Utilities › Invoke Java Operator › Input Parameters › Code › Java Code in the Invoke Java Operator

Java Code in the Invoke Java Operator

When using the Invoke Java operator, use the following guidelines for implementing Java code:

• CA Process Automation executes the Java code in a BeanShell interpreter. Use this operator with Java code syntax or BeanShell scripting syntax without use of BeanShell commands, in the following cases:
  • BeanShell commands do not work under Strict Java Mode (set at the module level).
  • BeanShell commands that modify the classpath are not recommended. They can affect the way CA Process Automation saves Java Object instances from the running Java code into the dataset of the operator.
  • BeanShell commands that modify the classpath can affect the way CA Process Automation loads Java Object instances from a CA Process Automation dataset into the code.

  For more information about BeanShell syntax and commands, see the following site: http://www.beanshell.org/

• You can use the standard Java variable modifiers on typed variables:
  • private / protected / public
  • transient
  • volatile
  • static
  • final

    The BeanShell interpreter only implements "final" (and ignores the others).

• You can use the standard Java modifiers on methods:
  • private / protected / public
  • final
  • native
  • abstract
  • static
  • synchronized

    Only "synchronized’ is currently implemented. The BeanShell interpreter ignores the others.

• Complete all class definitions in external JARS and use them in the Main Method code of the operator.
• The java rt.jar, which contains all the core java libraries, is automatically placed in the classpath of the operator at runtime.
• The JAR files used by CA Process Automation are in the classpath of the operator at runtime. Your code can work, even without listing all the needed JARS in the operator/category, if you happen to use classes already used by CA Process Automation.
• Common Java core packages and some extensions are automatically imported into your Java code at runtime. You do not need to import them in your code. Packages are as follows:
  • javax.swing.event
  • javax.swing
  • java.awt.event
  • java.awt
  • java.net
  • java.util
  • java.io
  • java.lang
  • bsh.EvalError
  • bsh.Interpreter
• The Java code can consist of normal Java statements and expressions. You can also define your own methods and use them inside the code. An example is as follows:

  // Import the classes that you want to use
  import ca.tech.pam.MyAccount;
  // Note: no need to import StringBuffer and Date because they are part of the 
  // automatically imported packages
  // import java.lang.StringBuffer;
  // import java.util.Date;
  // Note: the jar that contains the ca.tech.pam.MyAccount class 
  // must be in the list of External Jars of the operator or the module;
  // but java lang and java util are in rt.jar, which is automatically put in the classpath
  MyAccount acct = new MyAccount(newDate(),100);
  // Use the public methods of the MyAccount object
  acct.addFunds(34);
  acct.subFunds(10);
  // Define your own method
  String getStatement(MyAccount acc) {
      StringBuffer strBuff = new StringBuffer("Account Balance: " + acc.getBalance());
      Date dt = new Date(System.currentTimeMillis());
      strBuff.append(" on date: " + dt);
      return strBuff.toString();
  }
  // Use the method you defined
  // also print the statement using the 'logger' object that you 
  // setup in the 'Logger' page of the operator 
  logger.info(getStatement(acct));
  

  Note: To execute this statement, set the logger to true and provide the log file name. Otherwise an error occurs during execution.

  At the end of execution, the log message contains:

  Account Balance: 124.  on date: Wed Jul 13 12:53:37 EDT 2011
  

  (The message includes the correct date and time of execution.)