Tracing and Logging - JDK 5 Documentation v1.5.0, Java 2 SDK 英文文档

Tracing and Logging

Tracing and Logging includes the following topics:

Tracing

Tracing is a facility to redirect any output in the Java Console to a trace file.

Java Plug-in

Tracing can be turned on by enabling the property javaplugin.trace. However, it turns on all tracing facilities inside Java Plug-in. To enable more fine-grained tracing, javaplugin.trace.option may be used. You can set trace-level options (0-5) in the Java Console, shown in the previous chapter, with the following meanings:

0 — off
1 — basic
2 — network, cache, and basic
3 — security, network and basic
4 — extension, security, network and basic
5 — LiveConnect, extension, security, network, temp, and basic

This enables tracing on the fly.

Another way to set fine-grained tracing is through the Java Control Panel. For instance, to enable tracing for everthing (option 5 above), enter the following in the "Java Run Time Parameters" textfield:

-Djavaplugin.trace=true -Djavaplugin.trace.option=basic|net|cache|security|ext|liveconnect|temp

Tracing set through the Control Panel will take effect when the Plug-in is launched, but changes made through the Control Panel while a Plug-in is running will have no effect until restart.

Java Web Start

To set the initial trace level for a Java Web Start application, you can create a .javawsrc file in either your home directory or the jre/bin directory. This file can have entries:

TraceBasic=true TraceNetwork=true TraceSecurity=true TraceCache=true TraceExtensions=true TraceTemp=true

Logging

Similar to tracing, logging is a facility to redirect any output in the Java Console to a log file using the Java Logging API. Logging can be turned on by enabling the property javaplugin.logging:

-Djavaplugin.logging=true

Other Options

File Names

The names of the trace and log files are

plugin<modified version number>.trace
plugin<modified version number>.log

where the <modified version number> includes the major, minor and patch version numbers; e.g., plugin142_06.trace or plugin150.log

File Locations

The default location (directory) of the trace and log files is:

<user.home>/.java/deployment/log on Unix/Linux
<User Application Data Folder>\Sun\Java\Deployment\log on Windows

where <User Application Data Folder> is as defined here.

If the environment variable USER_JPI_PROFILE is set to <user plugin home> then the trace and log files will be written to:

<user plugin home>/.java/deployment/log on Unix/Linux
<user plugin home>\Sun\Java\Deployment\log on Windows

If the property javaplugin.outputfiles.path is set to <directory name> then the trace and log files will be written to <directory name>.

If both USER_JPI_PROFILE and javaplugin.outputfiles.path are set then the value of javaplugin.outputfiles.path takes precedence, and the trace and log files will be written to <directory name>.