Struts2 + Json Serializing Items

Question

I have the following classes:

public class Student { private Long id ; private String firstName; private String lastName; private Set<Enrollment> enroll = new HashSet<Enrollment>(); //Setters and getters } public class Enrollment { private Student student; private Course course; Long enrollId; //Setters and Getters } 

I have a Struts2 controller, and I would like to return a Serialized instance of the Student class.

 @ParentPackage("json-default") public class JsonAction extends ActionSupport{ private Student student; @Autowired DbService dbService; public String populate(){ return "populate"; } @Action(value="/getJson", results = { @Result(name="success", type="json")}) public String test(){ student = dbService.getSudent(new Long(1)); return "success"; } @JSON(name="student") public Student getStudent() { return student; } public void setStudent(Student student) { this.student = student; } } 

It returns me a serializable student object with all subclasses, but I would like to have only a student object without a hashset return. How can I tell Struts to serialize only an object? I have Lazy enabled, and hashset returns as a proxy class.

Answer 1

See the answer here for usage of include and exclude properties. I do not think that this example explicitly shows the exception of nested objects, however I used it for this purpose. If you still have problems, I will post a regular expression that will demonstrate this.

Problem with Json plugin in Struts 2

Edit : The following is an example of using excluded properties in an annotation that blocks serialization of a nested element:

 @ParentPackage("json-default") @Result(type = "json", params = { "excludeProperties", "^inventoryHistory\\[\\d+\\]\\.intrnmst, selectedTransactionNames, transactionNames" }) public class InventoryHistoryAction extends ActionSupport { ... 

inventoryHistory is of the JPA object type InventoryHistory object, intrnmst refers to another table, but due to lazy loading, if it was serialized, it will throw an exception when the JSON action is serialized for this reason, an exception parameter was added to exclude this parameter.

note that

 \\ 

is required for each \ character, so a single \ will only be used in xml, where two are required due to escaping for proper string handling.

Answer 2

  @Controller @Results({ @Result(name="json",type="json" , params={"root","outDataMap","excludeNullProperties","true" ,"excludeProperties","^ret\\[\\d+\\]\\.city\\.province,^ret\\[\\d+\\]\\.enterprise\\.userinfos","enableGZIP","true" }) }) public class UserinfoAction extends BaseAction { @Action(value="login") public String login(){ if(jsonQueryParam!=null && jsonQueryParam.length()>0) { user = JsonMapper.fromJson(jsonQueryParam, TUserinfo.class); } Assert.notNull(user); //RESULT="ret" addOutJsonData: put List<TUserinfo> into outDataMap with key RESULT for struts2 JSONResult addOutJsonData(RESULT, service.login(user)); return JSON; } public class TUserinfo implements java.io.Serializable { private static final long serialVersionUID = 1L; private String userid; private String username; private String userpwd; private TEnterpriseinfo enterprise; private String telphone; private TCity city; ...... } public class TEnterpriseinfo implements java.io.Serializable { private String enterpriseid; private String enterprisename; private Set<TUserinfo> userinfos = new HashSet<TUserinfo>(0); .......} 

before setting the excludeProperties property, the result will be lower:

  {"ret":[ { "city":{"cityename":"tianjin","cityid":"12","cityname":"天津" ,"province": {"provinceename":"tianjing","provinceid":"02","provincename":"天津"} } ,"createddate":"2014-01-07T11:13:58" ,"enterprise":{"createddate":"2014-01-07T08:38:00","enterpriseid":"402880a5436a227501436a2277140000","enterprisename":"测试企业2","enterprisestate":0 ,"userinfos":[null,{"city":{"cityename":"beijing","cityid":"11","cityname":"北京","province":{"provinceename":"beijing","provinceid":"01","provincename":"北京市"} },"comments":"ceshi","createddate":"2004-05-07T21:23:44","enterprise":null,"lastlogindate":"2014-01-08T08:50:34","logincount":11,"telphone":"2","userid":"402880a5436a215101436a2156e10000","username":"0.5833032879881197","userpwd":"12","userstate":1,"usertype":0}] } ,"lastlogindate":"2014-01-08T10:32:43","logincount":0,"telphone":"2","userid":"402880a5436ab13701436ab1b74a0000","username":"testUser","userpwd":"333","userstate":1,"usertype":0}] } 

after setting the excludeProperties property, there are no provincial nodes and userinfos, the result is below:

 {"ret": [{ "city":{"cityename":"tianjin","cityid":"12","cityname":"天津"} ,"createddate":"2014-01-07T11:13:58" ,"enterprise":{"createddate":"2014-01-07T08:38:00","enterpriseid":"402880a5436a227501436a2277140000","enterprisename":"测试企业2","enterprisestate":0} ,"lastlogindate":"2014-01-08T11:05:32","logincount":0,"telphone":"2","userid":"402880a5436ab13701436ab1b74a0000","username":"testUser","userpwd":"333","userstate":1,"usertype":0 }] }