1 Tools and Commands Reference

The JDK tools and their commands enable developers to handle development tasks such as compiling and running a program, packaging source files into a Java Archive (JAR) file, applying security policies to a JAR file, and more.

The tools and commands reference topic lists and describes the Java Development Kit (JDK) tools. They’re grouped into the following sections based on the related functions that they perform. Details about the tools and the commands that you use to run them are contained in the corresponding sections of this guide.

Main Tools

The following foundation tools and commands let you create and build applications:

  • javac: You can use the javac tool and its options to read Java class and interface definitions and compile them into bytecode and class files.

  • javap: You use the javap command to disassemble one or more class files.

  • javadoc: You use the javadoc tool and its options to generate HTML pages of API documentation from Java source files.

  • java: You can use the java command to launch a Java application.

  • jar: You can use the jar command to create an archive for classes and resources, and to manipulate or restore individual classes or resources from an archive.

  • jlink: You can use the jlink tool to assemble and optimize a set of modules and their dependencies into a custom runtime image.

  • jmod: You use the jmod tool to create JMOD files and list the content of existing JMOD files.

  • jdeps: You use the jdeps command to launch the Java class dependency analyzer.

  • jdeprscan: You use the jdeprscan tool as a static analysis tool that scans a jar file (or some other aggregation of class files) for uses of deprecated API elements.

Language Shell

The following tool gives you an interactive environment for trying out the Java language:

  • jshell: You use the jshell tool to interactively evaluate declarations, statements, and expressions of the Java programming language in a read-eval-print loop (REPL).

Security Tools

The following security tools set security policies on your system and create applications that can work within the scope of security policies set at remote sites:

  • keytool: You use the keytool command and options to manage a keystore (database) of cryptographic keys, X.509 certificate chains, and trusted certificates.

  • jarsigner: You use the jarsigner tool to sign and verify Java Archive (JAR) files.

The following tools obtain, list, and manage Kerberos tickets on Windows:

  • kinit: You use the kinit tool and its options to obtain and cache Kerberos ticket-granting tickets.

  • klist: You use the klist tool to display the entries in the local credentials cache and key table.

  • ktab: You use the ktab tool to manage the principal names and service keys stored in a local key table.

Remote Method Invocation (RMI) Tools

The following tools enable creating applications that interact over the Web or other network:

  • rmic: You use the rmic compiler to generate stub and skeleton class files using the Java Remote Method Protocol (JRMP).

  • rmiregistry: You use the rmiregistry command on UNIX-based systems to create and start a remote object registry on the specified port on the current host.

  • rmid: You use the rmid command to start the activation system daemon that enables objects to be registered and activated in a Java Virtual Machine (JVM).

  • serialver: You use the serialver command to return the serialVersionUID for one or more classes in a form suitable for copying into an evolving class.

Java Deployment Tools

The following utilities let you deploy Java applications:

Note:

pack 200 and unpack200 have been deprecated and might be removed in a future JDK release.

  • pack200: You use the pack200 command to transform a Java Archive (JAR) file into a compressed pack200 file with the Java gzip compressor.

  • unpack200: You use the unpack200 command to transform a packed file into a JAR file for web deployment.

Monitoring Tools

The following tools let you monitor performance statistics:

  • jconsole: You use the jconsole command to start a graphical console to monitor and manage Java applications.

Note:

The following experimental tools are unsupported and should be used with that understanding. They may not be available in future JDK versions.

  • jps: Experimental You use the jps command to list the instrumented JVMs on the target system.

  • jstat: Experimental You use the jstat command to monitor JVM statistics. This command is experimental and unsupported.

  • jstatd: Experimental You use the jstatd command to monitor the creation and termination of instrumented Java HotSpot VMs. This command is experimental and unsupported.

Java Accessibility Utilities

The following utilities let you check the accessibility of Java objects:

  • jaccessinspector: You use the jaccessinspector accessibility evaluation tool for the Java Accessibility Utilities API to examine accessible information about the objects in the Java Virtual Machine.

  • jaccesswalker: You use the jaccesswalker to navigate through the component trees in a particular Java Virtual Machine and presents the hierarchy in a tree view.

Troubleshooting Tools

The following tools let you perform specific troubleshooting tasks:

  • jcmd: You use the jcmd utility to send diagnostic command requests to a running Java Virtual Machine (JVM).

  • jdb: You use the jdb command and its options to find and fix bugs in Java platform programs.

  • jhsdb: You use the jhsdb tool to attach to a Java process or to launch a postmortem debugger to analyze the content of a core dump from a crashed Java Virtual Machine (JVM).

Note:

The following experimental tools are unsupported and should be used with that understanding. They may not be available in future JDK versions. Some of these tools aren’t currently available on Windows platforms.

  • jinfo: Experimental You use the jinfo command to generate Java configuration information for a specified Java process. This command is experimental and unsupported.

  • jmap: Experimental You use the jmap command to print details of a specified process. This command is experimental and unsupported.

  • jstack: Experimental You use the jstack command to print Java stack traces of Java threads for a specified Java process. This command is experimental and unsupported.

Scripting Tools

The following tools let you run scripts that interact with the Java platform:

Note:

The Nashorn JavaScript script engine, APIs, and the jjs tool have been deprecated and might be removed in a future JDK release.

  • jjs: You use the jjs command-line tool to invoke the Nashorn engine.

Note:

The following experimental tool is unsupported and should be used with that understanding. It may not be available in future JDK versions.

  • jrunscript: Experimental You use the jrunscript command to run a command-line script shell that supports interactive and batch modes.