Global Exception Mappings:

We have seen how we can handle action specific exception. We can set an exception globally which will apply to all the actions. For example, to catch the same NullPointerException exceptions, we could add <global-exception-mappings...> tag inside <package...> tag and its <result...> tag should be added inside the <action...> tag in struts.xml file as follows:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
   "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
   "http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
<constant name="struts.devMode" value="true" />
   <package name="helloworld" extends="struts-default">

      <global-exception-mappings>
         <exception-mapping exception="java.lang.NullPointerException"
         result="error" />
      </global-exception-mappings>

      <action name="hello" 
         class="com.tutorialspoint.struts2.HelloWorldAction" 
         method="execute">
         <result name="success">/HelloWorld.jsp</result>
         <result name="error">/Error.jsp</result>
      </action>

   </package>
</struts>

Type Conversion in struts 2.0

Struts knows how to display and convert the string "Windows XP SP3" and other built-in data types, but it does not know what to do with the the property of Environment type. So, it simply called the toString() method on the class. To resolve this problem, let us now create and register a simple TypeConverter for the Environment class. Create a class called EnvironmentConverter.java with the following.

package com.tutorialspoint.struts2; import java.util.Map; import org.apache.struts2.util.StrutsTypeConverter; public class EnvironmentConverter extends StrutsTypeConverter { @Override public Object convertFromString(Map context, String[] values, Class clazz) { Environment env = new Environment(values[0]); return env; } @Override public String convertToString(Map context, Object value) { Environment env = (Environment) value; return env == null ? null : env.getName(); } }

The EnvironmentConverter extends the StrutsTypeConverter class and tells Struts how to convert Environment to a String and vice versa by overriding two methods convertFromString() and convertToString(). Let us now register this converter before we us it in our application. There are two ways to register a converter. If the converter will be used only in a particular action, then you would have to create a property file needs to be named as '[action-class]'-converstion.properties, So, in our case we create a file called SystemDetails-converstion.properties with the following registration entery:

environment=com.tutorialspoint.struts2.EnvironmentConverter

In the above example, "environment" is the name of the property in the SystemDetails.java class and we are telling Struts to use the EnvironmentConverter for converting to and from this property. However, we are not going to do this, Instead we are going to register this converter globally so that it can be used throughout the application. To do this, create a property file called xwork-conversion.properties in the WEB-INF/classes folder with the following line:

com.tutorialspoint.struts2.Environment = \ com.tutorialspoint.struts2.EnvironmentConverter

This simply registers the converter globally, so that Struts can automatically do the conversion every time it encounters an object of type Environment. Now, if you re-compile and re-run the program, you will get a better output as follows:

Obviously, now result is better which means our Struts convertor is working fine. This is how you can create multiple convertors and register them to use as per your requirements.

Advantage of xml validation in strut 2.0

The advantage of having an xml file to store the configuration allows the separation of the validation from the application code. You could get a developer to write the code and a business analyst to create the validation xml files

struts-default.xml and struts.properties file

A base configuration file named struts-default.xml is included in the struts2.jar file. This file is automatically included into struts.xml file to provide the standard configuration settings without having to copy them.

To exclude the struts-default.xml or to provide your own version, see the struts.configuration.files setting in struts.properties.

The contents of struts-default.xml are here:

<?xml version="1.0" encoding="UTF-8" ?>
<!--
/*
 * $Id$
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
-->

<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>
    <bean class="com.opensymphony.xwork2.ObjectFactory" name="xwork" />
    <bean type="com.opensymphony.xwork2.ObjectFactory" name="struts" class="org.apache.struts2.impl.StrutsObjectFactory" />

    <bean type="com.opensymphony.xwork2.ActionProxyFactory" name="xwork" class="com.opensymphony.xwork2.DefaultActionProxyFactory"/>
    <bean type="com.opensymphony.xwork2.ActionProxyFactory" name="struts" class="org.apache.struts2.impl.StrutsActionProxyFactory"/>

    <bean type="com.opensymphony.xwork2.util.ObjectTypeDeterminer" name="tiger" class="com.opensymphony.xwork2.util.GenericsObjectTypeDeterminer"/>
    <bean type="com.opensymphony.xwork2.util.ObjectTypeDeterminer" name="notiger" class="com.opensymphony.xwork2.util.DefaultObjectTypeDeterminer"/>
    <bean type="com.opensymphony.xwork2.util.ObjectTypeDeterminer" name="struts" class="com.opensymphony.xwork2.util.DefaultObjectTypeDeterminer"/>

    <bean type="org.apache.struts2.dispatcher.mapper.ActionMapper" name="struts" class="org.apache.struts2.dispatcher.mapper.DefaultActionMapper" />
    <bean type="org.apache.struts2.dispatcher.mapper.ActionMapper" name="composite" class="org.apache.struts2.dispatcher.mapper.CompositeActionMapper" />
    <bean type="org.apache.struts2.dispatcher.mapper.ActionMapper" name="restful" class="org.apache.struts2.dispatcher.mapper.RestfulActionMapper" />
    <bean type="org.apache.struts2.dispatcher.mapper.ActionMapper" name="restful2" class="org.apache.struts2.dispatcher.mapper.Restful2ActionMapper" />

    <bean type="org.apache.struts2.dispatcher.multipart.MultiPartRequest" name="struts" class="org.apache.struts2.dispatcher.multipart.JakartaMultiPartRequest" scope="default" optional="true"/>
    <bean type="org.apache.struts2.dispatcher.multipart.MultiPartRequest" name="jakarta" class="org.apache.struts2.dispatcher.multipart.JakartaMultiPartRequest" scope="default" optional="true" />

    <bean type="org.apache.struts2.views.TagLibrary" name="s" class="org.apache.struts2.views.DefaultTagLibrary" />

    <bean class="org.apache.struts2.views.freemarker.FreemarkerManager" name="struts" optional="true"/>
    <bean class="org.apache.struts2.views.velocity.VelocityManager" name="struts" optional="true" />

    <bean class="org.apache.struts2.components.template.TemplateEngineManager" />
    <bean type="org.apache.struts2.components.template.TemplateEngine" name="ftl" class="org.apache.struts2.components.template.FreemarkerTemplateEngine" />
    <bean type="org.apache.struts2.components.template.TemplateEngine" name="vm" class="org.apache.struts2.components.template.VelocityTemplateEngine" />
    <bean type="org.apache.struts2.components.template.TemplateEngine" name="jsp" class="org.apache.struts2.components.template.JspTemplateEngine" />

    <bean type="com.opensymphony.xwork2.util.XWorkConverter" name="xwork1" class="com.opensymphony.xwork2.util.XWorkConverter" />
    <bean type="com.opensymphony.xwork2.util.XWorkConverter" name="struts" class="com.opensymphony.xwork2.util.AnnotationXWorkConverter" />

    <bean type="com.opensymphony.xwork2.TextProvider" name="xwork1" class="com.opensymphony.xwork2.TextProviderSupport" />
    <bean type="com.opensymphony.xwork2.TextProvider" name="struts" class="com.opensymphony.xwork2.TextProviderSupport" />

 <bean type="org.apache.struts2.components.UrlRenderer" name="struts" class="org.apache.struts2.components.ServletUrlRenderer"/>
 
    <!--  Only have static injections -->
    <bean class="com.opensymphony.xwork2.ObjectFactory" static="true" />
    <bean class="com.opensymphony.xwork2.util.XWorkConverter" static="true" />
    <bean class="com.opensymphony.xwork2.util.OgnlValueStack" static="true" />
    <bean class="org.apache.struts2.dispatcher.Dispatcher" static="true" />
    <bean class="org.apache.struts2.components.Include" static="true" />
    <bean class="org.apache.struts2.dispatcher.FilterDispatcher" static="true" />
    <bean class="org.apache.struts2.views.util.ContextUtil" static="true" />
    <bean class="org.apache.struts2.views.util.UrlHelper" static="true" />

    <package name="struts-default" abstract="true">
        <result-types>
            <result-type name="chain" class="com.opensymphony.xwork2.ActionChainResult"/>
            <result-type name="dispatcher" class="org.apache.struts2.dispatcher.ServletDispatcherResult" default="true"/>
            <result-type name="freemarker" class="org.apache.struts2.views.freemarker.FreemarkerResult"/>
            <result-type name="httpheader" class="org.apache.struts2.dispatcher.HttpHeaderResult"/>
            <result-type name="redirect" class="org.apache.struts2.dispatcher.ServletRedirectResult"/>
            <result-type name="redirectAction" class="org.apache.struts2.dispatcher.ServletActionRedirectResult"/>
            <result-type name="stream" class="org.apache.struts2.dispatcher.StreamResult"/>
            <result-type name="velocity" class="org.apache.struts2.dispatcher.VelocityResult"/>
            <result-type name="xslt" class="org.apache.struts2.views.xslt.XSLTResult"/>
            <result-type name="plainText" class="org.apache.struts2.dispatcher.PlainTextResult" />
        </result-types>

        <interceptors>
            <interceptor name="alias" class="com.opensymphony.xwork2.interceptor.AliasInterceptor"/>
            <interceptor name="autowiring" class="com.opensymphony.xwork2.spring.interceptor.ActionAutowiringInterceptor"/>
            <interceptor name="chain" class="com.opensymphony.xwork2.interceptor.ChainingInterceptor"/>
            <interceptor name="conversionError" class="org.apache.struts2.interceptor.StrutsConversionErrorInterceptor"/>
            <interceptor name="createSession" class="org.apache.struts2.interceptor.CreateSessionInterceptor" />
            <interceptor name="debugging" class="org.apache.struts2.interceptor.debugging.DebuggingInterceptor" />
            <interceptor name="externalRef" class="com.opensymphony.xwork2.interceptor.ExternalReferencesInterceptor"/>
            <interceptor name="execAndWait" class="org.apache.struts2.interceptor.ExecuteAndWaitInterceptor"/>
            <interceptor name="exception" class="com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor"/>
            <interceptor name="fileUpload" class="org.apache.struts2.interceptor.FileUploadInterceptor"/>
            <interceptor name="i18n" class="com.opensymphony.xwork2.interceptor.I18nInterceptor"/>
            <interceptor name="logger" class="com.opensymphony.xwork2.interceptor.LoggingInterceptor"/>
            <interceptor name="modelDriven" class="com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor"/>
            <interceptor name="scopedModelDriven" class="com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor"/>
            <interceptor name="params" class="com.opensymphony.xwork2.interceptor.ParametersInterceptor"/>
            <interceptor name="prepare" class="com.opensymphony.xwork2.interceptor.PrepareInterceptor"/>
            <interceptor name="staticParams" class="com.opensymphony.xwork2.interceptor.StaticParametersInterceptor"/>
            <interceptor name="scope" class="org.apache.struts2.interceptor.ScopeInterceptor"/>
            <interceptor name="servletConfig" class="org.apache.struts2.interceptor.ServletConfigInterceptor"/>
            <interceptor name="sessionAutowiring" class="org.apache.struts2.spring.interceptor.SessionContextAutowiringInterceptor"/>
            <interceptor name="timer" class="com.opensymphony.xwork2.interceptor.TimerInterceptor"/>
            <interceptor name="token" class="org.apache.struts2.interceptor.TokenInterceptor"/>
            <interceptor name="tokenSession" class="org.apache.struts2.interceptor.TokenSessionStoreInterceptor"/>
            <interceptor name="validation" class="org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor"/>
            <interceptor name="workflow" class="com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor"/>
            <interceptor name="store" class="org.apache.struts2.interceptor.MessageStoreInterceptor" />
            <interceptor name="checkbox" class="org.apache.struts2.interceptor.CheckboxInterceptor" />
            <interceptor name="profiling" class="org.apache.struts2.interceptor.ProfilingActivationInterceptor" />
            <interceptor name="roles" class="org.apache.struts2.interceptor.RolesInterceptor" />
            <interceptor name="jsonValidation" class="org.apache.struts2.interceptor.validation.JSONValidationInterceptor" />
            <interceptor name="annotationWorkflow" class="com.opensymphony.xwork2.interceptor.annotations.AnnotationWorkflowInterceptor" />

            <!-- Basic stack -->
            <interceptor-stack name="basicStack">
                <interceptor-ref name="exception"/>
                <interceptor-ref name="servletConfig"/>
                <interceptor-ref name="prepare"/>
                <interceptor-ref name="checkbox"/>
                <interceptor-ref name="params"/>
                <interceptor-ref name="conversionError"/>
            </interceptor-stack>

            <!-- Sample validation and workflow stack -->
            <interceptor-stack name="validationWorkflowStack">
                <interceptor-ref name="basicStack"/>
                <interceptor-ref name="validation"/>
                <interceptor-ref name="workflow"/>
            </interceptor-stack>
            
            <!-- Sample JSON validation stack -->
            <interceptor-stack name="jsonValidationWorkflowStack">
                <interceptor-ref name="basicStack"/>
                <interceptor-ref name="validation">
                    <param name="excludeMethods">input,back,cancel</param>
                </interceptor-ref>
                <interceptor-ref name="jsonValidation"/>
                <interceptor-ref name="workflow"/>
            </interceptor-stack>

            <!-- Sample file upload stack -->
            <interceptor-stack name="fileUploadStack">
                <interceptor-ref name="fileUpload"/>
                <interceptor-ref name="basicStack"/>
            </interceptor-stack>

            <!-- Sample model-driven stack  -->
            <interceptor-stack name="modelDrivenStack">
                <interceptor-ref name="modelDriven"/>
                <interceptor-ref name="basicStack"/>
            </interceptor-stack>

            <!-- Sample action chaining stack -->
            <interceptor-stack name="chainStack">
                <interceptor-ref name="chain"/>
                <interceptor-ref name="basicStack"/>
            </interceptor-stack>

            <!-- Sample i18n stack -->
            <interceptor-stack name="i18nStack">
                <interceptor-ref name="i18n"/>
                <interceptor-ref name="basicStack"/>
            </interceptor-stack>

            <!-- An example of the params-prepare-params trick. This stack
                 is exactly the same as the defaultStack, except that it
                 includes one extra interceptor before the prepare interceptor:
                 the params interceptor.

                 This is useful for when you wish to apply parameters directly
                 to an object that you wish to load externally (such as a DAO
                 or database or service layer), but can't load that object
                 until at least the ID parameter has been loaded. By loading
                 the parameters twice, you can retrieve the object in the
                 prepare() method, allowing the second params interceptor to
                 apply the values on the object. -->
            <interceptor-stack name="paramsPrepareParamsStack">
                <interceptor-ref name="exception"/>
                <interceptor-ref name="alias"/>
                <interceptor-ref name="params"/>
                <interceptor-ref name="servletConfig"/>
                <interceptor-ref name="prepare"/>
                <interceptor-ref name="i18n"/>
                <interceptor-ref name="chain"/>
                <interceptor-ref name="modelDriven"/>
                <interceptor-ref name="fileUpload"/>
                <interceptor-ref name="checkbox"/>
                <interceptor-ref name="staticParams"/>
                <interceptor-ref name="params"/>
                <interceptor-ref name="conversionError"/>
                <interceptor-ref name="validation">
                    <param name="excludeMethods">input,back,cancel</param>
                </interceptor-ref>
                <interceptor-ref name="workflow">
                    <param name="excludeMethods">input,back,cancel</param>
                </interceptor-ref>
            </interceptor-stack>

            <!-- A complete stack with all the common interceptors in place.
                 Generally, this stack should be the one you use, though it
                 may do more than you need. Also, the ordering can be
                 switched around (ex: if you wish to have your servlet-related
                 objects applied before prepare() is called, you'd need to move
                 servlet-config interceptor up.

                 This stack also excludes from the normal validation and workflow
                 the method names input, back, and cancel. These typically are
                 associated with requests that should not be validated.
                 -->
            <interceptor-stack name="defaultStack">
                <interceptor-ref name="exception"/>
                <interceptor-ref name="alias"/>
                <interceptor-ref name="servletConfig"/>
                <interceptor-ref name="prepare"/>
                <interceptor-ref name="i18n"/>
                <interceptor-ref name="chain"/>
                <interceptor-ref name="debugging"/>
                <interceptor-ref name="profiling"/>
                <interceptor-ref name="scopedModelDriven"/>
                <interceptor-ref name="modelDriven"/>
                <interceptor-ref name="fileUpload"/>
                <interceptor-ref name="checkbox"/>
                <interceptor-ref name="staticParams"/>
                <interceptor-ref name="params">
                  <param name="excludeParams">dojo\..*</param>
                </interceptor-ref>
                <interceptor-ref name="conversionError"/>
                <interceptor-ref name="validation">
                    <param name="excludeMethods">input,back,cancel,browse</param>
                </interceptor-ref>
                <interceptor-ref name="workflow">
                    <param name="excludeMethods">input,back,cancel,browse</param>
                </interceptor-ref>
            </interceptor-stack>

            <!-- The completeStack is here for backwards compatibility for
                 applications that still refer to the defaultStack by the
                 old name -->
            <interceptor-stack name="completeStack">
                <interceptor-ref name="defaultStack"/>
            </interceptor-stack>

            <!-- Sample execute and wait stack.
                 Note: execAndWait should always be the *last* interceptor. -->
            <interceptor-stack name="executeAndWaitStack">
                <interceptor-ref name="execAndWait">
                    <param name="excludeMethods">input,back,cancel</param>
                </interceptor-ref>
                <interceptor-ref name="defaultStack"/>
                <interceptor-ref name="execAndWait">
                    <param name="excludeMethods">input,back,cancel</param>
                </interceptor-ref>
            </interceptor-stack>

       </interceptors>

        <default-interceptor-ref name="defaultStack"/>
    </package>

</struts>

This file defines all of the default bundled results and interceptors and many interceptor stacks which you can use either as-is or as a basis for your own application-specific interceptor stacks. Notice the name of the package is "struts-default".
 ----------------------------------------------------------------------------------------------------------------------------------
struts-default.properties

All properties can also be set using Constant Configuration in an XML configuration file.
The framework uses a number of properties that can be changed to fit your needs. To change any of these properties, specify the property key and value in an struts.properties file. The properties file can be locate anywhere on the classpath, but it is typically found under /WEB-INF/class
The list of properties can be found in struts-default.properties (inside struts2.jar).

struts-default.properties

### Struts default properties
###(can be overridden by a struts.properties file in the root of the classpath)
###

### Specifies the Configuration used to configure Struts 
### one could extend org.apache.struts2.config.Configuration
### to build one's customize way of getting the configurations parameters into Struts
# struts.configuration=org.apache.struts2.config.DefaultConfiguration

### This can be used to set your default locale and encoding scheme
# struts.locale=en_US
struts.i18n.encoding=UTF-8

### if specified, the default object factory can be overridden here
### Note: short-hand notation is supported in some cases, such as "spring"
###       Alternatively, you can provide a com.opensymphony.xwork2.ObjectFactory subclass name here  
# struts.objectFactory = spring

### specifies the autoWiring logic when using the SpringObjectFactory.
### valid values are: name, type, auto, and constructor (name is the default)
struts.objectFactory.spring.autoWire = name

### indicates to the struts-spring integration if Class instances should be cached
### this should, until a future Spring release makes it possible, be left as true
### unless you know exactly what you are doing!
### valid values are: true, false (true is the default)
struts.objectFactory.spring.useClassCache = true

### if specified, the default object type determiner can be overridden here
### Note: short-hand notation is supported in some cases, such as "tiger" or "notiger"
###       Alternatively, you can provide a com.opensymphony.xwork2.util.ObjectTypeDeterminer implementation name here
### Note: By default, com.opensymphony.xwork2.util.DefaultObjectTypeDeterminer is used which handles type detection
###       using generics. com.opensymphony.xwork2.util.GenericsObjectTypeDeterminer was deprecated since XWork 2, it's
###       functions are integrated in DefaultObjectTypeDeterminer now.
###       To disable tiger support use the "notiger" property value here.
#struts.objectTypeDeterminer = tiger
#struts.objectTypeDeterminer = notiger

### Parser to handle HTTP POST requests, encoded using the MIME-type multipart/form-data
# struts.multipart.parser=cos
# struts.multipart.parser=pell
struts.multipart.parser=jakarta
# uses javax.servlet.context.tempdir by default
struts.multipart.saveDir=
struts.multipart.maxSize=2097152

### Load custom property files (does not override struts.properties!)
# struts.custom.properties=application,org/apache/struts2/extension/custom

### How request URLs are mapped to and from actions
#struts.mapper.class=org.apache.struts2.dispatcher.mapper.DefaultActionMapper

### Used by the DefaultActionMapper
### You may provide a comma separated list, e.g. struts.action.extension=action,jnlp,do
struts.action.extension=action

### Used by FilterDispatcher
### If true then Struts serves static content from inside its jar. 
### If false then the static content must be available at <context_path>/struts
struts.serve.static=true

### Used by FilterDispatcher
### This is good for development where one wants changes to the static content be
### fetch on each request. 
### NOTE: This will only have effect if struts.serve.static=true
### If true -> Struts will write out header for static contents such that they will
###             be cached by web browsers (using Date, Cache-Content, Pragma, Expires)
###             headers).
### If false -> Struts will write out header for static contents such that they are
###            NOT to be cached by web browser (using Cache-Content, Pragma, Expires
###            headers)
struts.serve.static.browserCache=true

### Set this to false if you wish to disable implicit dynamic method invocation
### via the URL request. This includes URLs like foo!bar.action, as well as params
### like method:bar (but not action:foo). 
### An alternative to implicit dynamic method invocation is to use wildcard 
### mappings, such as <action name="*/*" method="{2}" class="actions.{1}">
struts.enable.DynamicMethodInvocation = true

### Set this to true if you wish to allow slashes in your action names.  If false,
### Actions names cannot have slashes, and will be accessible via any directory
### prefix.  This is the traditional behavior expected of WebWork applications.
### Setting to true is useful when you want to use wildcards and store values
### in the URL, to be extracted by wildcard patterns, such as 
### <action name="*/*" method="{2}" class="actions.{1}"> to match "/foo/edit" or 
### "/foo/save".
struts.enable.SlashesInActionNames = false

### use alternative syntax that requires %{} in most places
### to evaluate expressions for String attributes for tags
struts.tag.altSyntax=true

### when set to true, Struts will act much more friendly for developers. This
### includes:
### - struts.i18n.reload = true
### - struts.configuration.xml.reload = true
### - raising various debug or ignorable problems to errors
###   For example: normally a request to foo.action?someUnknownField=true should
###                be ignored (given that any value can come from the web and it
###                should not be trusted). However, during development, it may be
###                useful to know when these errors are happening and be told of
###                them right away.
struts.devMode = false

### when set to true, resource bundles will be reloaded on _every_ request.
### this is good during development, but should never be used in production
struts.i18n.reload=false

### Standard UI theme
### Change this to reflect which path should be used for JSP control tag templates by default
struts.ui.theme=xhtml
struts.ui.templateDir=template
#sets the default template type. Either ftl, vm, or jsp
struts.ui.templateSuffix=ftl

### Configuration reloading
### This will cause the configuration to reload struts.xml when it is changed
struts.configuration.xml.reload=false

### Location of velocity.properties file.  defaults to velocity.properties
struts.velocity.configfile = velocity.properties

### Comma separated list of VelocityContext classnames to chain to the StrutsVelocityContext
struts.velocity.contexts =

### Location of the velocity toolbox
struts.velocity.toolboxlocation=

### used to build URLs, such as the UrlTag
struts.url.http.port = 80
struts.url.https.port = 443
### possible values are: none, get or all
struts.url.includeParams = get

### Load custom default resource bundles
# struts.custom.i18n.resources=testmessages,testmessages2

### workaround for some app servers that don't handle HttpServletRequest.getParameterMap()
### often used for WebLogic, Orion, and OC4J
struts.dispatcher.parametersWorkaround = false

### configure the Freemarker Manager class to be used
### Allows user to plug-in customised Freemarker Manager if necessary
### MUST extends off org.apache.struts2.views.freemarker.FreemarkerManager
#struts.freemarker.manager.classname=org.apache.struts2.views.freemarker.FreemarkerManager

### Enables caching of FreeMarker templates
### Has the same effect as copying the templates under WEB_APP/templates
struts.freemarker.templatesCache=false

### Enables caching of models on the BeanWrapper
struts.freemarker.beanwrapperCache=false

### See the StrutsBeanWrapper javadocs for more information
struts.freemarker.wrapper.altMap=true

### configure the XSLTResult class to use stylesheet caching.
### Set to true for developers and false for production.
struts.xslt.nocache=false

### A list of configuration files automatically loaded by Struts
struts.configuration.files=struts-default.xml,struts-plugin.xml,struts.xml

### Whether to always select the namespace to be everything before the last slash or not
struts.mapper.alwaysSelectFullNamespace=false

Result Types in struts 2.0

The dispatcher result type:

The dispatcher result type is the default type, and is used if no other result type is specified. It's used to forward to a servlet, JSP, HTML page, and so on, on the server. It uses the RequestDispatcher.forward() method.
We saw the "shorthand" version in our earlier examples, where we provided a JSP path as the body of the result tag.

<result name="success"> /HelloWorld.jsp </result>

We can also specify the JSP file using a <param name="location"> tag within the <result...> element as follows:

<result name="success" type="dispatcher">
   <param name="location">
      /HelloWorld.jsp
   </param >
</result>

The redirect result type:

The redirect result type calls the standard response.sendRedirect() method, causing the browser to create a new request to the given location.
We can provide the location either in the body of the <result...> element or as a <param name="location"> element. Redirect also supports the parse parameter. Here's an example configured using XML:
<action name="hello" class="com.tutorialspoint.struts2.HelloWorldAction" method="execute"> <result name="success" type="redirect"> <param name="location"> /NewWorld.jsp </param > </result> </action>

 Some more result type defined in default configirution is given as :

<package name="struts-default" abstract="true">
        <result-types>
            <result-type name="chain" class="com.opensymphony.xwork2.ActionChainResult"/>
            <result-type name="dispatcher" class="org.apache.struts2.dispatcher.ServletDispatcherResult" default="true"/>
            <result-type name="freemarker" class="org.apache.struts2.views.freemarker.FreemarkerResult"/>
            <result-type name="httpheader" class="org.apache.struts2.dispatcher.HttpHeaderResult"/>
            <result-type name="redirect" class="org.apache.struts2.dispatcher.ServletRedirectResult"/>
            <result-type name="redirectAction" class="org.apache.struts2.dispatcher.ServletActionRedirectResult"/>
            <result-type name="stream" class="org.apache.struts2.dispatcher.StreamResult"/>
            <result-type name="velocity" class="org.apache.struts2.dispatcher.VelocityResult"/>
            <result-type name="xslt" class="org.apache.struts2.views.xslt.XSLTResult"/>
            <result-type name="plainText" class="org.apache.struts2.dispatcher.PlainTextResult" />
        </result-types>

difference in redirect and forward

A Controller servlet can conclude either a forward or a redirect operation at the end of processing a request

RequestDispatcher vs sendRedirect

A Controller servlet can conclude either a forward or a redirect operation at the end of processing a request. Here are the basic differences between a requestDispatcher's forward() and sendRedirect() of the ServletResponse interface.

Forward

Since forward() method of RequestDispatcher is handled on the server , therefore the request and its associated session are available to the forwarded resource and you can pass data between them using request.setAttribute(). forward() separates the responsibilities for handling the requests among several components. This method generally sends a request and response object to resources (servlets or JSP's) of the same ServletContext. You can also decide to forward to one page in one condition and a different page in another. RequestDispatcher  transfers control immediately whenever the forward() method is called to the resource referenced by the RequestDispatcher.

sendRedirect
sendRedirect() method of a response object sends the url  to the browser that includes the parameter of sendRedirect() method Browser treats this a new request from the client. sendRedirect() forwards a requests to a resource outside of the current web application. Using sendRedirect is similar to open a new browser and type your url. A sendRedirect() also updates the browser history and transfers control only when the whole service method completes. There is only one way to pass data is through the session or using web parameters (url?name=value).

Note: Here are some more concepts that we must know:

• RequestDispatcher.forward() and PageContext.forward() are effectively the same. PageContext.forward is a helper method that calls the RequestDispatcher method.
• When you invoke RequestDispatcher.include(), the servlet engine transfers control of this HTTP request internally from your current servlet or JSP to another servlet or JSP or static file, while invoking response.sendRedirect() method sends an HTTP response to the browser to make another request at a different URL. In big applications, instead of forwarding to another servlet we generally use beans. Beans check a form, formats the response and returns to the servlet.

Action Interface implemented by ActionSupport class

Optionally you can extend the ActionSupport class which implements six interfaces including Action interface. The Action interface is as follows:

public interface Action {
   public static final String SUCCESS = "success";
   public static final String NONE = "none";
   public static final String ERROR = "error";
   public static final String INPUT = "input";
   public static final String LOGIN = "login";
   public String execute() throws Exception;
}