Problem:

• Product Name: VisiBroker for Java
• Product Version: 7.0, 8.0
• Product Component: vbjc compiler
• Platform/OS version: All
• JDK: Java 5 & later

 
The following warning messages are encountered when compiling the "Bank Agent" example in JDK 5 & later.
The "Bank Agent" example can be found in the directory: "/examples/vbroker/basic/bank_agent".
 
 

>vbmake
 Building the basic/bank_agent example ...
 Note: Some input files use unchecked or unsafe operations.
 Note: Recompile with -Xlint:unchecked for details.
 

To find out more about the warning messages, edit the vbmake file to add in the option "-Xlint:unchecked" to the vbjc command.

Example:
vbjc -Xlint:unchecked Client.java

vbjc -Xlint:unchecked Server.java


Next, run "vbmake clean", followed by "vbmake".
 

>vbmake
 Building the basic/bank_agent example ...
 .\\Bank\\AccountManagerPOA.java:38: warning: [unchecked] unchecked call to put(K,V) as a member of the raw type java.util.Dictionary
 _methods.put("open", new int[] { 0, 0 });
 ^
 .\\AccountManagerImpl.java:25: warning: [unchecked] unchecked call to put(K,V) as
 a member of the raw type java.util.Dictionary
 _accounts.put(name, account);
 ^
 .\\Bank\\AccountPOA.java:38: warning: [unchecked] unchecked call to put(K,V) as amember of the raw type java.util.Dictionary
 _methods.put("balance", new int[] { 0, 0 });
 ^
 3 warnings

Resolution:

 
Sun Microsystems introduce Generic classes in Java 5 & later.

The "unchecked or unsafe operations" warning is due to a missing type declaration.

For example:
ArrayList mylist = new ArrayList();

The above statement will generate a warning, there is no type declaration for ArrayList.

If the following is used, this statement will not generate a warning.

ArrayList<String> mylist = new ArrayList<String>();


The AccountManagerPOA.java (as well as the other POA java classes) which is generated by idl2java (a VisiBroker tool), will contain the declaration:

private static java.util.Dictionary _methods = new java.util.Hashtable();

Since there is no type declaration for java.util.Dictionary, this statement will generate a warning from the compiler.

The following provides a workaround,

1. Generating the xxxPOA files using "idl2java Bank.idl".

2. Edit the xxxPOA java files to add in the @SuppressWarnings("unchecked") string. The code provides a hint to the compiler to suppress the unchecked warnings.

Example: AccountManagerPOA.java

@SuppressWarnings("unchecked")
 public abstract class AccountManagerPOA extends org.omg.PortableServer.Servant implements
 org.omg.CORBA.portable.InvokeHandler, Bank.AccountManagerOperations {

...

}