Factory Pattern

Overview

The Factory Pattern in iDempiere allows you to:

Extend or replace standard model classes with custom implementations
Create custom process instances
Provide custom callout implementations
Implement plugin-based extensibility

Factories are registered as OSGi services and are invoked by the framework when models, processes, or callouts are instantiated. Base Package: org.adempiere.base Source Files:

org.adempiere.base/src/org/adempiere/base/IModelFactory.java
org.adempiere.base/src/org/adempiere/base/IProcessFactory.java
org.adempiere.base/src/org/adempiere/base/ICalloutFactory.java

IModelFactory

Provides custom model implementations for tables. Package: org.adempiere.base

Interface Methods

getClass

public Class<?> getClass(String tableName)

tableName

String

required

Database table name (e.g., “C_Order”, “C_Invoice”)

return

Class<?>

Model class for the table, or null if not handled by this factory

Returns the persistence class to use for a given table.

getPO (by ID)

public PO getPO(String tableName, int Record_ID, String trxName)

tableName

String

required

Database table name

Record_ID

int

required

Record ID to load

trxName

String

Transaction name

return

Loaded PO instance, or null if not handled by this factory

getPO (by UUID)

default public PO getPO(String tableName, String Record_UU, String trxName)

tableName

String

required

Database table name

Record_UU

String

required

Record UUID to load

trxName

String

Transaction name

return

Loaded PO instance, or null if not handled

throws

AdempiereException

If UUID constructor not implemented in this factory

getPO (from ResultSet)

public PO getPO(String tableName, ResultSet rs, String trxName)

tableName

String

required

Database table name

ResultSet

required

ResultSet positioned at row to load

trxName

String

Transaction name

return

Loaded PO instance, or null if not handled by this factory

Implementation Example

package com.example.factory;

import java.sql.ResultSet;
import org.adempiere.base.IModelFactory;
import org.compiere.model.PO;
import org.compiere.util.Env;
import com.example.model.MCustomOrder;
import com.example.model.MCustomInvoice;

/**
 * Custom Model Factory
 * Provides custom implementations for specific tables
 */
public class CustomModelFactory implements IModelFactory {
    
    @Override
    public Class<?> getClass(String tableName) {
        if (tableName.equals("C_Order")) {
            return MCustomOrder.class;
        }
        else if (tableName.equals("C_Invoice")) {
            return MCustomInvoice.class;
        }
        return null;
    }
    
    @Override
    public PO getPO(String tableName, int Record_ID, String trxName) {
        if (tableName.equals("C_Order")) {
            return new MCustomOrder(Env.getCtx(), Record_ID, trxName);
        }
        else if (tableName.equals("C_Invoice")) {
            return new MCustomInvoice(Env.getCtx(), Record_ID, trxName);
        }
        return null;
    }
    
    @Override
    public PO getPO(String tableName, String Record_UU, String trxName) {
        if (tableName.equals("C_Order")) {
            return new MCustomOrder(Env.getCtx(), Record_UU, trxName);
        }
        else if (tableName.equals("C_Invoice")) {
            return new MCustomInvoice(Env.getCtx(), Record_UU, trxName);
        }
        return null;
    }
    
    @Override
    public PO getPO(String tableName, ResultSet rs, String trxName) {
        if (tableName.equals("C_Order")) {
            return new MCustomOrder(Env.getCtx(), rs, trxName);
        }
        else if (tableName.equals("C_Invoice")) {
            return new MCustomInvoice(Env.getCtx(), rs, trxName);
        }
        return null;
    }
}

OSGi Service Registration

Using Declarative Services (component.xml):

<?xml version="1.0" encoding="UTF-8"?>
<scr:component xmlns:scr="http://www.osgi.org/xmlns/scr/v1.1.0" 
               name="com.example.factory.CustomModelFactory">
   <implementation class="com.example.factory.CustomModelFactory"/>
   <service>
      <provide interface="org.adempiere.base.IModelFactory"/>
   </service>
   <property name="service.ranking" type="Integer" value="100"/>
</scr:component>

Using Annotations:

import org.osgi.service.component.annotations.Component;

@Component(
    name = "com.example.factory.CustomModelFactory",
    service = IModelFactory.class,
    property = {"service.ranking:Integer=100"}
)
public class CustomModelFactory implements IModelFactory {
    // Implementation as above
}

IProcessFactory

Provides custom process instances. Package: org.adempiere.base

Interface Methods

newProcessInstance

public ProcessCall newProcessInstance(String className)

className

String

required

Fully qualified class name of the process

return

ProcessCall

New process instance, or null if not handled by this factory

Implementation Example

package com.example.factory;

import org.adempiere.base.IProcessFactory;
import org.compiere.process.ProcessCall;
import com.example.process.CustomOrderProcess;
import com.example.process.CustomInvoiceProcess;

/**
 * Custom Process Factory
 * Creates instances of custom processes
 */
public class CustomProcessFactory implements IProcessFactory {
    
    @Override
    public ProcessCall newProcessInstance(String className) {
        if (className.equals("com.example.process.CustomOrderProcess")) {
            return new CustomOrderProcess();
        }
        else if (className.equals("com.example.process.CustomInvoiceProcess")) {
            return new CustomInvoiceProcess();
        }
        return null;
    }
}

OSGi Service Registration

<?xml version="1.0" encoding="UTF-8"?>
<scr:component xmlns:scr="http://www.osgi.org/xmlns/scr/v1.1.0" 
               name="com.example.factory.CustomProcessFactory">
   <implementation class="com.example.factory.CustomProcessFactory"/>
   <service>
      <provide interface="org.adempiere.base.IProcessFactory"/>
   </service>
   <property name="service.ranking" type="Integer" value="10"/>
</scr:component>

ICalloutFactory

Provides custom callout instances. Package: org.adempiere.base

Interface Methods

getCallout

public Callout getCallout(String className, String methodName)

className

String

required

Fully qualified class name of the callout

methodName

String

required

Method name within the callout class

return

Callout

Callout instance, or null if not handled by this factory

Implementation Example

package com.example.factory;

import org.adempiere.base.ICalloutFactory;
import org.compiere.model.Callout;
import com.example.callout.CustomOrderCallout;
import com.example.callout.CustomInvoiceCallout;

/**
 * Custom Callout Factory
 * Creates instances of custom callouts
 */
public class CustomCalloutFactory implements ICalloutFactory {
    
    @Override
    public Callout getCallout(String className, String methodName) {
        Callout callout = null;
        
        if (className.equals("com.example.callout.CustomOrderCallout")) {
            callout = new CustomOrderCallout();
        }
        else if (className.equals("com.example.callout.CustomInvoiceCallout")) {
            callout = new CustomInvoiceCallout();
        }
        
        return callout;
    }
}

OSGi Service Registration with Priority

<?xml version="1.0" encoding="UTF-8"?>
<scr:component xmlns:scr="http://www.osgi.org/xmlns/scr/v1.1.0" 
               name="com.example.factory.CustomCalloutFactory">
   <implementation class="com.example.factory.CustomCalloutFactory"/>
   <service>
      <provide interface="org.adempiere.base.ICalloutFactory"/>
   </service>
   <property name="service.ranking" type="Integer" value="1"/>
</scr:component>

For callout factories, use service.ranking:Integer=1 or higher to prioritize your factory over the core factory.

Complete Plugin Example

A complete example showing factory integration in an OSGi plugin.

Project Structure

com.example.plugin/
├── META-INF/
│   └── MANIFEST.MF
├── OSGI-INF/
│   ├── ModelFactory.xml
│   ├── ProcessFactory.xml
│   └── CalloutFactory.xml
├── src/
│   └── com/example/
│       ├── factory/
│       │   ├── CustomModelFactory.java
│       │   ├── CustomProcessFactory.java
│       │   └── CustomCalloutFactory.java
│       ├── model/
│       │   └── MCustomOrder.java
│       ├── process/
│       │   └── CustomOrderProcess.java
│       └── callout/
│           └── CustomOrderCallout.java
└── build.properties

MANIFEST.MF

Manifest-Version: 1.0
Bundle-ManifestVersion: 2
Bundle-Name: Custom Plugin
Bundle-SymbolicName: com.example.plugin;singleton:=true
Bundle-Version: 1.0.0.qualifier
Bundle-RequiredExecutionEnvironment: JavaSE-17
Require-Bundle: org.adempiere.base;bundle-version="11.0.0"
Service-Component: OSGI-INF/ModelFactory.xml,
 OSGI-INF/ProcessFactory.xml,
 OSGI-INF/CalloutFactory.xml
Import-Package: org.osgi.service.component.annotations

Custom Model Implementation

package com.example.model;

import java.sql.ResultSet;
import java.util.Properties;
import org.compiere.model.MOrder;
import org.compiere.util.CLogger;

/**
 * Custom Order Model
 * Extends standard order with custom business logic
 */
public class MCustomOrder extends MOrder {
    
    private static final long serialVersionUID = 1L;
    private static CLogger log = CLogger.getCLogger(MCustomOrder.class);
    
    public MCustomOrder(Properties ctx, int C_Order_ID, String trxName) {
        super(ctx, C_Order_ID, trxName);
    }
    
    public MCustomOrder(Properties ctx, ResultSet rs, String trxName) {
        super(ctx, rs, trxName);
    }
    
    @Override
    protected boolean beforeSave(boolean newRecord) {
        if (!super.beforeSave(newRecord))
            return false;
        
        // Custom validation
        if (newRecord) {
            log.info("Creating custom order with special logic");
            // Add custom logic here
        }
        
        return true;
    }
    
    @Override
    protected boolean afterSave(boolean newRecord, boolean success) {
        if (!super.afterSave(newRecord, success))
            return false;
        
        if (newRecord) {
            // Custom post-save logic
            createCustomRecords();
        }
        
        return true;
    }
    
    private void createCustomRecords() {
        // Custom implementation
        log.info("Creating custom related records for order " + getDocumentNo());
    }
}

Service Ranking

The service.ranking property determines the order in which factories are invoked:

Higher values = Higher priority
Core iDempiere factories typically use ranking of 0
Plugin factories should use positive values to override core behavior
Typical values:
- 1-10: Minor extensions
- 10-50: Standard plugin priority
- 50-100: High priority overrides

Example with multiple factories:

// High priority factory - checked first
@Component(
    service = IModelFactory.class,
    property = {"service.ranking:Integer=100"}
)
public class HighPriorityFactory implements IModelFactory {
    // ...
}

// Standard priority factory - checked if high priority returns null
@Component(
    service = IModelFactory.class,
    property = {"service.ranking:Integer=10"}
)
public class StandardFactory implements IModelFactory {
    // ...
}

Factory Chain

When multiple factories are registered:

Framework sorts factories by service.ranking (descending)
Invokes each factory in order
First factory to return non-null result wins
If all factories return null, uses default implementation

Best Practices

Return Null: Always return null for tables/classes you don’t handle
Performance: Keep factory methods lightweight - they’re called frequently
Service Ranking: Use appropriate ranking to control factory precedence
Consistency: Implement all three getPO methods consistently
Testing: Test factory behavior in all three construction scenarios
Documentation: Document which tables/processes your factory handles
Namespace: Use unique package names to avoid class conflicts
Singleton: Factories are singletons - avoid instance state
Thread Safety: Ensure factory methods are thread-safe
Logging: Log factory instantiations for debugging

Debugging Factories

Enable factory debugging in iDempiere:

// Add to your factory for debugging
import org.compiere.util.CLogger;

private static CLogger log = CLogger.getCLogger(CustomModelFactory.class);

@Override
public PO getPO(String tableName, int Record_ID, String trxName) {
    if (tableName.equals("C_Order")) {
        log.info("CustomModelFactory creating MCustomOrder for ID " + Record_ID);
        return new MCustomOrder(Env.getCtx(), Record_ID, trxName);
    }
    return null;
}

Web Services

Java API

Extension Points

Overview

IModelFactory

Interface Methods

getClass

getPO (by ID)

getPO (by UUID)

getPO (from ResultSet)

Implementation Example

OSGi Service Registration

IProcessFactory

Interface Methods

newProcessInstance

Implementation Example

OSGi Service Registration

ICalloutFactory

Interface Methods

getCallout

Implementation Example

OSGi Service Registration with Priority

Complete Plugin Example

Project Structure

MANIFEST.MF

Custom Model Implementation

Service Ranking

Factory Chain

Best Practices

Debugging Factories

See Also

Build docs developers (and LLMs) love

Web Services

Java API

Extension Points

Documentation Index

​Overview

​IModelFactory

​Interface Methods

​getClass

​getPO (by ID)

​getPO (by UUID)

​getPO (from ResultSet)

​Implementation Example

​OSGi Service Registration

​IProcessFactory

​Interface Methods

​newProcessInstance

​Implementation Example

​OSGi Service Registration

​ICalloutFactory

​Interface Methods

​getCallout

​Implementation Example

​OSGi Service Registration with Priority

​Complete Plugin Example

​Project Structure

​MANIFEST.MF

​Custom Model Implementation

​Service Ranking

​Factory Chain

​Best Practices

​Debugging Factories

​See Also

Build docs developers (and LLMs) love

Overview

IModelFactory

Interface Methods

getClass

getPO (by ID)

getPO (by UUID)

getPO (from ResultSet)

Implementation Example

OSGi Service Registration

IProcessFactory

Interface Methods

newProcessInstance

Implementation Example

OSGi Service Registration

ICalloutFactory

Interface Methods

getCallout

Implementation Example

OSGi Service Registration with Priority

Complete Plugin Example

Project Structure

MANIFEST.MF

Custom Model Implementation

Service Ranking

Factory Chain

Best Practices

Debugging Factories

See Also