[appengine-java] Still have java.lang.IllegalArgumentException: Invalid Key PB: no elements. for one to many relation

[jimmy]

Hello

I have the java.lang.IllegalArgumentException: Invalid Key PB: no
elements for the one to many relation

Here is my parent code


package com.info.shareCar.data.entity;

import java.util.List;

import javax.jdo.annotations.IdGeneratorStrategy;
import javax.jdo.annotations.PersistenceCapable;
import javax.jdo.annotations.Persistent;
import javax.jdo.annotations.PrimaryKey;

import com.google.appengine.api.datastore.Key;

@PersistenceCapable
public class University {

        @PrimaryKey
    @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
    private Key key;

        @Persistent
        private String university;

        @Persistent
        private List<GroupInfo> groupList;

        @Persistent
        private String lowCaseUniversity;

        public void setUniversity(String mUniversity) {
                this.university = mUniversity;
        }

        public String getUniversity() {
                return university;
        }

        public void setLowCaseUniversity(String lowCaseUniversity) {
                this.lowCaseUniversity = lowCaseUniversity;
        }

        public String getLowCaseUniversity() {
                return lowCaseUniversity;
        }

        public void setGroupList(List<GroupInfo> groupList) {
                this.groupList = groupList;
        }

        public List<GroupInfo> getGroupList() {
                return groupList;
        }

        public void setKey(Key key) {
                this.key = key;
        }

        public Key getKey() {
                return key;
        }

}

here is my child code


package com.info.shareCar.data.entity;

import javax.jdo.annotations.IdGeneratorStrategy;
import javax.jdo.annotations.PersistenceCapable;
import javax.jdo.annotations.Persistent;
import javax.jdo.annotations.PrimaryKey;

import com.google.appengine.api.datastore.Key;

@PersistenceCapable
public class GroupInfo {
        @PrimaryKey
    @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
    private Key key;

        @Persistent
        private String groupName;

        @Persistent
        private String lowCaseGroupName;


        public void setKey(Key key) {
                this.key = key;
        }

        public Key getKey() {
                return key;
        }

        public void setGroupName(String groupName) {
                this.groupName = groupName;
        }

        public String getGroupName() {
                return groupName;
        }

        public void setLowCaseGroupName(String lowCaseGroupName) {
                this.lowCaseGroupName = lowCaseGroupName;
        }

        public String getLowCaseGroupName() {
                return lowCaseGroupName;
        }


}

here is the update method

public boolean update(RequestContext aContext) {
                Query query = mPm.newQuery(University.class,"lowCaseUniversity 
==
Uname");
                query.declareParameters("String Uname");
                Iterator<University> universityIter =((List<University>)
query.execute(aContext.getUniversity().toLowerCase())).iterator();
                while(universityIter.hasNext())
                {
                        University university = universityIter.next();
                        Iterator<GroupInfo> groupIter =
university.getGroupList().iterator();
                        while(groupIter.hasNext())
                        {
        
if(groupIter.next().getLowCaseGroupName().equals(aContext.getGroup().toLowerCase()))
                                {
                                        return false;
                                }
                        }
                        GroupInfo group = new GroupInfo();
        
group.setKey(KeyFactory.stringToKey(aContext.getUniversity().toLowerCase()
+ aContext.getGroup().toLowerCase()));
                        group.setGroupName(aContext.getGroup());
                        
group.setLowCaseGroupName(aContext.getGroup().toLowerCase());
                        university.getGroupList().add(group);
                        mPm.makePersistent(university);
                }
                return true;
}

both of their primary key are Key object. Thank you

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