javah | Native Method C Stub Generator
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Synopsis
javah [ options ] classnames
Description
javah generates C
header and source files
(.h and .c files) that are
used when implementing Java native methods in C. The preferred native
method interface changed between Java 1.0 and Java 1.1. In Java 1.1
and earlier, javah generated files for old-style
native methods. In Java 1.1, the -jni option
specified that javah should generate new-style
files. In Java 1.2 and later, this option is the default.
This section describes only how to use javah. A
full description of how to implement Java native methods in C is
beyond the scope of this book.
Options
- -bootclasspath
-
Specifies the path to search for
system classes. See javac for further
discussion. Java 1.2 and later.
- -classpath path
-
Specifies the path
javah uses to look up the classes named on the
command line. This option overrides any path specified by the
CLASSPATH environment variable. Prior to Java 1.2,
this option can specify the location of the system classes and
extensions. In Java 1.2 and later, it specifies only the location of
application classes. See -bootclasspath. See also
java for further discussion of the classpath.
- -d directory
-
Specifies the directory into which javah stores
the files it generates. By default, it stores them in the current
directory. This option cannot be used with -o.
- -force
-
Causes javah to always write output files, even
if they contain no useful content.
- -help
-
Causes javah to display a simple usage message
and exit.
- -J javaopt
-
Passes the option javaopt to the Java
interpreter.
- -jni
-
Specifies that javah
should output header files for use with the Java Native
Interface (JNI) rather than the old JDK 1.0 native interface. This
option is the default in Java 1.2 and later. See also
-old. Java 1.1 and later.
- -o outputfile
-
Combines all output into a single file,
outputfile, instead of creating separate
files for each specified class.
- -old
-
Outputs files for Java 1.0-style native methods. Prior to Java 1.2,
this was the default. See also -jni. Java 1.2 and
later.
- -stubs
-
Generates .c
stub files for the class or classes instead of header files. This
option is only for the Java 1.0 native methods interface. See
-old.
- -trace
-
Specifies that javah should include tracing
output commands in the stub files it generates. In Java 1.2 and
later, this option is obsolete and has been removed. In its place,
you can use the -verbose:jni option of the Java
interpreter.
- -v, -verbose
-
Specifies verbose mode. Causes javah to print
messages about what it is doing. In Java 1.2 and later,
-verbose is a synonym.
- -version
-
Causes javah to display its version number.
Environment
- CLASSPATH
-
Specifies the default classpath javah searches
to find the specified classes. See java for a
further discussion of the classpath.
See also
java, javac
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