A ClassVisitor that adds a serial version unique identifier to a class if missing. A typical usage of this class is:

  ClassWriter classWriter = new ClassWriter(...);
  ClassVisitor svuidAdder = new SerialVersionUIDAdder(classWriter);
  ClassVisitor classVisitor = new MyClassAdapter(svuidAdder);
  new ClassReader(orginalClass).accept(classVisitor, 0);

The SVUID algorithm can be found at https://docs.oracle.com/javase/10/docs/specs/serialization/class.html#stream-unique-identifiers:

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:

The class name written using UTF encoding.
The class modifiers written as a 32-bit integer.
The name of each interface sorted by name written using UTF encoding.
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
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, STATIC, written as a 32-bit integer.
3. The descriptor of the method, ()V, in UTF encoding.
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.
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.
The SHA-1 algorithm is executed on the stream of bytes produced by DataOutputStream and produces five 32-bit values sha[0..4].
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;

Nested and Inner Type Summary

Modifier and Type	Class and Description
private static class	SerialVersionUIDAdder.Item

Field Summary

Modifier and Type	Field and Description
private int	access The class access flags.
private static final String	CLINIT The JVM name of static initializer methods.
private boolean	computeSvuid A flag that indicates if we need to compute SVUID.
private boolean	hasStaticInitializer Whether the class has a static initializer.
private boolean	hasSvuid Whether the class already has a SVUID.
private String[]	interfaces The interfaces implemented by the class.
private String	name The internal name of the class.
private Collection<SerialVersionUIDAdder.Item>	svuidConstructors The constructors of the class that are needed to compute the SVUID.
private Collection<SerialVersionUIDAdder.Item>	svuidFields The fields of the class that are needed to compute the SVUID.
private Collection<SerialVersionUIDAdder.Item>	svuidMethods The methods of the class that are needed to compute the SVUID.

Inherited from org.objectweb.asm.ClassVisitor:: api cv

Access	Constructor and Description
public	SerialVersionUIDAdder(final ClassVisitor a `ClassVisitor` to which this visitor will delegate calls. classVisitor) Constructs a new `SerialVersionUIDAdder`.
protected	SerialVersionUIDAdder(final int the ASM API version implemented by this visitor. Must be one of the `ASM`x values in `Opcodes`. api, final ClassVisitor a `ClassVisitor` to which this visitor will delegate calls. classVisitor) Constructs a new `SerialVersionUIDAdder`.

Method Summary

Modifier and Type	Method and Description
protected void	addSVUID(final long the serialVersionUID field value. svuid) Adds a final static serialVersionUID field to the class, with the given value.
protected byte[]	Returns: the SHA-1 message digest of the given value. computeSHAdigest(final byte[] the value whose SHA message digest must be computed. value) Returns the SHA-1 message digest of the given value.
protected long	Returns: the serial version UID. computeSVUID() Computes and returns the value of SVUID.
public boolean	Returns: true if the class already has a SVUID field. hasSVUID() Returns true if the class already has a SVUID field.
public void	visit(final int the class version. The minor version is stored in the 16 most significant bits, and the major version in the 16 least significant bits. version, final int the class's access flags (see `Opcodes`). This parameter also indicates if the class is deprecated `Opcodes#ACC_DEPRECATED` or a record `Opcodes#ACC_RECORD`. access, final String the internal name of the class (see `Type#getInternalName()`). name, final String 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. signature, final String the internal of name of the super class (see `Type#getInternalName()`). For interfaces, the super class is `Object`. May be null, but only for the `Object` class. superName, final String[] the internal names of the class's interfaces (see `Type#getInternalName()`). May be null. interfaces) Overrides org.objectweb.asm.ClassVisitor.visit. Visits the header of the class.
public void	visitEnd() Overrides org.objectweb.asm.ClassVisitor.visitEnd. Visits the end of the class.
public FieldVisitor	visitField(final int the field's access flags (see `Opcodes`). This parameter also indicates if the field is synthetic and/or deprecated. access, final String the field's name. name, final String the field's descriptor (see `Type`). desc, final String the field's signature. May be null if the field's type does not use generic types. signature, final Object 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. value) Overrides org.objectweb.asm.ClassVisitor.visitField. Visits a field of the class.
public void	visitInnerClass(final String the internal name of C (see `Type#getInternalName()`). innerClassName, final String the internal name of the class or interface C is a member of (see `Type#getInternalName()`). Must be null if C is not the member of a class or interface (e.g. for local or anonymous classes). outerName, final String the (simple) name of C. Must be null for anonymous inner classes. innerName, final int the access flags of C originally declared in the source code from which this class was compiled. innerClassAccess) Overrides org.objectweb.asm.ClassVisitor.visitInnerClass. Visits information about an inner class.
public MethodVisitor	visitMethod(final int the method's access flags (see `Opcodes`). This parameter also indicates if the method is synthetic and/or deprecated. access, final String the method's name. name, final String the method's descriptor (see `Type`). descriptor, final String the method's signature. May be null if the method parameters, return type and exceptions do not use generic types. signature, final String[] the internal names of the method's exception classes (see `Type#getInternalName()`). May be null. exceptions) Overrides org.objectweb.asm.ClassVisitor.visitMethod. Visits a method of the class.
private static void	writeItems(final Collection<SerialVersionUIDAdder.Item> a collection of items. itemCollection, final DataOutput where the items must be written. dataOutputStream, final boolean whether package names must use dots, instead of slashes. dotted) Sorts the items in the collection and writes it to the given output stream.

Inherited from org.objectweb.asm.ClassVisitor:: getDelegate visitAnnotation visitAttribute visitModule visitNestHost visitNestMember visitOuterClass visitPermittedSubclass visitRecordComponent visitSource visitTypeAnnotation

Field Detail

access	back to summary
private int access The class access flags.

CLINIT	back to summary
private static final String CLINIT The JVM name of static initializer methods.

computeSvuid	back to summary
private boolean computeSvuid A flag that indicates if we need to compute SVUID.

hasStaticInitializer	back to summary
private boolean hasStaticInitializer Whether the class has a static initializer.

hasSvuid	back to summary
private boolean hasSvuid Whether the class already has a SVUID.

interfaces	back to summary
private String[] interfaces The interfaces implemented by the class.

name	back to summary
private String name The internal name of the class.

svuidConstructors	back to summary
private Collection<SerialVersionUIDAdder.Item> svuidConstructors The constructors of the class that are needed to compute the SVUID.

svuidFields	back to summary
private Collection<SerialVersionUIDAdder.Item> svuidFields The fields of the class that are needed to compute the SVUID.

svuidMethods	back to summary
private Collection<SerialVersionUIDAdder.Item> svuidMethods The methods of the class that are needed to compute the SVUID.

SerialVersionUIDAdder	back to summary
public SerialVersionUIDAdder(final ClassVisitor classVisitor) Constructs a new `SerialVersionUIDAdder`. Subclasses must not use this constructor. Instead, they must use the `SerialVersionUIDAdder(int, ClassVisitor)` version. Parameters classVisitor:ClassVisitor a `ClassVisitor` to which this visitor will delegate calls. Exceptions IllegalStateException: If a subclass calls this constructor.

SerialVersionUIDAdder	back to summary
protected SerialVersionUIDAdder(final int api, final ClassVisitor classVisitor) Constructs a new `SerialVersionUIDAdder`. Parameters api:int the ASM API version implemented by this visitor. Must be one of the `ASM`x values in `Opcodes`. classVisitor:ClassVisitor a `ClassVisitor` to which this visitor will delegate calls.

Method Detail

addSVUID	back to summary
protected void addSVUID(final long svuid) Adds a final static serialVersionUID field to the class, with the given value. Parameters svuid:long the serialVersionUID field value.

addSVUID

back to summary

protected void addSVUID(final long svuid)

Adds a final static serialVersionUID field to the class, with the given value.

Parameters

svuid:long: the serialVersionUID field value.

computeSHAdigest	back to summary
protected byte[] computeSHAdigest(final byte[] value) Returns the SHA-1 message digest of the given value. Parameters value:byte[] the value whose SHA message digest must be computed. Returns:byte[] the SHA-1 message digest of the given value.

computeSHAdigest

back to summary

protected byte[] computeSHAdigest(final byte[] value)

Returns the SHA-1 message digest of the given value.

Parameters

value:byte[]: the value whose SHA message digest must be computed.

Returns:byte[]

the SHA-1 message digest of the given value.

computeSVUID	back to summary
protected long computeSVUID() throws IOException Computes and returns the value of SVUID. Returns:long the serial version UID. Exceptions IOException: if an I/O error occurs.

computeSVUID

back to summary

protected long computeSVUID() throws IOException

Computes and returns the value of SVUID.

Returns:long

the serial version UID.

Exceptions

IOException:: if an I/O error occurs.

hasSVUID	back to summary
public boolean hasSVUID() Returns true if the class already has a SVUID field. The result of this method is only valid when visitEnd has been called. Returns:boolean true if the class already has a SVUID field.

hasSVUID

back to summary

public boolean hasSVUID()

Returns true if the class already has a SVUID field. The result of this method is only valid when visitEnd has been called.

Returns:boolean: true if the class already has a SVUID field.

visit back to summary

visit	back to summary
public void visit(final int version, final int access, final String name, final String signature, final String superName, final String[] interfaces) Overrides org.objectweb.asm.ClassVisitor.visit. Doc from org.objectweb.asm.ClassVisitor.visit. Visits the header of the class. Parameters version:int the class version. The minor version is stored in the 16 most significant bits, and the major version in the 16 least significant bits. access:int the class's access flags (see `Opcodes`). This parameter also indicates if the class is deprecated `Opcodes#ACC_DEPRECATED` or a record `Opcodes#ACC_RECORD`. name:String the internal name of the class (see `Type#getInternalName()`). signature:String 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:String the internal of name of the super class (see `Type#getInternalName()`). For interfaces, the super class is `Object`. May be null, but only for the `Object` class. interfaces:String[] the internal names of the class's interfaces (see `Type#getInternalName()`). May be null. Annotations @Override

public void visit(final int version, final int access, final String name, final String signature, final String superName, final String[] interfaces)

Overrides org.objectweb.asm.ClassVisitor.visit.

Doc from org.objectweb.asm.ClassVisitor.visit.

Visits the header of the class.

Parameters

version:int: the class version. The minor version is stored in the 16 most significant bits, and the major version in the 16 least significant bits.
access:int: the class's access flags (see Opcodes). This parameter also indicates if the class is deprecated Opcodes#ACC_DEPRECATED or a record Opcodes#ACC_RECORD.
name:String: the internal name of the class (see Type#getInternalName()).
signature:String: 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:String: the internal of name of the super class (see Type#getInternalName()). For interfaces, the super class is Object. May be null, but only for the Object class.
interfaces:String[]: the internal names of the class's interfaces (see Type#getInternalName()). May be null.

Annotations

@Override

visitEnd	back to summary
public void visitEnd() Overrides org.objectweb.asm.ClassVisitor.visitEnd. Doc from org.objectweb.asm.ClassVisitor.visitEnd. Visits the end of the class. This method, which is the last one to be called, is used to inform the visitor that all the fields and methods of the class have been visited. Annotations @Override

visitEnd

back to summary

public void visitEnd()

Overrides org.objectweb.asm.ClassVisitor.visitEnd.

Doc from org.objectweb.asm.ClassVisitor.visitEnd.

Visits the end of the class. This method, which is the last one to be called, is used to inform the visitor that all the fields and methods of the class have been visited.

Annotations

@Override

visitField back to summary

visitField	back to summary
public FieldVisitor visitField(final int access, final String name, final String desc, final String signature, final Object value) Overrides org.objectweb.asm.ClassVisitor.visitField. Doc from org.objectweb.asm.ClassVisitor.visitField. Visits a field of the class. Parameters access:int the field's access flags (see `Opcodes`). This parameter also indicates if the field is synthetic and/or deprecated. name:String the field's name. desc:String the field's descriptor (see `Type`). signature:String the field's signature. May be null if the field's type does not use generic types. value:Object 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. Returns:FieldVisitor a visitor to visit field annotations and attributes, or null if this class visitor is not interested in visiting these annotations and attributes. Annotations @Override

public FieldVisitor visitField(final int access, final String name, final String desc, final String signature, final Object value)

Overrides org.objectweb.asm.ClassVisitor.visitField.

Doc from org.objectweb.asm.ClassVisitor.visitField.

Visits a field of the class.

Parameters

access:int: the field's access flags (see Opcodes). This parameter also indicates if the field is synthetic and/or deprecated.
name:String: the field's name.
desc:String: the field's descriptor (see Type).
signature:String: the field's signature. May be null if the field's type does not use generic types.
value:Object: 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.

Returns:FieldVisitor

a visitor to visit field annotations and attributes, or null if this class visitor is not interested in visiting these annotations and attributes.

Annotations

@Override

visitInnerClass back to summary

visitInnerClass	back to summary
public void visitInnerClass(final String innerClassName, final String outerName, final String innerName, final int innerClassAccess) Overrides org.objectweb.asm.ClassVisitor.visitInnerClass. Doc from org.objectweb.asm.ClassVisitor.visitInnerClass. Visits information about an inner class. This inner class is not necessarily a member of the class being visited. More precisely, every class or interface C which is referenced by this class and which is not a package member must be visited with this method. This class must reference its nested class or interface members, and its enclosing class, if any. See the JVMS 4.7.6 section for more details. Parameters innerClassName:String the internal name of C (see `Type#getInternalName()`). outerName:String the internal name of the class or interface C is a member of (see `Type#getInternalName()`). Must be null if C is not the member of a class or interface (e.g. for local or anonymous classes). innerName:String the (simple) name of C. Must be null for anonymous inner classes. innerClassAccess:int the access flags of C originally declared in the source code from which this class was compiled. Annotations @Override

public void visitInnerClass(final String innerClassName, final String outerName, final String innerName, final int innerClassAccess)

Overrides org.objectweb.asm.ClassVisitor.visitInnerClass.

Doc from org.objectweb.asm.ClassVisitor.visitInnerClass.

Visits information about an inner class. This inner class is not necessarily a member of the class being visited. More precisely, every class or interface C which is referenced by this class and which is not a package member must be visited with this method. This class must reference its nested class or interface members, and its enclosing class, if any. See the JVMS 4.7.6 section for more details.

Parameters

innerClassName:String: the internal name of C (see Type#getInternalName()).
outerName:String: the internal name of the class or interface C is a member of (see Type#getInternalName()). Must be null if C is not the member of a class or interface (e.g. for local or anonymous classes).
innerName:String: the (simple) name of C. Must be null for anonymous inner classes.
innerClassAccess:int: the access flags of C originally declared in the source code from which this class was compiled.

Annotations

@Override

visitMethod back to summary

visitMethod	back to summary
public MethodVisitor visitMethod(final int access, final String name, final String descriptor, final String signature, final String[] exceptions) Overrides org.objectweb.asm.ClassVisitor.visitMethod. Doc from org.objectweb.asm.ClassVisitor.visitMethod. Visits a method of the class. This method must return a new `MethodVisitor` instance (or null) each time it is called, i.e., it should not return a previously returned visitor. Parameters access:int the method's access flags (see `Opcodes`). This parameter also indicates if the method is synthetic and/or deprecated. name:String the method's name. descriptor:String the method's descriptor (see `Type`). signature:String the method's signature. May be null if the method parameters, return type and exceptions do not use generic types. exceptions:String[] the internal names of the method's exception classes (see `Type#getInternalName()`). May be null. Returns:MethodVisitor an object to visit the byte code of the method, or null if this class visitor is not interested in visiting the code of this method. Annotations @Override

public MethodVisitor visitMethod(final int access, final String name, final String descriptor, final String signature, final String[] exceptions)

Overrides org.objectweb.asm.ClassVisitor.visitMethod.

Doc from org.objectweb.asm.ClassVisitor.visitMethod.

Visits a method of the class. This method must return a new MethodVisitor instance (or null) each time it is called, i.e., it should not return a previously returned visitor.

Parameters

access:int: the method's access flags (see Opcodes). This parameter also indicates if the method is synthetic and/or deprecated.
name:String: the method's name.
descriptor:String: the method's descriptor (see Type).
signature:String: the method's signature. May be null if the method parameters, return type and exceptions do not use generic types.
exceptions:String[]: the internal names of the method's exception classes (see Type#getInternalName()). May be null.

Returns:MethodVisitor

an object to visit the byte code of the method, or null if this class visitor is not interested in visiting the code of this method.

Annotations

@Override

writeItems	back to summary
private static void writeItems(final Collection<SerialVersionUIDAdder.Item> itemCollection, final DataOutput dataOutputStream, final boolean dotted) throws IOException Sorts the items in the collection and writes it to the given output stream. Parameters itemCollection:Collection<SerialVersionUIDAdder.Item> a collection of items. dataOutputStream:DataOutput where the items must be written. dotted:boolean whether package names must use dots, instead of slashes. Exceptions IOException: if an error occurs.

writeItems

back to summary

private static void writeItems(final Collection<SerialVersionUIDAdder.Item> itemCollection, final DataOutput dataOutputStream, final boolean dotted) throws IOException

Sorts the items in the collection and writes it to the given output stream.

Parameters

itemCollection:Collection<SerialVersionUIDAdder.Item>: a collection of items.
dataOutputStream:DataOutput: where the items must be written.
dotted:boolean: whether package names must use dots, instead of slashes.

Exceptions

IOException:: if an error occurs.

org.objectweb.asm.commons back to summary

private final Class SerialVersionUIDAdder.Item

Class Inheritance

extends Object
implements Comparable<SerialVersionUIDAdder.Item>

java.lang.Object
org.objectweb.asm.commons.SerialVersionUIDAdder.Item

All Implemented Interfaces

java.lang.Comparable

Field Summary

Modifier and Type	Field and Description
pack-priv final int	access
pack-priv final String	descriptor
pack-priv final String	name

Constructor Summary

Access	Constructor and Description
pack-priv	Item(final String name, final int access, final String descriptor)

Method Summary

Modifier and Type	Method and Description
public int	compareTo(final SerialVersionUIDAdder.Item the object to be compared. item) Implements java.lang.Comparable.compareTo. Compares this object with the specified object for order.
public boolean	equals(final Object the reference object with which to compare. other) Overrides java.lang.Object.equals. Indicates whether some other object is "equal to" this one.
public int	hashCode() Overrides java.lang.Object.hashCode. Returns a hash code value for the object.

Inherited from java.lang.Object:: clone finalize getClass notify notifyAll toString wait wait wait

Field Detail

access	back to summary
pack-priv final int access

descriptor	back to summary
pack-priv final String descriptor

name	back to summary
pack-priv final String name

Constructor Detail

Item	back to summary
pack-priv Item(final String name, final int access, final String descriptor)

Method Detail

compareTo back to summary

compareTo	back to summary
public int compareTo(final SerialVersionUIDAdder.Item item) Implements java.lang.Comparable.compareTo. Doc from java.lang.Comparable.compareTo. Compares this object with the specified object for order. Returns a negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object. The implementor must ensure `signum(x.compareTo(y)) == -signum(y.compareTo(x))` for all `x` and `y`. (This implies that `x.compareTo(y)` must throw an exception if and only if `y.compareTo(x)` throws an exception.) The implementor must also ensure that the relation is transitive: `(x.compareTo(y) > 0 && y.compareTo(z) > 0)` implies `x.compareTo(z) > 0`. Finally, the implementor must ensure that `x.compareTo(y)==0` implies that `signum(x.compareTo(z)) == signum(y.compareTo(z))`, for all `z`. Parameters item:SerialVersionUIDAdder.Item the object to be compared. Returns:int a negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object. Annotations @Override

public int compareTo(final SerialVersionUIDAdder.Item item)

Implements java.lang.Comparable.compareTo.

Doc from java.lang.Comparable.compareTo.

Compares this object with the specified object for order. Returns a negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object.

The implementor must ensure signum(x.compareTo(y)) == -signum(y.compareTo(x)) for all x and y. (This implies that x.compareTo(y) must throw an exception if and only if y.compareTo(x) throws an exception.)

The implementor must also ensure that the relation is transitive: (x.compareTo(y) > 0 && y.compareTo(z) > 0) implies x.compareTo(z) > 0.

Finally, the implementor must ensure that x.compareTo(y)==0 implies that signum(x.compareTo(z)) == signum(y.compareTo(z)), for all z.

Parameters

item:SerialVersionUIDAdder.Item: the object to be compared.

Returns:int

a negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object.

Annotations

@Override

equals back to summary

equals	back to summary
public boolean equals(final Object other) Overrides java.lang.Object.equals. Doc from java.lang.Object.equals. Indicates whether some other object is "equal to" this one. The `equals` method implements an equivalence relation on non-null object references: It is reflexive: for any non-null reference value `x`, `x.equals(x)` should return `true`. It is symmetric: for any non-null reference values `x` and `y`, `x.equals(y)` should return `true` if and only if `y.equals(x)` returns `true`. It is transitive: for any non-null reference values `x`, `y`, and `z`, if `x.equals(y)` returns `true` and `y.equals(z)` returns `true`, then `x.equals(z)` should return `true`. It is consistent: for any non-null reference values `x` and `y`, multiple invocations of `x.equals(y)` consistently return `true` or consistently return `false`, provided no information used in `equals` comparisons on the objects is modified. For any non-null reference value `x`, `x.equals(null)` should return `false`. An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes. Parameters other:Object the reference object with which to compare. Returns:boolean `true` if this object is the same as the obj argument; `false` otherwise. Annotations @Override

public boolean equals(final Object other)

Overrides java.lang.Object.equals.

Doc from java.lang.Object.equals.

Indicates whether some other object is "equal to" this one.

The equals method implements an equivalence relation on non-null object references:

It is reflexive: for any non-null reference value x, x.equals(x) should return true.
It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
For any non-null reference value x, x.equals(null) should return false.

An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes.

Parameters

other:Object: the reference object with which to compare.

Returns:boolean

true if this object is the same as the obj argument; false otherwise.

Annotations

@Override

hashCode back to summary

hashCode	back to summary
public int hashCode() Overrides java.lang.Object.hashCode. Doc from java.lang.Object.hashCode. Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by `java.util.HashMap`. The general contract of `hashCode` is: Whenever it is invoked on the same object more than once during an execution of a Java application, the `hashCode` method must consistently return the same integer, provided no information used in `equals` comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application. If two objects are equal according to the `equals` method, then calling the `hashCode` method on each of the two objects must produce the same integer result. It is not required that if two objects are unequal according to the `equals` method, then calling the `hashCode` method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables. Returns:int a hash code value for this object. Annotations @Override

public int hashCode()

Overrides java.lang.Object.hashCode.

Doc from java.lang.Object.hashCode.

Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by java.util.HashMap.

The general contract of hashCode is:

Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
If two objects are equal according to the equals method, then calling the hashCode method on each of the two objects must produce the same integer result.
It is not required that if two objects are unequal according to the equals method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

Returns:int

a hash code value for this object.

Annotations

@Override

public Class SerialVersionUIDAdder

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

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private final Class SerialVersionUIDAdder.Item

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