Using JasperReports with Hibernate

Hi,
I'm trying to use jasper with hibernate.

Can you give us the jasper xml template for this example?

I'm having trouble in defining the attribute's names. When working 
with normal datasets, the fieldnames are capitalized. 
What's the correct way to define them when the fieldnames relate to 
class attributes ?

Thanks in advance,
André Felipe
afconsult (at) yahoo (dot) com

Hi,
I would do interested in having this XML template as well.

Would it be possible to get it ?

Thanks in advance

sylvain_2020
sylvain_2020(at)msn(dot)com

I rewrote the getFieldValue to use reflection. Hope this helps.

-V

public class HibernateQueryResultDataSource implements JRDataSource { 

	  private Iterator iterator; 
	  private Object currentValue; 

	  public HibernateQueryResultDataSource(List list) { 
	    this.iterator = list.iterator(); 
	  } 

	  public Object getFieldValue(JRField field) throws JRException { 
	    Object value = null; 
		try {
		    Method fld = currentValue.getClass().getMethod("get" +
field.getName(),null);
		    System.out.println(fld.getName());
			value = fld.invoke(currentValue,null);
			System.out.println(value);
		}catch (IllegalAccessException iae) {
			iae.printStackTrace();
		} catch(InvocationTargetException ite) {
			ite.printStackTrace();
		}catch(NoSuchMethodException nsme) {
			nsme.printStackTrace();
		}
	    return value; 
	  } 

	  public boolean next() throws JRException { 
	    currentValue = iterator.hasNext() ? iterator.next() : null; 
	    return (currentValue != null); 
	  } 
	}

Here is a slightly reworked version of the previous post, which 
generates the getter's name with BeanUtils:

  public Object getFieldValue(JRField field) throws JRException {
        Object value = null;
        try {
            Method getter = PropertyUtils.getReadMethod(PropertyUtils.
getPropertyDescriptor(currentValue, field.getName()));
            value = getter.invoke(currentValue, null);
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        return value;
    }
    
(It might be a bit more standard.)

-Class for use relations many-to-one inside hibernate class.

public class HibernateQueryResultDataSource implements JRDataSource {
    
    private Iterator iterator;
    private Object currentValue;
    
    public HibernateQueryResultDataSource(List list) {
        this.iterator = list.iterator();
    }
    
    public Object getFieldValue(JRField field) throws JRException {
        Object value = null;
        String methodName = null;
        

           StringTokenizer st = new StringTokenizer(field.getName
(),"_");
            value = currentValue;  
            
            while(st.hasMoreTokens()){
                methodName = st.nextToken();
                methodName = "get"+methodName.replaceFirst
(methodName.substring(0,1), methodName.substring(0,1).toUpperCase
());                
                try{
                   
                    Method metodoFinal = value.getClass
().getDeclaredMethod(methodName);
                    value = metodoFinal.invoke(value);
                    
                }catch(Exception e){
                    throw new JRException("Error trying to instanciate 
hibernate class.");
                }
            }
        return value;
    }    
    
    public boolean next() throws JRException {
        currentValue = iterator.hasNext() ? iterator.next() : null;
        return (currentValue != null);
    }
    
}

Allows access to compenents (use __ instead of .).
Allows use of collection,map in subreports.

import java.lang.reflect.*;
import java.util.*;

import org.apache.commons.beanutils.*;
import org.apache.commons.logging.*;

import net.sf.jasperreports.engine.*;
import net.sf.jasperreports.engine.data.*;
import net.sf.jasperreports.engine.export.*;
import net.sf.jasperreports.engine.util.*;
import net.sf.jasperreports.view.*;


public class JRHibernateDataSource implements JRDataSource {

    protected HashMap fieldsToIdxMap=new HashMap();

    protected Iterator iterator;

    protected Object currentValue;


    public JRHibernateDataSource(Collection list) {
        this.iterator = list.iterator();
    }

    public JRHibernateDataSource(Map list) {
      this.iterator = list.values().iterator();
  }

    private Object nestedFieldValue(Object object, String field) {
        Object value = null;
        if (field.indexOf("__")>-1) {
            try {
                Method nestedGetter =
PropertyUtils.getReadMethod(PropertyUtils.getPropertyDescriptor(object,
field.substring(0,field.indexOf("__"))));
                Object nestedObject = nestedGetter.invoke(object, null);
               
value=nestedFieldValue(nestedObject,field.substring(field.indexOf("__")+2,field.length()));
            } catch (Exception ex) {
                ex.printStackTrace();
            }           
        } else {
            try {
                Method getter =
PropertyUtils.getReadMethod(PropertyUtils.getPropertyDescriptor(object,
field));
                value = getter.invoke(object, null);
               
if(Collection.class.isAssignableFrom(getter.getReturnType())) {
                    return new JRHibernateDataSource((Collection)value);
                }
                if(Map.class.isAssignableFrom(getter.getReturnType())) {
                    return new JRHibernateDataSource((Map)value);
                }
            } catch (Exception ex) {
                ex.printStackTrace();
            }           
        }
        return value;
    }
   
    public Object getCurrentValue() throws JRException {
        return currentValue;
    }

    public Object getFieldValue(JRField field) throws JRException {
        return nestedFieldValue(currentValue,field.getName());
    }
   
    public boolean next() throws JRException {
        currentValue = iterator.hasNext() ? iterator.next() : null;
        return currentValue != null;
    } 
}

Hello, 

How do we handle the case where we need subreports for a master 
report. 

I mean if we have cats and for each cat we want to list its kittens 
(one to many) how can we do that ??

Thank you.

You can use the code in my previous code and update your master report
like this :


...
   <field name="kittens" class="java.lang.Object">
   </field>
... 
   <subreport>
      <reportElement positionType="Float" isPrintRepeatedValues="false"
mode="Opaque" x="64" y="29" width="450" height="30"
isRemoveLineWhenBlank="true"/>
      <dataSourceExpression>
         <![CDATA[$F{kittens}]]>
      </dataSourceExpression>
      <subreportExpression class="java.lang.String">
         <![CDATA["kittens.jasper"]]>
      </subreportExpression>
   </subreport>

Hello, 

    With the above code, i think we should still use the HQL to do 
a "select cats.name, cats.kittens From cats".
One more doubt here is do we give the above HQL as part of the 
<queryString> in the report design ??

But with Hibernate i think in most of the cases we get the list of 
cats directly and so, if there is a way to just send in the List<cats> 
as a datasource and the JRHibernateDataSource be able to detect the 
Sublists(the lists to which it is related as one-to-many) 
automatically would be a great idea.

Thank you,

I need kittens as a subreport but only its age, not its name or 
anything. 

Well the point is when using sql queries, i simply used to give a 
query string in the subreport and some parameters which got its values 
from fields of the master report., Now with HQL, i cant insert the HQL 
query in querystring, so how can i generate such dynamic reports ?? 

Like depending on a particular field on the master report the 
subreport should be generated. 

For example if there is a field in the CAT table called "disabled"

I can have a parameter in subreport for this particular field of 
master report and a query in the subreport says 

Select  * from kitten,cat where kitten.catId=Cat.Id and Cat.disabled=$P
{disabled}(This value is obtained from the master reports field).

Thank you.

POST QUESTIONS ON THE FORUM! COMMENTS HERE SHOULD ADD VALUE TO THE PAGE!

Hi! I would be interested in seeing the XML Template used for this 
exmple too, as I am having problems understanding how all this works 
within the XML Template. The rest is all clearly understandable for me, 
but I need to know the structure of this jrxml, because I will need to 
handle it in order to build dynamic reports and I won't use iReport as 
it would be used for standard reports building. Thanks in advance!!!

I've actually found a real easy way to handle tuples without any
reflection or arrays of field names using aliases. 

It turns out there's a handy Query.getReturnAliases() method that will
return the names of all the aliases in a query so you can have the
following datasource.

(Note this class originally had some wrappers around the query and stuff
so there might be a trivial error since I didn't bother to write
something just to test it)
public class JRDataSourceHibQuery implements JRDataSource {

	private Query query;
	private Iterator<Object[]> results;
	private Object[] current;

	public JRDataSourceHibQuery(Query query) throws BasicException{
		this.query = query;
		results = query.list().iterator();
	}
	
	public Object getFieldValue(JRField fieldName) throws JRException {
		String[] aliases = query.getReturnAliases();
		for (int i = 0; i < aliases.length; i++) {
			if (aliases[i].equals(fieldName.getName()))
				return current[i];
		}
		return null;
	}

	public boolean next() throws JRException {
		current = (results.hasNext()? results.next(): null);
		return (current != null);
	}

}


The only quirk is instead of

"select cat.type, cat.birthdate, cat.name from eg.DomesticCat cat"

your query how has to be 

"select cat.type as type, cat.birthdate as birthdate, cat.name as name
from eg.DomesticCat cat"

Need to have those return aliases!

I am trying this code out, but it is not working for me. Here is my java
class

	 public void findItemDetails()
{
List Item=new ArrayList();
List outputRec = new ArrayList();
Criteria itemCrit = null;		
try 
{

Session session = HibernateUtil.getSessionFactory().getCurrentSession(); 
Transaction tx = (Transaction)session.beginTransaction(); 
itemCrit = session.createCriteria(Item.class);
System.out.println("the item crit is "+itemCrit);
QueryUtil101.createTypeCriteria("","",itemCrit,"");								
outputRec = itemCrit.list();
System.out.println("the outputrec is"+outputRec);

 Map parameters = new HashMap();
// parameters.put("Title", "The silaom Report");
 InputStream reportStream = this.class.getResourceAsStream("item.jrxml");
 InputStream reportStream =
this.getClass().getClassLoader().getResourceAsStream("item.jrxml");
 System.out.println("the reportstream is "+reportStream);
 JasperDesign jasperDesign = JRXmlLoader.load(reportStream);
 System.out.println("the jasperdesign is "+jasperDesign);
 JasperReport jasperReport =
JasperCompileManager.compileReport(jasperDesign);

	......
and other code here.

I also added a class path item called RESOURCES and added the folder
path where I have the item.jrxml. So the classpath has the report folder
in its path.

But i am not able to get past the getResourceAsStream command, it keeps
returning null. 
When i just copied the code above
this.class.getResourceAsStream("item.jrxml") i have a RED underline
under Class ("Syntax error on token class, "identifier" required). Not
sure why i am having this issue. 

Can you please elaborate on the directory structure you used and class
path components and also how this.class.getResourceAsStream works for
you and not for me. 

I am relatively new to java and jasper reports. So any insight and
detailed explanation would be greatly appreciated.