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|  | <title>7.  Custom Log</title><base href="display"><link rel="stylesheet" type="text/css" href="css/docbook.css"><meta name="generator" content="DocBook XSL Stylesheets V1.79.1"><link rel="home" href="manual.html" title="Apache OpenJPA 3.0 User's Guide"><link rel="up" href="ref_guide_logging.html" title="Chapter 3.  Logging and Auditing"><link rel="prev" href="ref_guide_logging_slf4j.html" title="6.  SLF4J"><link rel="next" href="ref_guide_audit.html" title="8. OpenJPA Audit"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">7.  | 
|  | Custom Log | 
|  | </th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ref_guide_logging_slf4j.html">Prev</a> </td><th width="60%" align="center">Chapter 3.  | 
|  | Logging and Auditing | 
|  | </th><td width="20%" align="right"> <a accesskey="n" href="ref_guide_audit.html">Next</a></td></tr></table><hr></div><div class="section" id="ref_guide_logging_custom"><div class="titlepage"><div><div><h2 class="title" style="clear: both">7.  | 
|  | Custom Log | 
|  | </h2></div></div></div> | 
|  |  | 
|  | <a class="indexterm" name="d5e9404"></a> | 
|  | <p> | 
|  | If none of available logging systems meet your needs, you can configure the | 
|  | logging system with a custom logger. You might use custom logging to integrate | 
|  | with a proprietary logging framework used by some applications servers, or for | 
|  | logging to a graphical component for GUI applications. | 
|  | </p> | 
|  | <p> | 
|  | A custom logging framework must include an implementation of the | 
|  | <a class="ulink" href="../../apidocs/org/apache/openjpa/lib/log/LogFactory.html" target="_top"><code class="classname"> | 
|  | org.apache.openjpa.lib.log.LogFactory</code></a> interface. We present | 
|  | a custom <code class="classname">LogFactory</code> below. | 
|  | </p> | 
|  | <div class="example" id="ref_guide_logging_custom_ex"><p class="title"><b>Example 3.6.  | 
|  | Custom Logging Class | 
|  | </b></p><div class="example-contents"> | 
|  |  | 
|  | <pre class="programlisting"> | 
|  | package com.xyz; | 
|  |  | 
|  | import org.apache.openjpa.lib.log.*; | 
|  |  | 
|  | public class CustomLogFactory | 
|  | implements LogFactory { | 
|  |  | 
|  | private String _prefix = "CUSTOM LOG"; | 
|  |  | 
|  | public void setPrefix(String prefix) { | 
|  | _prefix = prefix; | 
|  | } | 
|  |  | 
|  | public Log getLog(String channel) { | 
|  | // Return a simple extension of AbstractLog that will log | 
|  | // everything to the System.err stream. Note that this is | 
|  | // roughly equivalent to OpenJPA's default logging behavior. | 
|  | return new AbstractLog() { | 
|  |  | 
|  | protected boolean isEnabled(short logLevel) { | 
|  | // log all levels | 
|  | return true; | 
|  | } | 
|  |  | 
|  | protected void log(short type, String message, Throwable t) { | 
|  | // just send everything to System.err | 
|  | System.err.println(_prefix + ": " + type + ": " | 
|  | + message + ": " + t); | 
|  | } | 
|  | }; | 
|  | } | 
|  | } | 
|  | </pre> | 
|  | </div></div><br class="example-break"> | 
|  | <p> | 
|  | To make OpenJPA use your custom log factory, set the | 
|  | <a class="link" href="ref_guide_conf_openjpa.html#openjpa.Log" title="5.44.  openjpa.Log"><code class="literal">openjpa.Log</code></a> configuration | 
|  | property to your factory's full class name. Because this property is a plugin | 
|  | property (see <a class="xref" href="ref_guide_conf_plugins.html" title="4.  Plugin Configuration">Section 4, “ | 
|  | Plugin Configuration | 
|  | ”</a> ), you can also | 
|  | pass parameters to your factory. For example, to use the example factory above | 
|  | and set its prefix to "LOG MSG", you would set the <code class="literal">openjpa.Log | 
|  | </code> property to the following string: | 
|  | </p> | 
|  | <pre class="programlisting"> | 
|  | com.xyz.CustomLogFactory(Prefix="LOG MSG") | 
|  | </pre> | 
|  | </div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ref_guide_logging_slf4j.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="ref_guide_logging.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="ref_guide_audit.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">6.  | 
|  | SLF4J | 
|  |  </td><td width="20%" align="center"><a accesskey="h" href="manual.html">Home</a></td><td width="40%" align="right" valign="top"> 8. OpenJPA Audit</td></tr></table></div></body></html> |