org.netbeans.api.java/1 1.13.1

org.netbeans.api.java.classpath
Class ClassPath

java.lang.Object
  extended by org.netbeans.api.java.classpath.ClassPath

public final class ClassPath
extends Object

ClassPath objects should be used to access contents of the ClassPath, searching for resources, objects reachable using the ClassPath at runtime. It is intended to replace some of the functionality of org.openide.filesystems.Repository.
ClassPath instances should be used to map from Java-style resource names to FileObject (NetBeans-style resource) and vice versa. It should be also used whenever the operation requires inspection of development or runtime project environment instead. The service supports either searching in the classpath resource space, properly hiding resources as the ClassLoader would do at runtime. It can effectively say whether a FileObject is within the reach of a ClassPath or whether it is reachable (visible to a ClassLoader). One can translate filenames to resource names and vice versa.

A client may obtain a ClassPath instance using ClassPath.getClassPath(id) static method, where the ID is an abstract name for the classpath wanted. There are some predefined classpath names predefined as symbolic constants, following individual types of services (compiler, debugger, executor). Names are not limited to the listed ones; an extension module might add its own private classpath type.


Nested Class Summary
 class ClassPath.Entry
          Represents an individual entry in the ClassPath.
 
Field Summary
static String BOOT
          Boot ClassPath of the JDK.
static String COMPILE
          ClassPath for compiling things.
static String DEBUG
          Deprecated. Probably useless.
static String EXECUTE
          Classpath setting for executing things.
static String PROP_ENTRIES
          Name of the "entries" property
static String PROP_INCLUDES
          Property to be fired when include/exclude set changes.
static String PROP_ROOTS
          Name of the "roots" property
static String SOURCE
          ClassPath for project sources.
 
Method Summary
 void addPropertyChangeListener(PropertyChangeListener l)
          Adds a property change listener to the bean.
 boolean contains(FileObject f)
          Checks whether a FileObject lies on this classpath.
 List<ClassPath.Entry> entries()
          Returns list of classpath entries from the ClassPath definition.
 List<FileObject> findAllResources(String resourceName)
          Gives out an ordered collection containing all FileObjects, which correspond to a given ResourceName; only the first one is seen by the ClassLoader at runtime or can be linked against.
 FileObject findOwnerRoot(FileObject resource)
          Finds a root in this ClassPath, that owns the given file.
 FileObject findResource(String resourceName)
          Returns a FileObject for the specified resource.
 ClassLoader getClassLoader(boolean cache)
          Returns a ClassLoader for loading classes from this ClassPath.
static ClassPath getClassPath(FileObject f, String id)
          Find the classpath of a given type, if any, defined for a given file.
 String getResourceName(FileObject f)
          Creates a suitable resource name for the given FileObject within the classpath.
 String getResourceName(FileObject f, char dirSep, boolean includeExt)
          Computes a resource name for the FileObject, which uses `pathSep' character as a directory separator.
 FileObject[] getRoots()
          Retrieves valid roots of ClassPath, in the proper order.
 boolean isResourceVisible(FileObject resource)
          Determines if the resource is visible in the classpath, that is if the file will be reached when a process attempts to load a resource of that name.
 void removePropertyChangeListener(PropertyChangeListener l)
          Removes the listener registered by addPropertyChangeListener.
 String toString()
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

EXECUTE

public static final String EXECUTE
Classpath setting for executing things. This type can be used to learn runtime time classpath for execution of the file in question.

It corresponds to the -classpath option to java (the Java launcher): i.e. all compiled classes outside the JRE that will be needed to run the program, or at least to load a certain class. It may also be thought of as corresponding to the list of URLs in a URLClassLoader (plus URLs present in parent class loaders but excluding the bootstrap and extension class loaders).

See Also:
Constant Field Values

DEBUG

@Deprecated
public static final String DEBUG
Deprecated. Probably useless.
Classpath for debugging things

See Also:
Constant Field Values

COMPILE

public static final String COMPILE
ClassPath for compiling things. This type can be used to learn compilation time classpath for the file in question.

It corresponds to the -classpath option to javac: i.e. already-compiled classes which some new sources need to compile against, besides what is already in the JRE.

See Also:
Constant Field Values

SOURCE

public static final String SOURCE
ClassPath for project sources. This type can be used to learn package root of the file in question.

It is similar to the -sourcepath option of javac.

For typical source files, the sourcepath will consist of one element: the package root of the source file. If more than one package root is to be compiled together, all the sources should share a sourcepath with multiple roots.

Note that each source file for which editor code completion (and similar actions) should work should have a classpath of this type.

Since:
org.netbeans.api.java/1 1.4
See Also:
Constant Field Values

BOOT

public static final String BOOT
Boot ClassPath of the JDK. This type can be used to learn boot classpath which should be used for the file in question.

It corresponds to the -Xbootclasspath and -Xext options to java (the Java launcher): i.e. all compiled classes in the JRE that will be needed to run the program. It may also be thought of as corresponding to the classes loadable by the primordial bootstrap class loader plus the standard extension and endorsed-library class loaders; i.e. class loaders lying below the regular application startup loader and any custom loaders. Generally there ought to be a single boot classpath for the entire application.

Since:
org.netbeans.api.java/1 1.4
See Also:
Constant Field Values

PROP_ROOTS

public static final String PROP_ROOTS
Name of the "roots" property

See Also:
Constant Field Values

PROP_ENTRIES

public static final String PROP_ENTRIES
Name of the "entries" property

See Also:
Constant Field Values

PROP_INCLUDES

public static final String PROP_INCLUDES
Property to be fired when include/exclude set changes.

Since:
org.netbeans.api.java/1 1.13
See Also:
FilteringPathResourceImplementation, Constant Field Values
Method Detail

getRoots

public FileObject[] getRoots()
Retrieves valid roots of ClassPath, in the proper order. If there's an entry in the ClassPath, which cannot be accessed, its root is not returned by this method. FileObjects returned are all folders. Note that this method ignores includes and excludes.

Returns:
array of roots (folders) of the classpath. Never returns null.

entries

public List<ClassPath.Entry> entries()
Returns list of classpath entries from the ClassPath definition. The implementation must ensure that modifications done to the List are banned or at least not reflected in other Lists returned by this ClassPath instance. Clients must assume that the returned value is immutable.

Returns:
list of definition entries (Entry instances)

findResource

public final FileObject findResource(String resourceName)
Returns a FileObject for the specified resource. May return null, if the resource does not exist, or is not reachable through this ClassPath.
If the resourceName identifies a package, this method will return the FileObject for the first package fragment in the ClassPath. FilteringPathResourceImplementation may cause an actual file beneath a registered root to not be returned. Note: do not pass names starting with slash to this method.

Parameters:
resourceName - name of the resource as it would be passed to ClassLoader.getResource(java.lang.String)
Returns:
FileObject for the resource, or null if the resource cannot be found in this ClassPath.

findAllResources

public final List<FileObject> findAllResources(String resourceName)
Gives out an ordered collection containing all FileObjects, which correspond to a given ResourceName; only the first one is seen by the ClassLoader at runtime or can be linked against. The resource name uses slashes ('/') as folder separator and must not start with slash. FilteringPathResourceImplementation may cause an actual file beneath a registered root to not be returned.

Parameters:
resourceName - resource name
Returns:
list of resources identified by the given name.

getResourceName

public final String getResourceName(FileObject f)
Creates a suitable resource name for the given FileObject within the classpath. The method will return null if the fileobject is not underneath any of classpath roots.
The returned name uses uses slashes ('/') as folder separators and dot ('.') to separate file name and its extension. Note that if the file object is in the classpath subtree, but is not reachable (it is hidden by some other resource, or excluded), the resource name is still returned.

Parameters:
f - FileObject whose resource name is requested
Returns:
Java-style resource name for the given file object (the empty string for the package root itself), or null if not within the classpath

getResourceName

public final String getResourceName(FileObject f,
                                    char dirSep,
                                    boolean includeExt)
Computes a resource name for the FileObject, which uses `pathSep' character as a directory separator. The resource name can be returned without the file extension, if desired. Note that parent folder names are always returned with extension, if they have some.

Parameters:
f - FileObject whose resource name is requested.
dirSep - directory separator character
includeExt - whether the FileObject's extension should be included in the result
Returns:
resource name for the given FileObject (the empty string for the package root itself) or null

findOwnerRoot

public final FileObject findOwnerRoot(FileObject resource)
Finds a root in this ClassPath, that owns the given file. File resources, that are not reachable (they are hidden by other resources, or FilteringPathResourceImplementation excluded) are still considered to be part of the classpath and "owned" by one of its roots.
Note: This implementation assumes that the FileSystem hosting a classpath root contains the entire classpath subtree rooted at that root folder.

Parameters:
resource - resource to find root for.
Returns:
classpath root, which hosts the specified resouce. It can return null, if the resource is not within the ClassPath contents.

contains

public final boolean contains(FileObject f)
Checks whether a FileObject lies on this classpath. FilteringPathResourceImplementation is considered.

Parameters:
f - the FileObject to check
Returns:
true, if the parameter is inside one of the classpath subtrees, false otherwise.

isResourceVisible

public final boolean isResourceVisible(FileObject resource)
Determines if the resource is visible in the classpath, that is if the file will be reached when a process attempts to load a resource of that name. It will return false when the resource is not contained in the classpath, or the resource is excluded.

Parameters:
resource - the resource whose visibility should be tested
Returns:
true, if the resource is contained in the classpath and visible; false otherwise.

addPropertyChangeListener

public final void addPropertyChangeListener(PropertyChangeListener l)
Adds a property change listener to the bean.

Parameters:
l - a listener to add

removePropertyChangeListener

public final void removePropertyChangeListener(PropertyChangeListener l)
Removes the listener registered by addPropertyChangeListener.

Parameters:
l - a listener to remove

getClassPath

public static ClassPath getClassPath(FileObject f,
                                     String id)
Find the classpath of a given type, if any, defined for a given file.

This method may return null, if:

Generally you may pass either an individual Java file, or the root of a Java package tree, interchangeably, since in most cases all files in a given tree will share a single classpath.

Typically classpaths for files are defined by the owning project, but there may be other ways classpaths are defined. See ClassPathProvider for more details.

Parameters:
f - the file, whose classpath settings should be returned (may not be null as of org.netbeans.api.java/1 1.4)
id - the type of the classpath (e.g. COMPILE)
Returns:
classpath of the desired type for the given file object, or null, if there is no classpath available
See Also:
ClassPathProvider

toString

public String toString()
Overrides:
toString in class Object

getClassLoader

public final ClassLoader getClassLoader(boolean cache)
Returns a ClassLoader for loading classes from this ClassPath.

If cache is false, then the method will always return a new class loader. If that parameter is true, the method may return a loader which survived from a previous call to the same ClassPath.

Parameters:
cache - true if it is permissible to cache class loaders between calls
Returns:
class loader which uses the roots in this class path to search for classes and resources
Since:
1.2.1

org.netbeans.api.java/1 1.13.1

Built on January 29 2008.  |  Portions Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.