java.lang.Object
- org.apache.bcel.classfile.Utility

```
public abstract class Utility
extends java.lang.Object
```
Utility functions that do not really belong to any class in particular.

Constructor Summary

Constructors
Constructor Description

Utility()
Deprecated.
Will be private in the next major release.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static java.lang.String`	`accessToString(int accessFlags)`	Convert bit field of flags into string such as 'static final'.
`static java.lang.String`	`accessToString(int accessFlags, boolean forClass)`	Convert bit field of flags into string such as 'static final'.
`static java.lang.String`	`classOrInterface(int accessFlags)`	Gets the class or interface type name.
`static int`	`clearBit(int flag, int i)`	Clears a bit in a flag.
`static java.lang.String`	`codeToString(byte[] code, ConstantPool constantPool, int index, int length)`	Disassembles byte code.
`static java.lang.String`	`codeToString(byte[] code, ConstantPool constantPool, int index, int length, boolean verbose)`	Disassemble a byte array of JVM byte codes starting from code line 'index' and return the disassembled string representation.
`static java.lang.String`	`codeToString(ByteSequence bytes, ConstantPool constantPool)`	Disassembles byte code.
`static java.lang.String`	`codeToString(ByteSequence bytes, ConstantPool constantPool, boolean verbose)`	Disassemble a stream of byte codes and return the string representation.
`static java.lang.String`	`compactClassName(java.lang.String str)`	Shorten long class names, java/lang/String becomes String.
`static java.lang.String`	`compactClassName(java.lang.String str, boolean chopit)`	Shorten long class names, java/lang/String becomes java.lang.String, for example.
`static java.lang.String`	`compactClassName(java.lang.String str, java.lang.String prefix, boolean chopit)`	Shorten long class name str, that is, chop off the prefix, if the class name starts with this string and the flag chopit is true.
`static java.lang.String`	`convertString(java.lang.String label)`	Escape all occurrences of newline chars '\n', quotes \", etc.
`static byte[]`	`decode(java.lang.String s, boolean uncompress)`	Decode a string back to a byte array.
`static java.lang.String`	`encode(byte[] bytes, boolean compress)`	Encode byte array it into Java identifier string, that is, a string that only contains the following characters: (a, ...
`static java.lang.String`	`fillup(java.lang.String str, int length, boolean leftJustify, char fill)`	Fillup char with up to length characters with char 'fill' and justify it left or right.
`static java.lang.String`	`format(int i, int length, boolean leftJustify, char fill)`	Return a string for an integer justified left or right and filled up with 'fill' characters if necessary.
`static java.lang.String`	`getSignature(java.lang.String type)`	Parse Java type such as "char", or "java.lang.String[]" and return the signature in byte code format, for example "C" or "[Ljava/lang/String;" respectively.
`static boolean`	`isJavaIdentifierPart(char ch)`	Tests if a character is part of a Java identifier.
`static boolean`	`isSet(int flag, int i)`	Tests if a bit is set.
`static java.lang.String[]`	`methodSignatureArgumentTypes(java.lang.String signature)`	Converts argument list portion of method signature to string with all class names compacted.
`static java.lang.String[]`	`methodSignatureArgumentTypes(java.lang.String signature, boolean chopit)`	Converts argument list portion of method signature to string.
`static java.lang.String`	`methodSignatureReturnType(java.lang.String signature)`	Converts return type portion of method signature to string with all class names compacted.
`static java.lang.String`	`methodSignatureReturnType(java.lang.String signature, boolean chopit)`	Converts return type portion of method signature to string.
`static java.lang.String`	`methodSignatureToString(java.lang.String signature, java.lang.String name, java.lang.String access)`	Converts method signature to string with all class names compacted.
`static java.lang.String`	`methodSignatureToString(java.lang.String signature, java.lang.String name, java.lang.String access, boolean chopit)`	Converts method signature to string.
`static java.lang.String`	`methodSignatureToString(java.lang.String signature, java.lang.String name, java.lang.String access, boolean chopit, LocalVariableTable vars)`	This method converts a method signature string into a Java type declaration like 'void main(String[])' and throws a 'ClassFormatException' when the parsed type is invalid.
`static java.lang.String`	`methodTypeToSignature(java.lang.String ret, java.lang.String[] argv)`	Converts string containing the method return and argument types to a byte code method signature.
`static java.lang.String`	`packageToPath(java.lang.String name)`	Converts '.'s to '/'s.
`static java.lang.String`	`pathToPackage(java.lang.String str)`	Converts a path to a package name.
`static void`	`printArray(java.io.PrintStream out, java.lang.Object[] obj)`	Prints an array to a stream.
`static void`	`printArray(java.io.PrintWriter out, java.lang.Object[] obj)`	Prints an array to a writer.
`static java.lang.String`	`printArray(java.lang.Object[] obj)`	Prints an array to a string.
`static java.lang.String`	`printArray(java.lang.Object[] obj, boolean braces)`	Prints an array to a string.
`static java.lang.String`	`printArray(java.lang.Object[] obj, boolean braces, boolean quote)`	Prints an array to a string.
`static java.lang.String`	`replace(java.lang.String str, java.lang.String old, java.lang.String new_)`	Replace all occurrences of old in str with new.
`static short`	`searchOpcode(java.lang.String name)`	Map opcode names to opcode numbers.
`static int`	`setBit(int flag, int i)`	Sets a bit in a flag.
`static java.lang.String`	`signatureToString(java.lang.String signature)`	Converts a signature to a string with all class names compacted.
`static java.lang.String`	`signatureToString(java.lang.String signature, boolean chopit)`	Converts a signature to a string.
`static java.lang.String`	`toHexString(byte[] bytes)`	Convert bytes into hexadecimal string
`static byte`	`typeOfMethodSignature(java.lang.String signature)`	Return type of method signature as a byte value as defined in Constants
`static byte`	`typeOfSignature(java.lang.String signature)`	Return type of signature as a byte value as defined in Constants
`static java.lang.String`	`typeSignatureToString(java.lang.String signature, boolean chopit)`	This method converts a type signature string into a Java type declaration such as 'String[]' and throws a 'ClassFormatException' when the parsed type is invalid.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - Utility
```
public Utility()
```
    Deprecated.
    Will be private in the next major release.
    
    Constructs a Utility.
- Method Detail
  - accessToString
```
public static java.lang.String accessToString(int accessFlags)
```
    Convert bit field of flags into string such as 'static final'.
    
    Parameters:
    
    accessFlags - Access flags.
    
    Returns:
    
    String representation of flags.
  - accessToString
```
public static java.lang.String accessToString(int accessFlags,
                                              boolean forClass)
```
    Convert bit field of flags into string such as 'static final'.
    Special case: Classes compiled with new compilers and with the 'ACC_SUPER' flag would be said to be "synchronized". This is because SUN used the same value for the flags 'ACC_SUPER' and 'ACC_SYNCHRONIZED'.
    
    Parameters:
    
    accessFlags - Access flags.
    
    forClass - access flags are for class qualifiers ?.
    
    Returns:
    
    String representation of flags.
  - classOrInterface
```
public static java.lang.String classOrInterface(int accessFlags)
```
    Gets the class or interface type name.
    
    Parameters:
    
    accessFlags - The class flags.
    
    Returns:
    
    "class" or "interface", depending on the ACC_INTERFACE flag.
  - clearBit
```
public static int clearBit(int flag,
                           int i)
```
    Clears a bit in a flag.
    
    Parameters:
    
    flag - The flag value.
    
    i - The bit position.
    
    Returns:
    
    'flag' with bit 'i' set to 0.
  - codeToString
```
public static java.lang.String codeToString(byte[] code,
                                            ConstantPool constantPool,
                                            int index,
                                            int length)
```
    Disassembles byte code.
    
    Parameters:
    
    code - byte code array.
    
    constantPool - The constant pool.
    
    index - offset in code array.
    
    length - number of opcodes to decompile.
    
    Returns:
    
    disassembled string representation.
  - codeToString
```
public static java.lang.String codeToString(byte[] code,
                                            ConstantPool constantPool,
                                            int index,
                                            int length,
                                            boolean verbose)
```
    Disassemble a byte array of JVM byte codes starting from code line 'index' and return the disassembled string representation. Decode only 'num' opcodes (including their operands), use -1 if you want to decompile everything.
    
    Parameters:
    
    code - byte code array.
    
    constantPool - Array of constants.
    
    index - offset in 'code' array (number of opcodes, not bytes!).
    
    length - number of opcodes to decompile, -1 for all.
    
    verbose - be verbose, for example print constant pool index.
    
    Returns:
    
    String representation of byte codes.
  - codeToString
```
public static java.lang.String codeToString(ByteSequence bytes,
                                            ConstantPool constantPool)
                                     throws java.io.IOException
```
    Disassembles byte code.
    
    Parameters:
    
    bytes - stream of bytes.
    
    constantPool - The constant pool.
    
    Returns:
    
    disassembled string representation.
    
    Throws:
    
    java.io.IOException - Thrown if a failure from reading from the bytes argument occurs.
  - codeToString
```
public static java.lang.String codeToString(ByteSequence bytes,
                                            ConstantPool constantPool,
                                            boolean verbose)
                                     throws java.io.IOException
```
    Disassemble a stream of byte codes and return the string representation.
    
    Parameters:
    
    bytes - stream of bytes.
    
    constantPool - Array of constants.
    
    verbose - be verbose, for example print constant pool index.
    
    Returns:
    
    String representation of byte code.
    
    Throws:
    
    java.io.IOException - Thrown if a failure from reading from the bytes argument occurs
  - compactClassName
```
public static java.lang.String compactClassName(java.lang.String str)
```
    Shorten long class names, java/lang/String becomes String.
    
    Parameters:
    
    str - The long class name.
    
    Returns:
    
    Compacted class name.
  - compactClassName
```
public static java.lang.String compactClassName(java.lang.String str,
                                                boolean chopit)
```
    Shorten long class names, java/lang/String becomes java.lang.String, for example. If chopit is true the prefix java.lang is also removed.
    
    Parameters:
    
    str - The long class name.
    
    chopit - flag that determines whether chopping is executed or not.
    
    Returns:
    
    Compacted class name.
  - compactClassName
```
public static java.lang.String compactClassName(java.lang.String str,
                                                java.lang.String prefix,
                                                boolean chopit)
```
    Shorten long class name str, that is, chop off the prefix, if the class name starts with this string and the flag chopit is true. Slashes / are converted to dots ..
    
    Parameters:
    
    str - The long class name.
    
    prefix - The prefix the get rid off.
    
    chopit - flag that determines whether chopping is executed or not.
    
    Returns:
    
    Compacted class name.
  - convertString
```
public static java.lang.String convertString(java.lang.String label)
```
    Escape all occurrences of newline chars '\n', quotes \", etc.
    
    Parameters:
    
    label - The string to convert.
    
    Returns:
    
    The converted string.
  - decode
```
public static byte[] decode(java.lang.String s,
                            boolean uncompress)
                     throws java.io.IOException
```
    Decode a string back to a byte array.
    
    Parameters:
    
    s - The string to convert.
    
    uncompress - use gzip to uncompress the stream of bytes.
    
    Returns:
    
    The decoded byte array.
    
    Throws:
    
    java.io.IOException - Thrown if there's a gzip exception or the decompressed data exceeds MAX_DECODED_LENGTH.
  - encode
```
public static java.lang.String encode(byte[] bytes,
                                      boolean compress)
                               throws java.io.IOException
```
    Encode byte array it into Java identifier string, that is, a string that only contains the following characters: (a, ... z, A, ... Z, 0, ... 9, _, $). The encoding algorithm itself is not too clever: if the current byte's ASCII value already is a valid Java identifier part, leave it as it is. Otherwise it writes the escape character($) followed by:
    
    the ASCII value as a hexadecimal string, if the value is not in the range 200..247
    
    a Java identifier char not used in a lowercase hexadecimal string, if the value is in the range 200..247
    
    This operation inflates the original byte array by roughly 40-50%
    Parameters:
    
    bytes - The byte array to convert.
    
    compress - use gzip to minimize string.
    
    Returns:
    
    The encoded string.
    
    Throws:
    
    java.io.IOException - Thrown if there's a gzip exception.
  - fillup
```
public static java.lang.String fillup(java.lang.String str,
                                      int length,
                                      boolean leftJustify,
                                      char fill)
```
    Fillup char with up to length characters with char 'fill' and justify it left or right.
    
    Parameters:
    
    str - string to format.
    
    length - length of desired string.
    
    leftJustify - format left or right.
    
    fill - fill character.
    
    Returns:
    
    formatted string.
  - format
```
public static java.lang.String format(int i,
                                      int length,
                                      boolean leftJustify,
                                      char fill)
```
    Return a string for an integer justified left or right and filled up with 'fill' characters if necessary.
    
    Parameters:
    
    i - integer to format.
    
    length - length of desired string.
    
    leftJustify - format left or right.
    
    fill - fill character.
    
    Returns:
    
    formatted int.
  - getSignature
```
public static java.lang.String getSignature(java.lang.String type)
```
    Parse Java type such as "char", or "java.lang.String[]" and return the signature in byte code format, for example "C" or "[Ljava/lang/String;" respectively.
    
    Parameters:
    
    type - Java type.
    
    Returns:
    
    byte code signature.
  - isJavaIdentifierPart
```
public static boolean isJavaIdentifierPart(char ch)
```
    Tests if a character is part of a Java identifier.
    
    Parameters:
    
    ch - The character to test if it's part of an identifier.
    
    Returns:
    
    true, if character is one of (a, ... z, A, ... Z, 0, ... 9, _).
  - isSet
```
public static boolean isSet(int flag,
                            int i)
```
    Tests if a bit is set.
    
    Parameters:
    
    flag - The flag value.
    
    i - The bit position.
    
    Returns:
    
    true, if bit 'i' in 'flag' is set.
  - methodSignatureArgumentTypes
```
public static java.lang.String[] methodSignatureArgumentTypes(java.lang.String signature)
                                                       throws ClassFormatException
```
    Converts argument list portion of method signature to string with all class names compacted.
    
    Parameters:
    
    signature - Method signature.
    
    Returns:
    
    String Array of argument types.
    
    Throws:
    
    ClassFormatException - Thrown if a class is malformed or cannot be interpreted as a class file
  - methodSignatureArgumentTypes
```
public static java.lang.String[] methodSignatureArgumentTypes(java.lang.String signature,
                                                              boolean chopit)
                                                       throws ClassFormatException
```
    Converts argument list portion of method signature to string.
    
    Parameters:
    
    signature - Method signature.
    
    chopit - flag that determines whether chopping is executed or not.
    
    Returns:
    
    String Array of argument types.
    
    Throws:
    
    ClassFormatException - Thrown if a class is malformed or cannot be interpreted as a class file
  - methodSignatureReturnType
```
public static java.lang.String methodSignatureReturnType(java.lang.String signature)
                                                  throws ClassFormatException
```
    Converts return type portion of method signature to string with all class names compacted.
    
    Parameters:
    
    signature - Method signature.
    
    Returns:
    
    String representation of method return type.
    
    Throws:
    
    ClassFormatException - Thrown if a class is malformed or cannot be interpreted as a class file
  - methodSignatureReturnType
```
public static java.lang.String methodSignatureReturnType(java.lang.String signature,
                                                         boolean chopit)
                                                  throws ClassFormatException
```
    Converts return type portion of method signature to string.
    
    Parameters:
    
    signature - Method signature.
    
    chopit - flag that determines whether chopping is executed or not.
    
    Returns:
    
    String representation of method return type.
    
    Throws:
    
    ClassFormatException - Thrown if a class is malformed or cannot be interpreted as a class file
  - methodSignatureToString
```
public static java.lang.String methodSignatureToString(java.lang.String signature,
                                                       java.lang.String name,
                                                       java.lang.String access)
```
    Converts method signature to string with all class names compacted.
    
    Parameters:
    
    signature - to convert.
    
    name - of method.
    
    access - flags of method.
    
    Returns:
    
    Human readable signature.
  - methodSignatureToString
```
public static java.lang.String methodSignatureToString(java.lang.String signature,
                                                       java.lang.String name,
                                                       java.lang.String access,
                                                       boolean chopit)
```
    Converts method signature to string.
    
    Parameters:
    
    signature - to convert.
    
    name - of method.
    
    access - flags of method.
    
    chopit - flag that determines whether chopping is executed or not.
    
    Returns:
    
    Human readable signature.
  - methodSignatureToString
```
public static java.lang.String methodSignatureToString(java.lang.String signature,
                                                       java.lang.String name,
                                                       java.lang.String access,
                                                       boolean chopit,
                                                       LocalVariableTable vars)
                                                throws ClassFormatException
```
    This method converts a method signature string into a Java type declaration like 'void main(String[])' and throws a 'ClassFormatException' when the parsed type is invalid.
    
    Parameters:
    
    signature - Method signature.
    
    name - Method name.
    
    access - Method access rights.
    
    chopit - flag that determines whether chopping is executed or not.
    
    vars - The LocalVariableTable for the method.
    
    Returns:
    
    Java type declaration.
    
    Throws:
    
    ClassFormatException - Thrown if a class is malformed or cannot be interpreted as a class file
  - methodTypeToSignature
```
public static java.lang.String methodTypeToSignature(java.lang.String ret,
                                                     java.lang.String[] argv)
                                              throws ClassFormatException
```
    Converts string containing the method return and argument types to a byte code method signature.
    
    Parameters:
    
    ret - Return type of method.
    
    argv - Types of method arguments.
    
    Returns:
    
    Byte code representation of method signature.
    
    Throws:
    
    ClassFormatException - Thrown if the signature is for Void
  - packageToPath
```
public static java.lang.String packageToPath(java.lang.String name)
```
    Converts '.'s to '/'s.
    
    Parameters:
    
    name - Source.
    
    Returns:
    
    converted value.
    
    Since:
    
    6.7.0
  - pathToPackage
```
public static java.lang.String pathToPackage(java.lang.String str)
```
    Converts a path to a package name.
    
    Parameters:
    
    str - The source path.
    
    Returns:
    
    A package name.
    
    Since:
    
    6.6.0
  - printArray
```
public static java.lang.String printArray(java.lang.Object[] obj)
```
    Prints an array to a string.
    
    Parameters:
    
    obj - The array to print.
    
    Returns:
    
    The string representation.
  - printArray
```
public static java.lang.String printArray(java.lang.Object[] obj,
                                          boolean braces)
```
    Prints an array to a string.
    
    Parameters:
    
    obj - The array to print.
    
    braces - whether to include braces.
    
    Returns:
    
    The string representation.
  - printArray
```
public static java.lang.String printArray(java.lang.Object[] obj,
                                          boolean braces,
                                          boolean quote)
```
    Prints an array to a string.
    
    Parameters:
    
    obj - The array to print.
    
    braces - whether to include braces.
    
    quote - whether to quote elements.
    
    Returns:
    
    The string representation.
  - printArray
```
public static void printArray(java.io.PrintStream out,
                              java.lang.Object[] obj)
```
    Prints an array to a stream.
    
    Parameters:
    
    out - The output stream.
    
    obj - The array to print.
  - printArray
```
public static void printArray(java.io.PrintWriter out,
                              java.lang.Object[] obj)
```
    Prints an array to a writer.
    
    Parameters:
    
    out - The output writer.
    
    obj - The array to print.
  - replace
```
public static java.lang.String replace(java.lang.String str,
                                       java.lang.String old,
                                       java.lang.String new_)
```
    Replace all occurrences of old in str with new.
    
    Parameters:
    
    str - String to permute.
    
    old - String to be replaced.
    
    new_ - Replacement string.
    
    Returns:
    
    new String object.
  - searchOpcode
```
public static short searchOpcode(java.lang.String name)
```
    Map opcode names to opcode numbers. E.g., return Constants.ALOAD for "aload".
    
    Parameters:
    
    name - The opcode name.
    
    Returns:
    
    The value.
  - setBit
```
public static int setBit(int flag,
                         int i)
```
    Sets a bit in a flag.
    
    Parameters:
    
    flag - The flag value.
    
    i - The bit position.
    
    Returns:
    
    'flag' with bit 'i' set to 1.
  - signatureToString
```
public static java.lang.String signatureToString(java.lang.String signature)
```
    Converts a signature to a string with all class names compacted. Class, Method and Type signatures are supported. Enum and Interface signatures are not supported.
    
    Parameters:
    
    signature - signature to convert.
    
    Returns:
    
    String containg human readable signature.
  - signatureToString
```
public static java.lang.String signatureToString(java.lang.String signature,
                                                 boolean chopit)
```
    Converts a signature to a string. Class, Method and Type signatures are supported. Enum and Interface signatures are not supported.
    
    Parameters:
    
    signature - signature to convert.
    
    chopit - flag that determines whether chopping is executed or not.
    
    Returns:
    
    String containg human readable signature.
  - toHexString
```
public static java.lang.String toHexString(byte[] bytes)
```
    Convert bytes into hexadecimal string
    
    Parameters:
    
    bytes - An array of bytes to convert to hexadecimal.
    
    Returns:
    
    bytes as hexadecimal string, for example 00 fa 12 ...
  - typeOfMethodSignature
```
public static byte typeOfMethodSignature(java.lang.String signature)
                                  throws ClassFormatException
```
    Return type of method signature as a byte value as defined in Constants
    
    Parameters:
    
    signature - in format described above.
    
    Returns:
    
    type of method signature.
    
    Throws:
    
    ClassFormatException - Thrown if signature is not a method signature
    
    See Also:
    
    Const
  - typeOfSignature
```
public static byte typeOfSignature(java.lang.String signature)
                            throws ClassFormatException
```
    Return type of signature as a byte value as defined in Constants
    
    Parameters:
    
    signature - in format described above.
    
    Returns:
    
    type of signature.
    
    Throws:
    
    ClassFormatException - Thrown if signature isn't a known type
    
    See Also:
    
    Const
  - typeSignatureToString
```
public static java.lang.String typeSignatureToString(java.lang.String signature,
                                                     boolean chopit)
                                              throws ClassFormatException
```
    This method converts a type signature string into a Java type declaration such as 'String[]' and throws a 'ClassFormatException' when the parsed type is invalid.
    
    Parameters:
    
    signature - type signature.
    
    chopit - flag that determines whether chopping is executed or not.
    
    Returns:
    
    string containing human readable type signature.
    
    Throws:
    
    ClassFormatException - Thrown if a class is malformed or cannot be interpreted as a class file
    
    Since:
    
    6.4.0

Class Utility

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Utility

Method Detail

accessToString

accessToString

classOrInterface

clearBit

codeToString

codeToString

codeToString

codeToString

compactClassName

compactClassName

compactClassName

convertString

decode

encode

fillup

format

getSignature

isJavaIdentifierPart

isSet

methodSignatureArgumentTypes

methodSignatureArgumentTypes

methodSignatureReturnType

methodSignatureReturnType

methodSignatureToString

methodSignatureToString

methodSignatureToString

methodTypeToSignature

packageToPath

pathToPackage

printArray

printArray

printArray

printArray

printArray

replace

searchOpcode

setBit

signatureToString

signatureToString

toHexString

typeOfMethodSignature

typeOfSignature

typeSignatureToString