ERP 2.50:Developers Guide/Concepts/Servlet Structure

ERP 2.50:Developers Guide

ERP 2.50:Developers Guide/Fundamentals and Concepts ERP 2.50:Developers Guide/Concepts/Middle Tier Fundamentals ERP 2.50:Developers Guide/Concepts/Servlet Structure ERP 2.50:Developers Guide/Concepts/XMLEngine ERP 2.50:Developers Guide/Concepts/SQLC ERP 2.50:Developers Guide/Concepts/Data Access Layer ERP 2.50:Developers Guide/Concepts/Process Scheduling ERP 2.50:Developers Guide/Concepts/Authentication ERP 2.50:Developers Guide/Concepts/Utilities

Index

Contents 1 Introduction 2 Class Hierarchy 2.1 HttpBaseServlet 2.2 HttpSecureAppServlet 2.3 MyCustomServlet 3 Example Servlet 3.1 MyCustomServlet Example 3.1.1 doPost

Introduction

This document explains the current servlet hierarchy and structure in Openbravo ERP.

Class Hierarchy

HttpBaseServlet

Base class that extends from Sun's HttpServlet and implements ConnectionProvider interface. It contains all the methods to interact with the database connection pool. This class is part of Openbravo's core. Your servlet can extend from this class if you don't want authentication and authorization.

HttpSecureAppServlet

This class extends from HttpBaseServlet. The security of the application is implemented at this level. This class also contains common artifacts for things such as: render a JasperReport, Autosave implementation, Navigation history, etc.

MyCustomServlet

This is an example servlet class. All your servlets should extend from HttpSecureAppServlet if you want authentication and authorization mechanisms.

Example Servlet

MyCustomServlet Example

package com.somepackage.mymodule;
 
import java.io.IOException;
import java.io.PrintWriter;
 
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
import org.openbravo.base.secureApp.HttpSecureAppServlet;
import org.openbravo.base.secureApp.VariablesSecureApp;
 
public class MyCustomServlet extends HttpSecureAppServlet {
  private static final long serialVersionUID = 1L;
 
  public void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException,
      ServletException {
    VariablesSecureApp vars = new VariablesSecureApp(request);
 
    if (vars.commandIn("DEFAULT")) {
      printPageDataSheet(response, vars);
    } else
      pageError(response);
  }
 
  void printPageDataSheet(HttpServletResponse response, VariablesSecureApp vars)
      throws IOException, ServletException {
    response.setContentType("text/html; charset=UTF-8");
    PrintWriter out = response.getWriter();
    out.println("This is MyCustomServlet");
    out.close();
  }
}

doPost

Your servlet must override the doPost method with all the logic that you want to implement in the class. Generally you start with a new VariablesSecureApp object based on the request made. This object will contain all the data from the request, plus a lot of helper methods like commandIn(), etc. Your servlet should implement a "DEFAULT" action, that will be executed when no other command is passed to the servlet.

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ERP 2.50:Developers Guide/Concepts/Middle Tier Fundamentals | ERP 2.50:Developers Guide/Concepts/XMLEngine