SpringBoot2 JPA解决懒加载异常的问题

jpa解决懒加载异常

在我上一遍文章上进行行修改，springboot2 实现jpa分页和排序分页

实体类上改：

@entity
@table(name = "employee")
@jsonignoreproperties(value={"hibernatelazyinitializer", "department"})
public class employee {
 @id
 @generatedvalue(strategy = generationtype.identity)
 private integer empid;
 private string lastname;
 private string email;
 @temporal(temporaltype.date)
 private date birth;
 @temporal(temporaltype.timestamp)
 private date createtime;
 @manytoone(fetch = fetchtype.lazy)
 @joincolumn(name = "dept_id")
 private department department;
 public integer getempid() {
  return empid;
 }
 public void setempid(integer empid) {
  this.empid = empid;
 }
 public string getlastname() {
  return lastname;
 }
 public void setlastname(string lastname) {
  this.lastname = lastname;
 }
 public string getemail() {
  return email;
 }
 public void setemail(string email) {
  this.email = email;
 }
 public date getbirth() {
  return birth;
 }
 public void setbirth(date birth) {
  this.birth = birth;
 }
 public date getcreatetime() {
  return createtime;
 }
 public void setcreatetime(date createtime) {
  this.createtime = createtime;
 }
 public department getdepartment() {
  return department;
 }
 public void setdepartment(department department) {
  this.department = department;
 }
}

控制器验证

import java.util.iterator;
@restcontroller
public class employeecontroller {
 @autowired
 private employeeservice employeeservice;
 @getmapping("/emp")
 public page<employee> showpage(@requestparam(value = "page") integer page, @requestparam(value = "size") integer size){
  system.out.println("分页： page:"+page+"; size:"+size);
  return employeeservice.getpage(page, size);
 }
 @getmapping("/emp_sort")
 public page<employee> showsortpage(@requestparam(value = "page") integer page, @requestparam(value = "size") integer size){
  system.out.println("排序分页： page:"+page+"; size:"+size);
  page<employee> list = employeeservice.getpagesort(page, size);
  iterator<employee> it=list.iterator();
  while(it.hasnext()){
   system.out.println("value:"+(it.next()).getdepartment().getdeptname());
  }
  return list;
 }
}

我大概实现了一下，具体的如果大佬找到更好的方法或者发现我的方法是错的，希望各位大佬提醒一下！感谢！

补充：springboot jpa 使用懒加载时，报异常：session失效

报异常:

could not initialize proxy - no session

1、在方法上加@transactional 注解，失败

2、在application.yml 文件加上jpa.properties.open-in-view: true 失败

3、在resourceserverapplication.java 启动文件中加上：

 @bean
 public openentitymanagerinviewfilter openentitymanagerinviewfilter() {
   return new openentitymanagerinviewfilter();
 }

成功解决~

总结：

要解决no session 问题需要：

配置文件中加jpa.properties.open-in-view: true同时在启动文件中加@bean

以上为个人经验，希望能给大家一个参考，也希望大家多多支持。如有错误或未考虑完全的地方，望不吝赐教。