A servlet that receives data from an AS400 RPG program

A Servlet Connecting To AS400 RPG Program

package com.academy.wms.footwearsorter;

import java.util.ArrayList;
import java.util.List;
import java.io.IOException;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.sql.DataSource;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;

public class StartResourcesServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
	private static Logger LOGGER = LoggerFactory.getLogger(StartResourcesServlet.class);
	DataSource dataSource;
	public void init() throws ServletException {
		try {
			Context initContext  = new InitialContext();
			Context envContext  = (Context)initContext.lookup("java:/comp/env");
			dataSource = (DataSource)envContext.lookup("jdbc/testdb");
		} catch (NamingException e) {
			e.printStackTrace();
		} 
	}

	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		LOGGER.debug("servlet calling!"); 
		try {
			Connection conn = dataSource.getConnection();
			CallableStatement cs=null;
			ResultSet rs=null;
			String query = "call DEVDPGH/SQLRPGJDBC(?,?)";
			List<String> results = new ArrayList<String>();
			try {
				cs = conn.prepareCall(query);
				cs.setString(1, "Academy Sports ");
				cs.setString(2, "+ Outdoors");
				rs = cs.executeQuery();
				rs.next(); 
				String firstResult = rs.getString("FIRSTFIELD");
				String lastResult = rs.getString("LASTFIELD");
				request.getSession().setAttribute("line1", firstResult);
				request.getSession().setAttribute("line2", lastResult);  
			} catch(SQLException e){
				e.printStackTrace();
			} finally {
				try { if(null!=rs)rs.close();} catch (SQLException e) 
				{e.printStackTrace();}
				try { if(null!=cs)cs.close();} catch (SQLException e) 
				{e.printStackTrace();}
				try { if(null!=conn)conn.close();} catch (SQLException e) 
				{e.printStackTrace();}
			}
		} catch(Exception e) {
			System.out.println( e.getMessage() );
		}
		
		RequestDispatcher dispatcher = request.getRequestDispatcher("helloworld.jsp");
		dispatcher.forward(request, response);
	}

}

build.xml

<?xml version="1.0" ?> 
<project name="footwearsorter" default="war">
	<property file="build.properties"/>
	<property name="src.dir" value="src"/>
	<property name="web.src" value="src/WebContent"/>
	<property name="build.dir" value="bin"/>
	<property name="dist.dir" value="dist"/>

	<path id="compile.classpath">
		<fileset dir="${web.src}/WEB-INF/lib">
			<include name="*.jar"/>
		</fileset>
		<fileset dir="${appserver.home}/lib">
			<include name="*.jar"/>
		</fileset>
	</path>

	<target name="clean">
		<delete dir="${dist.dir}" />
		<delete dir="${build.dir}" />
	</target>
	
	<target name="init" depends="clean">
		<fail>
			<condition>
				<not>
					<resourcecount count="1">
						<fileset dir="src/main/resources" includes="log4j.properties"/>
					</resourcecount>
				</not>
			</condition>
		</fail>
		<mkdir dir="${build.dir}/classes"/>
		<mkdir dir="${dist.dir}" />
	</target>
	
	<target name="compile" depends="init" >
		<javac destdir="${build.dir}/classes" includeantruntime="false" debug="true" srcdir="${src.dir}/main/java">
			<classpath refid="compile.classpath"/>
		</javac>
	</target>
	
	<target name="war" depends="compile">
		<war destfile="${dist.dir}/${ant.project.name}.war" webxml="${web.src}/WEB-INF/web.xml">
			<lib dir="${web.src}/WEB-INF/lib"/>
			<fileset dir="${web.src}/"><include name="**/*.*"/></fileset>
			<classes dir="${src.dir}/main/resources"><include name="*.*"/></classes>
			<classes dir="${build.dir}/classes"/>
		</war>
	</target>

	<target name="deploywar" depends="war" description="Deploy application as a WAR file">
		<copy todir="${appserver.home}/webapps" preservelastmodified="true">
			<fileset dir="${dist.dir}">
				<include name="*.war"/>
			</fileset>
		</copy>
	</target>
		
</project>

helloworld.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>hello</title>
</head>
<body>
	<br/><br/>
		${line1} ${line2}
</body>
</html>

index.html

<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>hello</title>
</head>
<body>
	<br/><br/>
	<form id="form1" name="form1" action="start" method="POST">
		<br/><br/><br/>
		<input type="submit" value="Submit"/>
	</form>
</body>
</html>

rpgjdbc.rpgle

H OPTION(*SRCSTMT:*NODEBUGIO) DFTACTGRP(*NO)            
d                sds                                    
d  pgmnam                 1     10                      
d  usrprf               254    263                      
d  systim               282    287  0                   
                                                        
d rpgjdbc         PR                  ExtPgm('RPGJDBC') 
d  parm1                        15                      
d  parm2                        15                      
                                                        
d rpgjdbc         PI                                    
d  parm1                        15                      
d  parm2                        15                      
                                                        
d capitalize      PR            15                      
d  parm1                        15                      
                                                        
D Results         DS                  qualified dim(1)  
d firstField                    15 
d lastField                     15                                
                                                                  
d N               s              3P 0 inz(1)                      
 /free                                                            
              Results(1).firstField = capitalize(parm1);          
              Results(1).lastField  = capitalize(parm2);          
              exec sql  set result sets for return to client      
                    array :Results for :N rows;                   
              *INLR = *ON;                                        
 /end-free                                                        
                                                                  
p capitalize      b                   EXPORT                      
d                 pi            15A                               
d strToCap                      15A                               
d up              C                   'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
d lo              C                   'abcdefghijklmnopqrstuvwxyz'
d rtnval          s             15                                
C                   eval      rtnval = %xlate(lo:up:strToCap)     
C                   return    rtnval                              
p                 e                                               

sqljdbc.sql

-- run this on AS400 with command RUNSQLSTM
-- DROP PROCEDURE DEVDPGH/SQLRPGJDBC

CREATE PROCEDURE DEVDPGH/SQLRPGJDBC (IN CHAR(15), IN CHAR (15))

DYNAMIC RESULT SETS 1  
LANGUAGE RPGLE
READS SQL DATA
EXTERNAL NAME 'DEVDPGH/RPGJDBC'
PARAMETER STYLE GENERAL ; 

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
	<display-name>footwearsorter</display-name>
	<context-param>
		<param-name>contextConfigLocation</param-name>
		<param-value>/WEB-INF/context.xml</param-value>
	</context-param>

	<servlet>
		<servlet-name>startServlet</servlet-name>
		<servlet-class>com.academy.wms.footwearsorter.StartResourcesServlet</servlet-class>
	</servlet>

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

	<welcome-file-list>
		<welcome-file>index.jsp</welcome-file>
	</welcome-file-list>
</web-app>