Runtime Environment
The Java™ runtime environment provides runtime support for Java applications.
The runtime environment includes the IBM J9 Virtual Machine (JVM), which interprets Java bytecode at run time. For the z/TPF system, the runtime environment is provided as a downloadable package and is separate from the IBM® software developers kit (SDK) that is used for your Linux® development system. A number of tools that are included with the runtime environment are installed in the /sys/tpf_pbfiles/opt/ibm/java-s390x-80/jre/bin directory.
The z/TPF system only supports the java, rmid, and tnameserv tools.
Contents of the runtime environment
- Core Classes
- These classes are the compiled class files for the platform and must remain compressed for the compiler and interpreter to access them. Do not modify these classes; instead, create subclasses and override where you need to.
- Trusted root certificates
- From certificate signing authorities. These certificates are used to validate the identity of signed material.
- Runtime environment tools
- ControlPanel (Java Control Panel)
- AIX® and Linux operating systems only, except Linux on IBM Z®. Configures your Runtime Environment.
- ikeycmd (iKeyman command-line utility)
- Allows you to manage keys, certificates, and certificate requests from the command line. For more information, see the Security documentation.
- ikeyman (iKeyman GUI utility)
- Allows you to manage keys, certificates, and certificate requests. For more information see the Security documentation, which includes the iKeyman User Guide. There is also a command-line version of this utility.
- jaaslogon (Windows only)
- A Windows service that enables JAAS Active Login applications to change their effective user at run time using the JAAS Active Login API.
- java (Java Interpreter)
- Runs Java classes. The Java Interpreter runs programs that are written in the Java programming language.
- javacpl (Java Control Panel)
- Windows operating systems only. Configures your Runtime Environment.
- javaw (Java Interpreter)
- Runs Java classes in the same way as the java command does, but does not use a console window.
- jcontrol (Java Control Panel)
- AIX and Linux operating systems only, except Linux on IBM Z. Configures your Runtime Environment.
- jextract (AIX, Linux, Windows, and z/OS only)
- Converts a system-produced dump into a common format that can be used by jdmpview. For more information, see Using jextract.
- keytool (Key and Certificate Management Tool)
- Manages a keystore (database) of private keys and their associated X.509 certificate chains that authenticate the corresponding public keys.
- kinit
- Obtains and caches Kerberos ticket-granting tickets.
- klist
- Displays entries in the local credentials cache and key table.
- ktab
- Manages the principal names and service keys stored in a local key table.
- pack200
- Transforms a JAR file into a compressed pack200 file using the Java gzip compressor.
- policytool (Policy File Creation and Management Tool)
- Creates and modifies the external policy configuration files that define the Java security policy for your installation. From Version 8, the graphical user interface of this tool has a slightly different look and feel. See Accessibility issues with the policytool graphical user interface (GUI) utility.
- rmid (RMI activation system daemon)
- Starts the activation system daemon so that objects can be registered and activated in a Java Virtual Machine (JVM).
- rmiregistry (Java remote object registry)
- Creates and starts a remote object registry on the specified port of the current host.
- tnameserv (Common Object Request Broker Architecture (CORBA) transient naming service)
- Starts the CORBA transient naming service.
- unpack200
- Transforms a packed file produced by pack200 into a JAR file.