exception in gwt hibernate program - eclipse

Question

I am trying to make a simple GWT RPC Hibernate program that adds a user to MySQL database. I am using Eclipse EE. The application is successfully adding user to database but it raises exception when compiled.
Here is the exception & source of my application.
exception:
Exception in thread "UnitCacheLoader" java.lang.RuntimeException: Unable to read from byte cache
at com.google.gwt.dev.util.DiskCache.transferFromStream(DiskCache.java:166)
at com.google.gwt.dev.util.DiskCacheToken.readObject(DiskCacheToken.java:87)
at sun.reflect.GeneratedMethodAccessor2.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at java.io.ObjectStreamClass.invokeReadObject(Unknown Source)
at java.io.ObjectInputStream.readSerialData(Unknown Source)
at java.io.ObjectInputStream.readOrdinaryObject(Unknown Source)
at java.io.ObjectInputStream.readObject0(Unknown Source)
at java.io.ObjectInputStream.defaultReadFields(Unknown Source)
at java.io.ObjectInputStream.readSerialData(Unknown Source)
at java.io.ObjectInputStream.readOrdinaryObject(Unknown Source)
at java.io.ObjectInputStream.readObject0(Unknown Source)
at java.io.ObjectInputStream.readObject(Unknown Source)
at com.google.gwt.dev.javac.PersistentUnitCache.loadUnitMap(PersistentUnitCache.java:493)
at com.google.gwt.dev.javac.PersistentUnitCache.access$000(PersistentUnitCache.java:92)
at com.google.gwt.dev.javac.PersistentUnitCache$UnitCacheMapLoader.run(PersistentUnitCache.java:122)
Caused by: java.io.StreamCorruptedException: unexpected EOF in middle of data block
at java.io.ObjectInputStream$BlockDataInputStream.refill(Unknown Source)
at java.io.ObjectInputStream$BlockDataInputStream.read(Unknown Source)
at java.io.ObjectInputStream.read(Unknown Source)
at java.io.InputStream.read(Unknown Source)
at com.google.gwt.dev.util.DiskCache.transferFromStream(DiskCache.java:154)
... 16 more
entrypoint class:
package rpctest.client;
import rpctest.shared.FieldVerifier;
import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.core.client.GWT;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.dom.client.KeyCodes;
import com.google.gwt.event.dom.client.KeyUpEvent;
import com.google.gwt.event.dom.client.KeyUpHandler;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.rpc.AsyncCallback;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.DialogBox;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.user.client.ui.TextBox;
import com.google.gwt.user.client.ui.VerticalPanel;
/**
* Entry point classes define <code>onModuleLoad()</code>.
*/
public class Rpctest implements EntryPoint {
final TextBox firstName = new TextBox();
final TextBox lastName = new TextBox();
final Button ans = new Button("Add User");
final Label label1 = new Label("First Name");
final Label label2 = new Label("Last Name");
//final Label errorLabel = new Label();
private VerticalPanel mainpanel = new VerticalPanel();
private HorizontalPanel addpanel1 = new HorizontalPanel();
private HorizontalPanel addpanel2 = new HorizontalPanel();
private final RpctestServiceAsync calNumbers = GWT
.create(RpctestService.class);
/**
* This is the entry point method.
*/
public void onModuleLoad() {
addpanel1.add(label1);
addpanel1.add(firstName);
addpanel2.add(label2);
addpanel2.add(lastName);
mainpanel.add(addpanel1);
mainpanel.add(addpanel2);
mainpanel.add(ans);
ans.addClickHandler(new ClickHandler() {
#Override
public void onClick(ClickEvent event) {
String name1 = firstName.getValue();
String name2 = lastName.getValue();
calNumbers.addUser(name1,name2,
new AsyncCallback<String>() {
public void onFailure(Throwable caught) {
// Show the RPC error message to the user
Window.alert("check your inputs");
}
#Override
public void onSuccess(String result) {
// TODO Auto-generated method stub
Window.alert("User is ->"+result);
}
});}
});
// We can add style names to widgets
//sendButton.addStyleName("sendButton");
// Add the nameField and sendButton to the RootPanel
// Use RootPanel.get() to get the entire body element
/*RootPanel.get("nameFieldContainer").add(nameField);
*
RootPanel.get("sendButtonContainer").add(sendButton);
RootPanel.get("errorLabelContainer").add(errorLabel);*/
RootPanel.get().add(mainpanel);
}
}
interfaces:
import com.google.gwt.user.client.rpc.RemoteService;
import com.google.gwt.user.client.rpc.RemoteServiceRelativePath;
#RemoteServiceRelativePath("testService")
public interface RpctestService extends RemoteService {
String addUser(String firstName,String lastName) throws IllegalArgumentException;
}
package rpctest.client;
import com.google.gwt.user.client.rpc.AsyncCallback;
public interface RpctestServiceAsync {
void addUser(String firstName, String lastName,
AsyncCallback<String> callback);
}
service Implementation class:
package rpctest.server;
import com.google.gwt.user.server.rpc.RemoteServiceServlet;
import org.hibernate.Session;
import org.hibernate.Transaction;
import hibDomain.User;
import rpctest.client.RpctestService;
public class RpctestServiceImpl extends RemoteServiceServlet implements RpctestService {
public String addUser(String name1, String name2)
throws IllegalArgumentException {
Transaction trns = null;
Session session = HibernateUtil.getSessionFactory().openSession();
try {
trns = session.beginTransaction();
User user = new User();
user.setFirstName(name1);
user.setLastName(name2);
session.save(user);
session.getTransaction().commit();
} catch (RuntimeException e) {
if(trns != null){
trns.rollback();
}
e.printStackTrace();
} finally{
session.flush();
session.close();
}
return name1;
}
}
pojo class:
package hibDomain;
public class User {
private Integer id;
private String firstName;
private String lastName;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
}
mapping file:
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="hibDomain.User" table="users" >
<id name="id" type="int" column="id" >
<generator class="native"/>
</id>
<property name="firstName">
<column name="first_name" />
</property>
<property name="lastName">
<column name="last_name"/>
</property>
</class>
</hibernate-mapping>
cfg file:
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<!-- Database connection settings -->
<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="connection.url">jdbc:mysql://localhost/userdata</property>
<property name="connection.username">root</property>
<property name="connection.password"></property>
<!-- JDBC connection pool (use the built-in) -->
<property name="connection.pool_size">1</property>
<!-- SQL dialect -->
<property name="dialect">org.hibernate.dialect.MySQLDialect</property>
<!-- Enable Hibernate's automatic session context management -->
<property name="current_session_context_class">thread</property>
<!-- Disable the second-level cache -->
<property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
<!-- Echo all executed SQL to stdout -->
<property name="show_sql">true</property>
<!-- Drop and re-create the database schema on startup -->
<property name="hbm2ddl.auto">update</property>
<!-- Mapping files -->
<mapping resource="user.hbm.xml"/>
</session-factory>
</hibernate-configuration>
Util class:
package rpctest.server;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class HibernateUtil {
private static final SessionFactory sessionFactory = buildSessionFactory();
private static SessionFactory buildSessionFactory() {
try {
// Create the SessionFactory from hibernate.cfg.xml
return new Configuration().configure().buildSessionFactory();
}
catch (Throwable ex) {
// Make sure you log the exception, as it might be swallowed
System.err.println("Initial SessionFactory creation failed." + ex);
throw new ExceptionInInitializerError(ex);
}
}
public static SessionFactory getSessionFactory() {
return sessionFactory;
}
}

Answer 1

This unlikely to be related to running out of disk space.
Much more likely you either built as a different user or for some other reason there are existing, invalid, temporary files which are causing the problem.
Look in your GWT dir for the directories "gwt-unitCache", and "reports". Delete them. Then run ant clean, ant test; that should solve the problem~
Almost certainly the reason it 'suddenly started worked' was you did something like a fresh git clone or cleared out the directory, deleting these files. :)

Answer 2

Delete ./src/main/gwt-unitCache.

Answer 3

You ran out of disk space.
GWT compiler could not find temp space.