Prev Class | Next Class | Frames | No Frames |
Summary: Nested | Field | Method | Constr | Detail: Nested | Field | Method | Constr |
URLClassLoader
org.apache.catalina.loader.WebappClassLoader
URLClassLoader
from the JDK. It is desinged to be fully
compatible with a normal URLClassLoader
, although its internal
behavior may be completely different.
IMPLEMENTATION NOTE - This class loader faithfully follows
the delegation model recommended in the specification. The system class
loader will be queried first, then the local repositories, and only then
delegation to the parent class loader will occur. This allows the web
application to override any shared class except the classes from J2SE.
Special handling is provided from the JAXP XML parser interfaces, the JNDI
interfaces, and the classes from the servlet API, which are never loaded
from the webapp repository.
IMPLEMENTATION NOTE - Due to limitations in Jasper
compilation technology, any repository which contains classes from
the servlet API will be ignored by the class loader.
IMPLEMENTATION NOTE - The class loader generates source
URLs which include the full JAR URL when a class is loaded from a JAR file,
which allows setting security permission at the class level, even when a
class is contained inside a JAR.
IMPLEMENTATION NOTE - Local repositories are searched in
the order they are added via the initial constructor and/or any subsequent
calls to addRepository()
or addJar()
.
IMPLEMENTATION NOTE - No check for sealing violations or
security is made unless a security manager is present.
Nested Class Summary | |
protected class |
Field Summary | |
protected int |
|
protected boolean |
|
protected File[] |
|
protected boolean |
|
protected JarFile[] |
|
protected String[] |
|
protected String |
|
protected File[] |
|
protected long |
|
protected long[] |
|
protected HashMap |
|
protected String[] |
|
protected String[] |
|
protected URL[] |
|
protected HashMap |
|
protected DirContext |
|
protected static StringManager |
|
protected boolean |
|
Fields inherited from interface org.apache.catalina.Lifecycle | |
AFTER_START_EVENT , AFTER_STOP_EVENT , BEFORE_START_EVENT , BEFORE_STOP_EVENT , START_EVENT , STOP_EVENT |
Constructor Summary | |
| |
|
Method Summary | |
void |
|
void |
|
void |
|
void |
|
void |
|
protected void |
|
void |
|
protected static void |
|
protected boolean |
|
Class |
|
protected Class |
|
LifecycleListener[] |
|
protected Class |
|
protected InputStream |
|
String[] |
|
URL |
|
protected ResourceEntry |
|
Enumeration |
|
int |
|
boolean |
|
String |
|
protected PermissionCollection |
|
URL |
|
InputStream |
|
DirContext |
|
protected URL |
|
protected URL |
|
URL[] |
|
protected boolean |
|
Class |
|
Class |
|
boolean |
|
protected void |
|
protected void |
|
void |
|
void |
|
void |
|
void |
|
void |
|
void |
|
void |
|
void |
|
String |
|
protected boolean |
|
protected int debug
The debugging detail level of this component.
protected boolean delegate
Should this class loader delegate to the parent class loader before searching its own repositories (i.e. the usual Java2 delegation model)? If set tofalse
, this class loader will search its own repositories first, and delegate to the parent only if the class or resource is not found locally.
protected File[] files
Repositories translated as path in the work directory (for Jasper originally), but which is used to generate fake URLs should getURLs be called.
protected boolean hasExternalRepositories
Has external repositories.
protected JarFile[] jarFiles
The list of JARs, in the order they should be searched for locally loaded classes or resources.
protected String[] jarNames
The list of JARs, in the order they should be searched for locally loaded classes or resources.
protected String jarPath
The path which will be monitored for added Jar files.
protected File[] jarRealFiles
The list of JARs, in the order they should be searched for locally loaded classes or resources.
protected long lastJarAccessed
Last time a JAR was accessed.
protected long[] lastModifiedDates
The list of JARs last modified dates, in the order they should be searched for locally loaded classes or resources.
protected HashMap notFoundResources
The list of not found resources.
protected String[] paths
The list of resources which should be checked when checking for modifications.
protected String[] repositories
The list of local repositories, in the order they should be searched for locally loaded classes or resources.
protected URL[] repositoryURLs
Repositories URLs, used to cache the result of getURLs.
protected HashMap resourceEntries
The cache of ResourceEntry for classes and resources we have loaded, keyed by resource name.
protected DirContext resources
Associated directory context giving access to the resources in this webapp.
protected boolean started
Has this component been started?
public WebappClassLoader()
Construct a new ClassLoader with no defined repositories and no parent ClassLoader.
public WebappClassLoader(ClassLoader parent)
Construct a new ClassLoader with no defined repositories and no parent ClassLoader.
public void addLifecycleListener(LifecycleListener listener)
Add a lifecycle event listener to this component.
- Specified by:
- addLifecycleListener in interface Lifecycle
- Parameters:
listener
- The listener to add
public void addPermission(Permission permission)
If there is a Java SecurityManager create a Permission.
- Parameters:
public void addPermission(String path)
If there is a Java SecurityManager create a read FilePermission or JndiPermission for the file directory path.
- Parameters:
path
- file directory path
public void addPermission(URL url)
If there is a Java SecurityManager create a read FilePermission or JndiPermission for URL.
- Parameters:
url
- URL for a file or directory on local system
public void addRepository(String repository)
Add a new repository to the set of places this ClassLoader can look for classes to be loaded.
- Specified by:
- addRepository in interface Reloader
- Parameters:
repository
- Name of a source of classes to be loaded, such as a directory pathname, a JAR file pathname, or a ZIP file pathname
protected void addURL(URL url)
Add the specified URL to the classloader.
public void closeJARs(boolean force)
Used to periodically signal to the classloader to release JAR resources.
protected static void deleteDir(File dir)
Delete the specified directory, including all of its contents and subdirectories recursively.
- Parameters:
dir
- File object representing the directory to be deleted
protected boolean filter(String name)
Filter classes.
- Parameters:
name
- class name
- Returns:
- true if the class should be filtered
public Class findClass(String name) throws ClassNotFoundException
Find the specified class in our local repositories, if possible. If not found, throwClassNotFoundException
.
- Parameters:
name
- Name of the class to be loaded
protected Class findClassInternal(String name) throws ClassNotFoundException
Find specified class in local repositories.
- Returns:
- the loaded class, or null if the class isn't found
public LifecycleListener[] findLifecycleListeners()
Get the lifecycle listeners associated with this lifecycle. If this Lifecycle has no listeners registered, a zero-length array is returned.
- Specified by:
- findLifecycleListeners in interface Lifecycle
protected Class findLoadedClass0(String name)
Finds the class with the given name if it has previously been loaded and cached by this class loader, and return the Class object. If this class has not been cached, returnnull
.
- Parameters:
name
- Name of the resource to return
protected InputStream findLoadedResource(String name)
Finds the resource with the given name if it has previously been loaded and cached by this class loader, and return an input stream to the resource data. If this resource has not been cached, returnnull
.
- Parameters:
name
- Name of the resource to return
public String[] findRepositories()
Return a String array of the current repositories for this class loader. If there are no repositories, a zero-length array is returned.For security reason, returns a clone of the Array (since String are immutable).
- Specified by:
- findRepositories in interface Reloader
public URL findResource(String name)
Find the specified resource in our local repository, and return aURL
refering to it, ornull
if this resource cannot be found.
- Parameters:
name
- Name of the resource to be found
protected ResourceEntry findResourceInternal(String name, String path)
Find specified resource in local repositories.
- Returns:
- the loaded resource, or null if the resource isn't found
public Enumeration findResources(String name) throws IOException
Return an enumeration ofURLs
representing all of the resources with the given name. If no resources with this name are found, return an empty enumeration.
- Parameters:
name
- Name of the resources to be found
public int getDebug()
Return the debugging detail level for this component.
public boolean getDelegate()
Return the "delegate first" flag for this class loader.
public String getJarPath()
Return the JAR path.
protected PermissionCollection getPermissions(CodeSource codeSource)
Get the Permissions for a CodeSource. If this instance of WebappClassLoader is for a web application context, add read FilePermission or JndiPermissions for the base directory (if unpacked), the context URL, and jar file resources.
- Parameters:
codeSource
- where the code was loaded from
- Returns:
- PermissionCollection for CodeSource
public URL getResource(String name)
Find the resource with the given name. A resource is some data (images, audio, text, etc.) that can be accessed by class code in a way that is independent of the location of the code. The name of a resource is a "/"-separated path name that identifies the resource. If the resource cannot be found, returnnull
. This method searches according to the following algorithm, returning as soon as it finds the appropriate URL. If the resource cannot be found, returnsnull
.
- If the
delegate
property is set totrue
, call thegetResource()
method of the parent class loader, if any.- Call
findResource()
to find this resource in our locally defined repositories.- Call the
getResource()
method of the parent class loader, if any.
- Parameters:
name
- Name of the resource to return a URL for
public InputStream getResourceAsStream(String name)
Find the resource with the given name, and return an input stream that can be used for reading it. The search order is as described forgetResource()
, after checking to see if the resource data has been previously cached. If the resource cannot be found, returnnull
.
- Parameters:
name
- Name of the resource to return an input stream for
public DirContext getResources()
Get associated resources.
protected URL getURI(File file) throws MalformedURLException
Get URL.
protected URL getURL(File file) throws MalformedURLException
Get URL.
public URL[] getURLs()
Returns the search path of URLs for loading classes and resources. This includes the original list of URLs specified to the constructor, along with any URLs subsequently appended by the addURL() method.
- Returns:
- the search path of URLs for loading classes and resources.
protected boolean isPackageSealed(String name, Manifest man)
Returns true if the specified package name is sealed according to the given manifest.
public Class loadClass(String name) throws ClassNotFoundException
Load the class with the specified name. This method searches for classes in the same manner asloadClass(String, boolean)
withfalse
as the second argument.
- Parameters:
name
- Name of the class to be loaded
public Class loadClass(String name, boolean resolve) throws ClassNotFoundException
Load the class with the specified name, searching using the following algorithm until it finds and returns the class. If the class cannot be found, returnsClassNotFoundException
.If the class was found using the above steps, and the
- Call
findLoadedClass(String)
to check if the class has already been loaded. If it has, the sameClass
object is returned.- If the
delegate
property is set totrue
, call theloadClass()
method of the parent class loader, if any.- Call
findClass()
to find this class in our locally defined repositories.- Call the
loadClass()
method of our parent class loader, if any.resolve
flag istrue
, this method will then callresolveClass(Class)
on the resulting Class object.
- Parameters:
name
- Name of the class to be loadedresolve
- Iftrue
then resolve the class
public boolean modified()
Have one or more classes or resources been modified so that a reload is appropriate?
protected void openJARs()
Used to periodically signal to the classloader to release JAR resources.
protected void refreshPolicy()
Refresh the system policy file, to pick up eventual changes.
public void removeLifecycleListener(LifecycleListener listener)
Remove a lifecycle event listener from this component.
- Specified by:
- removeLifecycleListener in interface Lifecycle
- Parameters:
listener
- The listener to remove
public void setDebug(int debug)
Set the debugging detail level for this component.
- Parameters:
debug
- The new debugging detail level
public void setDelegate(boolean delegate)
Set the "delegate first" flag for this class loader.
- Parameters:
delegate
- The new "delegate first" flag
public void setJarPath(String jarPath)
Change the Jar path.
public void setResources(DirContext resources)
Set associated resources.
public void setWorkDir(File workDir)
Change the work directory.
public void start() throws LifecycleException
Start the class loader.
- Throws:
LifecycleException
- if a lifecycle error occurs
public void stop() throws LifecycleException
Stop the class loader.
- Throws:
LifecycleException
- if a lifecycle error occurs
public String toString()
Render a String representation of this object.
protected boolean validate(String name)
Validate a classname. As per SRV.9.7.2, we must restict loading of classes from J2SE (java.*) and classes of the servlet API (javax.servlet.*). That should enhance robustness and prevent a number of user error (where an older version of servlet.jar would be present in /WEB-INF/lib).
- Parameters:
name
- class name
- Returns:
- true if the name is valid