Error looping through a Set

[ruthlesset]

I am just on my first month still trying to learn SEAM and am having a hard time figuring out this error. I have two tables with the primary key of the table M_Module mapped to the foreign key module_recid of the table M_Function. When I try to loop through the functions of a module I get an error. What am I doing wrong?

MModule.java

package com.demo.model;
// Generated Mar 9, 2011 10:27:42 AM by Hibernate Tools 3.2.4.GA

import java.util.Date;
import java.util.HashSet;
import java.util.Set;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.OneToMany;
import javax.persistence.SequenceGenerator;
import javax.persistence.Table;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import javax.persistence.Transient;

import org.hibernate.validator.Length;
import org.hibernate.validator.NotNull;


@Entity
@Table(name = "M_MODULE")
@SequenceGenerator(name = "moduleSeq", sequenceName = "M_MODULE_SEQ")
public class MModule implements java.io.Serializable {

        private static final long serialVersionUID = 1L;
        private Integer recid;
        private String name;
    private Set<MFunction> MFunctions = new HashSet<MFunction>(0);

        public MModule() {
        }

        public MModule(Integer recid, String name) {
                this.recid = recid;
                this.name = name;
        }

        public MModule(Integer recid, String name,
                        Set<MFunction> MFunctions) {
                this.recid = recid;
                this.name = name;
                this.MFunctions = MFunctions;
        }

        @Id
        @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "moduleSeq")
        @Column(name = "RECID", unique = true, nullable = false, precision = 5, scale = 0)
        public Integer getRecid() {
                return this.recid;
        }
        public void setRecid(Integer recid) {
                this.recid = recid;
        }

        @Column(name = "NAME", nullable = false, length = 80)
        @NotNull
        @Length(max = 80)
        public String getName() {
                return this.name;
        }

        public void setName(String name) {
                this.name = name;
        }

        @OneToMany(fetch=FetchType.LAZY, mappedBy="MModule")
    public Set<MFunction> getMFunctions() {
        return this.MFunctions;
    }
   
    public void setMFunctions(Set<MFunction> MFunctions) {
        this.MFunctions = MFunctions;
    }

}


--------------------------------------------------------------------------------------------------------------
MModuleHome.java


package com.demo.action;

import java.util.ArrayList;
import java.util.List;

import javax.persistence.EntityManager;

import org.jboss.seam.ScopeType;
import org.jboss.seam.annotations.Factory;
import org.jboss.seam.annotations.In;
import org.jboss.seam.annotations.Name;
import org.jboss.seam.framework.EntityHome;

import com.demo.model.MFunction;
import com.demo.model.MModule;

@Name("mModuleHome")
public class MModuleHome extends EntityHome<MModule> {

        private static final long serialVersionUID = 1L;

        @In private EntityManager entityManager;

        public void setmModuleRecid(Integer id) {
                setId(id);
        }

        public Integer getmModuleRecid() {
                return (Integer) getId();
        }

        @Override
        protected MModule createInstance() {
                MModule mModule = new MModule();
                return mModule;
        }

        public void load() {
                if (isIdDefined()) {
                        wire();
                }
        }

        public void wire() {
                getInstance();
        }

        public boolean isWired() {
                return true;
        }

        public MModule getDefinedInstance() {
                return isIdDefined() ? getInstance() : null;
        }

        public List<MFunction> getMFunctions() {
                return getInstance() == null ? null : new ArrayList<MFunction>(
                                getInstance().getMFunctions());
        }

}



--------------------------------------------------------------------------------------------------------------
MFunction.java


package com.demo.model;
// Generated Mar 9, 2011 10:27:42 AM by Hibernate Tools 3.2.4.GA

import java.util.Date;
import java.util.HashSet;
import java.util.Set;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.OneToMany;
import javax.persistence.SequenceGenerator;
import javax.persistence.Table;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import javax.persistence.Transient;

import org.hibernate.validator.Length;
import org.hibernate.validator.NotNull;

/**
* MModule generated by hbm2java
*/
@Entity
@Table(name = "M_FUNCTION")
@SequenceGenerator(name = "functionSeq", sequenceName = "M_FUNCTION_SEQ")
public class MFunction implements java.io.Serializable {

        private static final long serialVersionUID = 1L;
        private Integer recid;
    private MModule MModule;
        private String name;
        private Set<MContext> MContexts = new HashSet<MContext>(0);

        public MFunction() {
        }

        public MFunction(Integer recid, MModule MModule, String name) {
                this.recid = recid;
        this.MModule = MModule;
                this.name = name;
        }

        public MFunction(Integer recid, MModule MModule, String name,
                        Set<MContext> MContexts) {
                this.recid = recid;
        this.MModule = MModule;
                this.name = name;
                this.MContexts = MContexts;
        }

        @Id
        @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "functionSeq")
        @Column(name = "RECID", unique = true, nullable = false, precision = 5, scale = 0)
        public Integer getRecid() {
                return this.recid;
        }

        public void setRecid(Integer recid) {
                this.recid = recid;
        }

        @ManyToOne(fetch=FetchType.LAZY)
    @JoinColumn(name="MODULE_RECID", nullable=false)
    @NotNull
    public MModule getMModule() {
        return this.MModule;
    }
   
    public void setMModule(MModule MModule) {
        this.MModule = MModule;
    }

        @Column(name = "NAME", nullable = false, length = 50)
        @NotNull
        @Length(max = 50)
        public String getName() {
                return this.name;
        }

        public void setName(String name) {
                this.name = name;
        }

        @OneToMany(fetch = FetchType.LAZY, mappedBy = "MFunction")
        public Set<MContext> getMContexts() {
                return this.MContexts;
        }

        public void setMContexts(Set<MContext> MContexts) {
                this.MContexts = MContexts;
        }

}



--------------------------------------------------------------------------------------------------------------
MFunctionHome.java



package com.demo.action;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;

import javax.persistence.EntityManager;

import org.jboss.seam.Component;
import org.jboss.seam.ScopeType;
import org.jboss.seam.annotations.Factory;
import org.jboss.seam.annotations.In;
import org.jboss.seam.annotations.Logger;
import org.jboss.seam.annotations.Name;
import org.jboss.seam.annotations.Transactional;
import org.jboss.seam.framework.EntityHome;
import org.jboss.seam.log.Log;

import com.demo.model.MContext;
import com.demo.model.MFunction;
import com.demo.model.MModule;

@Name("mFunctionHome")
public class MFunctionHome extends EntityHome<MFunction> {

        private static final long serialVersionUID = 1L;

        @In(create = true)
        MModuleHome mModuleHome;

        @Logger private Log log;

        public void setmFunctionRecid(Integer id) {
                setId(id);
        }

        public Integer getmFunctionRecid() {
                return (Integer) getId();
        }

        @Override
        protected MFunction createInstance() {
                MFunction mFunction = new MFunction();
                return mFunction;
        }

        public void load() {
                if (isIdDefined()) {
                        wire();
                }
        }

        public void wire() {
                getInstance();
                MModule MModule = mModuleHome.getDefinedInstance();
                if (MModule != null) {
                        getInstance().setMModule(MModule);
                }
        }

        public boolean isWired() {
                if (getInstance().getMModule() == null)
                        return false;
                return true;
        }

        public MFunction getDefinedInstance() {
                return isIdDefined() ? getInstance() : null;
        }

        public List<MContext> getMContexts() {
                return getInstance() == null ? null : new ArrayList<MContext>(
                                getInstance().getMContexts());
        }

}



--------------------------------------------------------------------------------------------------------------
modules.xhtml


        <ui:repeat value="#{moduleList}" var="module">
                <h:outputText value="[#{module.name}]" />
                <ui:repeat value="#{module.MFunctions}" var="function">
                        <h:outputText value=" -- #{function.name} -- " />
                </ui:repeat>
                <h:outputText value="," />
        </ui:repeat>


I get the error

        /modules.xhtml @75,53 value=" -- #{function.name} -- ": The class 'org.hibernate.collection.PersistentSet' does not have the property 'name'.

[ruthlesset]

I missed one factory method that should go under MModuleHome.java

        @SuppressWarnings("unchecked")
        @Factory(value="moduleList",scope=ScopeType.EVENT)
        public List<MModule> getModuleList() {
                return entityManager.createQuery("SELECT mModule FROM MModule mModule ORDER BY mModule.name").getResultList();         
        }

[lvdberg]

Hi,

Use a List (implementation to do the trick), Just put the values from the Set in an ArrayList:

List<YourEntity> list = new ArryList<YourEntity>(yourEntitySet);

... Add the get and set..

and use the list in your view instead of the set. To make it even better, you ould use a unmodifiable List.

Leo

[jseanjensen]

I had the same problem recently and solved it by like this:

<rich:dataList var='user'
     value="#{_parentObject.users.toArray()}">
     <h:outputText value="#{user.displayName}" />
</rich:dataList>

This lets you leave the generated entity as a Set.  I'm not sure if one is preferred over the other but it does work.

[ruthlesset]

Thank you so much for the quick response. Converting the Set to a ArrayList using .toArray() resolved the issue.

[ruthlesset]

Another quick question regarding this:

Let us assume MFunction.java has another property displaySequence (which also exists in the database).

Now when I get the List of MFunction for a given MModule, I want it sorted out by the numeric value of displaySequence. MFunction already implements java.io.Serializable and hence I won't be able to implement Comparable<MFunction>.

What would be the best way to implement this?

[lvdberg]

Hi,

already implements java.io.Serializable and hence I won't be able to implement Comparable<MFunction>.

Your class can implement as many interfaces as needed.

public class MFunction implements Serializable, Comparable<MFunction>
...

Leo

[ruthlesset]

Leo van den Berg wrote on Jun 23, 2011 02:45:


Hi,

already implements java.io.Serializable and hence I won't be able to implement Comparable<MFunction>.

Your class can implement as many interfaces as needed.

public class MFunction implements Serializable, Comparable<MFunction>
...

Leo

Thanks.