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<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
<chapter id="JCR.FAQ">
  <?dbhtml filename="ch-jcr-faq.html"?>

  <title>JCR FAQ</title>

  <para>It's the draft for a future FAQ of JCR usage.</para>

  <section>
    <title>Kernel</title>

    <section>
      <title>What is the best, standardized way to get the instance of a
      service ?</title>

      <programlisting language="java">container.getComponentInstanceOfType(ServiceName.class);</programlisting>
    </section>
  </section>

  <section>
    <title>JCR</title>

    <section>
      <title>JCR core</title>

      <section>
        <title>Is it better to use Session.getNodeByUUID or
        Session.getItem?</title>

        <para>Session.getNodeByUUID() about 2.5 times faster of
        Session.getItem(String) and only 25% faster of Node.getNode(String).
        See the daily tests results for such comparisons, e.g.</para>

        <para><ulink
        url="http://tests.exoplatform.org/JCR/1.12.2-GA/rev.2442/daily-performance-testing-results/jcr.core./index.html">http://tests.exoplatform.org/JCR/1.12.2-GA/rev.2442/daily-performance-testing-results/jcr.core./index.html</ulink></para>
      </section>

      <section>
        <title>Does it make sense to have all the node referencable to use
        getNodeByUUID all the time?</title>

        <para>Until it's applicable for a business logic it can be. But take
        in account the paths are human readable and lets you think in
        hierarchy. If it's important a location based approach is
        preferable.</para>
      </section>

      <section>
        <title>What should I use to check if an Item exists before getting the
        Value?</title>

        <para>Use Session.itemExists(String absPath), Node.hasNode(String
        relPath) or Property.hasProperty(String name). It's also is possible
        to check Node.hasNodes() and Node.hasProprties().</para>
      </section>

      <section>
        <title>How to use Observation properly?</title>

        <para>JCR Observation's a way to listen on persistence changes of a
        Repository. It provides several options to configure the listener for
        an interesting only changes. To use properly, it's important to
        understand concept of events filtering for a registered EventListener
        (8.3.3 Observation Manager). An often confusing part, it's the
        <emphasis role="bold">absPath</emphasis>, it's an associated parent of
        a location you want to observe events on. I.e. it's a parent of child
        node(s) or this parent property(ies); if <emphasis
        role="bold">isDeep</emphasis> is true then you'll get events of all
        the subtree of child nodes also. The same actual for <emphasis
        role="bold">uuid</emphasis> and <emphasis
        role="bold">nodeTypeName</emphasis> parameters of
        ObservationManager.addEventListener() method.</para>
      </section>

      <section>
        <title>Is it better to use queries that to access the data by the JCR
        API?</title>

        <para>No, direct access to items via JCR API is more efficient. Search
        will consume additional resources for index querying and only then
        return the items.</para>
      </section>

      <section>
        <title>What is default query ordering?</title>

        <para>By default (if query do not contains any ordering statements)
        result nodes is sorted by document order.</para>
      </section>

      <section>
        <title>Is ordering by jcr:path or Item name supported?</title>

        <para>No, it does not supported. There is two ways to ordering
        results, when path may be used as criteria:</para>

        <itemizedlist>
          <listitem>
            <para>Order by property with value type NAME or PATH (jcr supports
            it).</para>
          </listitem>

          <listitem>
            <para>Order by jcr:path - sort by exact path of node (jcr do not
            supports it).</para>
          </listitem>
        </itemizedlist>

        <para>Order by jcr:path</para>

        <para>If no order specification is supplied in the query statement,
        implementations may support document order on the result nodes (see
        6.6.4.2 Document Order). And it is sorted by order number.</para>

        <para>By default, (if query do not contains any ordering statements)
        result nodes is sorted by document order.</para>

        <programlisting>SELECT * FROM nt:unstructured WHERE jcr:path LIKE 'testRoot/%'</programlisting>

        <para>For specified jcr:path ordering there is different proceeding in
        XPath and SQL:</para>

        <itemizedlist>
          <listitem>
            <para>SQL no matter ascending or descending - query returns result
            nodes in random order: {code}SELECT * FROM nt:unstructured WHERE
            jcr:path LIKE 'testRoot/%' ORDER BY jcr:path{code}</para>
          </listitem>
        </itemizedlist>

        <itemizedlist>
          <listitem>
            <para>XPath - jcr:path order construction is ignored (so result is
            not sorted according path); {code}/testRoot/* <ulink
            url="@jcr:primaryType='nt:unstructured'">@jcr:primaryType='nt:unstructured'</ulink>
            order by jcr:path{code}</para>
          </listitem>
        </itemizedlist>
      </section>

      <section>
        <title>How eXo JCR indexer uses content encoding?</title>

        <para>1. Indexer uses jcr:encoding property of nt:resource node (used
        as jcr:content child node of nt:file) 2. if no jcr:encoding property
        set the Document Service will use the one configured in the service
        (defaultEncoding) 3. if nothing is configured a JVM, the default
        encoding will be used</para>
      </section>

      <section>
        <title>Which database server is better for eXo JCR?</title>

        <para>If the question is a performance, it's difficult question, as
        each database can be configured to be more (and more) faster for each
        special case. MySQL with MyISAM engine will be faster. But MySQL has
        limitations for indexes for multilingual columns (Item names
        actually). So, with long Item names (larger ofOracle or PostgreSQL
        also are good for performance. DB2 and MSSQL are slower in default
        configurations. Default configuration of Sybase leader of slowness.
        But in this question, take the database server maintenance in account.
        MySQL and PostgreSQL are simple in installation and can work even on
        limited hardware. Oracle, DB2, MSSQL or Sybase need more efforts. The
        same actual for maintenance during the work. Note for Sybase:
        "check-sns-new-connection" data container configuration parameter
        should be set to "true". For testing purpose, embedded database such
        as HSQLDB is the best choice. Apache Derby and H2 also supported. But
        H2 surprisingly needs "beta" feature enabled - MVCC=TRUE in JDBC
        url.</para>
      </section>

      <section>
        <title>How to setup eXo JCR for mutilingial content on MySQL?</title>

        <para>To allow multiple character sets to be sent from the client, the
        UTF-8 encoding should be used, either by configuring utf8 as the
        default server character set, or by configuring the JDBC driver to use
        UTF-8 through the characterEncoding property. MySQL database should be
        created in single-byte encoding, e.g. "latin1": </para>

        <programlisting>CREATE DATABASE db1 CHARACTER SET latin1 COLLATE latin1_general_cs;</programlisting>

        <para>eXo JCR application (e.g. GateIn) should use JCR dialect
        "MySQL-UTF8".</para>

        <para>In other words: MySQL database default encoding and JCR dialect
        cannot be UTF8 both. Use single-byte encoding (e.g. "latin1") for
        database and "mysql-utf8" dialect for eXo JCR.</para>

        <para>Notice: "MySQL-UTF8" dialect cannot be auto-detected, it should
        be set explicitly in configuration.</para>
      </section>

      <section>
        <title>Does MySQL have limitation affecting on eXo JCR
        features?</title>

        <para>Index's key length of JCR_SITEM (JCR_MITEM) table for mysql-utf8
        dialect is reduced to 765 bytes (or 255 chars).</para>
      </section>

      <section>
        <title>Does use of Sybase database need special options in eXo JCR
        configuration?</title>

        <para>To enable JCR working properly with Sybase, a property
        'check-sns-new-connection' with 'false' value is required for each
        workspace data container:</para>

        <programlisting language="xml">&lt;container class="org.exoplatform.services.jcr.impl.storage.jdbc.optimisation.CQJDBCWorkspaceDataContainer"&gt;
  &lt;properties&gt;
    &lt;property name="source-name" value="jdbcjcr" /&gt;
    &lt;property name="dialect" value="auto" /&gt;
    &lt;property name="multi-db" value="true" /&gt;
    &lt;property name="update-storage" value="false" /&gt;
    &lt;property name="max-buffer-size" value="200k" /&gt;
    &lt;property name="swap-directory" value="target/temp/swap/ws" /&gt;
    &lt;property name="swap-directory" value="target/temp/swap/ws" /&gt;
    &lt;property name="check-sns-new-connection" value="false" /&gt;
  &lt;/properties&gt;</programlisting>
      </section>

      <section>
        <title>How to open and close a session properly to avoid memory
        leaks?</title>

        <programlisting language="java">Session session = repository.login(credentials);
try
{
// here your code
}
finally
{
session.logout();
}</programlisting>
      </section>

      <section>
        <title>Can I use Session after loging out?</title>

        <para>No. Any instance of Session or Node (acquired through session)
        shouldn't be used after loging out anymore. At least, it is highly
        recommended not to use.</para>
      </section>

      <section>
        <title>How to configure jcr for cluster ?</title>

        <para>So we have configured JCR in standalone mode and want to
        reconfigure it for clustered environment. First of all, let's check
        whether all requirements are satisfied:</para>

        <itemizedlist>
          <listitem>
            <para>Dedicated RDBMS anyone like MySQL, Postges, Oracle and, etc
            but just not HSSQL;</para>
          </listitem>

          <listitem>
            <para>Shared storage. The simplest thing is to use shared FS like
            NFS or SMB mounted in operation system, but they are rather slow.
            The best thing is to use SAN (Storage Area Network);</para>
          </listitem>

          <listitem>
            <para>Fast network between JCR nodes.</para>
          </listitem>
        </itemizedlist>

        <para>So now, need to configure Container a bit. Check
        exo-configuration.xml to be sure that you are using JBossTS
        Transaction Service and JBossCache Transaction Manager, as shown
        below.</para>

        <programlisting language="xml">&lt;component&gt;
   &lt;key&gt;org.jboss.cache.transaction.TransactionManagerLookup&lt;/key&gt;
   &lt;type&gt;org.jboss.cache.GenericTransactionManagerLookup&lt;/type&gt;
&lt;/component&gt;

&lt;component&gt;
   &lt;key&gt;org.exoplatform.services.transaction.TransactionService&lt;/key&gt;
   &lt;type&gt;org.exoplatform.services.transaction.jbosscache.JBossTransactionsService&lt;/type&gt;
   &lt;init-params&gt;
      &lt;value-param&gt;
         &lt;name&gt;timeout&lt;/name&gt;
         &lt;value&gt;300&lt;/value&gt;
      &lt;/value-param&gt;
   &lt;/init-params&gt;
&lt;/component&gt;</programlisting>

        <para>Next stage is actually the JCR configuration. We need JBossCache
        configuration templates for : data-cache, indexer-cache and
        lock-manager-cache. Later they will be used to configure JCR's core
        components. There are pre-bundled templates in EAR or JAR in
        conf/standalone/cluster. They can be used as is or re-written if
        needed. And now, re-configure a bit each workspace. Actually, a few
        parameters need changing, e.g. &lt;cache&gt;, &lt;query-handler&gt;
        and &lt;lock-manager&gt;.</para>

        <itemizedlist>
          <listitem>
            <para>&lt;cache&gt; configuration should look like this:</para>

            <programlisting language="xml">&lt;cache enabled="true"
     class="org.exoplatform.services.jcr.impl.dataflow.persistent.jbosscache.JBossCacheWorkspaceStorageCache"&gt;
     &lt;properties&gt;
        &lt;property name="jbosscache-configuration" value="test-jbosscache-data.xml" /&gt;
        &lt;property name="jgroups-configuration" value="udp-mux.xml" /&gt;
        &lt;property name="jgroups-multiplexer-stack" value="true" /&gt;
        &lt;property name="jbosscache-cluster-name" value="JCR-cluster-db1-ws" /&gt;
     &lt;/properties&gt;
&lt;/cache&gt;</programlisting>

            <itemizedlist>
              <listitem>
                <para>"jbosscache-configuration" is the path to configuration
                template;</para>
              </listitem>

              <listitem>
                <para>"jgroups-configuration" is path to JGroups configuration
                that is multiplexer stack is used (default). This file is also
                pre-bundled with templates and is recommended for use;</para>
              </listitem>

              <listitem>
                <para>"jgroups-multiplexer-stack" just simply "true". Strongly
                recommended;</para>
              </listitem>

              <listitem>
                <para>"jbosscache-cluster-name" is the name of cluster group.
                It should be different for each workspace and each workspace
                component. I.e.:
                &lt;repository_name&gt;-&lt;ws_name&gt;-&lt;component(cache\|lock\|index)&gt;</para>
              </listitem>
            </itemizedlist>
          </listitem>
        </itemizedlist>

        <itemizedlist>
          <listitem>
            <para>&lt;query-handler&gt; configuration</para>

            <itemizedlist>
              <listitem>
                <para>You must replace or add in &lt;query-handler&gt; block
                the "changesfilter-class" parameter equals with:</para>

                <programlisting language="xml">&lt;property name="changesfilter-class" value="org.exoplatform.services.jcr.impl.core.query.jbosscache.JBossCacheIndexChangesFilter"/&gt;</programlisting>
              </listitem>

              <listitem>
                <para>add JBossCache-oriented configuration:</para>

                <programlisting language="xml">&lt;property name="jbosscache-configuration" value="test-jbosscache-indexer.xml" /&gt;
&lt;property name="jgroups-configuration" value="udp-mux.xml" /&gt;
&lt;property name="jgroups-multiplexer-stack" value="true" /&gt;
&lt;property name="jbosscache-cluster-name" value="JCR-cluster-indexer-db1-ws" /&gt;
&lt;property name="max-volatile-time" value="60" /&gt;</programlisting>
              </listitem>
            </itemizedlist>
          </listitem>
        </itemizedlist>

        <para>Those properties have the same meaning and restrictions as in
        the previous block. The last property "max-volatile-time" is not
        mandatory but recommended. This notifies that the latest changes in
        index will be visible for each cluster node not later than in
        60s.</para>

        <itemizedlist>
          <listitem>
            <para>&lt;lock-manager&gt; configuration</para>

            <para>Maybe this is the hardest element to configure, because we
            have to define access to DB where locks will be stored. Replace
            exsiting lock-manager configuration with shown below.</para>

            <programlisting language="xml">
&lt;lock-manager class="org.exoplatform.services.jcr.impl.core.lock.jbosscache.CacheableLockManagerImpl"&gt;
   &lt;properties&gt;
      &lt;property name="time-out" value="15m" /&gt;
      &lt;property name="jbosscache-configuration" value="test-jbosscache-lock.xml" /&gt;
      &lt;property name="jgroups-configuration" value="udp-mux.xml" /&gt;
      &lt;property name="jgroups-multiplexer-stack" value="true" /&gt;
      &lt;property name="jbosscache-cluster-name" value="JCR-cluster-locks-db1-ws" /&gt;
      &lt;property name="jbosscache-cl-cache.jdbc.table.name" value="jcrlocks_db1_ws" /&gt;
      &lt;property name="jbosscache-cl-cache.jdbc.table.create" value="true" /&gt;
      &lt;property name="jbosscache-cl-cache.jdbc.table.drop" value="false" /&gt;
      &lt;property name="jbosscache-cl-cache.jdbc.table.primarykey" value="jcrlocks_db1_ws_pk" /&gt;
      &lt;property name="jbosscache-cl-cache.jdbc.fqn.column" value="fqn" /&gt;
      &lt;property name="jbosscache-cl-cache.jdbc.node.column" value="node" /&gt;
      &lt;property name="jbosscache-cl-cache.jdbc.parent.column" value="parent" /&gt;
      &lt;property name="jbosscache-cl-cache.jdbc.datasource" value="jdbcjcr" /&gt;
   &lt;/properties&gt;
&lt;/lock-manager&gt;

</programlisting>

            <para>First few properties are the same as in the previous
            components, but here you can see some strange
            "jbosscache-cl-cache.jdbc.*" properties. They define access
            parameters for database where lock are persisted.</para>

            <itemizedlist>
              <listitem>
                <para>"jbosscache-cl-cache.jdbc.table.create" - whether to
                create it or not. Usually "true";</para>
              </listitem>

              <listitem>
                <para>"jbosscache-cl-cache.jdbc.table.drop" - whether to drop
                on a start or not. Use "false";</para>
              </listitem>

              <listitem>
                <para>"jbosscache-cl-cache.jdbc.table.primarykey" - the name
                of column with pk;</para>
              </listitem>

              <listitem>
                <para>"jbosscache-cl-cache.jdbc.fqn.column" - the name of one
                more column. If you are not sure how to use, follow the
                example above (if much interested, please refer to JBossCache
                JDBCCacheLoader documentation)</para>
              </listitem>

              <listitem>
                <para>"jbosscache-cl-cache.jdbc.node.column" - the name of one
                more column. If you are not sure how to use, follow the
                example above (if much interested, please refer to JBossCache
                JDBCCacheLoader documentation)</para>
              </listitem>

              <listitem>
                <para>"jbosscache-cl-cache.jdbc.parent.column" - name of one
                more column. If you are not sure how to use, follow the
                example above if you are not sure (if much interested, please
                refer to JBossCache JDBCCacheLoader documentation)</para>
              </listitem>

              <listitem>
                <para>"jbosscache-cl-cache.jdbc.datasource" - name of
                configured in Container datasource, where you want to store
                locks. The best idea is to use the same as for
                workspace.</para>
              </listitem>
            </itemizedlist>
          </listitem>
        </itemizedlist>

        <para>That's all. JCR is ready for running in a cluster.</para>
      </section>

      <section>
        <title>Is JCR suitable for remote sites\* synchronization?</title>

        <itemizedlist>
          <listitem>
            <para>Remote sites can be visualized as different buildings
            seperated by a WAN network.</para>
          </listitem>
        </itemizedlist>
      </section>

      <section>
        <title>How to use lucene spellchecker?</title>

        <para>There is few steps:</para>

        <itemizedlist>
          <listitem>
            <para>Enable lucene spellchecker in jcr QueryHandler
            configuration:</para>

            <programlisting language="xml">&lt;query-handler class="org.exoplatform.services.jcr.impl.core.query.lucene.SearchIndex"&gt;
   &lt;properties&gt;
      ...
      &lt;property name="spellchecker-class" value="org.exoplatform.services.jcr.impl.core.query.lucene.spell.LuceneSpellChecker$FiveSecondsRefreshInterval" /&gt;
      ...
   &lt;/properties&gt;
&lt;/query-handler&gt;</programlisting>
          </listitem>
        </itemizedlist>

        <itemizedlist>
          <listitem>
            <para>Execute query with rep:spellcheck function and word that is
            checked:</para>

            <programlisting language="java">Query query = qm.createQuery("select rep:spellcheck() from nt:base where " + "jcr:path = '/' and spellcheck('word that is checked')", Query.SQL);
RowIterator rows = query.execute().getRows();</programlisting>
          </listitem>
        </itemizedlist>

        <itemizedlist>
          <listitem>
            <para>Fetch a result:</para>

            <programlisting language="java">Row r = rows.nextRow();
Value v = r.getValue("rep:spellcheck()");</programlisting>
          </listitem>
        </itemizedlist>

        <para>If there is no any results, that means there is no suggestion,
        so word is correct or spellcheckers dictionary do not contain any
        words like the checked word.</para>
      </section>

      <section>
        <title>How can I affect to spellchecker results?</title>

        <para>There is two parameters in jcr QueryHandler
        configuration:</para>

        <itemizedlist>
          <listitem>
            <para>Minimal distance between checked word and proposed
            suggestion;</para>
          </listitem>

          <listitem>
            <para>Search for more popular suggestions;</para>

            <programlisting language="xml">&lt;query-handler class="org.exoplatform.services.jcr.impl.core.query.lucene.SearchIndex"&gt;
   &lt;properties&gt;
      ...
      &lt;property name="spellchecker-class" value="org.exoplatform.services.jcr.impl.core.query.lucene.spell.LuceneSpellChecker$FiveSecondsRefreshInterval" /&gt;
      &lt;property name="spellchecker-more-popular" value="false" /&gt;
      &lt;property name="spellchecker-min-distance" value="0.55" /&gt;
      ...
   &lt;/properties&gt;
&lt;/query-handler&gt;</programlisting>
          </listitem>
        </itemizedlist>

        <para>Minimal distance is counted as Levenshtein distance between
        checked word and spellchecker suggestion.</para>

        <para>MorePopular paramter affects in next way: If "morePopular"
        disabled:</para>

        <itemizedlist>
          <listitem>
            <para>If the proposed word exists in the directory - no suggestion
            given;</para>
          </listitem>

          <listitem>
            <para>If the proposed word doesn't exist in the directory -
            propose the closed word;</para>
          </listitem>
        </itemizedlist>

        <para>If "morePopular" enabled:</para>

        <itemizedlist>
          <listitem>
            <para>No matter word exists or not, checker will propose the
            closed word that is more popular than the checked word.</para>
          </listitem>
        </itemizedlist>
      </section>
    </section>

    <section>
      <title>JCR extensions</title>

      <section>
        <title>How to restore repository to existing repository ?</title>

        <orderedlist>
          <listitem>
            <para>Remove existing repository, use:</para>

            <programlisting language="java">RepositoryService.removeRepository(String repositoryName)</programlisting>
          </listitem>

          <listitem>
            <para>Restore repository, use</para>

            <programlisting language="java">BackupManager.restore(RepositoryBackupChainLog log, RepositoryEntry repositoryEntry, boolean asynchronous)</programlisting>
          </listitem>
        </orderedlist>
      </section>

      <section>
        <title>How to restore workspace to existing worksapce?</title>

        <orderedlist>
          <listitem>
            <para>Remove existing workspace, use:</para>

            <programlisting language="java">ManageableRepository.removeWorkspace(String workspaceName)</programlisting>
          </listitem>

          <listitem>
            <para>Restore workspace, use:</para>

            <programlisting language="java">BackupManager.restore(BackupChainLog log, String repositoryName, WorkspaceEntry workspaceEntry, boolean asynchronous)</programlisting>
          </listitem>
        </orderedlist>
      </section>

      <section>
        <title>Does JCR support hot backup?</title>

        <para>Yes, JCR is support hot backup. Will use
        org.exoplatform.services.jcr.ext.backup.BackupManager.</para>
      </section>
    </section>

    <section>
      <title>WebDAV</title>

      <section>
        <title>I uploaded a file to WebDAV server using Mac OS Finder, but the
        file size is '0', what is wrong ?</title>

        <para>This is known as a finder bug started from Mac OS v.10.5.3 and
        not yet fixed, .</para>

        <para>For more details follow:&amp;nbsp; <ulink
        url="http://discussions.apple.com/thread.jspa?threadID=1538882&amp;start=0&amp;tstart=0">Apple
        Disscussion thread.</ulink></para>
      </section>

      <section>
        <title>Can I manage 'cache-control' value for different media-types
        from server configuration ?</title>

        <para>Use "cache-control" configuration parameter.</para>

        <para>The value of this parameter must contain colon-separated pairs
        "MediaType:cache-control value"</para>

        <para>For example, if you need to cache all text/xml and text/plain
        files for 5 minutes (300 sec.) and other text/\* files for 10 minutes
        (600 sec.), use the next configuration:</para>

        <programlisting language="xml">&lt;component&gt;
   &lt;type&gt;org.exoplatform.services.jcr.webdav.WebDavServiceImpl&lt;/type&gt;
   &lt;init-params&gt;
      &lt;value-param&gt;
         &lt;name&gt;cache-control&lt;/name&gt;
         &lt;value&gt;text/xml,text/plain:max-age=300;text/*:max-age=600;&lt;/value&gt;
      &lt;/value-param&gt;
   &lt;init-params&gt;
&lt;component&gt;
</programlisting>
      </section>

      <section>
        <title>How to perform WebDAV requests using curl ?</title>

        <para>Simple Requests</para>

        <para>For simple request such as: GET, HEAD, MKCOL, COPY, MOVE,
        DELETE, CHECKIN, CHECKOUT, UNCHECKOUT, LOCK, UNLOCK, VERSIONCONTROL,
        OPTIONS</para>

        <para>perform:</para>

        <programlisting>curl -i -u 'user:pass' -X 'METHOD_NAME' 'resource_url'</programlisting>

        <para>for example to create a folder named test perform:</para>

        <programlisting>curl -i -u 'root:exo' -X MKCOL 'http://localhost:8080/rest/jcr/repository/production/test</programlisting>

        <para>to PUT a test.txt file from your current folder to "test "folder
        on server perform:</para>

        <programlisting>curl -i -u 'root:exo' -X PUT 'http://localhost:8080/rest/jcr/repository/production/test/test.txt' -d @test.txt</programlisting>

        <para>Requests with XML body</para>

        <para>For requests which contains xml body such as: ORDER, PROPFIND,
        PROPPATCH, REPORT, SEARCH</para>

        <para>add <emphasis role="bold">-d 'xml_body text'</emphasis> or
        <emphasis role="bold">-d @body.xml</emphasis></para>

        <para>(body.xml must contain a valid xml request bidy.) to you
        curl-command:</para>

        <programlisting>curl -i -u 'user:pass'  -X 'METHOD_NAME' -H 'Headers' 'resource_url' -d 'xml_body text'</programlisting>

        <para>For example about finding all files containing "test"
        perform:</para>

        <programlisting>curl -i -u "root:exo" -X "SEARCH" "http://192.168.0.7:8080/rest/jcr/repository/production/" -d
"&lt;?xml version='1.0' encoding='UTF-8' ?&gt;
   &lt;D:searchrequest xmlns:D='DAV:'&gt;
      &lt;D:sql&gt;SELECT * FROM nt:base WHERE contains(*, 'text')&lt;/D:sql&gt;
&lt;/D:searchrequest&gt;"</programlisting>

        <para>If you need to add some headers to your request, use \-H
        key.</para>

        <para>To have more information about methods parameters, you can find
        in <ulink url="http://www.ietf.org/rfc/rfc2518.txt">HTTP Extensions
        for Distributed Authoring</ulink> specification.</para>
      </section>

      <section>
        <title>How eXo JCR WebDAV server treats content encoding?</title>

        <para>OS client (Windows, Linux etc) doesn't set an encoding in a
        request. But eXo JCR WebDAV server looks for an encoding in a
        Content-Type header and set it to jcr:encoding. See <ulink
        url="http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html,">http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html,</ulink>
        14.17 Content-Type. e.g. Content-Type: text/html; charset=ISO-8859-4
        So, if a client will set Content-Type header, e.g. JS code from a
        page, it will works for a text file as expected.</para>

        <para>If WebDAV request doesn't contain a content encoding, it's
        possible to write a dedicated action in a customer application. The
        action will set jcr:encoding using its own logic, e.g. based on IP or
        user preferences.</para>
      </section>
    </section>
  </section>
</chapter>
