public class SerialVersionUIDAdder extends ClassVisitor
ClassVisitor that adds a serial version unique identifier to a
class if missing. Here is typical usage of this class:
ClassWriter cw = new ClassWriter(...); ClassVisitor sv = new SerialVersionUIDAdder(cw); ClassVisitor ca = new MyClassAdapter(sv); new ClassReader(orginalClass).accept(ca, false);The SVUID algorithm can be found http://java.sun.com/j2se/1.4.2/docs/guide/serialization/spec/class.html:
The serialVersionUID is computed using the signature of a stream of bytes that reflect the class definition. The National Institute of Standards and Technology (NIST) Secure Hash Algorithm (SHA-1) is used to compute a signature for the stream. The first two 32-bit quantities are used to form a 64-bit hash. A java.lang.DataOutputStream is used to convert primitive data types to a sequence of bytes. The values input to the stream are defined by the Java Virtual Machine (VM) specification for classes. The sequence of items in the stream is as follows: 1. The class name written using UTF encoding. 2. The class modifiers written as a 32-bit integer. 3. The name of each interface sorted by name written using UTF encoding. 4. For each field of the class sorted by field name (except private static and private transient fields): 1. The name of the field in UTF encoding. 2. The modifiers of the field written as a 32-bit integer. 3. The descriptor of the field in UTF encoding 5. If a class initializer exists, write out the following: 1. The name of the method, <clinit>, in UTF encoding. 2. The modifier of the method, java.lang.reflect.Modifier.STATIC, written as a 32-bit integer. 3. The descriptor of the method, ()V, in UTF encoding. 6. For each non-private constructor sorted by method name and signature: 1. The name of the method, <init>, in UTF encoding. 2. The modifiers of the method written as a 32-bit integer. 3. The descriptor of the method in UTF encoding. 7. For each non-private method sorted by method name and signature: 1. The name of the method in UTF encoding. 2. The modifiers of the method written as a 32-bit integer. 3. The descriptor of the method in UTF encoding. 8. The SHA-1 algorithm is executed on the stream of bytes produced by DataOutputStream and produces five 32-bit values sha[0..4]. 9. The hash value is assembled from the first and second 32-bit values of the SHA-1 message digest. If the result of the message digest, the five 32-bit words H0 H1 H2 H3 H4, is in an array of five int values named sha, the hash value would be computed as follows: long hash = ((sha[0] >>> 24) & 0xFF) | ((sha[0] >>> 16) & 0xFF) << 8 | ((sha[0] >>> 8) & 0xFF) << 16 | ((sha[0] >>> 0) & 0xFF) << 24 | ((sha[1] >>> 24) & 0xFF) << 32 | ((sha[1] >>> 16) & 0xFF) << 40 | ((sha[1] >>> 8) & 0xFF) << 48 | ((sha[1] >>> 0) & 0xFF) << 56;
api, cv| Modifier | Constructor and Description |
|---|---|
|
SerialVersionUIDAdder(ClassVisitor cv)
Creates a new
SerialVersionUIDAdder. |
protected |
SerialVersionUIDAdder(int api,
ClassVisitor cv)
Creates a new
SerialVersionUIDAdder. |
| Modifier and Type | Method and Description |
|---|---|
protected void |
addSVUID(long svuid) |
protected byte[] |
computeSHAdigest(byte[] value)
Returns the SHA-1 message digest of the given value.
|
protected long |
computeSVUID()
Computes and returns the value of SVUID.
|
boolean |
hasSVUID()
Returns true if the class already has a SVUID field.
|
void |
visit(int version,
int access,
String name,
String signature,
String superName,
String[] interfaces)
Visits the header of the class.
|
void |
visitEnd()
Visits the end of the class.
|
FieldVisitor |
visitField(int access,
String name,
String desc,
String signature,
Object value)
Visits a field of the class.
|
void |
visitInnerClass(String aname,
String outerName,
String innerName,
int attr_access)
Handle a bizarre special case.
|
MethodVisitor |
visitMethod(int access,
String name,
String desc,
String signature,
String[] exceptions)
Visits a method of the class.
|
visitAnnotation, visitAttribute, visitOuterClass, visitSourcepublic SerialVersionUIDAdder(ClassVisitor cv)
SerialVersionUIDAdder. Subclasses must not use
this constructor. Instead, they must use the
SerialVersionUIDAdder(int, ClassVisitor) version.cv - a ClassVisitor to which this visitor will delegate
calls.protected SerialVersionUIDAdder(int api,
ClassVisitor cv)
SerialVersionUIDAdder.api - the ASM API version implemented by this visitor. Must be one
of Opcodes.ASM4.cv - a ClassVisitor to which this visitor will delegate
calls.public void visit(int version,
int access,
String name,
String signature,
String superName,
String[] interfaces)
ClassVisitorvisit in class ClassVisitorversion - the class version.access - the class's access flags (see Opcodes). This parameter
also indicates if the class is deprecated.name - the internal name of the class (see
getInternalName).signature - the signature of this class. May be null if the class
is not a generic one, and does not extend or implement generic
classes or interfaces.superName - the internal of name of the super class (see
getInternalName). For
interfaces, the super class is Object. May be
null, but only for the Object class.interfaces - the internal names of the class's interfaces (see
getInternalName). May be
null.public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions)
ClassVisitorMethodVisitor instance (or null) each time it is called,
i.e., it should not return a previously returned visitor.visitMethod in class ClassVisitoraccess - the method's access flags (see Opcodes). This
parameter also indicates if the method is synthetic and/or
deprecated.name - the method's name.desc - the method's descriptor (see Type).signature - the method's signature. May be null if the method
parameters, return type and exceptions do not use generic
types.exceptions - the internal names of the method's exception classes (see
getInternalName). May be
null.public FieldVisitor visitField(int access, String name, String desc, String signature, Object value)
ClassVisitorvisitField in class ClassVisitoraccess - the field's access flags (see Opcodes). This parameter
also indicates if the field is synthetic and/or deprecated.name - the field's name.desc - the field's descriptor (see Type).signature - the field's signature. May be null if the field's
type does not use generic types.value - the field's initial value. This parameter, which may be
null if the field does not have an initial value,
must be an Integer, a Float, a Long, a
Double or a String (for int,
float, long or String fields
respectively). This parameter is only used for static
fields. Its value is ignored for non static fields, which
must be initialized through bytecode instructions in
constructors or methods.public void visitInnerClass(String aname, String outerName, String innerName, int attr_access)
visitInnerClass in class ClassVisitoraname - the internal name of an inner class (see
getInternalName).outerName - the internal name of the class to which the inner class
belongs (see getInternalName).
May be null for not member classes.innerName - the (simple) name of the inner class inside its enclosing
class. May be null for anonymous inner classes.attr_access - the access flags of the inner class as originally declared in
the enclosing class.public void visitEnd()
ClassVisitorvisitEnd in class ClassVisitorpublic boolean hasSVUID()
protected void addSVUID(long svuid)
protected long computeSVUID()
throws IOException
IOException - if an I/O error occursprotected byte[] computeSHAdigest(byte[] value)
value - the value whose SHA message digest must be computed.