
- 二分贪心专题B
- Android.mk详解
- 米洛个人修炼术:快速提升能力的简单方法
- 解决Spring Data JPA延迟加载no session错误
- java poi 读取Excel
- Java基本概念-杂记
- 【二叉树】二叉树序列化和反序列化
- Flume入门概念
- mac os x 使用外接摄像头
- Docker部署
- A1083. List Grades (25)
- LeetCode 151. Reverse Words in a String