title: Start hsqldb server through maven exec plugin failed
body: <p>I try to start an hsqldb server for developpement use. I had hsqldb dependency :</p>
  
  <pre><code>&lt;dependency&gt;
     &lt;groupId&gt;org.hsqldb&lt;/groupId&gt;
     &lt;artifactId&gt;hsqldb&lt;/artifactId&gt;
     &lt;version&gt;2.2.4&lt;/version&gt;
  &lt;/dependency&gt;
  </code></pre>
  
  <p>I had in build exec-maven-build :</p>
  
  <pre><code>&lt;plugin&gt;
      &lt;groupId&gt;org.codehaus.mojo&lt;/groupId&gt;
      &lt;artifactId&gt;exec-maven-plugin&lt;/artifactId&gt;
      &lt;version&gt;1.2.1&lt;/version&gt;
      &lt;executions&gt;
          &lt;execution&gt;
              &lt;goals&gt;
                  &lt;goal&gt;java&lt;/goal&gt;
              &lt;/goals&gt;
          &lt;/execution&gt;
      &lt;/executions&gt;
      &lt;configuration&gt;
          &lt;mainClass&gt;org.hsqldb.server.Server&lt;/mainClass&gt;
          &lt;arguments&gt;
              &lt;argument&gt;--database.0 file:target/monitoring&lt;/argument&gt;
          &lt;/arguments&gt;
      &lt;/configuration&gt;
  &lt;/plugin&gt;
  </code></pre>
  
  <p>And I launch mvn exec:java, server starts and i have this error :</p>
  
  <pre><code>[Server@6e9770a3]: [Thread[org.hsqldb.server.Server.main(),5,org.hsqldb.server.Server]]: Failed to set properties
  org.hsqldb.HsqlException: no valid database paths: maformed database enumerator: server.database.0 mem:monitoring
  </code></pre>
  
  <p>I search through the code, what this error means, and i found in hsqldb code the error on this page => <a href="http://hsqldb.svn.sourceforge.net/viewvc/hsqldb/base/tags/2.2.5/src/org/hsqldb/server/Server.java?revision=4369&amp;view=markup" rel="noreferrer">http://hsqldb.svn.sourceforge.net/viewvc/hsqldb/base/tags/2.2.5/src/org/hsqldb/server/Server.java?revision=4369&amp;view=markup</a></p>
  
  <pre><code>private IntKeyHashMap getDBNameArray() {
  
      final String  prefix       = ServerProperties.sc_key_dbname + ".";
      final int     prefixLen    = prefix.length();
      IntKeyHashMap idToAliasMap = new IntKeyHashMap();
      Enumeration   en           = serverProperties.propertyNames();
  
      for (; en.hasMoreElements(); ) {
          String key = (String) en.nextElement();
  
          if (!key.startsWith(prefix)) {
              continue;
          }
  
          int dbNumber;
  
          try {
              dbNumber = Integer.parseInt(key.substring(prefixLen));
          } catch (NumberFormatException e1) {
              **printWithThread("maformed database enumerator: " + key);**
  
              continue;
          }
  
          String alias = serverProperties.getProperty(key).toLowerCase();
  
          if (!aliasSet.add(alias)) {
              printWithThread("duplicate alias: " + alias);
          }
  
          Object existing = idToAliasMap.put(dbNumber, alias);
  
          if (existing != null) {
              printWithThread("duplicate database enumerator: " + key);
          }
      }
  
      return idToAliasMap;
  }
  </code></pre>
  
  <p>So hsqldb use as a key all argument : "no valid database paths: maformed database enumerator: <strong>server.database.0 mem:monitoring</strong>"</p>
  
  <p>So it looks like a bug, or did I make something wrong ? </p>
  
  <p>OK i found the solution, I changed the way i give arguments to exec maven plugin. </p>
  
  <p>from this : </p>
  
  <pre><code>&lt;plugin&gt;
      &lt;groupId&gt;org.codehaus.mojo&lt;/groupId&gt;
      &lt;artifactId&gt;exec-maven-plugin&lt;/artifactId&gt;
      &lt;version&gt;1.2.1&lt;/version&gt;
      &lt;executions&gt;
          &lt;execution&gt;
              &lt;goals&gt;
                  &lt;goal&gt;java&lt;/goal&gt;
              &lt;/goals&gt;
          &lt;/execution&gt;
      &lt;/executions&gt;
      &lt;configuration&gt;
          &lt;mainClass&gt;org.hsqldb.server.Server&lt;/mainClass&gt;
          &lt;arguments&gt;
              &lt;argument&gt;--database.0 file:target/monitoring&lt;/argument&gt;
          &lt;/arguments&gt;
      &lt;/configuration&gt;
  &lt;/plugin&gt;
  </code></pre>
  
  <p>to this : </p>
  
  <pre><code>&lt;plugin&gt;
      &lt;groupId&gt;org.codehaus.mojo&lt;/groupId&gt;
      &lt;artifactId&gt;exec-maven-plugin&lt;/artifactId&gt;
      &lt;version&gt;1.2.1&lt;/version&gt;
      &lt;executions&gt;
          &lt;execution&gt;
              &lt;goals&gt;
                  &lt;goal&gt;java&lt;/goal&gt;
              &lt;/goals&gt;
          &lt;/execution&gt;
      &lt;/executions&gt;
      &lt;configuration&gt;
          &lt;mainClass&gt;org.hsqldb.server.Server&lt;/mainClass&gt;
          &lt;arguments&gt;
              &lt;argument&gt;--database.0&lt;/argument&gt;
              &lt;argument&gt;file:target/monitoring&lt;/argument&gt;
          &lt;/arguments&gt;
      &lt;/configuration&gt;
  &lt;/plugin&gt;
  </code></pre>
  
  <p>And it works</p>