echo 'export PATH=$PATH:/Path/To/Add' >> ~/.bash_profile

<web-app>
  <icon>
    <small-icon>
    <large-icon>
  </icon>

  <display-name>
  <description>
  <distributable>

  <context-param>
    <param-name>
    <param-value>
    <description>
  </context-param>

  <filter>
    <icon>
      <small-icon>
      <large-icon>
    </icon>
    <filter-name>
    <display-name>
    <description>
    <filter-class>
    <init-param>
      <param-name>
      <param-value>
      <description>
    </init-param>
  </filter>

  <filter-mapping>
    <filter-name>
    <url-pattern>
    <servlet>
  </filter-mapping>

  <listener>
    <listener-class>
  </listener>

  <servlet>
    <icon>
      <small-icon>
      <large-icon>
    </icon>
    <servlet-name>
    <display-name>
    <description>
    <servlet-class> or <jsp-file>
    <init-param>
      <param-name>
      <param-value>
      <description>
    </init-param>
    <load-on-startup>
    <security-role-ref>
      <description>
      <role-name>
      <role-link>
    </security-role-ref>
  </servlet>

  <servlet-mapping>
    <servlet-name>
    <url-pattern>
  </servlet-mapping>

  <session-config>
    <session-timeout>
  </session-config>

  <mime-mapping>
    <extension>
    <mime-type>
  </mime-mapping>

  <welcome-file-list>
    <welcome-file>
  </welcome-file-list>

  <error-page>
    <error-code>
    <exception-type>
    <location>
  </error-page>

  <taglib>
    <taglib-location>
    <taglib-uri>
  </taglib>

  <resource-ref>
    <description>
    <res-ref-name>
    <res-ref-type>
    <res-ref-auth>
    <res-sharing-scope>
  </resource-ref>

  <security-constraint>
    <web-resource-collection>
      <web-resource-name>
      <description>
      <url-pattern>
      <http-method>
    </web-resource-collection>
    <auth-contraint>
      <description>
      <role-name>
    </auth-constraint>
    <user-data-contraint>
      <description>
      <transport-guarantee>
    <user-data-contraint>
  </security-constraint>

  <login-config>
    <auth-method>
    <realm-name>
    <form-login-config>
      <form-login-page>
      <form-error-page>
    </form-login-config>
  </login-config>

  <security-role>
    <description>
    <role-name>
  </security-role>

  <env-entry>
    <description>
    <env-entry-name>
    <env-entry-value>
    <env-entry-type>
  </env-entry>

  <ejb-ref>
    <description>
    <ejb-ref-name>
    <ejb-ref-type>
    <home>
    <remote>
    <ejb-link>
    <run-as>
  </ejb-ref>
</web-app>

• The configuration is a three step process:

1. Copy the MySQL JDBC driver JAR file to CATALINA_HOME/common/lib.
2. Edit the CATALINA_HOME/conf/server.xml file so that it includes a context definition for the web application that will use the data source. The first code block below shows the main elements of server.xml and the second shows the detail of the context definition for a fictious web application called MyWebApp:

   <Server>
     <Service>
       <Engine>
         <Host>
           :
           <Context>
             <!-- Existing context definitions. -->
           </Context>
           :
           <!--
             | Paste in context definition shown below right here.
             +-->
         </Host>
       </Engine>
     </Service>
   </Server>

   <!--
      | Begin MyWebApp context definition.
      +-->
   <Context path="/MyWebApp" docBase="MyWebApp"
       reloadable="true">
   
     <Logger className="org.apache.catalina.logger.FileLogger"
         prefix="localhost_MyWebApp." suffix=".txt" timestamp="true"/>
   
     <Resource name="jdbc/MyWebAppDS" auth="Container"
         type="javax.sql.DataSource"/>
   
     <ResourceParams name="jdbc/MyWebAppDS">
       <parameter>
         <name>factory</name>
         <value>org.apache.commons.dbcp.BasicDataSourceFactory</value>
       </parameter>
   
       <!--
         | The JDBC connection URL for connecting to your MySQL DB.
         | The autoReconnect=true argument to the URL makes sure that the
         | MySQL JDBC Driver will automatically reconnect if mysqld closed
         | the connection. mysqld by default closes idle connections after
         | 8 hours.
         +-->
       <parameter>
         <name>url</name>
         <value>jdbc:mysql://localhost:3306/mywebapp_db_name?
             autoReconnect=true</value>
       </parameter>
   
       <!--
         | MySQL username and password for DB connections.
         +-->
       <parameter>
         <name>username</name>
         <value>username</value>
       </parameter>
       <parameter>
         <name>password</name>
         <value>password</value>
       </parameter>
   
       <!--
         | Class name for MySQL JDBC driver.
         +-->
       <parameter>
         <name>driverClassName</name>
         <value>com.mysql.jdbc.Driver</value>
       </parameter>
   
       <!--
         | Maximum number of DB connections in pool. Make sure you
         | configure your mysqld max_connections large enough to handle
         | all of your DB connections. Set to 0 for no limit.
         +-->
       <parameter>
         <name>maxActive</name>
         <value>100</value>
       </parameter>
   
       <!--
         | Maximum number of idle DB connections to retain in pool.
         | Set to 0 for no limit.
         +-->
       <parameter>
         <name>maxIdle</name>
         <value>30</value>
       </parameter>
   
       <!--
         | Maximum time to wait for a DB connection to become available
         | in ms, in this example 10 seconds. An exception is thrown if
         | this timeout is exceeded.
         | Set to -1 to wait indefinitely.
         +-->
       <parameter>
         <name>maxWait</name>
         <value>10000</value>
       </parameter>
     </ResourceParams>
   </Context>
   <!--
     | End MyWebApp context definition.
     +-->

3. Edit the web application's web.xml file to add a resource reference definition for the JNDI data source:

   <resource-ref>
     <description>MyWebApp data source.</description>
     <res-ref-name>jdbc/MyWebAppDS</res-ref-name>
     <res-type>javax.sql.DataSource</res-type>
     <res-auth>Container</res-auth>
   </resource-ref>

• Demystifying tomcat 4's server.xml file.

SELECT username FROM all_users ORDER BY username;

To get Oracle SQL*Plus to display a page at a time, use:

set pause on

—And press Enter to page.

SELECT table_name FROM user_tables;

To display the names of all the tables that the current user has access to, use:

SELECT table_name FROM all_tables;

ALTER USER user IDENTIFIED BY password

The code given below shows how to retain the time component. In this example, “pstmt” is a variable of type java.sql.PreparedStatement and the current date and time are used. Note that java.util.Date's getTime method can be used when specific dates need to be passed to the setTimestamp method.

pstmt.setTimestamp(1, new Timestamp(System.currentTimeMillis()));

The code given below shows how to retain the time component. “rset” is a variable of type java.sql.ResultSet.

java.util.Date dateUpdated
  = new Date(rset.getTimestamp("DateUpdated").getTime());

The code given below displays the exception message and the stack trace. A page-scope JavaBean named “exception” is defined that contains the Exception object that Struts has placed under the HTTP request key “org.apache.struts.action.EXCEPTION”. The bean is given the type “java.lang.Throwable” so that any runtime exceptions are caught and displayed too.

The Struts <bean:write> tag is then used to write the contents of that bean to the JSP. This displays the exception message. A scriptlet can be used to call the printStackTrace method, passing it a PrintWriter object that itself is passed the implicit “out” variable, so that the stack trace can be written to the page.

Note that typically when using Struts the text strings would be looked up from a resources file using the <bean:message> tag (not shown here).

Download 0032.txt

• The JSP:

<%@ taglib uri="http://jakarta.apache.org/struts/tags-bean" prefix="bean" %>

<bean:define id="exception" name="org.apache.struts.action.EXCEPTION"
  type="java.lang.Throwable" />

<p>
  Exception message:
</p>
<p>
  <bean:write name="exception" />
</p>
<p>
  Stack trace:
</p>
<p>
  <%
    exception.printStackTrace(new java.io.PrintWriter(out));
  %>
</p>

The code given below displays “Microsoft Internet Explorer 6.0” if running IE 6.0, or “Opera” or “Mozilla” if running any version of those browsers.

Download 0031.txt

• The JSP:

<logic:match header="User-Agent" value="IE">
  <logic:match header="User-Agent" value="6.0">
    <p>Microsoft Internet Explorer 6.0</p>
  </logic:match>
</logic:match>
<logic:match header="User-Agent" value="Opera">
  <p>Opera</p>
</logic:match>
<logic:match header="User-Agent" value="Mozilla">
  <p>Mozilla</p>
</logic:match>