Interface JavaClass
- All Known Implementing Classes:
DTFJJavaClass
,JavaAbstractClass
,JavaArrayClass
,JavaClass
,JCJavaClass
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Field Summary
Modifier and TypeFieldDescriptionstatic final int
MODIFIERS_UNAVAILABLE is returned by getModifiers() when the modifiers are unavailable. -
Method Summary
Modifier and TypeMethodDescriptionboolean
Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.Fetch the class loader associated with this class.For array classes, returns a JavaClass representing the component type of this array class.Java classes may refer to other classes and to String objects via the class's constant pool.Get the set of fields declared in this class.Get the set of methods declared in this class.getID()
The ID of a class is a pointer to a section of memory which identifies the class.long
Returns the size in bytes of an instance of this class on the heap.Get the set of names of interfaces directly implemented by this class.int
Return the Java language modifiers for this class.getName()
Get the name of the class.Fetch the java.lang.Class object associated with this class.Returns the protection domain for this class.Get the set of references from this class.Get the immediate superclass of this class.int
hashCode()
Answers an integer hash code for the receiver.boolean
isArray()
Is this an array class ?
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Field Details
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MODIFIERS_UNAVAILABLE
static final int MODIFIERS_UNAVAILABLEMODIFIERS_UNAVAILABLE is returned by getModifiers() when the modifiers are unavailable. The value 0xff000000 is chosen as it is a value that can never return true to any of the java.reflect.Modifier methods that test the modifier: isNative(), isPublic(), etc. while at the same time not being 0 which is a possible value when no modifier at all is present i.e. "default". All other values for the modifier returned are defined in java.lang.reflect.Modifiers- See Also:
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Method Details
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getObject
Fetch the java.lang.Class object associated with this class.In some implementations this may be null if no object has been created to represent this class, or if the class is synthetic.
- Returns:
- the java.lang.Class object associated with this class
- Throws:
CorruptDataException
- See Also:
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getClassLoader
Fetch the class loader associated with this class. Classes defined in the bootstrap class loader (including classes representing primitive types or void) will always return a JavaClassLoader representing the bootstrap class loader. This asymmetry with java.lang.Class#getClassLoader() is intentional.- Returns:
- the JavaClassLoader in which this class was defined
- Throws:
CorruptDataException
- if the class loader for this class cannot be found (a class cannot exist without a loader so this implies corruption)
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getName
Get the name of the class.- Returns:
- the name of the class in the form: "full/package/class$innerclass"
- Throws:
CorruptDataException
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getSuperclass
Get the immediate superclass of this class.- Returns:
- the immediate superclass of this class, or null if this class has no superclass. For interfaces, Object, primitive types and void null is always returned.
- Throws:
CorruptDataException
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getInterfaces
Iterator getInterfaces()Get the set of names of interfaces directly implemented by this class.- Returns:
- an iterator over the collection of the names of interfaces directly implemented by this class. Some JVM implementations may choose to load interfaces lazily, so only the names are returned. The JavaClass objects may be found through the defining class loader.
- See Also:
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getModifiers
Return the Java language modifiers for this class.The modifiers are defined by the JVM Specification.
Return MODIFIERS_UNAVAILABLE if the modifiers are unavailable. This might be the case if DTFJ is operating against an artefact such as a portable heap dump that does not contain information about a class's modifiers.
Note that, for inner classes, the actual modifiers are returned, not the synthetic modifiers. For instance, a class will never have its 'protected' modifier set, even if the inner class was a protected member, since 'protected' is not a legal modifier for a class file.
- Returns:
- the modifiers for this class
- Throws:
CorruptDataException
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isArray
Is this an array class ?- Returns:
- true if this class is an array class
- Throws:
CorruptDataException
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getComponentType
For array classes, returns a JavaClass representing the component type of this array class.- Returns:
- a JavaClass representing the component type of this array class
- Throws:
CorruptDataException
IllegalArgumentException
- if this JavaClass does not represent an array class
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getDeclaredFields
Iterator getDeclaredFields()Get the set of fields declared in this class.- Returns:
- an iterator over the collection of fields declared in this class.
- See Also:
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getDeclaredMethods
Iterator getDeclaredMethods()Get the set of methods declared in this class.- Returns:
- an iterator over the collection of methods declared in this class.
- See Also:
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getConstantPoolReferences
Iterator getConstantPoolReferences()Java classes may refer to other classes and to String objects via the class's constant pool. These references are followed by the garbage collector, forming edges on the graph of reachable objects. This getConstantPoolReferences() may be used to determine which objects are referred to by the receiver's constant pool.Although Java VMs typically permit only Class and String objects in the constant pool, some esoteric or future virtual machines may permit other types of objects to occur in the constant pool. This API imposes no restrictions on the types of JavaObjects which might be included in the Iterator.
No assumption should be made about the order in which constant pool references are returned.
Classes may also refer to objects through static variables. These may be found with the getDeclaredFields() API. Objects referenced by static variables are not returned by getConstantPoolReferences() unless the object is also referenced by the constant pool.
- Returns:
- an iterator over the collection of JavaObjects which are referred to by the constant pool of this class
- See Also:
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getID
ImagePointer getID()The ID of a class is a pointer to a section of memory which identifies the class. The contents of this memory are implementation defined.In some implementations getID() and getObject().getID() may return the same value. This implies that the class object is also the primary internal representation of the class. DTFJ users should not rely on this behaviour.
In some implementations, getID() may return null for some classes. This indicates that the class is a synthetic class which has been constructed for DTFJ purposes only. The class has no physical representation in the VM.
- Returns:
- a pointer to the class
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getReferences
Iterator getReferences()Get the set of references from this class.- Returns:
- an iterator of JavaReferences
- See Also:
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equals
Description copied from class:java.lang.Object
Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison. The implementation in Object answers true only if the argument is the exact same object as the receiver (==). -
getInstanceSize
Returns the size in bytes of an instance of this class on the heap.The call is only meaningful for a non-array JavaClass, where all instances of the class are of the same size. If this method is called on a JavaArrayClass, where instances can be of different sizes, an UnsupportedOperationException will be thrown. DataUnavailable can be thrown if no value is available: for example when DTFJ is examining a javacore, where the instance size for a class is not recorded.
- Returns:
- size in bytes of an instance
- Throws:
DataUnavailable
CorruptDataException
UnsupportedOperationException
- if the JavaClass is an instance of JavaArrayClass- Since:
- 1.6
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hashCode
int hashCode()Description copied from class:java.lang.Object
Answers an integer hash code for the receiver. Any two objects which answertrue
when passed to.equals
must answer the same value for this method. -
getProtectionDomain
Returns the protection domain for this class.- Returns:
- the protection domain or null for the default protection domain
- Throws:
DataUnavailable
CorruptDataException
- Since:
- 9
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