13
Java-Related Issues

This chapter describes migration steps to take if your Forms applications use Java-related components.

Using oracle.ewt Classes in Pluggable Java Components

Pluggable Java Components (PJCs) and JavaBeans use classes that are part of the oracle.ewt framework. When upgrading to Oracle9i Forms, there are steps you must take to ensure equivalent functionality.

• Be sure to set the following:
  SET FORMS90_BUILDER_CLASSPATH=%ORACLE_HOME%\forms90\java\f90all.jar
  The Oracle9i Forms JAR files (f90all.jar and f90all_jinit.jar) only contain the ewt classes, which are required by the Forms Java Client. Therefore, PJCs that had been used with Forms6i may fail at runtime in Oracle9i Forms because the classes that were available in Forms6i can no longer be located. Missing oracle.ewt classes are available in ewt.jar, which is supplied with Oracle9i JDeveloper.

  Because of security constraints related to Java 1.3, which is used by Oracle9i Forms, you must re-sign all of the classes (including the Forms classes) with your own certificate. Java 1.3 requires that all classes from the same package be signed with the same certificate. Therefore, if you need to use extra classes from ewt.jar in combination with f90all.jar, you must re-sign all of the classes with your own certificate.

  The sample PJCs and JavaBeans provided by Oracle are re-coded to use Swing classes or oracle.ewt classes. The sample PJCs and JavaBeans that are provided with Oracle9i Forms will not encounter this problem.

JDK Versions and Font-Rendering Issues

When migrating Forms applications from JDK 1.1 to JDK 1.3 or higher, you may encounter font height changes. This is because the code that renders fonts underwent significant changes from JDK 1.1 to JDK 1.3. As a result of these changes, the font height for logical fonts of the same size increased in JDK 1.3. For example, a dialog font of size 12 points has a height of 15 points in JDK 1.1 and a height of 17 points in JDK 1.3.

In Forms applications, the font size changes may affect labels, which can overlap text fields. One possible workaround is to set the following applet parameter to "yes":

<PARAM NAME = "mapFonts" VALUE = "yes" >

After making this change, check the appearance of the font size to be sure it is acceptable. You may still need to modify the form if this workaround does not provide acceptable font sizes. See the Oracle9iAS Forms Services Deployment Guide for details.