(The latest version of this document is at http://www.milkywaygalaxy.freeservers.com. You may want to check there for changes).
Java compiler compiles the Java source code files (*.java) into binaries files (*.class). You would use the Java de-compiler to convert java class files into source code files (*.java).
Java de-compiler is very useful especially if you have *.class files and you do not have access to the source code. Some vendors do not ship the source code for java class files, in which case you use the java decompiler to look at the source code.
See also the "javap" command from Sun Microsystems. This command is available as soon as you install the JDK from Sun Microsystems. At unix prompt type -
bash$ javap -help bash$ javap -c <filename>.class
The following are the list of Java decompilers available -
For 100% assurance you need a SCIENTIFIC way to validate and trust the Java Decompiler program. The method described in this section will enable the decompiler program to be accepted as "trust-worthy" and reliable.
In order to verify that the decompiler program is regenerating the Java source-code properly, use the following technique -
Generate the class file from the generated source code using the compiler -
bash$ mv myprogram.class myprogram_orig.class bash$ javac myprogram.java
Now use the unix 'diff' command to compare the two class files -
bash$ diff myprogram.class myprogram_orig.class
This step gives 100% guarantee and 100% quality assurance and life term or long term WARRANTY on decompiler programs.
It is strongly recommended that you do these steps every time you run decompiler programs.
Visit following locators which are related to Java -
This document is published in 14 different formats namely - DVI, Postscript, Latex, Adobe Acrobat PDF, LyX, GNU-info, HTML, RTF(Rich Text Format), Plain-text, Unix man pages, single HTML file, SGML (Linuxdoc format), SGML (Docbook format), MS WinHelp format.
This howto document is located at -
You can also find this document at the following mirrors sites -
Single HTML file can be created with command (see man sgml2html) - sgml2html -split 0 xxxxhowto.sgml
PDF file can be generated from postscript file using either acrobat distill or Ghostscript. And postscript file is generated from DVI which in turn is generated from LaTex file. You can download distill software from http://www.adobe.com. Given below is a sample session:
bash$ man sgml2latex bash$ sgml2latex filename.sgml bash$ man dvips bash$ dvips -o filename.ps filename.dvi bash$ distill filename.ps bash$ man ghostscript bash$ man ps2pdf bash$ ps2pdf input.ps output.pdf bash$ acroread output.pdf &
This document is written in linuxdoc SGML format. The Docbook SGML format supercedes the linuxdoc format and has lot more features than linuxdoc. The linuxdoc is very simple and is easy to use. To convert linuxdoc SGML file to Docbook SGML use the program ld2db.sh and some perl scripts. The ld2db output is not 100% clean and you need to use the clean_ld2db.pl perl script. You may need to manually correct few lines in the document.
bash$ ld2db.sh file-linuxdoc.sgml db.sgml bash$ cleanup.pl db.sgml > db_clean.sgml bash$ gvim db_clean.sgml bash$ docbook2html db.sgml
You can convert the SGML howto document to Microsoft Windows Help file, first convert the sgml to html using:
bash$ sgml2html xxxxhowto.sgml (to generate html file) bash$ sgml2html -split 0 xxxxhowto.sgml (to generate a single page html file)
In order to view the document in dvi format, use the xdvi program. The xdvi program is located in tetex-xdvi*.rpm package in Redhat Linux which can be located through ControlPanel | Applications | Publishing | TeX menu buttons. To read dvi document give the command -
And resize the window with mouse. To navigate use Arrow keys, Page Up, Page Down keys, also you can use 'f', 'd', 'u', 'c', 'l', 'r', 'p', 'n' letter keys to move up, down, center, next page, previous page etc. To turn off expert menu press 'x'.
xdvi -geometry 80x90 howto.dvi man xdvi
You can read postscript file using the program 'gv' (ghostview) or 'ghostscript'. The ghostscript program is in ghostscript*.rpm package and gv program is in gv*.rpm package in Redhat Linux which can be located through ControlPanel | Applications | Graphics menu buttons. The gv program is much more user friendly than ghostscript. Also ghostscript and gv are available on other platforms like OS/2, Windows 95 and NT, you view this document even on those platforms.
To read postscript document give the command -
gv howto.ps ghostscript howto.ps
You can read HTML format document using Netscape Navigator, Microsoft Internet explorer, Redhat Baron Web browser or any of the 10 other web browsers.
You can read the latex, LyX output using LyX a X-Windows front end to latex.
Copyright policy is GNU/GPL as per LDP (Linux Documentation project). LDP is a GNU/GPL project. Additional requests are - you retain the author's name, email address and this copyright notice on all the copies. If you make any changes or additions to this document then you should intimate all the authors of this document.