Peculiar error for foreign key constraint [many-to-one]

pavanlimo · **Posted:** Tue Sep 30, 2008 8:52 am

Hibernate version: 3.2.3

Mapping documents:
Mother.hbm.xml
Child.hbm.xml

Full stack trace of any exception that occurs:

Code:

- Hibernate 3.2.3
- loaded properties from resource hibernate.properties: {hibernate.connection.username=db2inst1, hibernate.connection.password=****, hibernate.dialect=org.hibernate.dialect.DB2Dialect, hibernate.connection.url=jdbc:db2://10.244.6.207:50000/pavan, hibernate.bytecode.use_reflection_optimizer=false, hibernate.connection.driver_class=com.ibm.db2.jcc.DB2Driver, hibernate.hbm2ddl.auto=create}
- Bytecode provider name : cglib
- using JDK 1.4 java.sql.Timestamp handling
- configuring from resource: /hibernate.cfg.xml
- Configuration resource: /hibernate.cfg.xml
- Reading mappings from resource : Mother.hbm.xml
- Mapping class: Mother -> Mother
- Reading mappings from resource : Child.hbm.xml
- Mapping class: Child -> Child
- Configured SessionFactory: null
- C3P0 using driver: com.ibm.db2.jcc.DB2Driver at URL: jdbc:db2://10.244.6.207:50000/pavan
- Connection properties: {user=db2inst1, password=****}
- autocommit mode: false
- MLog clients using log4j logging.
- Initializing c3p0-0.9.1.2 [built 21-May-2007 15:04:56; debug? true; trace: 10]
- JDBC isolation level: READ_COMMITTED
- Initializing c3p0 pool... com.mchange.v2.c3p0.PoolBackedDataSource@ff1526c1 [ connectionPoolDataSource -> com.mchange.v2.c3p0.WrapperConnectionPoolDataSource@9a6987d2 [ acquireIncrement -> 5, acquireRetryAttempts -> 30, acquireRetryDelay -> 1000, autoCommitOnClose -> false, automaticTestTable -> null, breakAfterAcquireFailure -> false, checkoutTimeout -> 0, connectionCustomizerClassName -> null, connectionTesterClassName -> com.mchange.v2.c3p0.impl.DefaultConnectionTester, debugUnreturnedConnectionStackTraces -> false, factoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> false, identityToken -> 31epo67w1ddywll4aht98|bb0d0d, idleConnectionTestPeriod -> 120, initialPoolSize -> 3, maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, maxIdleTime -> 120, maxIdleTimeExcessConnections -> 0, maxPoolSize -> 20, maxStatements -> 0, maxStatementsPerConnection -> 0, minPoolSize -> 3, nestedDataSource -> com.mchange.v2.c3p0.DriverManagerDataSource@e633ba2a [ description -> null, driverClass -> null, factoryClassLocation -> null, identityToken -> 31epo67w1ddywll4aht98|765a16, jdbcUrl -> jdbc:db2://10.244.6.207:50000/pavan, properties -> {user=******, password=******} ], preferredTestQuery -> null, propertyCycle -> 0, testConnectionOnCheckin -> false, testConnectionOnCheckout -> false, unreturnedConnectionTimeout -> 0, usesTraditionalReflectiveProxies -> false; userOverrides: {} ], dataSourceName -> null, factoryClassLocation -> null, identityToken -> 31epo67w1ddywll4aht98|7f4ec, numHelperThreads -> 3 ]
- RDBMS: DB2/LINUX, version: SQL09014
- JDBC driver: IBM DB2 JDBC Universal Driver Architecture, version: 3.50.152
- Using dialect: org.hibernate.dialect.DB2Dialect
- Using default transaction strategy (direct JDBC transactions)
- No TransactionManagerLookup configured (in JTA environment, use of read-write or transactional second-level cache is not recommended)
- Automatic flush during beforeCompletion(): disabled
- Automatic session close at end of transaction: disabled
- Scrollable result sets: enabled
- JDBC3 getGeneratedKeys(): enabled
- Connection release mode: auto
- Default batch fetch size: 1
- Generate SQL with comments: disabled
- Order SQL updates by primary key: disabled
- Query translator: org.hibernate.hql.ast.ASTQueryTranslatorFactory
- Using ASTQueryTranslatorFactory
- Query language substitutions: {}
- JPA-QL strict compliance: disabled
- Second-level cache: enabled
- Query cache: disabled
- Cache provider: org.hibernate.cache.HashtableCacheProvider
- Optimize cache for minimal puts: disabled
- Structured second-level cache entries: disabled
- Statistics: disabled
- Deleted entity synthetic identifier rollback: disabled
- Default entity-mode: pojo
- Named query checking : enabled
- building session factory
- Not binding factory to JNDI, no JNDI name configured
- Running hbm2ddl schema export
- exporting generated schema to database
- schema export complete
- IllegalArgumentException in class: Mother, getter method of property: id
Exception in thread "main" org.hibernate.PropertyAccessException: IllegalArgumentException occurred calling getter of Mother.id
   at org.hibernate.property.BasicPropertyAccessor$BasicGetter.get(BasicPropertyAccessor.java:171)
   at org.hibernate.tuple.entity.AbstractEntityTuplizer.getIdentifier(AbstractEntityTuplizer.java:183)
   at org.hibernate.persister.entity.AbstractEntityPersister.getIdentifier(AbstractEntityPersister.java:3589)
   at org.hibernate.persister.entity.AbstractEntityPersister.isTransient(AbstractEntityPersister.java:3305)
   at org.hibernate.engine.ForeignKeys.isTransient(ForeignKeys.java:181)
   at org.hibernate.event.def.AbstractSaveEventListener.getEntityState(AbstractSaveEventListener.java:512)
   at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.performSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:80)
   at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:70)
   at org.hibernate.impl.SessionImpl.fireSaveOrUpdate(SessionImpl.java:507)
   at org.hibernate.impl.SessionImpl.saveOrUpdate(SessionImpl.java:499)
   at org.hibernate.engine.CascadingAction$1.cascade(CascadingAction.java:218)
   at org.hibernate.engine.Cascade.cascadeToOne(Cascade.java:268)
   at org.hibernate.engine.Cascade.cascadeAssociation(Cascade.java:216)
   at org.hibernate.engine.Cascade.cascadeProperty(Cascade.java:169)
   at org.hibernate.engine.Cascade.cascade(Cascade.java:130)
   at org.hibernate.event.def.AbstractSaveEventListener.cascadeBeforeSave(AbstractSaveEventListener.java:431)
   at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:265)
   at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:181)
   at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:121)
   at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:187)
   at org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:33)
   at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:172)
   at org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:27)
   at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:70)
   at org.hibernate.impl.SessionImpl.fireSave(SessionImpl.java:535)
   at org.hibernate.impl.SessionImpl.save(SessionImpl.java:523)
   at org.hibernate.impl.SessionImpl.save(SessionImpl.java:519)
   at InsertProduct.main(InsertProduct.java:49)
Caused by: java.lang.IllegalArgumentException: object is not an instance of declaring class
   at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
   at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
   at java.lang.reflect.Method.invoke(Unknown Source)
   at org.hibernate.property.BasicPropertyAccessor$BasicGetter.get(BasicPropertyAccessor.java:145)
   ... 27 more

Name and version of the database you are using: DB2 9.x

Please find corresponding code for the below explanation immediately after the explanation.

I want to test a simple parent child relationship. Hence, I have written 2 simple beans Mother.java and Child.java and corresponding hbm files, Child will have Mother's id as foreign key.

In the main java program(Insertproduct.java, see below for code), I set simple values for Mother and Child. When I try to save the the Child instance, I get the exception mentioned above.

Code for this simple exercise follows.

Mother.hbm.xml

Code:

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-mapping PUBLIC 
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
   <class name="Mother" table="Mother">
      <id name="id" type="long" column="Id">
         <generator class="increment" />
      </id>
      
      <property name="age" type="java.lang.Long" column="age" />
      
      

   </class>
</hibernate-mapping>

Mother.java

Code:

public class Mother {
   
   private long id;
   private Long age;
   
   public long getId() {
      return id;
   }
   public void setId(long id) {
      this.id = id;
   }
   public Long getAge() {
      return age;
   }
   public void setAge(Long age) {
      this.age = age;
   }

}

Child.hbm.xml

Code:

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-mapping PUBLIC 
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
   <class name="Child" table="Child">
      <id name="id" type="long" column="Id">
         <generator class="increment" />
      </id>
      
      <property name="age" type="java.lang.Long" column="age" />
      
      <many-to-one name="mothersId" class="Mother" 
      column="mothersId" cascade="save-update" />

   </class>
</hibernate-mapping>

Child.java

Code:

public class Child {
   

   private long id;
   private Long age;
   private Long mothersId;
   
   public long getId() {
      return id;
   }
   public void setId(long id) {
      this.id = id;
   }
   public Long getAge() {
      return age;
   }
   public void setAge(Long age) {
      this.age = age;
   }
   public void setMothersId(Long mothersId) {
      this.mothersId = mothersId;
   }
   public Long getMothersId() {
      return mothersId;
   }
}

InsertProduct.java (main program)

Code:

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;

public class InsertProduct {

    public static void main(String[] args) 
                        throws Exception {

       Mother m=new Mother();
       m.setAge(25L);
       m.setId(1L);       
             

        // 2. Fire up Hibernate
        SessionFactory sf = new Configuration().configure().buildSessionFactory(); 

        // 3. Open Session
        Session sess = sf.openSession();

        // 4. Save Product and close Session
        Transaction t = sess.beginTransaction();
        sess.save(m);
        t.commit();
        sess.close();
        
        
        Child c=new Child();
       c.setAge(10L);
       c.setId(1L);
       Long l=new Long(1);
       c.setMothersId(l);
        
       
        // 3. Open Session
        sess = sf.openSession();

        // 4. Save Product and close Session
        t = sess.beginTransaction();
        sess.save(c);
        t.commit();
        sess.close();
    }
}

Your help will be greatly appreciated as it has stopped our project from enforcing foreign key constraints this way. And no, I dont want to enforce many-to-one using Set.

Thanks a lot in anticipation.

croudet · **Joined:** Mon Apr 19, 2004 6:54 pm **Posts:** 79

Hibernate expects a Mother in the Child class (not an id)

Code:

class Child {
....
   public void setMother(Mother mother) {
      this.mother = mothers;
   }
   public Mother getMother() {
      return mother;
   } 
...
}

Christophe

pavanlimo · **Posted:** Tue Sep 30, 2008 10:05 am

Is it not possible to have a field as a foreign key in the bean?.
Here, I need 'mothersId' in 'Child'.