我在网上看了一些资料，似乎说跟Hibernate的一些机制有关所导致，但看了一些解决方案都没多大帮助。
[b]异常信息：[/b]
net.sf.json.JSONException: There is a cycle in the hierarchy!
[b]问题概述：[/b]
我希望前台点击某个BUTTON后通过AJAX调用方法查询出所有的教师信息。
List已经得到，但将其进行JSON的转换时有异常抛出。
异常信息为net.sf.json.JSONException: There is a cycle in the hierarchy!
后台持久层采用了Hibernate，实体Bean由MyEclipse根据DB反向生成。
[b]异常代码段：[/b]
就是在 JSONArray jslist = JSONArray.fromObject(list); 这一句出问题
[code="java"]
public class Stu_GetAllTeachers_AJAX extends Action {
private TeachersServiceImpl tsi;
public TeachersServiceImpl getTsi() {[code="java"][/code]
return tsi;
}
public void setTsi(TeachersServiceImpl tsi) {
this.tsi = tsi;
}
public ActionForward execute(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response) throws Exception{
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
List list=new ArrayList();
list=tsi.getAllTeachers();
JSONArray jslist = JSONArray.fromObject(list);
response.setContentType("application/javascript;charset=utf-8");
PrintWriter out = response.getWriter();
out.print(jslist);
return null;
}
}
[/code]
[b]相关代码段:[/b]
Teachers实体BEAN的部分代码
[code="java"]
public class Teachers implements java.io.Serializable {
// Fields
private String id;
private Positions positions;
private String name;
private String sex;
private Date birth;
private String edulevel;
private String discovery;
private String phone;
private String course;
private String pwd;
private Integer flag;
private Set thesises = new HashSet(0);
private Set results = new HashSet(0);
// Constructors
[/code]
把Teachers实体的Hibernate配置文件发一下，不知道有没有用。
[code="java"]
[/code]
[b]问题补充：[/b]
嗯，我发现了，是嵌套了，我的Thesis和Result两个实体BEAN里都定义了Teachers。
可是，我具体要怎么改呢？说具体点好吗？
Thesis&Result
[code="java"]
public class Result implements java.io.Serializable {
// Fields
private String studentId;
private Thesis thesis;
private Teachers teachers;
private Students students;
private Byte change;
[/code]
[code="java"]
public class Thesis implements java.io.Serializable {
// Fields
private String id;
private Major major;
private Teachers teachers;
private String title;
private String discovery;
private String doc;
private Integer stuAllownum;
private String description;
private Set results = new HashSet(0);
[/code]
