集成spring的hibernate懒加载

package com.test.service.impl; import static org.junit.Assert.*; import java.util.List; import javax.annotation.Resource; import org.junit.Before; import org.junit.Test; import org.junit.runner.RunWith; import org.springframework.test.context.ContextConfiguration; import org.springframework.test.context.junit4.SpringJUnit4ClassRunner; import org.springframework.test.context.support.AnnotationConfigContextLoader; import com.test.config.AppConfig; import com.test.domain.Department; import com.test.domain.User; import com.test.service.DepartmentService; import com.test.service.UserService; @RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration(loader=AnnotationConfigContextLoader.class,classes={AppConfig.class}) public class UserServiceImplTest { @Resource(name="userServiceImpl") private UserService userService; @Resource(name="departmentServiceImpl") private DepartmentService departmentService; @Before public void setUp(){ userService.updateByJpql("delete from User"); departmentService.updateByJpql("delete from Department"); } @Test public void testGetCount() { //新建一个用户,并且设置这个用户是develop部门的. User user=new User(); user.setUsername("username"); userService.persist(user); assertEquals(1, (long)userService.getCount()); } @Test public void testSave() { //新建一个develop部门 Department department=new Department(); department.setName("develop"); departmentService.persist(department); //新建一个用户,并且设置这个用户是develop部门的. User user=new User(); user.setUsername("username"); //通过id去查找develop部门出来 //(这个例子也表明:持久化到数据库后,表的主键值也和这个对象的字段进行了映射 //,即主键的自增值也这样拿到了,但得到这个值没有输出select语名,不明!) Department develop=departmentService.findById(department.getId()); user.setDepartment(develop); userService.persist(user); } @Test public void testUpdate() { Department department=new Department(); department.setName("develop"); departmentService.persist(department); User user=new User(); user.setUsername("username"); Department develop=departmentService.findById(department.getId()); user.setDepartment(develop); userService.persist(user); //-----------以上是保存,以下是更新----------------- //新增一个market部门 Department market=new Department(); market.setName("market"); departmentService.persist(market); //找到这个用户 user=userService.findById(user.getId()); //找到market部门,并将这个用户的部门设为market部门 user.setDepartment(departmentService.findById(market.getId())); //更新用户信息 userService.merge(user); } @Test public void testRemove() { //新建一个用户 User user=new User(); user.setUsername("username"); userService.persist(user); userService.remove(user.getId()); assertEquals(0, userService.findAll().size()); } @Test public void testFindById() { //新建一个用户 User user=new User(); user.setUsername("username"); userService.persist(user); //通过id去查找出来 User userFinded=userService.findById(user.getId()); assertEquals(user.getId(), userFinded.getId()); } @Test public void testFindAll() { //新建两个用户 User user=new User(); user.setUsername("username1"); userService.persist(user); user=new User(); user.setUsername("username2"); userService.persist(user); assertEquals(2, userService.findAll().size()); } @Test public void testFindByJpql() { //新建两个用户 User user=new User(); user.setUsername("username1"); userService.persist(user); user=new User(); user.setUsername("username2"); userService.persist(user); //jpql很不好吧,这里的select u不要写u.*哦... 查询的是对象!!!必须要把所有字段都查出来. //但可以使用createNativeQuery,这样就可以写本地的sql了. assertEquals(1, userService.findByJpql("select u from User u where u.username=?", 0, 10,"username1").size()); } @Test public void testUpdateByJpql() { //新建一个用户,并且设置这个用户是develop部门的. User user=new User(); user.setUsername("username1"); userService.persist(user); assertEquals(1, userService.updateByJpql("update User u set u.username=?","username2")); } @Test public void testFindAllWithoutDepartment() { //新建两个用户 User user=new User(); user.setUsername("username1"); Department department=new Department(); department.setName("department1"); departmentService.persist(department); user.setDepartment(departmentService.findById(department.getId())); userService.persist(user); user=new User(); user.setUsername("username2"); userService.persist(user); List<User> list=userService.findByJpql("select u from User u", 0, 10); for (User u : list) { System.out.println(u.getUsername()); //没有加载关联对象的信息,严禁使用关联对象的get方法,用了你就等着抛no session异常吧.也不要指望在这里加载关联对象的信息. //请在服务层另起方法,使用@Transactional /* Department d=u.getDepartment(); if(d!=null){ System.out.println(d.getName()); } */ } } @Test public void testFindAllWithDepartment() { //新建两个用户 User user=new User(); user.setUsername("username1"); Department department=new Department(); department.setName("department1"); departmentService.persist(department); user.setDepartment(departmentService.findById(department.getId())); userService.persist(user); user=new User(); user.setUsername("username2"); userService.persist(user); //默认的懒加载是不能加载用户的部门信息,去get必然出错.就因为查一般用户信息和查用户部门信息是多个sql语句. //所以有可能出现查一般用户信息,spring就关闭了session,而再没有开新的session. //重新写了findAllWithDepartment方法就是为了查一般用户信息和查用户部门信息在同一个事务(session). //所以就不会出现关闭session或session没初始化的异常了 List<User> list=userService.findAllWithDepartment(); for (User u : list) { //System.out.println(u.getUsername()); Department d=u.getDepartment(); if(d!=null){ System.out.println(d.getName()); } } } }