jmap \- Prints shared object memory maps or heap memory details for a process, core file, or remote debug server\&. This command is experimental and unsupported\&.
The process ID for which the memory map is to be printed\&. The process must be a Java process\&. To get a list of Java processes running on a machine, use the jps(1) command\&.
The \f3jmap\fR command prints shared object memory maps or heap memory details of a specified process, core file, or remote debug server\&. If the specified process is running on a 64-bit Java Virtual Machine (JVM), then you might need to specify the \f3-J-d64\fR option, for example: \f3jmap\fR\f3-J-d64 -heap pid\fR\&.
\fINote:\fR This utility is unsupported and might not be available in future releases of the JDK\&. On Windows Systems where the \f3dbgeng\&.dll\fR file is not present, Debugging Tools For Windows must be installed to make these tools work\&. The \f3PATH\fR environment variable should contain the location of the \f3jvm\&.dll\fR file that is used by the target process or the location from which the crash dump file was produced, for example: \f3set PATH=%JDK_HOME%\ejre\ebin\eclient;%PATH%\fR\&.
When no option is used, the \f3jmap\fR command prints shared object mappings\&. For each shared object loaded in the target JVM, the start address, size of the mapping, and the full path of the shared object file are printed\&. This behavior is similar to the Oracle Solaris \f3pmap\fR utility\&.
Dumps the Java heap in \f3hprof\fR binary format to \f3filename\fR\&. The \f3live\fR suboption is optional, but when specified, only the active objects in the heap are dumped\&. To browse the heap dump, you can use the jhat(1) command to read the generated file\&.
Prints a heap summary of the garbage collection used, the head configuration, and generation-wise heap usage\&. In addition, the number and size of interned Strings are printed\&.
Prints a histogram of the heap\&. For each Java class, the number of objects, memory size in bytes, and the fully qualified class names are printed\&. The JVM internal class names are printed with an asterisk (*) prefix\&. If the \f3live\fR suboption is specified, then only active objects are counted\&.
Prints class loader wise statistics of Java heap\&. For each class loader, its name, how active it is, address, parent class loader, and the number and size of classes it has loaded are printed\&.
Force\&. Use this option with the \f3jmap -dump\fR or \f3jmap -histo\fR option when the pid does not respond\&. The \f3live\fR suboption is not supported in this mode\&.