从ajax调用时，Controller返回Java.lang.stackoverflow错误。
我的Ajax功能是这样的。
$.ajax({
url: '${pageContext.servletContext.contextPath}/exam/test',
type: 'POST',
data: 'examName='+examName,
success: function(response) {
alert(response);
}
});
控制器
@RequestMapping(value = "/exam/test", method = RequestMethod.POST)
public @ResponseBody List<SchoolExam> examsTest(@ModelAttribute(value = "examName") String examName, BindingResult result, WebRequest webRequest, ModelMap map, Principal principal) {
User loggedUser = userService.getUserByUserName(principal.getName());
***********************
Some code here
***********************
List<SchoolExam> schoolExams = new ArrayList<SchoolExam>();
for (School school : schools) {
if (student) {
Set<Student> students = school.getStudents();
for(Student std : students) {
if (std != null && !std.isEmpty()) {
schoolExams.add(new SchoolExam(std, true));
}
}
}
if (teacher) {
Set<Teacher> teachers = school.getEvents();
for (Teacher tchr : teachers) {
if (loggedUser.equals(tchr.getOwner())) {
schoolExams.add(new SchoolExam(tchr, true));
}
}
}
if (exam) {
Set<Exam> exams = school.getCampaigns();
for (Exam exam1 : exams) {
if (loggedUser.equals(exam1.getOwner())) {
schoolExams.add(new SchoolExam(exam1, true));
}
}
}
}
return schoolExams;
}
SchoolExam
public SchoolExam(Object obj, boolean editable) {
this.editable = editable;
if (obj instanceof Student) {
Student student = (Student) obj;
this.id = student.getId();
this.name = student.getName();
this.type = Constants.Student;
this.obj = student; // <-- This is causing issue here
}
if (obj instanceof Teacher) {
Teacher teacher = (Teacher) obj;
this.id = teacher.getId();
this.name = teacher.getName();
this.type = Constants.Teacher;
this.obj = teacher; // <-- This is causing issue here
}
if (obj instanceof Exam) {
Exam exam = (Exam) obj;
this.id = exam.getId();
this.name = exam.getName();
this.type = Constants.Exam;
this.obj = exam; // <-- This is causing issue here
}
}
问题：
当表单提交时，这工作正常然后我可以通过在jsp中运行foreach循环来使用所有数据但是当我尝试在我的函数中返回列表然后ajax成功工作并且它也返回我的响应
response in ajax
[
{
"id":"2123244",
"name":"UK School",
"type":"exam",
"editable":true,
"obj":
{
"id":"2123244",
"authorizationRequired":false,
"owner":
{
"id":"5676764554",
"company":
{
"id":"55435435345",
"name":"SchoolTest Software",
"enabled":true,
"size":3,
"sector":null,
"phone":"1231231232",
"schoolFees":5000,
"location":"US",
"users":
[
{
"id":"5676764554",
"company": // <-- Start Repeating here
{
"id":"55435435345",
"name":"SchoolTest Software",
"enabled":true,
"size":3,
"sector":null,
"phone":"1231231232",
"schoolFees":5000,
"location":"US",
"users":
[
{
"id":"5676764554",
"company": // <-- Repeating again
{
"id":"55435435345",
"name":"SchoolTest Software",
"enabled":true,
"size":3,
"sector":null,
"phone":"1231231232",
"schoolFees":5000,
"location":"US",
"users":
[
{
"id":"5676764554",
"company":// <-- It keeps repeating it self
但是当我尝试在控制器中打印列表值时，它只打印一个值。
e.g:
for (SchoolExam schoolExam : schoolExams) {
System.out.println("Name: " + schoolExam.getName());
System.out.println("ID: " + schoolExam.getId());
Exam exam = (Exam) schoolExam.getObj();
System.out.println("Exam Name: " + exam.getName());
}
Output:
Name: UK School
ID: 2123244
Exam Name: UK School
注意：
如果我评论obj线，那么一切都适合我。
e.g:
this.obj = student;
this.obj = teacher;
this.obj = exam;
但我需要使用它来获取数据，因为它包含不同表的数据。
请查看this file以获取我在控制台中收到的错误日志。
所以，我做错了导致这个问题，或者我需要用其他任何方法来防止这个问题。
任何建议或链接都会有所帮助。
答案 0 :(得分：0)
根据您的错误日志文件，您的Java类中有一个循环递归。所以杰克逊试图无限地序列化一些物体。
主要问题在于：com.school.model.Company_$$_javassist_8["users"]->org.hibernate.collection.PersistentSet[0]->com.school.model.User["company"]->com.school.model.Company_$$_javassist_8["users"]
您有一个属性users，其中包含一组User，其中包含属性ompany，其中包含Company users个{{1}}。无限循环。