Class DatabaseClasses
- All Implemented Interfaces:
ClassFactory
,ModuleControl
- Direct Known Subclasses:
ReflectClassesJava2
This class manages a hash table of loaded generated classes and their GeneratedClass objects. A loaded class may be referenced multiple times -- each class has a reference count associated with it. When a load request arrives, if the class has already been loaded, its ref count is incremented. For a remove request, the ref count is decremented unless it is the last reference, in which case the class is removed. This is transparent to users.
- See Also:
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Field Summary
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoid
boot
(boolean create, Properties startParams) Boot this module with the given properties.Return a ClassInspector objectint
Return the in-memory "version" of the class manager.private static ModuleFactory
Privileged Monitor lookup.boolean
isApplicationClass
(Class theClass) Was the passed in class loaded by a ClassManager.final Class
loadApplicationClass
(ObjectStreamClass classDescriptor) Load an application class, or a class that is potentially an application class.final Class
loadApplicationClass
(String className) Load an application class, or a class that is potentially an application class.(package private) abstract Class
loadClassNotInDatabaseJar
(String className) final GeneratedClass
loadGeneratedClass
(String fullyQualifiedName, ByteArray classDump) Here we load the newly added class now, rather than waiting for the findGeneratedClass().(package private) abstract LoadedGeneratedClass
loadGeneratedClassFromData
(String fullyQualifiedName, ByteArray classDump) protected ClassInspector
For creating the class inspector.void
notifyModifyClasspath
(String classpath) Notify the class manager that the classpath has been modified.void
notifyModifyJar
(boolean reload) Notify the class manager that a jar file has been modified.void
stop()
Stop the module.private static void
WriteClassFile
(String fullyQualifiedName, ByteArray bytecode, Throwable t)
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Field Details
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classInspector
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applicationLoader
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Constructor Details
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DatabaseClasses
DatabaseClasses()
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Method Details
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boot
Description copied from interface:ModuleControl
Boot this module with the given properties. Creates a module instance that can be found using the findModule() methods of Monitor. The module can only be found using one of these findModule() methods once this method has returned.An implementation's boot method can throw StandardException. If it is thrown the module is not registered by the monitor and therefore cannot be found through a findModule(). In this case the module's stop() method is not called, thus throwing this exception must free up any resources.
When create is true the contents of the properties object will be written to the service.properties of the persistent service. Thus any code that requires an entry in service.properties must explicitly place the value in this properties set using the put method.
Typically the properties object contains one or more default properties sets, which are not written out to service.properties. These default sets are how callers modify the create process. In a JDBC connection database create the first set of defaults is a properties object that contains the attributes that were set on the jdbc:derby: URL. This attributes properties set has the second default properties set as its default. This set (which could be null) contains the properties that the user set on their DriverManager.getConnection() call, and are thus not owned by Derby code, and thus must not be modified by Derby code.When create is false the properties object contains all the properties set in the service.properties file plus a limited number of attributes from the JDBC URL attributes or connection properties set. This avoids properties set by the user compromising the boot process. An example of a property passed in from the JDBC world is the bootPassword for encrypted databases.
Code should not hold onto the passed in properties reference after boot time as its contents may change underneath it. At least after the complete boot is completed, the links to all the default sets will be removed.
- Specified by:
boot
in interfaceModuleControl
- Throws:
StandardException
- Module cannot be started.- See Also:
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stop
public void stop()Description copied from interface:ModuleControl
Stop the module. The module may be found via a findModule() method until some time after this method returns. Therefore the factory must be prepared to reject requests to it once it has been stopped. In addition other modules may cache a reference to the module and make requests of it after it has been stopped, these requests should be rejected as well.- Specified by:
stop
in interfaceModuleControl
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makeClassInspector
For creating the class inspector. -
loadGeneratedClass
public final GeneratedClass loadGeneratedClass(String fullyQualifiedName, ByteArray classDump) throws StandardException Here we load the newly added class now, rather than waiting for the findGeneratedClass(). Thus we are assuming that the class is going to be used sometime soon. Delaying the load would mean storing the class data in a file, this wastes cycles and compilcates the cleanup.- Specified by:
loadGeneratedClass
in interfaceClassFactory
- Throws:
StandardException
- Class format is bad.- See Also:
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WriteClassFile
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getClassInspector
Description copied from interface:ClassFactory
Return a ClassInspector object- Specified by:
getClassInspector
in interfaceClassFactory
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loadApplicationClass
Description copied from interface:ClassFactory
Load an application class, or a class that is potentially an application class.- Specified by:
loadApplicationClass
in interfaceClassFactory
- Throws:
ClassNotFoundException
- Class cannot be found, or a SecurityException or LinkageException was thrown loading the class.
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loadClassNotInDatabaseJar
- Throws:
ClassNotFoundException
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loadApplicationClass
public final Class loadApplicationClass(ObjectStreamClass classDescriptor) throws ClassNotFoundException Description copied from interface:ClassFactory
Load an application class, or a class that is potentially an application class.- Specified by:
loadApplicationClass
in interfaceClassFactory
- Throws:
ClassNotFoundException
- Class cannot be found, or a SecurityException or LinkageException was thrown loading the class.
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isApplicationClass
Description copied from interface:ClassFactory
Was the passed in class loaded by a ClassManager.- Specified by:
isApplicationClass
in interfaceClassFactory
- Returns:
- true if the class was loaded by a Derby class manager, false it is was loaded by the system class loader, or another class loader.
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notifyModifyJar
Description copied from interface:ClassFactory
Notify the class manager that a jar file has been modified.- Specified by:
notifyModifyJar
in interfaceClassFactory
- Parameters:
reload
- Restart any attached class loader- Throws:
StandardException
- thrown on error
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notifyModifyClasspath
Notify the class manager that the classpath has been modified.- Specified by:
notifyModifyClasspath
in interfaceClassFactory
- Throws:
StandardException
- thrown on error
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getClassLoaderVersion
public int getClassLoaderVersion()Description copied from interface:ClassFactory
Return the in-memory "version" of the class manager. The version is bumped everytime the classes are re-loaded.- Specified by:
getClassLoaderVersion
in interfaceClassFactory
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loadGeneratedClassFromData
abstract LoadedGeneratedClass loadGeneratedClassFromData(String fullyQualifiedName, ByteArray classDump) -
getMonitor
Privileged Monitor lookup. Must be private so that user code can't call this entry point.
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