C Environment Variables and System Properties
This appendix describes environment variables and system properties that can be useful for troubleshooting problems with the Java HotSpot VM.
Submit a Bug Report contains information on collecting environment variables in Environment Variables.
This appendix contains the following sections:
The JAVA_TOOL_OPTIONS Environment Variable
In many environments, the command line is not readily accessible to start the application with the necessary command-line options.
This often happens with applications that use embedded VMs (meaning they use the Java Native Interface (JNI) Invocation API to start the VM), or where the startup is deeply nested in scripts. In these environments the JAVA_TOOL_OPTIONS environment variable can be useful to augment a command line.
Note:
In some cases, this option is disabled for security reasons.
This environment variable allows you to specify the initialization of tools, specifically the launching of native or Java programming language agents using the -agentlib or -javaagent options.
This variable can also be used to augment the command line with other options for diagnostic purposes. For example, you can supply the -XX:OnError option to specify a script or command to be executed when a fatal error occurs.
Because this environment variable is examined at the time, that the JNI_CreateJavaVM function is called, it cannot be used to augment the command line with options that would normally be handled by the launcher, for example, VM selection using the -client option or the -server option.
The java.security.debug System Property
This system property controls whether the security system of the Java runtime prints trace messages during execution.
This option can be useful when diagnosing issues involving the security libraries in the JDK.
To learn more about the java.security.debug system property, see Troubleshooting Security in the Java Platform, Standard Edition Security Developer's Guide.