WebSphere Studio Application Developer Version 5 Programming Guide part 7 doc

? Show members in Package Explorer, if enabled, displays Java elements below the level of Java files and Class files as well ? Compress package name segments, if enabled, compresses pack

Figure 2-9 Classpath variables preferences Figure 2-10 shows the New Variable Entry dialog with a DB2Java variable that points to the DB2 JDBC driver class The name of the file containing the class,

db2java.zip, is specified along with the file system path to it

Appearance of Java elements

The page Java -> Appearance provides a dialog with some settings regarding the appearance of Java elements in viewers Here you can change the following options:

򐂰 Show method return types, methods in views display their return types

򐂰 Show override indicators in outline and hierarchy displays an indicator for overridden and implemented methods in the Outline and the Type Hierarchy views

򐂰 Show members in Package Explorer, if enabled, displays Java elements below the level of Java files and Class files as well

򐂰 Compress package name segments, if enabled, compresses package names according to the compression pattern

򐂰 Stack views vertically in the Java Browsing perspective stacks the views in the Java Browsing perspective vertically rather than horizontally

Code formatter

The Java editor in the Workbench can be configured to format code in conformance with personal preferences or team standards When setting up the Workbench you can decide what formatting should be applied

To modify the default code formatting select Windows -> Preferences -> Java -> Code Formatter as shown in Figure 2-11

Use the tabs at the top of the page to modify various aspects of the code formatting The sample code in the bottom right pane shows you a preview of the effects of changes that you make

The code formatting options are almost self explaining However, a detailed description of each option is provided in Application Developer’s help manual

Note: To apply the formatting rules defined here, select Format from the Java editor context menu Some formatting, for example indenting of braces, will be done on the fly while you are editing the source code

Figure 2-11 Code Formatter preferences

Compiler options

Problems detected by the compiler are classified as either warnings or errors The existence of a warning does not affect the execution of the program The code executes as if it had been written correctly Compile-time errors (as specified by the Java Language Specification) are always reported as errors by the Java compiler

For some other types of problems you can, however, specify if you want the Java

Figure 2-12 Java compiler preferences dialog

Java Editor settings

By default the Java editor will use the standard Workbench font If you want to

Note: The Java compiler can create .class files even in presence of compilation errors In the case of serious errors (for example, references to inconsistent binaries, most likely related to an invalid build path), the Java builder does not produce any class file

Besides the font, the following Java editor preferences can be set on this page:

򐂰 Appearance

򐂰 Syntax

򐂰 Code Assist

򐂰 Problem Indication Figure 2-13 shows the Java editor preferences dialog

Figure 2-13 Java editor preferences There are a number of options for the code assist feature, which specify the behavior and appearance of code assist A description of how to use the code

Installed JREs

Application Developer allows you to specify which Java Runtime Environment (JRE) should be used by the Java builder By default the standard Java VM that comes with Application Developer is used, but if you have special requirements you may want to add another JRE to be used as default or for special projects Select Window -> Preferences -> Java -> Installed JREs to display the dialog as shown in Figure 2-14

Figure 2-14 Installed JREs

By default, the JRE used to run the Workbench will be used to build and run Java programs It appears with a check mark in the list of installed JREs You can add another JRE and indicate whether it should be the default JRE or not

When setting up the project you can also choose which of the JREs you would

You can either add, edit or remove a JRE by using this dialog To add a new JRE click Add This brings up a new dialog (Figure 2-15)

Figure 2-15 Add JRE dialog

In the JRE type field, select the type of JRE you want to add from the drop-down list and enter a unique name in the JRE name field In the JRE home directory field, type or click Browse to select the path to the root directory of the JRE installation (usually the directory containing the bin and lib directories for the JRE) This location is checked automatically to make sure it is a valid path

In the Javadoc URL field, type or click Browse to select the URL location The location is used by the Javadoc export wizard as a default value If you want to use the default libraries and source files for this JRE, select the Use default system libraries check box Otherwise, clear it and customize as desired Source can be attached for the referenced JARs as well

For more information regarding Javadoc, see this Web site:

http://java.sun.com/j2se/javadoc/

The JDT uses the Javadoc command (typically available in JDK distributions) to generate Javadoc documentation from source files Before you create Javadoc documentation, you have to set the location of the Javadoc command

Select Window -> Preferences -> Java -> Javadoc to open the Javadoc

preferences page (Figure 2-16)

Figure 2-16 Javadoc preferences

In the Javadoc command field you have to enter the absolute path to the Javadoc command A javadoc.exe file is located any JDK installed on your system, for

Once you have set the Javadoc command, you can start creating Javadoc documentation Therefore, select the set (containing one or more elements) of packages, source folders or projects for which you want to generate Javadoc documentation Then open the Export wizard by selecting File -> Export from the menu bar and Javadoc and click Next Now you have to go through three pages

of a wizard to customize the Javadoc export:

򐂰 In the first page of the wizard, select the types for which Javadoc will be generated and the members with visibility Also specify the destination folder where the documentation should be created

򐂰 In the second page of the wizard, you can specify a style sheet, the document title, document tags and basic options as well as the referenced classes to which Javadoc should create links

򐂰 In the third page of the wizard you can specify some extra Javadoc options and save the settings of the export as an Ant script

For an example of Javadoc generation see “Javadoc” on page 133

Organize imports

You can specify how you want the Java editor to handle imports when using the automatic import generation feature For more information on this feature see

“Import generation” on page 120

In the Organize Imports preferences (Figure 2-17) you can specify the order of the import statements You can also control at what stage <package name>.*

import statements should be generated rather than fully qualified import statements The default number of fully-qualified import statements that are allowed from the same package before <package>.* is 99

Use the Up and Down buttons to change the order to imports You can also add, edit and remove imports To add a new import entry, click New

In the new dialog, simply type the package name or the package name prefix you would like a add to the import statements list and confirm the dialog with OK

Tip: You can also save and load your import statements settings by using the

Figure 2-17 Organize Imports preferences

Refactoring

Refactoring refers to the process of moving or renaming Java elements A more detailed description about Application Developer’s refactoring capabilities and the refactoring preferences is provided in “Refactoring” on page 122

Templates

Application Developer also provides templates Templates are often reoccurring source code patterns The JDT of Application Developer offers support for creating, managing, and using templates

You can use a template in the Java editor by pressing Ctrl-Space (see “Code