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| <title>Chapter 3. Logging</title><link rel="stylesheet" href="css/docbook.css" type="text/css"><meta name="generator" content="DocBook XSL Stylesheets V1.72.0"><link rel="start" href="manual.html" title="Apache OpenJPA User's Guide"><link rel="up" href="ref_guide.html" title="Part 3. Reference Guide"><link rel="prev" href="ref_guide_conf_jdbc.html" title="6. OpenJPA JDBC Properties"><link rel="next" href="ref_guide_logging_openjpa.html" title="2. OpenJPA Logging"></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">Chapter 3. |
| Logging |
| </th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ref_guide_conf_jdbc.html">Prev</a> </td><th width="60%" align="center">Part 3. Reference Guide</th><td width="20%" align="right"> <a accesskey="n" href="ref_guide_logging_openjpa.html">Next</a></td></tr></table><hr></div><div class="chapter" lang="en" id="ref_guide_logging"><div class="titlepage"><div><div><h2 class="title"><a name="ref_guide_logging"></a>Chapter 3. |
| Logging |
| </h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="section"><a href="ref_guide_logging.html#ref_guide_logging_channels">1. |
| Logging Channels |
| </a></span></dt><dt><span class="section"><a href="ref_guide_logging_openjpa.html">2. |
| OpenJPA Logging |
| </a></span></dt><dt><span class="section"><a href="ref_guide_logging_noop.html">3. |
| Disabling Logging |
| </a></span></dt><dt><span class="section"><a href="ref_guide_logging_log4j.html">4. |
| Log4J |
| </a></span></dt><dt><span class="section"><a href="ref_guide_logging_commons.html">5. |
| Apache Commons Logging |
| </a></span></dt><dd><dl><dt><span class="section"><a href="ref_guide_logging_commons.html#ref_guide_logging_jdk14">5.1. |
| JDK 1.4 java.util.logging |
| </a></span></dt></dl></dd><dt><span class="section"><a href="ref_guide_logging_custom.html">6. |
| Custom Log |
| </a></span></dt></dl></div><a class="indexterm" name="d0e16813"></a><a class="indexterm" name="d0e16816"></a><p> |
| Logging is an important means of gaining insight into your application's runtime |
| behavior. OpenJPA provides a flexible logging system that integrates with many |
| existing runtime systems, such as application servers and servlet runners. |
| </p><p> |
| There are four built-in logging plugins: a |
| <a href="ref_guide_logging_openjpa.html" title="2. OpenJPA Logging">default logging framework</a> that |
| covers most needs, a <a href="ref_guide_logging_log4j.html" title="4. Log4J"> Log4J</a> |
| delegate, an <a href="ref_guide_logging_commons.html" title="5. Apache Commons Logging"> Apache Commons Logging |
| </a> delegate, and a <a href="ref_guide_logging_noop.html" title="3. Disabling Logging">no-op</a> |
| implementation for disabling logging. |
| </p><div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Warning</h3><p> |
| Logging can have a negative impact on performance. Disable verbose logging (such |
| as logging of SQL statements) before running any performance tests. It is |
| advisable to limit or disable logging for a production system. You can disable |
| logging altogether by setting the <code class="literal">openjpa.Log</code> property to |
| <code class="literal">none</code>. |
| </p></div><div class="section" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="ref_guide_logging_channels"></a>1. |
| Logging Channels |
| </h2></div></div></div><a class="indexterm" name="d0e16847"></a><p> |
| Logging is done over a number of <span class="emphasis"><em>logging channels</em></span>, each of |
| which has a <span class="emphasis"><em>logging level</em></span> which controls the verbosity of |
| log messages recorded for the channel. OpenJPA uses the following logging |
| channels: |
| </p><div class="itemizedlist"><ul type="disc"><li><p> |
| <code class="literal">openjpa.Tool</code>: Messages issued by the OpenJPA command line |
| and Ant tools. Most messages are basic statements detailing which classes or |
| files the tools are running on. Detailed output is only available via the |
| logging category the tool belongs to, such as <code class="literal">openjpa.Enhance</code> |
| for the enhancer (see <a href="ref_guide_pc_enhance.html" title="2. Enhancement">Section 2, “ |
| Enhancement |
| ”</a>) or <code class="literal"> |
| openjpa.MetaData</code> for the mapping tool (see |
| <a href="ref_guide_mapping.html#ref_guide_mapping_mappingtool" title="1. Forward Mapping">Section 1, “ |
| Forward Mapping |
| ”</a>). This logging category |
| is provided so that you can get a general idea of what a tool is doing without |
| having to manipulate logging settings that might also affect runtime behavior. |
| </p></li><li><p> |
| <a class="indexterm" name="d0e16880"></a> |
| <code class="literal">openjpa.Enhance</code>: Messages pertaining to enhancement and |
| runtime class generation. |
| </p></li><li><p> |
| <a class="indexterm" name="d0e16892"></a> |
| <code class="literal">openjpa.MetaData</code>: Details about the generation of metadata |
| and object-relational mappings. |
| </p></li><li><p> |
| <code class="literal">openjpa.Runtime</code>: General OpenJPA runtime messages. |
| </p></li><li><p> |
| <a class="indexterm" name="d0e16910"></a> |
| <code class="literal">openjpa.Query</code>: Messages about queries. Query strings and any |
| parameter values, if applicable, will be logged to the <code class="literal">TRACE</code> |
| level at execution time. Information about possible performance concerns will be |
| logged to the <code class="literal">INFO</code> level. |
| </p></li><li><p> |
| <a class="indexterm" name="d0e16928"></a> |
| <code class="literal">openjpa.DataCache</code>: Messages from the L2 data cache plugins. |
| </p></li><li><p> |
| <a class="indexterm" name="d0e16940"></a> |
| <code class="literal">openjpa.jdbc.JDBC</code>: JDBC connection information. General JDBC |
| information will be logged to the <code class="literal">TRACE</code> level. Information |
| about possible performance concerns will be logged to the <code class="literal">INFO |
| </code> level. |
| </p></li><li><p> |
| <a class="indexterm" name="d0e16958"></a> |
| <code class="literal">openjpa.jdbc.SQL</code>: This is the most common logging channel to |
| use. Detailed information about the execution of SQL statements will be sent to |
| the <code class="literal">TRACE</code> level. It is useful to enable this channel if you |
| are curious about the exact SQL that OpenJPA issues to the datastore. |
| </p><p> |
| When using the built-in OpenJPA logging facilities, you can enable SQL logging |
| by adding <code class="literal">SQL=TRACE</code> to your <code class="literal">openjpa.Log</code> |
| property. |
| </p><p> |
| OpenJPA can optionally reformat the logged SQL to make it easier to read. To |
| enable pretty-printing, add <code class="literal">PrettyPrint=true</code> to the |
| <a href="ref_guide_conf_openjpa.html#openjpa.ConnectionFactoryProperties" title="5.14. openjpa.ConnectionFactoryProperties"><code class="literal"> |
| openjpa.ConnectionFactoryProperties</code></a> property. You can control |
| how many columns wide the pretty-printed SQL will be with the <code class="literal"> |
| PrettyPrintLineLength</code> property. The default line length is 60 columns. |
| </p><p> |
| While pretty printing makes things easier to read, it can make output harder to |
| process with tools like grep. |
| </p><p> |
| Pretty-printing properties configuration might look like so: |
| </p><pre class="programlisting"> |
| <property name="openjpa.Log" value="SQL=TRACE"/> |
| <property name="openjpa.ConnectionFactoryProperties" |
| value="PrettyPrint=true, PrettyPrintLineLength=72"/> |
| </pre></li><li><p> |
| <a class="indexterm" name="d0e16999"></a> |
| <code class="literal">openjpa.jdbc.Schema</code>: Details about operations on the |
| database schema. |
| </p></li></ul></div></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ref_guide_conf_jdbc.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="ref_guide.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="ref_guide_logging_openjpa.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">6. |
| OpenJPA JDBC Properties |
| </td><td width="20%" align="center"><a accesskey="h" href="manual.html">Home</a></td><td width="40%" align="right" valign="top"> 2. |
| OpenJPA Logging |
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