Use the factory to implement IOC

Content of the IOC. properties file (configuration file ):

# Interface = implementation class
Com. Kay. Struts. Dao. userdao=Com. Kay. Struts. Dao. impl. userdaoimpl

Factory type:PackageCom. Kay. Struts. Common;

ImportJava. Io. inputstream;
ImportJava. util. hashmap;
ImportJava. util. iterator;
ImportJava. util. Map;
ImportJava. util. properties;

Public   Final   Class Iocutil
{
// File Path
Private   Static   Final String filepath = " COM/Kay/struts/common/IOC. Properties " ;
Private   Static Map < Class, Object > Map;

/**
* Initialization Method
* @ Return
*/
Private   Static Map Init (){
Inputstream Input = Iocutil. Class . Getclassloader (). getresourceasstream (filepath );

Properties pro =   New Properties ();
Try
{
Pro. Load (input );
Input. Close ();
// Obtain the key set
Iterator ITER = Pro. keyset (). iterator ();
String key =   "" ;
String Value =   "" ;
Map =   New Hashmap < Class, Object > ();
While (ITER. hasnext ()){
Key = (String) ITER. Next ();
Value = Pro. getproperty (key );
Class CIA = Class. forname (key );
Object OBJ = Class. forname (value). newinstance ();
Map. Put (linoleic, OBJ );
}
Return Map;
}
Catch (Exception E)
{
E. printstacktrace ();
Return   Null ;
}
}

Public   Static Object Lookup (class CLs ){
If (Map =   Null ){
Map =   New Hashmap < Class, Object > ();
Init ();
}
Object OBJ = Map. Get (CLS );
If (OBJ ! =   Null ){
Return OBJ;
}
Return   Null ;
}

}

Userdao interface:PackageCom. Kay. Struts. Dao;

ImportCom. Kay. Struts. Common. Exception. daoexception;
ImportCom. Kay. Struts. VO. user;

Public InterfaceUserdao
{
PublicUser findbynameandpass (string name, string pass)ThrowsDaoexception;
}

Userdao interface implementation class:PackageCom. Kay. Struts. Dao. impl;

ImportCom. Kay. Struts. Common. Exception. daoexception;
ImportCom. Kay. Struts. Dao. userdao;
ImportCom. Kay. Struts. VO. user;

Public ClassUserdaoimpl
ImplementsUserdao
{

Public User findbynameandpass (string name, string pass)
Throws Daoexception
{
User user =   Null ;
If (Name. Equals ( " Tom " ) && Pass. Equals ( " 123 " )){
User =   New User ();
User. setid ( 1 );
User. setname (name );
User. setpass (PASS );
}
Return User;
}

}

Call method:
Userdao Dao = (userdao) iocutil. Lookup (userdao. Class );