org.apache.bytecode

Class ParamReader

java.lang.Object

java.io.InputStream

java.io.ByteArrayInputStream

org.apache.bytecode.ClassReader

org.apache.bytecode.ParamReader

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

public class ParamReader
extends ClassReader

This is the class file reader for obtaining the parameter names for declared methods in a class. The class must have debugging attributes for us to obtain this information.

This does not work for inherited methods. To obtain parameter names for inherited methods, you must use a paramReader for the class that originally declared the method.

don't get tricky, it's the bare minimum. Instances of this class are not threadsafe -- don't share them.

Field Summary

Fields inherited from class java.io.ByteArrayInputStream

buf, count, mark, pos

Constructor Summary

Constructors

Constructor and Description
ParamReader(byte[] b) Processes the given class bytes directly.
ParamReader(java.lang.Class c) Processes a class file, given it's class.

Method Summary

Modifier and Type	Method and Description
java.lang.String[]	getParameterNames(java.lang.reflect.Constructor ctor) Returns the names of the declared parameters for the given constructor.
protected java.lang.String[]	getParameterNames(java.lang.reflect.Member member, java.lang.Class[] paramTypes)
java.lang.String[]	getParameterNames(java.lang.reflect.Method method) Returns the names of the declared parameters for the given method.
void	readCode() Reads a code attribute.
void	readLocalVariableTable() This is invoked when a LocalVariableTable attribute is encountered.

Methods inherited from class org.apache.bytecode.ClassReader

findAttributeReaders, getBytes, getSignature, readAttributes, readCpool, readInt, readShort, resolveClass, resolveField, resolveMethod, resolveNameAndType, resolveUtf8, skipAttributes, skipFully

Methods inherited from class java.io.ByteArrayInputStream

available, close, mark, markSupported, read, read, reset, skip

Methods inherited from class java.io.InputStream

read

Methods inherited from class java.lang.Object

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

Constructor Detail

ParamReader

public ParamReader(java.lang.Class c)
            throws java.io.IOException

Processes a class file, given it's class. We'll use the defining classloader to locate the bytecode.

Parameters:

c -

Throws:

java.io.IOException

ParamReader

public ParamReader(byte[] b)
            throws java.io.IOException

Processes the given class bytes directly.

Parameters:

b -

Throws:

java.io.IOException

Method Detail

readCode

public void readCode()
              throws java.io.IOException

Description copied from class: ClassReader

Reads a code attribute.

Overrides:

readCode in class ClassReader

Throws:

java.io.IOException

getParameterNames

public java.lang.String[] getParameterNames(java.lang.reflect.Constructor ctor)

Returns the names of the declared parameters for the given constructor. If we cannot determine the names, return null. The returned array will have one name per parameter. The length of the array will be the same as the length of the Class[] array returned by Constructor.getParameterTypes().

Parameters:

ctor -

Returns:

Returns String[] array of names, one per parameter, or null

getParameterNames

public java.lang.String[] getParameterNames(java.lang.reflect.Method method)

Returns the names of the declared parameters for the given method. If we cannot determine the names, return null. The returned array will have one name per parameter. The length of the array will be the same as the length of the Class[] array returned by Method.getParameterTypes().

Parameters:

method -

Returns:

Returns String[] array of names, one per parameter, or null

getParameterNames

protected java.lang.String[] getParameterNames(java.lang.reflect.Member member,
                                               java.lang.Class[] paramTypes)

readLocalVariableTable

public void readLocalVariableTable()
                            throws java.io.IOException

This is invoked when a LocalVariableTable attribute is encountered.

Throws:

java.io.IOException