javap(1) Basic Tools javap(1) (NAME) javap - class. (SYNOPSIS) javap [options] classfile... options . . classfile (annotations) DocFooter.class. (class path) URL file:///home/user/myproject/src/DocFooter.class . (DESCRIPTION) javap class . . javap (package) (protected) (public) . javap stdout . (OPTIONS) -help --help -? javap . -version . -l . -public (public) . -protected (protected) . -private -p . -Joption JVM . : javap -J-version javap -J-Djava.security.manager -J-Djava.security.policy=MyPolicy MyClassName JVM . -s (type signatures) . -sysinfo ( MD5) . -constants static final . -c . -verbose (stack size) . -classpath path javap . CLASSPATH . -bootclasspath path (bootstrap) . bootstrap jre/lib/rt.jar JAR . -extdir dirs . java.ext.dirs . (EXAMPLES) DocFooter : import java.awt.*; import java.applet.*; public class DocFooter extends Applet { String date; String email; public void init() { resize(500,100); date = getParameter("LAST_UPDATED"); email = getParameter("EMAIL"); } public void paint(Graphics g) { g.drawString(date + " by ",100, 15); g.drawString(email,290,15); } } javap DocFooter.class : Compiled from "DocFooter.java" public class DocFooter extends java.applet.Applet { java.lang.String date; java.lang.String email; public DocFooter(); public void init(); public void paint(java.awt.Graphics); } javap -c DocFooter.class : Compiled from "DocFooter.java" public class DocFooter extends java.applet.Applet { java.lang.String date; java.lang.String email; public DocFooter(); Code: 0: aload_0 1: invokespecial #1 // Method java/applet/Applet."":()V 4: return public void init(); Code: 0: aload_0 1: sipush 500 4: bipush 100 6: invokevirtual #2 // Method resize:(II)V 9: aload_0 10: aload_0 11: ldc #3 // String LAST_UPDATED 13: invokevirtual #4 // Method getParameter:(Ljava/lang/String;)Ljava/lang/String; 16: putfield #5 // Field date:Ljava/lang/String; 19: aload_0 20: aload_0 21: ldc #6 // String EMAIL 23: invokevirtual #4 // Method getParameter:(Ljava/lang/String;)Ljava/lang/String; 26: putfield #7 // Field email:Ljava/lang/String; 29: return public void paint(java.awt.Graphics); Code: 0: aload_1 1: new #8 // class java/lang/StringBuilder 4: dup 5: invokespecial #9 // Method java/lang/StringBuilder."":()V 8: aload_0 9: getfield #5 // Field date:Ljava/lang/String; 12: invokevirtual #10 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder; 15: ldc #11 // String by 17: invokevirtual #10 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder; 20: invokevirtual #12 // Method java/lang/StringBuilder.toString:()Ljava/lang/String; 23: bipush 100 25: bipush 15 27: invokevirtual #13 // Method java/awt/Graphics.drawString:(Ljava/lang/String;II)V 30: aload_1 31: aload_0 32: getfield #7 // Field email:Ljava/lang/String; 35: sipush 290 38: bipush 15 40: invokevirtual #13 // Method java/awt/Graphics.drawString:(Ljava/lang/String;II)V 43: return } (SEE ALSO) o java(1) o javac(1) o javadoc(1) o jdb(1) o jdeps(1) JDK 8 8 August 2014 javap(1)