The command-line options separated by spaces\&. See Options\&.
.TP
\fIurl\fR
The location of the documents or resources to be displayed\&. You can specify multiple URLs separated by spaces\&.
.SH DESCRIPTION
The \f3appletviewer\fR command connects to the documents or resources designated by \fIurls\fR and displays each applet referenced by the documents in its own window\&. If the documents referred to by urls do not reference any applets with the \f3OBJECT\fR, \f3EMBED\fR, or \f3APPLET\fR tag, then the \f3appletviewer\fR command does nothing\&. For details about the HTML tags that the \f3appletviewer\fR command supports, see AppletViewer Tags at http://docs\&.oracle\&.com/javase/8/docs/technotes/tools/appletviewertags\&.html
.PP
The \f3appletviewer\fR command requires encoded URLs according to the escaping mechanism defined in RFC2396\&. Only encoded URLs are supported\&. However, file names must be unencoded, as specified in RFC2396\&.
.PP
\fINote:\fR The \f3appletviewer\fR command is intended for development purposes only\&. For more information, see About Sample/Test Applications and Code at http://docs\&.oracle\&.com/javase/8/docs/technotes/samples/aboutCodeSamples\&.html
.SH OPTIONS
.TP
-debug
.br
Starts the Applet Viewer in the Java debugger with the \f3jdb\fR command to debug the applets in the document\&.
.TP
-encoding \fIencoding-name\fR
.br
Specifies the input HTML file encoding name\&.
.TP
-J\fIjavaoption\fR
.br
Passes the string \f3javaoption\fR as a single argument to the Java interpreter, which runs the Applet Viewer\&. The argument should not contain spaces\&. Multiple argument words must all begin with the prefix \f3-J\fR\&. This is useful for adjusting the compiler\&'s execution environment or memory usage\&.
.PP
.SH NAME
appletviewer \- Runs applets outside of a web browser\&.
The command-line options separated by spaces\&. See Options\&.
.TP
\fIurl\fR
The location of the documents or resources to be displayed\&. You can specify multiple URLs separated by spaces\&.
.SH DESCRIPTION
The \f3appletviewer\fR command connects to the documents or resources designated by \fIurls\fR and displays each applet referenced by the documents in its own window\&. If the documents referred to by urls do not reference any applets with the \f3OBJECT\fR, \f3EMBED\fR, or \f3APPLET\fR tag, then the \f3appletviewer\fR command does nothing\&. For details about the HTML tags that the \f3appletviewer\fR command supports, see AppletViewer Tags at http://docs\&.oracle\&.com/javase/8/docs/technotes/tools/appletviewertags\&.html
.PP
The \f3appletviewer\fR command requires encoded URLs according to the escaping mechanism defined in RFC2396\&. Only encoded URLs are supported\&. However, file names must be unencoded, as specified in RFC2396\&.
.PP
\fINote:\fR The \f3appletviewer\fR command is intended for development purposes only\&. For more information, see About Sample/Test Applications and Code at http://docs\&.oracle\&.com/javase/8/docs/technotes/samples/aboutCodeSamples\&.html
.SH OPTIONS
.TP
-debug
.br
Starts the Applet Viewer in the Java debugger with the \f3jdb\fR command to debug the applets in the document\&.
.TP
-encoding \fIencoding-name\fR
.br
Specifies the input HTML file encoding name\&.
.TP
-J\fIjavaoption\fR
.br
Passes the string \f3javaoption\fR as a single argument to the Java interpreter, which runs the Applet Viewer\&. The argument should not contain spaces\&. Multiple argument words must all begin with the prefix \f3-J\fR\&. This is useful for adjusting the compiler\&'s execution environment or memory usage\&.
The target JAR file against which the currently installed extension JAR files are compared to detect version conflicts\&.
.SH DESCRIPTION
The \f3extcheck\fR command checks a specified JAR file for title and version conflicts with any extensions installed in the Java SE SDK\&. Before installing an extension, you can use this utility to see whether the same or a more recent version of the extension is already installed\&.
.PP
The \f3extcheck\fR command compares the Specification-title and Specification-version headers in the manifest of the \f3targetfile\&.jar\fR file against the corresponding headers in all JAR files currently installed in the extension directory\&. By default, the extension directory is \f3jre/lib/ext\fR on Oracle Solaris and \f3\ejre\elib\eext\fR on Windows\&. The \f3extcheck\fR command compares version numbers in the same way as the \f3java\&.lang\&.Package\&.isCompatibleWith\fR method\&.
.PP
If no conflict is detected, then the return code is 0\&.
.PP
If the manifest of any JAR file in the extensions directory has the same \f3Specification-title\fR and the same or a newer \f3Specification-version\fR number, then a non-zero error code is returned\&. A non-zero error code is also returned when \f3targetfile\&.jar\fR does not have the \f3Specification-title\fR or \f3Specification-version\fR attributes in its manifest file\&.
.SH OPTIONS
.TP
-verbose
.br
Lists JAR files in the extension directory as they are checked\&. Additionally, manifest attributes of the target JAR file and any conflicting JAR files are also reported\&.
.TP
-J\fIoption\fR
.br
Passes \fIoption\fR to the Java Virtual Machine (JVM), where option is one of the options described on the reference page for the Java launcher\&. For example, \f3-J-Xms48m\fR sets the startup memory to 48 MB\&. See java(1)\&.
.SH SEE\ ALSO
.TP 0.2i
\(bu
jar(1)
.SH NAME
extcheck \- Detects version conflicts between a target Java Archive (JAR) file and currently installed extension JAR files\&.
The target JAR file against which the currently installed extension JAR files are compared to detect version conflicts\&.
.SH DESCRIPTION
The \f3extcheck\fR command checks a specified JAR file for title and version conflicts with any extensions installed in the Java SE SDK\&. Before installing an extension, you can use this utility to see whether the same or a more recent version of the extension is already installed\&.
.PP
The \f3extcheck\fR command compares the Specification-title and Specification-version headers in the manifest of the \f3targetfile\&.jar\fR file against the corresponding headers in all JAR files currently installed in the extension directory\&. By default, the extension directory is \f3jre/lib/ext\fR on Oracle Solaris and \f3\ejre\elib\eext\fR on Windows\&. The \f3extcheck\fR command compares version numbers in the same way as the \f3java\&.lang\&.Package\&.isCompatibleWith\fR method\&.
.PP
If no conflict is detected, then the return code is 0\&.
.PP
If the manifest of any JAR file in the extensions directory has the same \f3Specification-title\fR and the same or a newer \f3Specification-version\fR number, then a non-zero error code is returned\&. A non-zero error code is also returned when \f3targetfile\&.jar\fR does not have the \f3Specification-title\fR or \f3Specification-version\fR attributes in its manifest file\&.
.SH OPTIONS
.TP
-verbose
.br
Lists JAR files in the extension directory as they are checked\&. Additionally, manifest attributes of the target JAR file and any conflicting JAR files are also reported\&.
.TP
-J\fIoption\fR
.br
Passes \fIoption\fR to the Java Virtual Machine (JVM), where option is one of the options described on the reference page for the Java launcher\&. For example, \f3-J-Xms48m\fR sets the startup memory to 48 MB\&. See java(1)\&.
The fully qualified location of the classes to be converted to C header and source files\&.
.SH DESCRIPTION
The \f3javah\fR command generates C header and source files that are needed to implement native methods\&. The generated header and source files are used by C programs to reference an object\&'s instance variables from native source code\&. The \f3\&.h\fR file contains a \f3struct\fR definition with a layout that parallels the layout of the corresponding class\&. The fields in the \f3struct\fR correspond to instance variables in the class\&.
.PP
The name of the header file and the structure declared within it are derived from the name of the class\&. When the class passed to the \f3javah\fR command is inside a package, the package name is added to the beginning of both the header file name and the structure name\&. Underscores (_) are used as name delimiters\&.
.PP
By default the \f3javah\fR command creates a header file for each class listed on the command line and puts the files in the current directory\&. Use the \f3-stubs\fR option to create source files\&. Use the \f3-o\fR option to concatenate the results for all listed classes into a single file\&.
.PP
The Java Native Interface (JNI) does not require header information or stub files\&. The \f3javah\fR command can still be used to generate native method function prototypes needed for JNI-style native methods\&. The \f3javah\fR command produces JNI-style output by default and places the result in the \f3\&.h\fR file\&.
.SH OPTIONS
.TP
-o \fIoutputfile\fR
.br
Concatenates the resulting header or source files for all the classes listed on the command line into an output file\&. Only one of \f3-o\fR or \f3-d\fR can be used\&.
.TP
-d \fIdirectory\fR
.br
Sets the directory where the \f3javah\fR command saves the header files or the stub files\&. Only one of \f3-d\fR or \f3-o\fR can be used\&.
.TP
-stubs
.br
Causes the \f3javah\fR command to generate C declarations from the Java object file\&.
.TP
-verbose
.br
Indicates verbose output and causes the \f3javah\fR command to print a message to \f3stdout\fR about the status of the generated files\&.
.TP
-help
.br
Prints a help message for \f3javah\fR usage\&.
.TP
-version
.br
Prints \f3javah\fR command release information\&.
.TP
-jni
.br
Causes the \f3javah\fR command to create an output file containing JNI-style native method function prototypes\&. This is the default output; use of \f3-jni\fR is optional\&.
.TP
-classpath \fIpath\fR
.br
Specifies the path the \f3javah\fR command uses to look up classes\&. Overrides the default or the \f3CLASSPATH\fR environment variable when it is set\&. Directories are separated by colons on Oracle Solaris and semicolons on Windows\&. The general format for path is:
As a special convenience, a class path element that contains a base name of * is considered equivalent to specifying a list of all the files in the directory with the extension \f3\&.jar\fR or \f3\&.JAR\fR\&.
For example, if directory \f3mydir\fR contains \f3a\&.jar\fR and \f3b\&.JAR\fR, then the class path element \f3mydir/*\fR is expanded to a \f3A\fR\f3\&.jar:b\&.JAR\fR, except that the order of jar files is unspecified\&. All JAR files in the specified directory, including hidden ones, are included in the list\&. A class path entry that consists of * expands to a list of all the JAR files in the current directory\&. The \f3CLASSPATH\fR environment variable, where defined, is similarly expanded\&. Any class path wild card expansion occurs before the Java Virtual Machine (JVM) is started\&. A Java program will never see unexpanded wild cards except by querying the environment\&. For example, by calling \f3System\&.getenv("CLASSPATH")\fR\&.
.TP
-bootclasspath \fIpath\fR
.br
Specifies the path from which to load bootstrap classes\&. By default, the bootstrap classes are the classes that implement the core Java platform located in \f3jre\elib\ert\&.jar\fR and several other JAR files\&.
.TP
-old
.br
Specifies that old JDK 1\&.0-style header files should be generated\&.
.TP
-force
.br
Specifies that output files should always be written\&.
.TP
-J\fIoption\fR
.br
Passes \f3option\fR to the Java Virtual Machine, where \f3option\fR is one of the options described on the reference page for the Java application launcher\&. For example, \f3-J-Xms48m\fR sets the startup memory to 48 MB\&. See java(1)\&.
.SH SEE\ ALSO
.TP 0.2i
\(bu
javah(1)
.TP 0.2i
\(bu
java(1)
.TP 0.2i
\(bu
jdb(1)
.TP 0.2i
\(bu
javap(1)
.TP 0.2i
\(bu
javadoc(1)
.SH NAME
javah \- Generates C header and source files from a Java class\&.
The fully qualified location of the classes to be converted to C header and source files\&.
.SH DESCRIPTION
The \f3javah\fR command generates C header and source files that are needed to implement native methods\&. The generated header and source files are used by C programs to reference an object\&'s instance variables from native source code\&. The \f3\&.h\fR file contains a \f3struct\fR definition with a layout that parallels the layout of the corresponding class\&. The fields in the \f3struct\fR correspond to instance variables in the class\&.
.PP
The name of the header file and the structure declared within it are derived from the name of the class\&. When the class passed to the \f3javah\fR command is inside a package, the package name is added to the beginning of both the header file name and the structure name\&. Underscores (_) are used as name delimiters\&.
.PP
By default the \f3javah\fR command creates a header file for each class listed on the command line and puts the files in the current directory\&. Use the \f3-stubs\fR option to create source files\&. Use the \f3-o\fR option to concatenate the results for all listed classes into a single file\&.
.PP
The Java Native Interface (JNI) does not require header information or stub files\&. The \f3javah\fR command can still be used to generate native method function prototypes needed for JNI-style native methods\&. The \f3javah\fR command produces JNI-style output by default and places the result in the \f3\&.h\fR file\&.
.SH OPTIONS
.TP
-o \fIoutputfile\fR
.br
Concatenates the resulting header or source files for all the classes listed on the command line into an output file\&. Only one of \f3-o\fR or \f3-d\fR can be used\&.
.TP
-d \fIdirectory\fR
.br
Sets the directory where the \f3javah\fR command saves the header files or the stub files\&. Only one of \f3-d\fR or \f3-o\fR can be used\&.
.TP
-stubs
.br
Causes the \f3javah\fR command to generate C declarations from the Java object file\&.
.TP
-verbose
.br
Indicates verbose output and causes the \f3javah\fR command to print a message to \f3stdout\fR about the status of the generated files\&.
.TP
-help
.br
Prints a help message for \f3javah\fR usage\&.
.TP
-version
.br
Prints \f3javah\fR command release information\&.
.TP
-jni
.br
Causes the \f3javah\fR command to create an output file containing JNI-style native method function prototypes\&. This is the default output; use of \f3-jni\fR is optional\&.
.TP
-classpath \fIpath\fR
.br
Specifies the path the \f3javah\fR command uses to look up classes\&. Overrides the default or the \f3CLASSPATH\fR environment variable when it is set\&. Directories are separated by colons on Oracle Solaris and semicolons on Windows\&. The general format for path is:
As a special convenience, a class path element that contains a base name of * is considered equivalent to specifying a list of all the files in the directory with the extension \f3\&.jar\fR or \f3\&.JAR\fR\&.
For example, if directory \f3mydir\fR contains \f3a\&.jar\fR and \f3b\&.JAR\fR, then the class path element \f3mydir/*\fR is expanded to a \f3A\fR\f3\&.jar:b\&.JAR\fR, except that the order of jar files is unspecified\&. All JAR files in the specified directory, including hidden ones, are included in the list\&. A class path entry that consists of * expands to a list of all the JAR files in the current directory\&. The \f3CLASSPATH\fR environment variable, where defined, is similarly expanded\&. Any class path wild card expansion occurs before the Java Virtual Machine (JVM) is started\&. A Java program will never see unexpanded wild cards except by querying the environment\&. For example, by calling \f3System\&.getenv("CLASSPATH")\fR\&.
.TP
-bootclasspath \fIpath\fR
.br
Specifies the path from which to load bootstrap classes\&. By default, the bootstrap classes are the classes that implement the core Java platform located in \f3jre\elib\ert\&.jar\fR and several other JAR files\&.
.TP
-old
.br
Specifies that old JDK 1\&.0-style header files should be generated\&.
.TP
-force
.br
Specifies that output files should always be written\&.
.TP
-J\fIoption\fR
.br
Passes \f3option\fR to the Java Virtual Machine, where \f3option\fR is one of the options described on the reference page for the Java application launcher\&. For example, \f3-J-Xms48m\fR sets the startup memory to 48 MB\&. See java(1)\&.
The \f3pid\fR value is the process ID of a local Java Virtual Machine (JVM)\&. The JVM must be running with the same user ID as the user ID running the \f3jconsole\fR command\&.The \f3host:port\fR values are the name of the host system on which the JVM is running, and the port number specified by the system property \f3com\&.sun\&.management\&.jmxremote\&.port\fR when the JVM was started\&.The \f3jmxUrl\fR value is the address of the JMX agent to be connected to as described in JMXServiceURL\&.
For more information about the \f3connection\fR parameter, see Monitoring and Management Using JMX Technology at http://docs\&.oracle\&.com/javase/8/docs/technotes/guides/management/agent\&.html
See also the \f3JMXServiceURL\fR class description at http://docs\&.oracle\&.com/javase/8/docs/api/javax/management/remote/JMXServiceURL\&.html
.SH DESCRIPTION
The \f3jconsole\fR command starts a graphical console tool that lets you monitor and manage Java applications and virtual machines on a local or remote machine\&.
.PP
On Windows, the \f3jconsole\fR command does not associate with a console window\&. It does, however, display a dialog box with error information when the \f3jconsole\fR command fails\&.
.SH OPTIONS
.TP
-interval\fI=n\fR
.br
Sets the update interval to \fIn\fR seconds (default is 4 seconds)\&.
.TP
-notile
.br
Does not tile windows initially (for two or more connections)\&.
.TP
-pluginpath \fIplugins\fR
.br
Specifies a list of directories or JAR files to be searched for \f3JConsole\fR plug-ins\&. The \fIplugins\fR path should contain a provider-configuration file named \f3META-INF/services/com\&.sun\&.tools\&.jconsole\&.JConsolePlugin\fR that contains one line for each plug-in\&. The line specifies the fully qualified class name of the class implementing the \f3com\&.sun\&.tools\&.jconsole\&.JConsolePlugin\fR class\&.
.TP
-version
.br
Displays release information and exits\&.
.TP
-help
.br
Displays a help message\&.
.TP
-J\fIflag\fR
.br
Passes \f3flag\fR to the JVM on which the \f3jconsole\fR command is run\&.
.SH SEE\ ALSO
.TP 0.2i
\(bu
Using JConsole at http://docs\&.oracle\&.com/javase/8/docs/technotes/guides/management/jconsole\&.html
.TP 0.2i
\(bu
Monitoring and Management Using JMX Technology at http://docs\&.oracle\&.com/javase/8/docs/technotes/guides/management/agent\&.html
.TP 0.2i
\(bu
The \f3JMXServiceURL\fR class description at http://docs\&.oracle\&.com/javase/8/docs/api/javax/management/remote/JMXServiceURL\&.html
.SH NAME
jconsole \- Starts a graphical console that lets you monitor and manage Java applications\&.
The \f3pid\fR value is the process ID of a local Java Virtual Machine (JVM)\&. The JVM must be running with the same user ID as the user ID running the \f3jconsole\fR command\&.The \f3host:port\fR values are the name of the host system on which the JVM is running, and the port number specified by the system property \f3com\&.sun\&.management\&.jmxremote\&.port\fR when the JVM was started\&.The \f3jmxUrl\fR value is the address of the JMX agent to be connected to as described in JMXServiceURL\&.
For more information about the \f3connection\fR parameter, see Monitoring and Management Using JMX Technology at http://docs\&.oracle\&.com/javase/8/docs/technotes/guides/management/agent\&.html
See also the \f3JMXServiceURL\fR class description at http://docs\&.oracle\&.com/javase/8/docs/api/javax/management/remote/JMXServiceURL\&.html
.SH DESCRIPTION
The \f3jconsole\fR command starts a graphical console tool that lets you monitor and manage Java applications and virtual machines on a local or remote machine\&.
.PP
On Windows, the \f3jconsole\fR command does not associate with a console window\&. It does, however, display a dialog box with error information when the \f3jconsole\fR command fails\&.
.SH OPTIONS
.TP
-interval\fI=n\fR
.br
Sets the update interval to \fIn\fR seconds (default is 4 seconds)\&.
.TP
-notile
.br
Does not tile windows initially (for two or more connections)\&.
.TP
-pluginpath \fIplugins\fR
.br
Specifies a list of directories or JAR files to be searched for \f3JConsole\fR plug-ins\&. The \fIplugins\fR path should contain a provider-configuration file named \f3META-INF/services/com\&.sun\&.tools\&.jconsole\&.JConsolePlugin\fR that contains one line for each plug-in\&. The line specifies the fully qualified class name of the class implementing the \f3com\&.sun\&.tools\&.jconsole\&.JConsolePlugin\fR class\&.
.TP
-version
.br
Displays release information and exits\&.
.TP
-help
.br
Displays a help message\&.
.TP
-J\fIflag\fR
.br
Passes \f3flag\fR to the JVM on which the \f3jconsole\fR command is run\&.
.SH SEE\ ALSO
.TP 0.2i
\(bu
Using JConsole at http://docs\&.oracle\&.com/javase/8/docs/technotes/guides/management/jconsole\&.html
.TP 0.2i
\(bu
Monitoring and Management Using JMX Technology at http://docs\&.oracle\&.com/javase/8/docs/technotes/guides/management/agent\&.html
.TP 0.2i
\(bu
The \f3JMXServiceURL\fR class description at http://docs\&.oracle\&.com/javase/8/docs/api/javax/management/remote/JMXServiceURL\&.html
Java binary heap dump file to be browsed\&. For a dump file that contains multiple heap dumps, you can specify which dump in the file by appending \f3#<number>\fR to the file name, for example, \f3myfile\&.hprof#3\fR\&.
.SH DESCRIPTION
The \f3jhat\fR command parses a Java heap dump file and starts a web server\&. The \f3jhat\fR command lets you to browse heap dumps with your favorite web browser\&. The \f3jhat\fR command supports predesigned queries such as show all instances of a known class \f3MyClass\fR, and Object Query Language (OQL)\&. OQL is similar to SQL, except for querying heap dumps\&. Help on OQL is available from the OQL help page shown by the \f3jhat\fR command\&. With the default port, OQL help is available at http://localhost:7000/oqlhelp/
.PP
There are several ways to generate a Java heap dump:
.TP 0.2i
\(bu
Use the \f3jmap -dump\fR option to obtain a heap dump at runtime\&. See jmap(1)\&.
.TP 0.2i
\(bu
Use the \f3jconsole\fR option to obtain a heap dump through \f3HotSpotDiagnosticMXBean\fR at runtime\&. See jconsole(1) and the \f3HotSpotDiagnosticMXBean\fR interface description at http://docs\&.oracle\&.com/javase/8/docs/jre/api/management/extension/com/sun/management/HotSpotDiagnosticMXBean\&.html
.TP 0.2i
\(bu
Heap dump is generated when an \f3OutOfMemoryError\fR is thrown by specifying the \f3-XX:+HeapDumpOnOutOfMemoryError\fR Java Virtual Machine (JVM) option\&.
.TP 0.2i
\(bu
Use the \f3hprof\fR command\&. See the HPROF: A Heap/CPU Profiling Tool at http://docs\&.oracle\&.com/javase/8/docs/technotes/samples/hprof\&.html
.SH OPTIONS
.TP
-stack false|true
.br
Turns off tracking object allocation call stack\&. If allocation site information is not available in the heap dump, then you have to set this flag to \f3false\fR\&. The default is \f3true\fR\&.
.TP
-refs false|true
.br
Turns off tracking of references to objects\&. Default is \f3true\fR\&. By default, back pointers, which are objects that point to a specified object such as referrers or incoming references, are calculated for all objects in the heap\&.
.TP
-port \fIport-number\fR
.br
Sets the port for the \f3jhat\fR HTTP server\&. Default is 7000\&.
.TP
-exclude \fIexclude-file\fR
.br
Specifies a file that lists data members that should be excluded from the reachable objects query\&. For example, if the file lists \f3java\&.lang\&.String\&.value\fR, then, then whenever the list of objects that are reachable from a specific object \f3o\fR are calculated, reference paths that involve \f3java\&.lang\&.String\&.value\fR field are not considered\&.
.TP
-baseline \fIexclude-file\fR
.br
Specifies a baseline heap dump\&. Objects in both heap dumps with the same object ID are marked as not being new\&. Other objects are marked as new\&. This is useful for comparing two different heap dumps\&.
.TP
-debug \fIint\fR
.br
Sets the debug level for this tool\&. A level of 0 means no debug output\&. Set higher values for more verbose modes\&.
.TP
-version
.br
Reports the release number and exits
.TP
-h
.br
Dsiplays a help message and exits\&.
.TP
-help
.br
Displays a help message and exits\&.
.TP
-J\fIflag\fR
.br
Passes \f3flag\fR to the Java Virtual Machine on which the \f3jhat\fR command is running\&. For example, \f3-J-Xmx512m\fR to use a maximum heap size of 512 MB\&.
.SH SEE\ ALSO
.TP 0.2i
\(bu
jmap(1)
.TP 0.2i
\(bu
jconsole(1)
.TP 0.2i
\(bu
HPROF: A Heap/CPU Profiling Tool at http://docs\&.oracle\&.com/javase/8/docs/technotes/samples/hprof\&.html
.SH NAME
jhat \- Analyzes the Java heap\&. This command is experimental and unsupported\&.
Java binary heap dump file to be browsed\&. For a dump file that contains multiple heap dumps, you can specify which dump in the file by appending \f3#<number>\fR to the file name, for example, \f3myfile\&.hprof#3\fR\&.
.SH DESCRIPTION
The \f3jhat\fR command parses a Java heap dump file and starts a web server\&. The \f3jhat\fR command lets you to browse heap dumps with your favorite web browser\&. The \f3jhat\fR command supports predesigned queries such as show all instances of a known class \f3MyClass\fR, and Object Query Language (OQL)\&. OQL is similar to SQL, except for querying heap dumps\&. Help on OQL is available from the OQL help page shown by the \f3jhat\fR command\&. With the default port, OQL help is available at http://localhost:7000/oqlhelp/
.PP
There are several ways to generate a Java heap dump:
.TP 0.2i
\(bu
Use the \f3jmap -dump\fR option to obtain a heap dump at runtime\&. See jmap(1)\&.
.TP 0.2i
\(bu
Use the \f3jconsole\fR option to obtain a heap dump through \f3HotSpotDiagnosticMXBean\fR at runtime\&. See jconsole(1) and the \f3HotSpotDiagnosticMXBean\fR interface description at http://docs\&.oracle\&.com/javase/8/docs/jre/api/management/extension/com/sun/management/HotSpotDiagnosticMXBean\&.html
.TP 0.2i
\(bu
Heap dump is generated when an \f3OutOfMemoryError\fR is thrown by specifying the \f3-XX:+HeapDumpOnOutOfMemoryError\fR Java Virtual Machine (JVM) option\&.
.TP 0.2i
\(bu
Use the \f3hprof\fR command\&. See the HPROF: A Heap/CPU Profiling Tool at http://docs\&.oracle\&.com/javase/8/docs/technotes/samples/hprof\&.html
.SH OPTIONS
.TP
-stack false|true
.br
Turns off tracking object allocation call stack\&. If allocation site information is not available in the heap dump, then you have to set this flag to \f3false\fR\&. The default is \f3true\fR\&.
.TP
-refs false|true
.br
Turns off tracking of references to objects\&. Default is \f3true\fR\&. By default, back pointers, which are objects that point to a specified object such as referrers or incoming references, are calculated for all objects in the heap\&.
.TP
-port \fIport-number\fR
.br
Sets the port for the \f3jhat\fR HTTP server\&. Default is 7000\&.
.TP
-exclude \fIexclude-file\fR
.br
Specifies a file that lists data members that should be excluded from the reachable objects query\&. For example, if the file lists \f3java\&.lang\&.String\&.value\fR, then, then whenever the list of objects that are reachable from a specific object \f3o\fR are calculated, reference paths that involve \f3java\&.lang\&.String\&.value\fR field are not considered\&.
.TP
-baseline \fIexclude-file\fR
.br
Specifies a baseline heap dump\&. Objects in both heap dumps with the same object ID are marked as not being new\&. Other objects are marked as new\&. This is useful for comparing two different heap dumps\&.
.TP
-debug \fIint\fR
.br
Sets the debug level for this tool\&. A level of 0 means no debug output\&. Set higher values for more verbose modes\&.
.TP
-version
.br
Reports the release number and exits
.TP
-h
.br
Dsiplays a help message and exits\&.
.TP
-help
.br
Displays a help message and exits\&.
.TP
-J\fIflag\fR
.br
Passes \f3flag\fR to the Java Virtual Machine on which the \f3jhat\fR command is running\&. For example, \f3-J-Xmx512m\fR to use a maximum heap size of 512 MB\&.
.SH SEE\ ALSO
.TP 0.2i
\(bu
jmap(1)
.TP 0.2i
\(bu
jconsole(1)
.TP 0.2i
\(bu
HPROF: A Heap/CPU Profiling Tool at http://docs\&.oracle\&.com/javase/8/docs/technotes/samples/hprof\&.html
The process ID of the process to which the debug server attaches\&. The process must be a Java process\&. To get a list of Java processes running on a machine, use the jps(1) command\&. At most one instance of the debug server can be attached to a single process\&.
.TP
\fIexecutable\fR
The Java executable from which the core dump was produced\&.
.TP
\fIcore\fR
The core file to which the debug server should attach\&.
.TP
\fIserver-id\fR
An optional unique ID that is needed when multiple debug servers are started on the same machine\&. This ID must be used by remote clients to identify the particular debug server to which to attach\&. Within a single machine, this ID must be unique\&.
.SH DESCRIPTION
The \f3jsadebugd\fR command attaches to a Java process or core file and acts as a debug server\&. Remote clients such as \f3jstack\fR, \f3jmap\fR, and \f3jinfo\fR can attach to the server through Java Remote Method Invocation (RMI)\&. Before you start the \f3jsadebugd\fR command, start the RMI registry with the \f3rmiregistry\fR command as follows where \fI$JAVA_HOME\fR is the JDK installation directory:
If the RMI registry was not started, then the \f3jsadebugd\fR command starts an RMI registry in a standard (1099) port internally\&. The debug server can be stopped by sending a \f3SIGINT\fR to it\&. To send a SIGINT press \fICtrl+C\fR\&.
.PP
\fINote:\fR This utility is unsupported and may or may not be available in future releases of the JDK\&. In Windows Systems where \f3dbgeng\&.dll\fR is not present, Debugging Tools For Windows must be installed to have these tools working\&. The \f3PATH\fR environment variable should contain the location of jvm\&.dll used by the target process or the location from which the crash dump file was produced\&. For example, \f3s\fR\f3et PATH=%JDK_HOME%\ejre\ebin\eclient;%PATH%\fR\&.
.SH SEE\ ALSO
.TP 0.2i
\(bu
jinfo(1)
.TP 0.2i
\(bu
jmap(1)
.TP 0.2i
\(bu
jps(1)
.TP 0.2i
\(bu
jstack(1)
.TP 0.2i
\(bu
rmiregistry(1)
.SH NAME
jsadebugd \- Attaches to a Java process or core file and acts as a debug server\&. This command is experimental and unsupported\&.
The process ID of the process to which the debug server attaches\&. The process must be a Java process\&. To get a list of Java processes running on a machine, use the jps(1) command\&. At most one instance of the debug server can be attached to a single process\&.
.TP
\fIexecutable\fR
The Java executable from which the core dump was produced\&.
.TP
\fIcore\fR
The core file to which the debug server should attach\&.
.TP
\fIserver-id\fR
An optional unique ID that is needed when multiple debug servers are started on the same machine\&. This ID must be used by remote clients to identify the particular debug server to which to attach\&. Within a single machine, this ID must be unique\&.
.SH DESCRIPTION
The \f3jsadebugd\fR command attaches to a Java process or core file and acts as a debug server\&. Remote clients such as \f3jstack\fR, \f3jmap\fR, and \f3jinfo\fR can attach to the server through Java Remote Method Invocation (RMI)\&. Before you start the \f3jsadebugd\fR command, start the RMI registry with the \f3rmiregistry\fR command as follows where \fI$JAVA_HOME\fR is the JDK installation directory:
If the RMI registry was not started, then the \f3jsadebugd\fR command starts an RMI registry in a standard (1099) port internally\&. The debug server can be stopped by sending a \f3SIGINT\fR to it\&. To send a SIGINT press \fICtrl+C\fR\&.
.PP
\fINote:\fR This utility is unsupported and may or may not be available in future releases of the JDK\&. In Windows Systems where \f3dbgeng\&.dll\fR is not present, Debugging Tools For Windows must be installed to have these tools working\&. The \f3PATH\fR environment variable should contain the location of jvm\&.dll used by the target process or the location from which the crash dump file was produced\&. For example, \f3s\fR\f3et PATH=%JDK_HOME%\ejre\ebin\eclient;%PATH%\fR\&.
