javah
C Header and Stub File Generator javah produces C header files and C source files from a Java class. These files provide the connective glue that allow your Java and C code to interact.
Synopsis
javah [
options ] fully-qualified-classname. . .
javah_g [ options ] fully-qualified-classname. .
.
add an example, a script, a trick and tips
examples
source
javah -classpath ../bin/ com.seleuco.xpectrum.Emulator
source
cd ../bin
javah jsyphon.JSyphonClient
javah jsyphon.JSyphonImage
javah jsyphon.JSyphonServer
javah jsyphon.JSyphonServerList
source
javah -classpath ../bin/classes -o
parson-android-javah.h mn.uwvm.Parson
source
javac vrpn/*.java
javah -jni -classpath . vrpn.AnalogOutputRemote
javah -jni -classpath . vrpn.AnalogRemote
javah -jni -classpath . vrpn.AuxiliaryLoggerRemote
javah -jni -classpath . vrpn.AuxiliaryLoggerRemote
javah -jni -classpath . vrpn.ButtonRemote
javah -jni -classpath . vrpn.ForceDeviceRemote
javah -jni -classpath . vrpn.PoserRemote
source
javah -jni -classpath build
com.theveganrobot.cmake.HelloWorld
source
javah -jni -classpath build
com.theveganrobot.cmake.HelloEigen
description
javah
generates C header and source files that are needed to
implement native methods. The generated header and source
files are used by C programs to reference an object’s
instance variables from native source code. The .h file
contains a struct definition whose layout parallels the
layout of the corresponding class. The fields in the struct
correspond to instance variables in the class.
The name of the
header file and the structure declared within it are derived
from the name of the class. If the class passed to
javah is inside a package, the package name is
prepended to both the header file name and the structure
name. Underscores (_) are used as name delimiters.
By default
javah creates a header file for each class listed on
the command line and puts the files in the current
directory. Use the -stubs option to create
source files. Use the -o option to concatenate
the results for all listed classes into a single file.
The new native
method interface, Java Native Interface (JNI), does not
require header information or stub files. javah can
still be used to generate native method function proptotypes
needed for JNI-style native methods. javah
produces JNI-style output by default, and places the
result in the .h file.
javah_g
is a non-optimized version of javah suitable
for use with debuggers like jdb.
options
-o
outputfile
Concatenates the resulting
header or source files for all the classes listed on the
command line into outputfile. Only one of
-o or -d may be used.
-d directory
Sets the directory where
javah saves the header files or the stub files. Only
one of -d or -o may be used.
-stubs
Causes javah to generate
C declarations from the Java object file.
-verbose
Indicates verbose output and
causes javah to print a message to stdout concerning
the status of the generated files.
-help
Print help message for
javah usage.
-version
Print out javah version
information.
-jni
Causes javah to create
an output file containing JNI-style native method
function prototypes. This is the default output, so use of
-jni is optional.
-classpath path
Specifies the path javah
uses to look up classes. Overrides the default or the
CLASSPATH environment variable if it is set. Directories are
separated by colons. Thus the general format for path
is:
.:<your_path>
For example:
.:/home/avh/classes:/usr/local/java/classes
As a special
convenience, a class path element containing a basename of
* is considered equivalent to specifying a list of
all the files in the directory with the extension
.jar or .JAR (a java program cannot tell the
difference between the two invocations).
For example, if directory foo contains a.jar
and b.JAR, then the class path element foo/*
is expanded to a A.jar:b.JAR, except that the order
of jar files is unspecified. All jar files in the specified
directory, even hidden ones, are included in the list. A
classpath entry consisting simply of * expands to a
list of all the jar files in the current directory. The
CLASSPATH environment variable, where defined, will
be similarly expanded. Any classpath wildcard expansion
occurs before the Java virtual machine is started
-- no Java program will ever see unexpanded
wildcards except by querying the environment. For example;
by invoking System.getenv("CLASSPATH").
-bootclasspath path
Specifies path from which to
load bootstrap classes. By default, the bootstrap classes
are the classes implementing the core Java 2 platform
located in jre/lib/rt.jar and several other jar
files.
-old
Specifies that old
JDK1.0-style header files should be generated.
-force
Specifies that output files
should always be written.
-Joption
Pass option to the Java
virtual machine, where option is one of the options
described on the reference page for the java application
launcher. For example, -J-Xms48m sets the
startup memory to 48 megabytes.
environment variables
CLASSPATH
Used to provide the system a path to user-defined classes.
Directories are separated by colons, for example,
see also
javac, java,
jdb, javap, javadoc