ClassPathProvider (NetBeans Java Support APIs) - NetBeans API Javadoc 4.1.0

Note that to make editor code completion functionality work for a Java source file the following classpaths must be available for it:

1. The ClassPath.BOOT type of classpath is required or the source file will not be parsable and code completion will be disabled. See also SourceLevelQueryImplementation.
2. The ClassPath.SOURCE type of classpath is required or code completion will be disabled. Providing this classpath will enable code completion, but only elements defined on this classpath will be offered if the compile classpath is missing.
3. The ClassPath.COMPILE type of classpath is recommended to be provide to make code completion work fully by suggesting all classes against which the source is developed.

ClassPath.EXECUTE is also recommended for e.g. I18N functionality to work. This should contain the full run-time classpath of the class, including its build location (bytecode).

You should return these classpaths for the package root folder and any files or folders inside it.

You should register classpaths for source files of all these types in GlobalPathRegistry when they are to be exposed in the GUI as available for use (e.g. for the editor's Fast Open dialog), and unregister them when they are no longer to be exposed. Typically this is done as part of ProjectOpenedHook.

It is also desirable to produce classpath information for compiled class files (bytecode), including their package roots (whether a disk folder or a JAR root). This will enable parsing of the class files, which is sometimes needed (e.g. for expanding the class file node and seeing its members). Compiled classes should have:

1. ClassPath.BOOT corresponding to the Java platform to be used with the classes.
2. ClassPath.EXECUTE containing the bytecode's package root itself, plus any other libraries it needs to resolve against. Should normally be the same as the execute classpath of the corresponding source files.

If no specific class path providers are available for a given source file or bytecode file, i.e. null is returned from all providers, there may be a fallback implementation which would provide reasonable defaults. For source files, this could mean a boot classpath corresponding to the default Java platform (i.e. the JDK being used to run the IDE); empty compile and execute classpaths; and a sourcepath computed based on the package statement in the source file (if this is possible). For class files, this could mean a boot classpath determined as for source files, and an execute classpath containing the package root apparently owning the class file (computed according to the class file's package information, if this is possible).