java web applications based on new struts 2.5 and angularjs (apachecon na 2016)

Java Web applicationsbased on

and

ApacheCon North America 2016 by ( )Johannes Geppert @jogep

About meApache Member and Struts PMC Member

Software Developer @

Living and working in Leipzig

About Struts2Action based Javaweb frameworkBuilt upon aRequest/ResponsecycleClean architectureEasy to extendwith plugins

Conceptual Overview

Struts 2.5 is released on11 May 2016!

Cleanup and Maintenance!Switch to Java7Increased Security withSMIxwork­core merged intostruts­coreRemoval of deprecatedpluginsDojo PluginCode Behind PluginJSF PluginStruts1 Plugin

Support for bean validation

Now as a (built­in) plugin available

Log4j2 as new Logging Layer

Replacement for Struts2Logging LayerSupport for multiplelogging implementationsBetter performance

First release is available!

Why AngularJS? AngularJS is a structural framework for dynamic web apps.It lets you use HTML as your template language and letsyou extend HTML's syntax to express your application'scomponents clearly and succinctly. Angular's data bindingand dependency injection eliminate much of the code youwould otherwise have to write. And it all happens within the

browser, making it an ideal partner with any servertechnology.

https://docs.angularjs.org/guide/introduction

Google TrendsAngularJS, React, Backbone and ember.js

Blue line is the trend for AngularJS

AngularJS ­ Overview

Quickstart with MavenArchetypes

mvn archetype:generate ­B \ ­DgroupId=com.mycompany.mysystem \ ­DartifactId=myWebApp \ ­DarchetypeGroupId=org.apache.struts \ ­DarchetypeArtifactId=struts2­archetype­angularjs \ ­DarchetypeVersion=<CURRENT_STRUTS_VERSION> \ ­DremoteRepositories=http://struts.apache.org

cd myWebApp mvn jetty:run

Open Browser http://localhost:8080

Live Demo

REST Based Actionswith Struts2 REST Plugin

REST ­ Action MappingHTTP method URI Class.method ParametersGET /order OrderController.index

GET /order/1 OrderController.show id="1"

POST /order OrderController.create

PUT /order/1 OrderController.update id="1"

DELETE /order/1 OrderController.destroy id="1"

Configure the REST PluginAdd the rest plugin to the dependencies

<dependency> <groupId>org.apache.struts</groupId> <artifactId>struts2­rest­plugin</artifactId> <version>$struts2.version</version> </dependency>

Disable restrictToGET default behaviour<constant name="struts.rest.content.restrictToGET" value="false"/>

Create packages for applications<constant name="struts.convention.default.parent.package" value="rest­angular"/> <package name="rest­angular" extends="rest­default"> <default­action­ref name="index" /> </package><package name="data" extends="rest­angular" namespace="/data"> </package>

REST ­ Content Type Handler/order/1 or /order/1.action Dispatcher (e.g. JSP)

/order/1.xml XML Handler

/order/1.json JSON HandlerEasy to build e.g. for CSV resultBuilt­in Jackson support for JSON serialization

<bean type="org.apache.struts2.rest.handler.ContentTypeHandler" name="jackson" class="org.apache.struts2.rest.handler.JacksonLibHandler"/> <constant name="struts.rest.handlerOverride.json" value="jackson"/>

Live Demo

Exception Handling

Custom ExceptionInterceptor

protected String doIntercept(ActionInvocation actionInvocation) throws Exception try return actionInvocation.invoke(); catch (Exception exception) Map<String, Object> errors = new HashMap<>(); HttpHeaders httpHeaders = new DefaultHttpHeaders() .disableCaching().withStatus(HttpServletResponse.SC_BAD_REQUEST) .renderResult(Action.INPUT); if(exception instanceof SecurityException) errors.put(ACTION_ERROR, "Operation not allowed!"); httpHeaders.setStatus(HttpServletResponse.SC_FORBIDDEN); else errors.put(ACTION_ERROR, exception.getMessage()); return manager.handleResult(actionInvocation.getProxy().getConfig(), httpHeaders, errors);

Extend the DefaultInterceptor Stack

<package name="data" extends="rest­angular" namespace="/data"> <interceptors> <interceptor name="dataError" class="....ExceptionHandlerInterceptor"/>

<interceptor­stack name="dataDefaultStack"> <interceptor­ref name="dataError"/> <interceptor­ref name="restDefaultStack"/> </interceptor­stack> </interceptors> <default­interceptor­ref name="dataDefaultStack"/> </package>

Dispatch an error eventExtend the generic _request method in DataService$http(req).success(function(data) def.resolve(data); ).error(function(data, code) def.reject(data); if(data.actionError) $rootScope.$emit('data­error', msg: data.actionError ); );

Listen to error eventse.g in a Controller

$rootScope.$on('data­error', function(event, alert) console.log(alert.msg); );

Live Demo

Bean Validation

Client and Server sideNew bean validation plugin

Setup bean validation

Add the bean validation plugin to thedependencies

<dependency> <groupId>org.apache.struts</groupId> <artifactId>struts2­bean­validation­plugin</artifactId> <version>$struts2.version</version> </dependency>

Specify a validation http status codelike "Not Acceptable"

<!­­ Set validation failure status code ­­> <constant name="struts.rest.validationFailureStatusCode" value="406"/>

Change rest interceptor stackDefault validation interceptor is using the old validationinterceptorCopy the rest default interceptor stackDefine the new one<interceptor name="beanValidation" class="....interceptor.BeanValidationInterceptor"/>

Replace the "validation" reference with "beanValidation"reference in the stack

Live Demo

Multi­Language Support

Where do we need it?

Frontend Validation Backend

Resource BundlesSplit them up!

<constant name="struts.custom.i18n.resources" value="frontend,validation,exceptions"/>

Sample for validation messages#validation_en.properties validation.order.client = Client name can not be blank validation.order.amount = Order amount needs to be between 10 and 666

#validation_de.properties validation.order.client = Kunden Name darf nicht leer sein validation.order.amount = Anzahl muss zwischen 10 und 666 sein

Language Controllerpublic class LanguageController extends RestActionSupport implements ModelDriven<Map<String, String>>

private Map<String, String> model;

public String index() throws Exception ResourceBundle bundle = getTexts("frontend"); this.model = bundle.keySet().stream() .collect(Collectors.toMap( key ­> key, key ­> bundle::getString));

return Action.SUCCESS;

public Map<String, String> getModel() return model;

Setup Angular Translate

(function() 'use strict';

angular .module('app', ['ngRoute', 'ui.bootstrap', 'pascalprecht.translate']); )();

$translateProvider.registerAvailableLanguageKeys(['en', 'de']); $translateProvider.fallbackLanguage('en'); $translateProvider.useUrlLoader('data/language.json', queryParameter: 'request_locale' ); $translateProvider.determinePreferredLanguage();

With translate filter in templates'order.client' | translate

In validation messages@NotBlank(message = "validation.order.client") @Min(value = 10, message = "validation.order.amount") @Max(value = 666, message = "validation.order.amount")

In java codethrow new RuntimeException(getText("exception.not.supported"));

Live Demo

Thank you!https://twitter.com/jogep

Resources ­

­ ­

­ ­

Apache Struts Project https://struts.apache.orgStruts2 Maven Archetypes https://struts.apache.org/docs/struts­2­maven­archetypes.htmlStruts2 Examples https://github.com/apache/struts­examplesAngularJS https://angularjs.orgAngular Translate https://angular­translate.github.io

AttributionsLeipzig Pictures by

by by

by by

by by

Ruthe Cartoon by by

by by

by by

Johannes GeppertModel in the wind tunnel DLR ­ German Aerospace CenterSky lanterns ( Bhavishya GoelClean Up Allen GoldblattBeans MatthewMatrix pills ThomasThomasShaking Hands Aaron Gilson

ruthe.deLanguage Scramble Eric AndresenWindows Box Perfection Rachel KramerKrakow Door John Finn1949 Ford Coupe ­ flat head V8 engine dave_7Questions Alexander Henning Drachmann