i am new to hibernate i am getting the null pointer exception as shown below
i am trying left outer join with unidirectional foreign key mapping
could you please point out where i had done the mistake.
java.lang.NullPointerException
at org.hibernate.hql.ast.LiteralProcessor.lookupConstant(LiteralProcessor.java:67)
at org.hibernate.hql.ast.DotNode.resolve(DotNode.java:171)
at org.hibernate.hql.ast.FromReferenceNode.resolve(FromReferenceNode.java:87)
at org.hibernate.hql.ast.HqlSqlWalker.createFromJoinElement(HqlSqlWalker.java:266)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.joinElement(HqlSqlBaseWalker.java:2475)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromElement(HqlSqlBaseWalker.java:2323)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromElementList(HqlSqlBaseWalker.java:2232)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromClause(HqlSqlBaseWalker.java:498)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:356)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:184)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:140)
at org.hibernate.hql.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:189)
at org.hibernate.hql.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:130)
at org.hibernate.hql.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:83)
at org.hibernate.impl.SessionFactoryImpl.getQuery(SessionFactoryImpl.java:414)
at org.hibernate.impl.SessionImpl.getQueries(SessionImpl.java:814)
at org.hibernate.impl.SessionImpl.list(SessionImpl.java:773)
at org.hibernate.impl.QueryImpl.list(QueryImpl.java:74)
at sample.Inner.main(Inner.java:24)
my main class
package simple;
import org.hibernate.Query;
import org.hibernate.MappingException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import java.util.*;
import simple.Contact;
import simple.Insurance;
public class Inner {
public static void main(
String[] args) {
// TODO Auto-generated method stub
Session sess = null;
try{
SessionFactory fact = new
Configuration().configure().buildSessionFactory();
sess = fact.openSession();
String sql_query = "select emp.firstname,Insurance.InsuranceName,Insurance.InvestmentAmount FROM simple.Contact emp left outer join simple.Insurance Insurance where emp.insid = Insurance.insid";
Query query = sess.createQuery(sql_query);
Iterator ite = query.list().iterator();
System.out.println("First Name\t"+"Insurance Name\t"+"InvestmentAmount");
while ( ite.hasNext() ) {
Object[] pair = (Object[]) ite.next();
/*Contact con = (Contact) pair[0];
Insurance ins = (Insurance) pair[1];
System.out.print(con.getFirstName());
System.out.print("\t"+ins.getInsuranceName());
System.out.print("\t\t"+ins.getInvestementAmount());
System.out.println();*/
System.out.println(pair[0]+"\t"+pair[1]+"\t"+pair[2]+"\n");
/*System.out.println("First Name:"+pair[0]);
System.out.println("Insurance name:"+pair[1]);
System.out.println("InvestmentAmount:"+pair[2]);*/
}
sess.close();
}
catch(Exception e ){
System.out.println(e.getMessage());
e.printStackTrace();
}
}
}
Contact.java
package simple;
import java.util.*;
public class Contact {
private String firstName;
private String lastName;
private int insid;
private int id;
private List insurance;
public List getInsurance()
{
return insurance;
}
public void setInsurance(List insurance)
{
this.insurance = insurance;
}
/**
* @return insid
*/
/**
* @return First Name
*/
public String getFirstName() {
return firstName;
}
/**
* @return Last name
*/
public String getLastName() {
return lastName;
}
public int getinsid() {
return insid;
}
/**
* @param string Sets the Insid
*/
public void setinsid(int i) {
insid = i;
}
/**
* @param string Sets the First Name
*/
public void setFirstName(String string) {
firstName = string;
}
/**
* @param string sets the Last Name
*/
public void setLastName(String string) {
lastName = string;
}
public int getId() {
return id;
}
/**
* @param l Sets the ID
*/
public void setId(int i) {
id = i;
}
}
Insurance.java
package simple;
import java.util.List;
public class Insurance {
private String insuranceName;
private double investementAmount;
private int insid;
private Contact contact;
public Contact getContact()
{
return contact;
}
public void setContact(Contact contact)
{
this.contact = contact;
}
public String getInsuranceName() {
return insuranceName;
}
public void setInsuranceName(String insuranceName) {
this.insuranceName = insuranceName;
}
public double getInvestementAmount() {
return investementAmount;
}
public void setInvestementAmount(double investementAmount) {
this.investementAmount = investementAmount;
}
public int getinsid() {
return insid;
}
public void setinsid(int Id) {
this.insid = insid;
}
}
contact.hbm.xml
<?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 package="simple" >
<class name="Contact" table="emp">
<id name="id" type="int" column="ID" >
<generator class="increment"/>
</id>
<property name="insid" column ="InsID"/>
<property name="firstName" column ="firstname"/>
<property name="lastName" column ="lastname"/>
<bag name="Insurance" inverse="true" cascade="all,delete-orphan" >
<key column="InsID" not-null="true"/>
<one-to-many class="simple.Insurance"/>
</bag>
</class>
</hibernate-mapping>
insurance.hbm.xml
<?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 package="simple">
<class name="Insurance" table="Insurance">
<id name="insid" column ="InsID" type="int">
<generator class="increment"/>
</id>
<property name="insuranceName" column="InsuranceName" type="string" />
<property name="investementAmount" column="InvestmentAmount" type="double"/>
<many-to-one name="Contact" class="simple.Contact" column="InsID"
insert="false" update="false"/>
</class>
</hibernate-mapping>
hibernate.cfg.xml
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="hibernate.connection.driver_class">
com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.url">
jdbc:mysql://localhost/sakthi</property>
<property name="hibernate.connection.username">root</property>
<property name="hibernate.connection.password">admin</property>
<property name="hibernate.connection.pool_size">10</property>
<property name="hibernate.jdbc.batch_size">50</property>
<property name="show_sql">true</property>
<property name="connection.autocommit">false</property>
<property name="dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="hibernate.hbm2ddl.auto">update</property>
<!-- Mapping files -->
<mapping resource="contact.hbm.xml"/>
<mapping resource="insurance.hbm.xml"/>
</session-factory>
</hibernate-configuration>