...

1. Create the webapp directory (you may use any name you want):
   mkdir [dspace]/webapps-jython/
   Tip: The jython webapp is just another webapp like the individual DSpace webapps. So while you could put it next to the DSpace webapps into [dspace]/webapps/jython/, it's preferable to choose a different location (e.g. [dspace]/webapps-jython/) because the [dspace]/webapps/ directory is replaced every time you run "ant update" (the old webapps directory will not be deleted, it will be renamed to "webapps-[timestamp]").
2. Download the latest Jython installer jar (e.g. jython-installer-2.7.1.jar) from http://www.jython.org/downloads.html (the jython.org website was last updated around 2015 [issue2658]; check Maven Central for latest jython version)
   curl -O -J http://search.maven.org/remotecontent?filepath=org/python/jython-installer/2.7.1/jython-installer-2.7.1.jar
3. Get jython.jar and the Lib directory.;
   
   1. either unzip the installer jar:
      unzip -d [dspace]/lib/ jython-installer-2.7.1.jar jython.jar 'Lib/*'
unzip -d [dspace]/webapps-jython/WEB-INF/lib/ jython-installer-2.7.1.jar jython.jar 'Lib/*'
   2. or use it to install Jython: 
      java -jar jython-installer-2.7.1.jar --console
      Note: Installation location doesn't matter, this is not necessary for DSpace. You can safely delete it after you retrieve jython.jar and Lib

4. Associate .py files with Jython's PyServlet
   

   Code Block
   language xml title \[dspace\]/webapps/jython/WEB-INF/web.xml
   <web-app> <servlet> <servlet-name>PyServlet</servlet-name> <servlet-class>org.python.util.PyServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>PyServlet</servlet-name> <url-pattern>*.py</url-pattern> </servlet-mapping> </web-app>

    

5. Create a Hello World servlet:

   Code Block
   language py title \[dspace\]/webapps/jython/hello.py
   # -*- coding: utf-8 -*- from javax.servlet.http import HttpServlet class hello(HttpServlet): def doGet(self, request, response): self.doPost(request, response) def doPost(self, request, response): response.setContentType("text/html") response.setCharacterEncoding("utf-8") toClient = response.getWriter() toClient.println("<h1>Hello World!</h1>") toClient.println(u"<p>To make sure utf-8 works, here's a Czech pangram for you:</p><p>Příliš žluťoučký kůň úpěl ďábelské ódy.</p>"

   Access to DSpace classes from Jython

6. Copy DSpace jars to the jython webapp's lib directory:
   cp -r [dspace]/lib/* [dspace]/webapps-jython/WEB-INF/lib/

7. Start up DSpace kernel on webapp startup and point it to your DSpace configuration:

   Code Block
   language xml title \[dspace\]/webapps/-jython/WEB-INF/web.xml
   <web-app> ... <!-- DSpace Configuration Information --> <context-param> <param-name>dspace-config</param-name> <param-value>/dspace/config/dspace.cfg</param-value> </context-param> <!-- new ConfigurationService initialization for dspace.dir --> <context-param> <description>The location of the main DSpace configuration file</description> <param-name>dspace.dir</param-name> <param-value>/dspace</param-value> </context-param> <listener> <listener-class>org.dspace.app.util.DSpaceContextListener</listener-class> </listener> <listener> <listener-class>org.dspace.servicemanager.servlet.DSpaceKernelServletContextListener</listener-class> </listener> </web-app>

   
   

8. Define the context in Tomcat's configuration. There are several ways how you can do that, so just use the same way you use for configuring DSpace contexts. The recommended one is to use a context fragment:

   Code Block
   language xml title sudo vim /etc/tomcat7/Catalina/localhost/jython.xml
   <Context docBase="/dspace/webapps-jython" reloadable="true" cachingAllowed="false" />

   A few seconds after you save the file, Tomcat will notice it and load the "jython" context.

...

<web-app>
    ...
    <servlet-mapping>
        <servlet-name>SherpaRomeo</servlet-name>
        <url-pattern>/SherpaRomeo</url-pattern>
    </servlet-mapping>
</web-app>

Example of connection to the DSpace DB via ZxJDB

# -*- coding: utf-8 -*-

from javax.servlet.http import HttpServlet
from com.ziclix.python.sql import zxJDBC
from java.util import Properties

DSPACE_DIR = '/dspace'


class db_example(HttpServlet):
    def doGet(self, request, response):
        self.doPost(request, response)

    def doPost(self, request, response):
        response.setContentType("text/html")
        response.setCharacterEncoding("utf-8")
        toClient = response.getWriter()
        toClient.println("<h1>Example of connection to the DSpace DB via ZxJDBC</h1>")

        rows = self.get_data_from_db()
        toClient.println("<h2>Results</h2>")
        toClient.println("<table>")

        toClient.println("<tr>")
        for column in rows[0]:
            toClient.println("<th>%s</th>" % column)
        toClient.println("</tr>")

        for row in rows:
            toClient.println("<tr>")
            for column in row:
                toClient.println("<td>%s</td>" % row[column])
            toClient.println("</tr>")

        toClient.println("</table>")

    def read_dspace_config(self, filename):
        """read dspace.cfg"""
        with open(filename, 'r') as f:
            props = Properties()
            props.load(f)
            return props

    def connect_db(self):
        """
        get DB config from DSpace config, connect in autocommit mode (each
        individual query is commited automatically)
        """
        self.conn = zxJDBC.connect(
            self.props.getProperty('db.url'),
            self.props.getProperty('db.username'),
            self.props.getProperty('db.password'),
            self.props.getProperty('db.driver'),
        )
        self.conn.autocommit = True

    def init(self, config):
        """servlet startup"""
        try:
            self.props = self.read_dspace_config(DSPACE_DIR + '/config/local.cfg')
        except IOError:
            self.props = self.read_dspace_config(DSPACE_DIR + '/config/dspace.cfg')
        self.connect_db()

    def destroy(self):
        """servlet shutdown: clean up DB connections"""
        self.conn.close()

    def get_data_from_db(self):
        """
        Query the DB and return a list of rows
        where each row is a dict of column names and values
        """
        with self.conn.cursor() as c:
            c.execute("SELECT version, description FROM schema_version ORDER BY version DESC")

            columns = [col[0] for col in c.description]
            rows = []
            for row in c:
                rowdata = dict(zip(columns, row))
                rows.append(rowdata)
            return rows

See also

• Curation tasks in Jython

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