com.sibvisions.rad.server
Class GenericBean

java.lang.Object
  java.util.AbstractMap<String,Object>
      javax.rad.type.bean.AbstractBean<BeanType>
          javax.rad.type.bean.Bean
              com.sibvisions.rad.server.GenericBean

All Implemented Interfaces:

Map<String,Object>, IBean

public abstract class GenericBean
extends Bean

The GenericBean handles the access to the values of cached members and defined methods. If a member is uninitialized the GenericBean will try to initialize it by calling the init method for the member.

Examples for using implementing a GenericBean subclass

The fastest and safest way to use the GenericBean is to implement an init method for every property. If you have init methods you don't have to implement the get methods, but it's good style to implement both:

 public class Session extends GenericBean
 {
     private DBAccess initDataSource() throws Exception
     {
         IConfiguration cfgSession = session.getCurrentSessionConfig();
         
         OracleDBAccess dba = new OracleDBAccess();
         
         dba.setConnection(cfgSession.getProperty("/application/securitymanager/database/url")); 
         dba.setUser(cfgSession.getProperty("/application/securitymanager/database/username"));
         dba.setPassword(cfgSession.getProperty("/application/securitymanager/database/password"));
         dba.open();
         
         return dba;
     }
     
     private DBStorage initPerson() throws Exception
     {
         DBStorage dbsPerson = new DBStorage();
        
         dbsPerson.setDBAccess(getDataSource());
         dbsPerson.setWriteBackTable("V_PERSON");
         dbsPerson.setFromClause("V_PERSON");
         dbsPerson.open();
        
         return dbsPerson;
     }
     
     public DBAccess getDataSource()
     {
         return (DBAccess)get("dataSource");
     }
     
     public DBStorage getPerson()
     {
         return (DBStorage)get("person");
     }
 }
 

It's also possible to integrate the initialization into the get method, thats recommended. The disadvantage of this implementation is that more calls will be made (That's the result of avoiding recursive calls, because getPerson calls get("person") and this calls getPerson again), but you have the same flexibility as above and you have only one method where your object will be accessed:

 public class Session extends GenericBean
 {
     public DBAccess getDataSource() throws Exception
     {
         OracleDBAccess dba = (OracleDBAccess)get("dataSource");
         
         if (dba == null)
         {
             IConfiguration cfgSession = session.getCurrentSessionConfig();
             
             dba = new OracleDBAccess();
         
             dba.setConnection(cfgSession.getProperty("/application/securitymanager/database/url")); 
             dba.setUser(cfgSession.getProperty("/application/securitymanager/database/username"));
             dba.setPassword(cfgSession.getProperty("/application/securitymanager/database/password"));
             dba.open();
         }
         
         return dba;
     }
     
     public DBStorage getPerson() throws Exception
     {
         DBStorage dbsPerson = (DBStorage)get("person");
        
         if (dbsPerson == null)
         {
             dbsPerson = new DBStorage();
            
             dbsPerson.setDBAccess(getDataSource());
             dbsPerson.setWriteBackTable("V_PERSON");
             dbsPerson.setFromClause("V_PERSON");
             dbsPerson.open();
         }
        
         return dbsPerson;
     }
 }
 

The EJB like implementation looks like the following:

 public class Session extends GenericBean
 {
     private DBAccess dba;
     
     private DBStorage dbsPerson;
     
 
     public DBAccess getDataSource() throws Exception
     {
         if (dba == null)
         {
             IConfiguration cfgSession = session.getCurrentSessionConfig();
             
             dba = new OracleDBAccess();
         
             dba.setConnection(cfgSession.getProperty("/application/securitymanager/database/url")); 
             dba.setUser(cfgSession.getProperty("/application/securitymanager/database/username"));
             dba.setPassword(cfgSession.getProperty("/application/securitymanager/database/password"));
             dba.open();
             
             put("dataSource", dba);
         }
         
         return dba;
     }
     
     public DBStorage getPerson() throws Exception
     {
         if (dbsPerson == null)
         {
             dbsPerson = new DBStorage();
            
             dbsPerson.setDBAccess(getDataSource());
             dbsPerson.setWriteBackTable("V_PERSON");
             dbsPerson.setFromClause("V_PERSON");
             dbsPerson.open();
         }
        
         return dbsPerson;
     }
 }
 

The problem with above implementation is that the objects won't be managed from the expected GenericBean, if use extends from another GenericBean implementation like Session. That's the case because the extended class inherits all methods from the super class and all objects will be created in the inherited class if you call a method. But the objects from the super class should be stored in the super class instance!
We recommend to use the second or first implementation mechanism!

It's also possible to ignore lazy loading and generic object access. When you call get("person") you will get another object as dba, when you didn't put the object. And with this solutions you get the exception before using the object and that's not always the right place.
You can use one of the following mechanism:

 public class Session extends GenericBean
 {
     private DBAccess dba = createDataSource();
     
     private DBStorage dbsPerson = createPerson();
     
 
     public Session() throws Exception
     {
         //important because the create methods throws Exceptions
     }
 
     //dont set the name to initDataSource, unless you put(...) the instance, because thats the name 
     //of an automatic called method
     private DBAccess createDataSource() throws Exception
     {
         IConfiguration cfgSession = session.getCurrentSessionConfig();
         
         OracleDBAccess dba = new OracleDBAccess();
         
         dba.setConnection(cfgSession.getProperty("/application/securitymanager/database/url")); 
         dba.setUser(cfgSession.getProperty("/application/securitymanager/database/username"));
         dba.setPassword(cfgSession.getProperty("/application/securitymanager/database/password"));
         dba.open();
         
         //with this call you can set the method name to initDataSource and you can use get("dataSource")
         //and getDataSource without problems
         put("dataSource", dba);
         
         return dba;
     }
     
     //dont set the name to initDataSource, unless you put(...) the instance, because thats the name 
     //of an automatic called method
     private DBStorage createPerson() throws Exception
     {
         DBStorage dbsPerson = new DBStorage();
        
         dbsPerson.setDBAccess(getDataSource());
         dbsPerson.setWriteBackTable("V_PERSON");
         dbsPerson.setFromClause("V_PERSON");
         dbsPerson.open();
        
         //with this call you can set the method name to initPerson and you can use get("person")
         //and getPerson without problems
         put("person", dbsPerson);
        
         return dbsPerson;
     }
     
     public DBAccess getDataSource()
     {
         return dba;
     }
     
     public DBStorage getPerson()
     {
         return dbsPerson;
     }
 }
 

Another way is:

 public class Session extends GenericBean
 {
     private DBAccess dba;
     
     private DBStorage dbsPerson;
     
 
     public Session() throws Exception
     {
         IConfiguration cfgSession = session.getCurrentSessionConfig();
         
         OracleDBAccess dba = new OracleDBAccess();
         
         dba.setConnection(cfgSession.getProperty("/application/securitymanager/database/url")); 
         dba.setUser(cfgSession.getProperty("/application/securitymanager/database/username"));
         dba.setPassword(cfgSession.getProperty("/application/securitymanager/database/password"));
         dba.open();
         
         DBStorage dbsPerson = new DBStorage();
        
         dbsPerson.setDBAccess(getDataSource());
         dbsPerson.setWriteBackTable("V_PERSON");
         dbsPerson.setFromClause("V_PERSON");
         dbsPerson.open();
     }
     
     public DBAccess getDataSource()
     {
         return dba;
     }
     
     public DBStorage getPerson()
     {
         return dbsPerson;
     }
 }
 

Nested Class Summary

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K,V>

Field Summary

Fields inherited from class javax.rad.type.bean.AbstractBean

beanType

Constructor Summary

GenericBean()
Creates a new instance of GenericBean without a parent.

Method Summary

Object	get(int pIndex) Gets the value for a cached member variable.
Object	get(String pName) Gets the value of the property name.
Bean	getParent() Gets the parent, if set.
Object	invoke(String pMethod, Object... pParams) Invokes a method of this object via reflective call.
void	setParent(Bean pParent) Sets the parent bean for this bean.

Methods inherited from class javax.rad.type.bean.Bean

getObject, put

Methods inherited from class javax.rad.type.bean.AbstractBean

entrySet, getBeanType, put

Methods inherited from class java.util.AbstractMap

clear, clone, containsKey, containsValue, equals, get, hashCode, isEmpty, keySet, putAll, remove, size, toString, values

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

GenericBean

public GenericBean()

Creates a new instance of GenericBean without a parent.

Method Detail

get

public Object get(String pName)

Description copied from class: AbstractBean

Gets the value of the property name.

Specified by:

get in interface IBean

Overrides:

get in class AbstractBean<BeanType>

Parameters:

pName - the property name.

Returns:

the value of the property name.

get

public Object get(int pIndex)

Gets the value for a cached member variable. If the value for the member is not cached, it will be created with following rules:

• call the init<membername> method
• call the get<membername> method
• delegate to the parent, if available

Overrides:

get in class Bean

Parameters:

pIndex - the index of the property from the bean type

Returns:

the cached or created value; null if it's not possible to create a value

Throws:

RuntimeException - if an error occurs during object creation

setParent

public void setParent(Bean pParent)

Sets the parent bean for this bean.

Parameters:

pParent - the parent bean

getParent

public Bean getParent()

Gets the parent, if set.

Returns:

the parent or null if not set

invoke

public Object invoke(String pMethod,
                     Object... pParams)

Invokes a method of this object via reflective call. If the method is not declared, te invocation will be delegated to the parent, if available.

Parameters:

pMethod - the method name

pParams - the params for the method

Returns:

the return value of the method or null if the method doesn't return a value

Throws:

RuntimeException - if the desired method is not available or the method throws an erroror during execution