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POjava.lang.NullPointerException selectOneMenu convertor
 

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  1. POjava.lang.NullPointerException selectOneMenu convertor
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    <p>I have a class Specialization</p> <pre><code>public class Specialization implements Serializable { private static final long serialVersionUID = 1L; @Id @Basic(optional = false) @NotNull @Column(name = "id") private Integer id; @Basic(optional = false) @NotNull @Size(min = 1, max = 45) @Column(name = "name") private String name; @OneToMany(cascade = CascadeType.ALL, mappedBy = "specialization") private Collection&lt;Doctor&gt; doctorCollection; </code></pre> <p>In my webpage i have a selectOneMenu</p> <pre><code> &lt;h:selectOneMenu value="#{specializationMB.specialization}" converter="#{specializationConverter}"&gt; &lt;f:selectItems value="#{specializationMB.allSpecializations}" var="specialization" itemLabel="#{specialization.name}" itemValue="#{specialization}" /&gt; &lt;/h:selectOneMenu&gt; </code></pre> <p>GenericDao where is the find method</p> <pre><code>public abstract class GenericDao&lt;T&gt; { @PersistenceContext private EntityManager em; private Class&lt;T&gt; entityClass; public GenericDao(Class&lt;T&gt; entityClass) { this.entityClass = entityClass; } public void create(T entity) { em.persist(entity); } public void delete(T entity) { T toRemoved = em.merge(entity); em.remove(toRemoved); } public T update(T entity) { return em.merge(entity); } public T find(int entityID) { return em.find(entityClass, entityID); } @SuppressWarnings({"unchecked", "rawtypes"}) public List&lt;T&gt; findAll() { CriteriaQuery cq = em.getCriteriaBuilder().createQuery(); cq.select(cq.from(entityClass)); return em.createQuery(cq).getResultList(); } } </code></pre> <p>I create the converter for my class Specialization </p> <pre><code>public class SpecializationConverter implements Converter{ private static SpecializationDao sdao = new SpecializationDao(); @Override public Object getAsObject(FacesContext context, UIComponent component, String value) { //throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates. return sdao.find(new Integer(value)); } @Override public String getAsString(FacesContext context, UIComponent component, Object value) { //throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates. return ((Specialization) value).getId().toString(); } } </code></pre> <p>But I get an error with my selectOneMenu, when i go to the next page.</p> <pre><code>java.lang.NullPointerException at pl.ePrzychodnia.dao.GenericDao.find(GenericDao.java:40) at pl.ePrzychodnia.converter.SpecializationConverter.getAsObject(SpecializationConverter.java:24) at com.sun.faces.renderkit.html_basic.HtmlBasicInputRenderer.getConvertedValue(HtmlBasicInputRenderer.java:171) at com.sun.faces.renderkit.html_basic.MenuRenderer.convertSelectOneValue(MenuRenderer.java:202) at com.sun.faces.renderkit.html_basic.MenuRenderer.getConvertedValue(MenuRenderer.java:319) at javax.faces.component.UIInput.getConvertedValue(UIInput.java:1030) at javax.faces.component.UIInput.validate(UIInput.java:960) at javax.faces.component.UIInput.executeValidate(UIInput.java:1233) at javax.faces.component.UIInput.processValidators(UIInput.java:698) at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1214) at javax.faces.component.UIForm.processValidators(UIForm.java:253) at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1214) at javax.faces.component.UIComponentBase.processValidators(UIComponentBase.java:1214) at javax.faces.component.UIViewRoot.processValidators(UIViewRoot.java:1172) at com.sun.faces.lifecycle.ProcessValidationsPhase.execute(ProcessValidationsPhase.java:76) at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118) at javax.faces.webapp.FacesServlet.service(FacesServlet.java:593) at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1550) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175) at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655) at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:161) at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:331) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:231) at com.sun.enterprise.v3.services.impl.ContainerMapper$AdapterCallable.call(ContainerMapper.java:317) at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:195) at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:860) at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:757) at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1056) at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:229) at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137) at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104) at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90) at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79) at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54) at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59) at com.sun.grizzly.ContextTask.run(ContextTask.java:71) at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532) at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513) at java.lang.Thread.run(Thread.java:722) </code></pre> <p>I don't now why. Can anyone help?</p>
    singulars
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    1. This table or related slice is empty.
    1. PTQuestion
    1. USLuiggi Mendoza
    1. USThe Nightmare
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
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      1. PTAnswer
    1. This table or related slice is empty.
    1. COPost the line at `pl.ePrzychodnia.dao.GenericDao.find(GenericDao.java:40)`.
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      1. POjava.lang.NullPointerException selectOneMenu convertor
      1. USNINCOMPOOP
    2. COUse `Integer.parseInt()` instead of allocating a `new Integer`, you don't necessarily want to create a new instance.
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      1. POjava.lang.NullPointerException selectOneMenu convertor
      1. USBalázs Mária Németh
    3. COI added find method in post. Integer.parseInt() does not help.
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      1. POjava.lang.NullPointerException selectOneMenu convertor
      1. USThe Nightmare
 

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