This chapter describes the command-line options, also called startup commands or startup options, available in Oracle JRockit JVM. These options are self-describing tags that you either enter at the command line or include in startup scripts for applications running on a JVM. These options are used to override the JVM default settings and otherwise define to the JVM how you want your application to run. For example, you can use the command-line option -Xmx to set the maximum heap size.
Command-line options can be either valid for any JVM regardless of the vendor (standard options) or specific to a JVM (nonstandard).
This chapter contains the following sections:
Table 1-1 lists the standard command-line options that the Oracle JRockit JVM recognizes.
Table 1-1 Standard Command-Line Options Accepted by the Oracle JRockit JVM
| Option (Alternate Usage) | Description |
|---|---|
|
|
Loads the specified native agent library |
-agentpath:path-to-agent[=options |
Loads the native agent library that is located at the specified path |
-client |
Selects the JRockit client JVM |
-javaagent |
Loads a Java programming language agent (see |
-jrockit |
Selects the JRockit server JVM This is equivalent to |
-version |
Displays version information and then exits the application |
-showversion |
Displays version information and continues the application |
-verbose:area[,options] |
Displays specific information about the system For more information, see -Xverbose. |
-cp (-classpath) |
Specifies a list of directories, JAR files, and ZIP archives to search for class files. Classpath entries are separated by semicolons ( |
-ea (-enableassertions) |
Enables assertions, which are disabled by default Depending on the arguments specified, this option either enables assertions, enables assertions in the specified package and any subpackages, enables assertions in the unnamed package in the current working directory, or enables assertions in the specified class. |
-da (-disableassertions) |
Disables assertions Depending on the arguments specified, this option either disables assertions, disables assertions in the specified package and any subpackages, disables assertions in the unnamed package in the current working directory, or disables assertions in the specified class |
-esa (-enablesystemassertions) |
Enables assertions in all system classes by setting the default assertion status for system classes to |
-dsa (-disablesystemassertions) |
Disables assertions in all system classes |
For more information about these standard command-line options, see the Java documentation at the following locations:
The JRockit JVM uses a set of nonstandard command-line options to control JVM behavior. Because these options are nonstandard, they do not work with other JVMs. If you use the nonstandard options that are specific to a JVM with other JVMs, the results can be erroneous or an error condition might occur.
The nonstandard command-line options of JRockit JVM are divided into two groups:
-X command-line options, which are the most commonly used nonstandard options
-XX command-line options, which are often experimental options that have specific system requirements for their implementation
The nonstandard options described in this document (Chapter 2, "-X Command-Line Options" and Chapter 3, "-XX Command-Line Options") are subject to change or deprecation at any time.
Note:
Occasionally, you might encounter JRockit JVM internal properties set with the-D option (for example, -Djrockit.lockprofiling=true). The -D option sets values for parameters that are used by Java programs. In the Oracle JRockit JVM, some of those parameters are read by the JVM and change how the JVM works. The -D properties are for internal use; so they are not described in this document.System properties define traits or attributes of the current working environment. When the Java application starts, the system properties are initialized with information about the run-time environment, including information about the current user, the current version of the Java run time, and the product vendor's bug report URL.
For information about the system properties available with the JRockit JVM, see Chapter 4, "Oracle JRockit JVM System Properties."