ClassFileAnalyzer - Analyzer and Disassembler for Java class files

This software is an analyzer and disassembler (Jasmin syntax 2, http://jasmin.sourceforge.net) for Java class files and is based on the specification of the Java Virtual Machine (Chapter: The class File Format). ClassFileAnalyzer is released as free software, provided under the terms of the GPL 2.0.

This software is licensed under the CC-GNU GPL.

Diese Software fällt unter den Lizenzvertrag CC-GNU GPL.
Die Software ist ein Analyseprogramm und ein Disassembler für Java-Klassendateien - siehe auch javaseiten.de/bytecode.html und javaseiten.de/jasmin.html.

HelloWorld Example

/* HelloWorld.java */

public class HelloWorld {
  
  public static void main(String[] args) {
    System.out.println("Hello World!");    
  }
}

> javac HelloWorld.java
  --> HelloWorld.class
> java ClassFileAnalyzer HelloWorld.class

The following code is generated by ClassFileAnalyzer from the class file HelloWorld.class:

; HelloWorld.j

; Generated by ClassFileAnalyzer (Can)
; Analyzer and Disassembler for Java class files
; (Jasmin syntax 2, http://jasmin.sourceforge.net)
;
; ClassFileAnalyzer, version 0.7.0 


.bytecode 50.0
.source HelloWorld.java
.class public HelloWorld
.super java/lang/Object

.method public <init>()V
  .limit stack 1
  .limit locals 1
  .line 3
  0: aload_0
  1: invokespecial java/lang/Object/<init>()V
  4: return
.end method

.method public static main([Ljava/lang/String;)V
  .limit stack 2
  .limit locals 1
  .line 6
  0: getstatic java/lang/System/out Ljava/io/PrintStream;
  3: ldc "Hello World!"
  5: invokevirtual java/io/PrintStream/println(Ljava/lang/String;)V
  .line 7
  8: return
.end method

Downloads

JAR file `classfileanalyzer.jar` only:	`classfileanalyzer-bin-0-7-0.zip`
Source code of ClassFileAnalyzer:	`classfileanalyzer-src-0-7-0.zip`
ClassFileAnalyzer as NetBeans project:	`classfileanalyzer-nb-0-7-0.zip`

Usage

java -jar classfileanalyzer.jar [options] [<jarfile>] <classfile>

java ClassFileAnalyzer [options] [<jarfile>] <classfile>
java Can [options] [<jarfile>] <classfile>

classfile:
  Java class file to be disassembled.

jarfile:
  Java Archive (JAR) file, which includes the Java class file to be
  disassembled (optional).

options:
  -version
    Print version information.
  -file
    Generate file in actual directory with assembler source text.
  -info
    Print additional informations, e.g. hexdump of classfile.
  -nopc
    Omit pc label before mnemonic.
  -help, -?
    Print usage message.

Notes:

Download and install Java SE: Java SE Downloads

Execute ClassFileAnalyzer encapsulated in the JAR file classfileanalyzer.jar:
```
    java -jar classfileanalyzer.jar HelloWorld.class
```
If classfileanalyzer.jar is already in the classpath:
```
    java ClassFileAnalyzer HelloWorld.class
```
Examples for using the classpath (modify path to JAR file classfileanalyzer.jar):
```
    java -classpath classfileanalyzer.jar ClassFileAnalyzer HelloWorld.class
```
```
    set CLASSPATH=classfileanalyzer.jar
    java ClassFileAnalyzer HelloWorld.class
```
(The setting of the CLASSPATH environment variable depends on your operating system. Windows: It can be set using the System utility in the Control Panel.)
Copy classfileanalyzer.jar in the directory (optional package, extension mechanism):
```
    lib/ext    [in the JRE]
```
Classes within JAR files in this directory can then be used by applications, without having to explicitly include them in the classpath:
```
    java ClassFileAnalyzer HellowWorld.class
```

Example: Disassemble classfileanalyzer/ClassFile.class

java ClassFileAnalyzer c:/classfileanalyzer.jar classfileanalyzer/ClassFile.class

Examples

Option -info: TestCanOptionInfo

.annotation default directive: TestCanAnnotationDefault, TestCanAnnotationDefault2, TestCanAnnotationDefault3

.annotation invisible directive: TestCanRuntimeInvisibleAnnotations, TestCanRuntimeInvisibleAnnotations2

.annotation invisibleparam directive: TestCanRuntimeVisibleParameterAnnotations

.annotation visible directive: TestCanRuntimeVisibleAnnotations, TestCanRuntimeVisibleAnnotations2, TestCanRuntimeVisibleAnnotations3, TestCanRuntimeVisibleAnnotations4

.annotation visibleparam directive: TestCanRuntimeVisibleParameterAnnotations

.debug directive: TestCanDebug

.deprecated directive: TestCanDeprecated

.enclosing method directive: TestCanInner2

.field directive: TestCanField

.inner directive: TestCanInner, TestCanInner2, TestCanInner3

.interface directive: TestCanInterface

.signature directive: TestCanSignature

.stack directive: TestCanStack, TestCanStack2

.var directive: TestCanVar

JVM instructions: TestCanWide, TestCanLookupswitch, TestCanTableswitch

Mapping: Attributes - Directives

	Attribute	Directive
1.	ConstantValue	(`.field`)
2.	Code	(`.limit stack`, `.limit locals`, `.catch`)
3.	StackMapTable	`.stack`
4.	Exceptions	`.throws`
5.	InnerClasses	`.inner class`, `.inner interface`
6.	EnclosingMethod	`.enclosing method`
7.	Synthetic ^*
8.	Signature	`.signature`
9.	SourceFile	`.source`
10.	SourceDebugExtension	`.debug`
11.	LineNumberTable	`.line`
12.	LocalVariableTable	`.var`
13.	LocalVariableTypeTable	`.var`
14.	Deprecated	`.deprecated`
15.	RuntimeVisibleAnnotations	`.annotation visible`
16.	RuntimeInvisibleAnnotations	`.annotation invisible`
17.	RuntimeVisibleParamterAnnotations	`.annotation visibleparam`
18.	RuntimeInvisibleParameterAnnotations	`.annotation invisibleparam`
19.	AnnotationDefault	`.annotation default`

^* A class, field or method that does not appear in the source code (it was generated by the compiler/assembler) must be marked using a Synthetic attribute, or else it must have its ACC_SYNTHETIC bit set. The only exceptions to this requirement are for default constructors and the class initialization method. The Synthetic attribute was originally introduced in JDK 1.1 to support nested classes (nested interfaces). Example: .field private static final synthetic $VALUES ... (TestCanRuntimeInvisibleAnnotations2)

Class file format: Attributes

Attributes are used in the following structures of the class file format: ClassFile, field_info, method_info and Code_attribute.

	ClassFile	field_info	method_info	Code_attribute
ConstantValue		X
Code			X
StackMapTable				X
Exceptions			X
InnerClasses	X
EnclosingMethod	X
Synthetic	X	X	X
Signature	X	X	X
SourceFile	X
SourceDebugExtension	X
LineNumberTable				X
LocalVariableTable				X
LocalVariableTypeTable				X
Deprecated	X	X	X
RuntimeVisibleAnnotations	X	X	X
RuntimeInvisibleAnnotations	X	X	X
RuntimeVisibleParameterAnnotations			X
RuntimeInvisibleParameterAnnotations			X
AnnotationDefault			X

Frequently Asked Questions (FAQ)

Is Can an abbreviation?

Can is an abbreviation for ClassFileAnalyzer.

Log

ClassFileAnalyzer 0.7.0 released - 19. February 2008
     New name: ClassFileAnalyzer (Can).
     Line terminator: \n replaced by System.getProperty("line.separator")
     Source code slightly changed.

Clara 0.6.3 beta released - 01. November 2007
     Source code slightly changed.
     Clara 0.6.2 beta. Bug fix: attributes field_info (only one attribute recognized).
     Clara 0.6.1 beta. Bug fix: JVM instruction lookupswitch (labels).

Clara 0.6.0 beta released - 03. September 2007
First public version of Clara disassembler.