Example of stateful and stateless Session Bean Development

For EJB development, you must first find it in the Client Directory of the JBoss installation path. Generally, all jar files under the Client Directory are added to the class path of the project.

Write an interface, and then write a class that implements the interface. The following example shows the call between beans,CodeHave detailed annotations

Example:

1. Write Interfaces

Other

 
PackageCom. tjp. ejb3;

Public InterfaceOther {

PublicString say (string Str );
}
 

Helloword

PackageCom. tjp. ejb3;

Public InterfaceHelloword {

PublicString sayhello (string Str );
}
 

Hellowordlocal

 
PackageCom. tjp. ejb3;

Public InterfaceHellowordlocalExtendsHelloword {

}
 

2. Compile the implementation class

Otherbean

 Package  Com. tjp. ejb3.impl;

  Import  Javax. EJB. stateless;

  Import  Com. tjp. ejb3.other;

  /**  
*
* Stateless Bean
* The Local interface is used by default.
*  @ Author  Tanjianping
*
  */  
@ Stateless
  Public    Class  Otherbean  Implements  Other {

@ Override
  Public  String say (string Str ){
  //  Todo auto-generated method stub  
    Return  STR;
}

} 

Hellowordbean

 Package Com. tjp. ejb3.impl;

  Import  Javax. Activation. datasource;
  Import  Javax. annotation. resource;
  Import  Javax. EJB. EJB;
  Import  Javax. EJB. Local;
  Import  Javax. EJB. Remote;
  Import  Javax. EJB. stateful;
  Import Javax. EJB. stateless;
  Import  Javax. Naming. initialcontext;

  Import  Org. Omg. costime. timeservice;

  Import  Com. tjp. ejb3.helloword;
  Import  Com. tjp. ejb3.hellowordlocal;
  Import  Com. tjp. ejb3.other;

  /** 
*
* @ Stateless bean, @ stateful is stateful Bean
* @ Remote (helloword. Class) helloword is a remote interface. If this parameter is left blank, it is a local interface.
* @ Local (hellowordlocal. Class) Local interface
*  @ Author  Tanjianping
*
  */  
@ Stateful
@ Remote (helloword.  Class  )
@ Local (hellowordlocal.  Class  )
  Public     Class  Hellowordbean Implements  Helloword, hellowordlocal {

@ EJB (beanname  =  "  Otherbean/local  "  )
Other;  //  Injection of other ejbs using annotations  
  
@ Resource timeservice;  //  Scheduled service resource introduces other services  
  @ Resource (mappedname =  "  Java: XXX  "  ) Datasource;  //  Reference Data Source  
  
@ Override
  Public  String sayhello (string Str ){

  /* Try {
Initialcontext CTX = new initialcontext (); // use the attribute File
Other = (other) CTX. Lookup ("otherbean/local ");
Return "Other said:" + other. Say (STR );
} Catch (exception e ){
// Todo auto-generated Catch Block
E. printstacktrace ();
}  */  
  Return     "  Other said:  "  +  Other. Say (STR );
}

} 

Build. xml

<?  XML version = "1.0" encoding = "UTF-8"  ?>  
  <! --  Name indicates the directory where the project name basedir project is located, 1 point indicates that the project is in the same directory of build. XML, and 2 points indicates the parent directory of build. xml.  -->  
  <  Project  Name  = "Helloejb"  Basedir  = "."  >  
 <! --  The $ {basedir} directory of the specified project source file indicates that the source directory is under the SRC of the project.  -->  
  <  Property  Name  = "Src. dir"  Value  = "$ {Basedir}/src"     />  
  <! --  Environment variable to the operating system: Environment = "env"  --> 
  <  Property  Environment  = "Env"     />  
  <! --  $ {Env. jboss_home} The jboos environment variable is the installation directory.  -->  
  <  Property  Name  = "JBoss. Home" Value  = "$ {Env. jboss_home }"     />  
  <! --  Configuration items currently used by JBoss  -->  
  <  Property  Name  = "JBoss. server. config"  Value  = "Default"    />  
  <! --  $ {Basedir}/build the directory where the source file class is stored  -->  
  <  Property  Name  = "Build. dir"  Value  = "$ {Basedir}/build"     />  

  < Path  ID  = "Build. classpath"  >  
  <! --  Convert all the jar packages of the client under JBoss  -->  
  <  Fileset  Dir  = "$ {JBoss. Home}/client"  >  
  <  Include Name  = "*. Jar"     />  
  </  Fileset  >  
  <  Pathelement  Location  = "$ {Build. dir }"     />  
  </ Path  >  

  <! --  Define a job to create a directory for storing class files.  -->  
  <  Target  Name  = "Prepare"  >  
  <  Delete  Dir  = "$ {Build. dir }"    />  
  <  Mkdir  Dir  = "$ {Build. dir }"     />  
  </  Target  >  

  <! --  Depends = "prepare": run the prepare task first.  --> 
  <  Target  Name  = "Compile"  Depends  = "Prepare"  Description  = "Compile"  >  
  <  Javac  Srcdir  = "$ {SRC. dir }"  Destdir  = "$ {Build. dir }" >  
  <  Classpath  RefID  = "Build. classpath"     />  
  </  Javac  >  
  </  Target  >  

 <  Target  Name  = "Ejbjar"  Depends  = "Compile"  Description  = "Create an EJB release package"  >  
  <  Jar  Jarfile  = "$ {Basedir}/$ {ant. Project. name}. Jar"  >  
 <  Fileset  Dir  = "$ {Build. dir }"  >  
  <  Include  Name  = "**/*. Class"     />  
  </  Fileset  >  
 </  Jar  >  
  </  Target  >  

  <  Target  Name  = "Deploy"  Depends  = "Ejbjar"  Description  = "Publishing EJB"  > 
  <  Copy  File  = "$ {Basedir}/$ {ant. Project. name}. Jar"  
Todir  = "$ {JBoss. Home}/Server/$ {JBoss. server. config}/deploy"     />  
  </  Target  >  

  <  Target Name  = "Undeploy"  Description  = "Uninstall EJB"  >  
  <  Delete
  File  = "$ {JBoss. Home}/Server/$ {JBoss. server. config}/deploy"     />  
  </  Target  > 
  </  Project  >