classfile
Class methodInfo

java.lang.Object
  |
  +--util.dataRead
        |
        +--classfile.methodInfo

class methodInfo

extends dataRead

implements access_and_modifier_flags

The fields of the methodInfo structure are the same as those of the fieldInfo structure. However, the semantics of the two structures differ enough that they are implemented by two different objects. For example, in the case of the fieldInfo structure only the constValueAttr is allowed. The attributes that are allowed for a methodInfo attribute are:

• Code
• Exceptions
• Synthetic
• Deprecated

Allowed access modifiers for a method are:

• private
• protected
• public

Other modifiers are

• abstract
• final
• native
• static
• strict
• synchronized

method_info {
u2 access_flags;
u2 name_index;        (Utf8 in the constant pool)
u2 descriptor_index;  (Utf8 in the constant pool)
u2 attributes_cnt;
attribute_info attributes[ attributes_cnt ];
}

There should not be more than one code attribute for a method. Code attributes are special in that they provide extra information about the method in the code attribute attribute table. For example, the code attribute contains information about the local variables in the method.

Author:

Ian Kaplan

Inner Class Summary

(package private) class

methodInfo.methodTypes The methodTypes class is used by the methodTypes method to return the argument list string and the return type that are built from the method descriptor.

Field Summary

(package private) int	access_flags
(package private) attrInfo[]	attributes
(package private) codeAttr	codeAttribute
(package private) java.lang.String	constructorName
(package private) constUtf8	descriptor
(package private) constUtf8	name

Fields inherited from class util.dataRead

bytesRead

Fields inherited from interface util.access_and_modifier_flags

ACC_ABSTRACT, ACC_FINAL, ACC_INTERFACE, ACC_NATIVE, ACC_PRIVATE, ACC_PROTECTED, ACC_PUBLIC, ACC_STATIC, ACC_STRICT, ACC_SYNC, ACC_TRANSIENT, ACC_VOLATILE

Constructor Summary

(package private)

methodInfo(java.io.DataInputStream dStream, constPool constPoolSec)

Method Summary

private java.lang.String	commentString() If there are synthetic or deprecated attributes in the method attribute table, return a comment string showing the appropriate attribute.
private methodInfo.methodTypes	decodeMethodDesc(java.lang.String methodDesc) Decode the method descriptor and return the argument list and return type.
private java.lang.String	exceptionString() Return a string containing "\n throws " if the method has associated exceptions.
java.lang.String	getConstructorName()
boolean	isConstructor() Class constructors have the internal name "".
(package private) java.lang.String	methodString(java.lang.String terminalStr) This method is passed the string that should be used to terminate the method declaration.
(package private) void	pr() Print method declaration (e.g., private int foobar( int x ) and any local variables.
void	setConstructorName(java.lang.String newName) Set the name of the constructor name

Methods inherited from class util.dataRead

getBytesRead, readU1, readU2, readU4

Methods inherited from class java.lang.Object

, clone, equals, finalize, getClass, hashCode, notify, notifyAll, registerNatives, toString, wait, wait, wait

Field Detail

access_flags

int access_flags

name

constUtf8 name

constructorName

java.lang.String constructorName

descriptor

constUtf8 descriptor

attributes

attrInfo[] attributes

codeAttribute

codeAttr codeAttribute

Constructor Detail

methodInfo

methodInfo(java.io.DataInputStream dStream,
           constPool constPoolSec)

Method Detail

isConstructor

public boolean isConstructor()

Class constructors have the internal name "". Return true if this is the name of the current constructor.

setConstructorName

public void setConstructorName(java.lang.String newName)

Set the name of the constructor name

getConstructorName

public java.lang.String getConstructorName()

Returns:

return the constructor name

commentString

private java.lang.String commentString()

If there are synthetic or deprecated attributes in the method attribute table, return a comment string showing the appropriate attribute. Otherwise return null.

exceptionString

private java.lang.String exceptionString()

Return a string containing "\n throws " if the method has associated exceptions. Otherwise return null.

The exception attribute has a table of exceptions that are associated with the class method. So there should only be one exceptions attribute associated with a given method.

decodeMethodDesc

private methodInfo.methodTypes decodeMethodDesc(java.lang.String methodDesc)

Decode the method descriptor and return the argument list and return type.

The method descriptor describes the arguments to the method. The format for the method descriptor is: '(' (type-descriptor)* ')' return-type The method argument descriptor starts with '(' and consists of zero or more type descriptions. Types are described by either a single letter (see util.typeDesc class) or an object path terminated by a semicolon. In the same way, the return type will either be an object path, an atomic type or "void", which is indicated by the letter 'V'. See section 4.3.3 of the JVM Spec. Note that the character that denotes an object path start is "L". So lets say we have the following method declaration: myObj foo(int i, double d, long l, barObj b, char c) {...} This method would have the method descriptor (IDJLmypkg/barObj;C)Lmypkg/myObj; The descriptor arguments are enclosed by parenthesis. The IDJ represents the int, double and long arguments. The barObj argument is represented by the "Lmypkg/barObj;", where 'L' denotes the start of the object path and ';' terminates the path.

methodString

java.lang.String methodString(java.lang.String terminalStr)

This method is passed the string that should be used to terminate the method declaration. If there are local variable declarations in the codeAttribute table (e.g., the class was compiled with debug) the terminal string will be " {". If there are no local variables or the class was compiled without debug the terminal character will be ";"

pr

void pr()

Print method declaration (e.g., private int foobar( int x ) and any local variables.