First application (Avalanche - application framework for Java)

"Avalanche - application framework for Java" - implementation of technology erasing the differences between
local and remote code calls. Fault tolerance, scalability,
modifiability, continuous availability come bundled with nice bonuses.

All programming languages suggest starting with writing a simple output program.
Hello world messages. This example is not suitable for demonstrating functional
features of "Avalanche - application framework for Java", since calling this example is always
returns the same string and does not allow to identify the source that returned this
result.

For the first application, you need to implement two classes (function and application), one
interface (function adapter) and one JSP page to display the result. Designed by
the application will run under Tomcat.

Function Class Implementation - DemoFunction

There is nothing special in the function implementation class; it is a regular Java class. As
function class any class can be used. Let the function demo class
returns the following information from the operating system: PID of the process and server name;
operating system version; name of the operating system.

Class Code DemoFunction.java

package ru.funsys.demo.avalanche;

import java.lang.management.ManagementFactory;
import java.util.Hashtable;

public class DemoFunction {

    /**
     *     .<br>
     * <br>
     *      <br>
     * <b>os.name</b> -  ,<br>
     * <b>os.version</b> -  <br>
     *  <b>PID@name</b> -      
     * 
     * @return     
     */
    public Hashtable<String, String> getInfo() {
        Hashtable<String, String> result = new Hashtable<String, String>();
        result.put("os.name", System.getProperty("os.name"));
        result.put("os.version", System.getProperty("os.version"));
        result.put("PID@name", ManagementFactory.getRuntimeMXBean().getName());
        return result;
    }

}

— DemoAdapter

Java, — ,
,
. DemoFunction

DemoAdapter.java

package ru.funsys.demo.avalanche;

import java.util.Hashtable;

import ru.funsys.avalanche.AvalancheRemote;

public interface DemoAdapter {

    public Hashtable<String, String> getInfo() throws AvalancheRemote;

}

, DemoAdapter
AvalancheException.
RMI Java,
:

( — DemoFunction)
( — DemoAdapter)
( — DemoAdapter)
(, DemoFunction), ,
.

, .

— DemoApplication

DemoApplication — getInfo() DemoFunction
DemoAdapter. DemoApplication
getInfo() TXT HTML.

DemoApplication.java

package ru.funsys.demo.avalanche;

import java.util.Enumeration;
import java.util.Hashtable;

import ru.funsys.avalanche.Application;
import ru.funsys.avalanche.AvalancheRemote;

public class DemoApplication extends Application {

    /**
     *      
     */
    private DemoAdapter info;

    /**
     *        
     *      HTML     .
     * 
     * @param html true,    HTML,  false
     * 
     * @return    HTML   
     */
    public String getInfo(boolean html) {
        StringBuilder builder = new StringBuilder();
        if (html) {
            builder.append("<table border=\"1\">");
            builder.append("<tr><th>key</th><th>value</th></tr>");
        }
        try {
            //   
            Hashtable<String, String> result = info.getInfo();

            for (Enumeration<String> enumeration = result.keys(); enumeration.hasMoreElements(); ) {
                String key = enumeration.nextElement();
                String value = result.get(key);
                if (html) {
                    builder.append("<tr><td>").append(key).append("</td><td>").append(value).append("</td></tr>");
                } else {
                    builder.append(key).append(": ").append(value).append("\r\n");
                }
            }
        } catch (AvalancheRemote e) {
            if (html) {
                builder.append("<tr><td>").append("error").append("</td><td>").append(e.getLocalizedMessage()).append("</td></tr>");
            } else {
                builder.append("error").append(": ").append(e.getLocalizedMessage()).append("\r\n");
            }
        }
        if (html) builder.append("</table>");
        return builder.toString();
    }

}

: ru.funsys.avalanche.Application.

info , , getAdapter(String name) ru.funsys.avalanche.Application. . .

JSP — first.jsp

JSP . DemoApplication getInfo c true.

<%@ page import="ru.funsys.demo.avalanche.DemoApplication"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!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=UTF-8">
<title> </title>
</head>
<body>
<h1> </h1>
<jsp:useBean id='DemoApp' scope='application' class='ru.funsys.demo.avalanche.DemoApplication'/>

<%= DemoApp.getInfo(true) %>
<br>

</body>
</html>

. .

web.xml

web.xml AvalancheServlet, log4j. AvalancheServlet avalanche-config.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" 
-->
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">

    <display-name>Demo Avalanche</display-name>
    <description>
            framework Avalanche
    </description>

    <welcome-file-list>
        <welcome-file>index.html</welcome-file>
        <welcome-file>index.htm</welcome-file>
        <welcome-file>index.jsp</welcome-file>
        <welcome-file>default.html</welcome-file>
        <welcome-file>default.htm</welcome-file>
        <welcome-file>default.jsp</welcome-file>
    </welcome-file-list>

    <servlet>
        <display-name>AvalancheServlet</display-name>
        <servlet-name>AvalancheServlet</servlet-name>
        <servlet-class>ru.funsys.servlet.http.AvalancheServlet</servlet-class>
        <init-param>
            <param-name>avalanche.config</param-name>
            <param-value>${catalina.base}/conf/avalanche-config.xml</param-value>
        </init-param>
        <init-param>
            <param-name>avalanche.log4j</param-name>
            <param-value>${catalina.base}/conf/avalanche-log4j.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>

</web-app>

avalanche-config.xml

<?xml version="1.0" encoding="UTF-8"?>
<avalanche name="Demo Application">

    <function class="ru.funsys.demo.avalanche.DemoFunction" name="info-function" description="   " />

    <application class="ru.funsys.demo.avalanche.DemoApplication" name="DemoApp" >
        <adapter class="ru.funsys.demo.avalanche.DemoAdapter" name="info" uri="info-function" />
    </application>

</avalanche>

<function> <application>. <application> <adapter>, uri (. name <function>).

name <application>, DemoApp id DemoApplication JSP .

DemoFunction

, , REST, SOAP .

"Avalanche — application framework for Java" DemoFunction. .

avalanche-config.xml :

<interface>,
<connector>, .

RMI

<interface name="rmi-interface" uri="rmi://localhost:23000/rmi-connector" />

localhost
23000 RMI Remote Server
rmi-connector

<connector class="RMIConnector" name="rmi-connector" port="23000" >
    <publish name="info" function="info-function" />
</connector>

rmi-connector
23000 RMI Remote Server
<publish> info-function , info-function info

HTTP

<interface name="http-interface" uri="http://localhost:8080/demo/connector/http-connector" />

localhost
8080 HTTP Server
demo
connector AvalancheServlet
http-connector

<connector class="HTTPConnector" name="http-connector" >
    <publish name="info" function="info-function" />
</connector>

http-connector
<publish> info-function , info-function info

! HTTP , HTTP (Tomcat).

<multipart-config> AvalancheServlet <servlet-mapping> URI web.xml.

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" 
-->
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">

    <display-name>Demo Avalanche</display-name>
    <description>
            framework Avalanche
    </description>

    <welcome-file-list>
        <welcome-file>index.html</welcome-file>
        <welcome-file>index.htm</welcome-file>
        <welcome-file>index.jsp</welcome-file>
        <welcome-file>default.html</welcome-file>
        <welcome-file>default.htm</welcome-file>
        <welcome-file>default.jsp</welcome-file>
    </welcome-file-list>

    <servlet>
        <display-name>AvalancheServlet</display-name>
        <servlet-name>AvalancheServlet</servlet-name>
        <servlet-class>ru.funsys.servlet.http.AvalancheServlet</servlet-class>
        <init-param>
            <param-name>avalanche.config</param-name>
            <param-value>${catalina.base}/conf/avalanche-config.xml</param-value>
        </init-param>
        <init-param>
            <param-name>avalanche.log4j</param-name>
            <param-value>${catalina.base}/conf/avalanche-log4j.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
        <multipart-config>
            <!-- 50MB max -->
            <max-file-size>52428800</max-file-size>
            <max-request-size>52428800</max-request-size>
            <file-size-threshold>0</file-size-threshold>
        </multipart-config>
    </servlet>

    <servlet-mapping>
        <servlet-name>AvalancheServlet</servlet-name>
        <url-pattern>/connector/*</url-pattern>
    </servlet-mapping>

</web-app>

, <application> RMIApp HTTPApp. uri <adapter> -/- , .. rmi-interface/info http-interface/info.

avalanche-config.xml RMI HTTP

<?xml version="1.0" encoding="UTF-8"?>
<avalanche name="Demo Application">

    <interface name="rmi-interface" uri="rmi://localhost:23000/rmi-connector" />

    <interface name="http-interface" uri="http://localhost:8080/demo/connector/http-connector" />

    <function class="ru.funsys.demo.avalanche.DemoFunction" name="info-function" description="   " />

    <application class="ru.funsys.demo.avalanche.DemoApplication" name="DemoApp" >
        <adapter class="ru.funsys.demo.avalanche.DemoAdapter" name="info" uri="info-function" />
    </application>

    <application class="ru.funsys.demo.avalanche.DemoApplication" name="RMIApp" >
        <adapter class="ru.funsys.demo.avalanche.DemoAdapter" name="info" uri="rmi-interface/info" />
    </application>

    <application class="ru.funsys.demo.avalanche.DemoApplication" name="HTTPApp" >
        <adapter class="ru.funsys.demo.avalanche.DemoAdapter" name="info" uri="http-interface/info" />
    </application>

    <connector class="RMIConnector" name="rmi-connector" port="23000" >
        <publish name="info" function="info-function" />
    </connector>

    <connector class="HTTPConnector" name="http-connector" >
        <publish name="info" function="info-function" />
    </connector>

</avalanche>

JSP first.jsp RMI HTTP, id RMIApp HTTPApp .

rmi.jsp

<%@ page import="ru.funsys.demo.avalanche.DemoApplication"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!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=UTF-8">
<title>  - RMI</title>
</head>
<body>
<h1>  - RMI</h1>
<p>
  -  RMI
</p>
<jsp:useBean id='RMIApp' scope='application' class='ru.funsys.demo.avalanche.DemoApplication'/>

<%= RMIApp.getInfo(true) %>

</body>
</html>

http.jsp

<%@ page import="ru.funsys.demo.avalanche.DemoApplication"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!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=UTF-8">
<title>  - HTTP</title>
</head>
<body>
<h1>  - HTTP</h1>
<p>
  -  HTTP
</p>
<jsp:useBean id='HTTPApp' scope='application' class='ru.funsys.demo.avalanche.DemoApplication'/>

<%= HTTPApp.getInfo(true) %>

</body>
</html>

, localhost <interface> avalanche-config.xml, .

, .

, , GitHub

First application (Avalanche - application framework for Java)

First application (Avalanche - application framework for Java)

Function Class Implementation - DemoFunction

— DemoAdapter

— DemoApplication

JSP — first.jsp

web.xml

avalanche-config.xml

DemoFunction

RMI

HTTP

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