ValidationInterceptor.java
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* distributed with this work for additional information
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* to you under the Apache License, Version 2.0 (the
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*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
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* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
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*/
package org.apache.struts2.validator;
import org.apache.struts2.ActionInvocation;
import org.apache.struts2.ActionProxy;
import org.apache.struts2.Validateable;
import org.apache.struts2.inject.Inject;
import org.apache.struts2.interceptor.MethodFilterInterceptor;
import org.apache.struts2.interceptor.PrefixMethodInvocationUtil;
import org.apache.struts2.interceptor.ValidationAware;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
/**
* <!-- START SNIPPET: description -->
*
* <p>
* This interceptor runs the action through the standard validation framework, which in turn checks the action against
* any validation rules (found in files such as <i>ActionClass-validation.xml</i>) and adds field-level and action-level
* error messages (provided that the action implements {@link ValidationAware}). This interceptor
* is often one of the last (or second to last) interceptors applied in a stack, as it assumes that all values have
* already been set on the action.
* </p>
*
* <p>
* This interceptor does nothing if the name of the method being invoked is specified in the <b>excludeMethods</b>
* parameter. <b>excludeMethods</b> accepts a comma-delimited list of method names. For example, requests to
* <b>foo!input.action</b> and <b>foo!back.action</b> will be skipped by this interceptor if you set the
* <b>excludeMethods</b> parameter to "input, back".
* </p>
*
* <p>
* The workflow of the action request does not change due to this interceptor. Rather,
* this interceptor is often used in conjunction with the <b>workflow</b> interceptor.
* </p>
*
* <p>
* <b>NOTE:</b> As this method extends off MethodFilterInterceptor, it is capable of
* deciding if it is applicable only to selective methods in the action class. See
* <code>MethodFilterInterceptor</code> for more info.
* </p>
*
* <!-- END SNIPPET: description -->
*
* <p><u>Interceptor parameters:</u></p>
*
* <!-- START SNIPPET: parameters -->
*
* <ul>
*
* <li>alwaysInvokeValidate - Defaults to true. If true validate() method will always
* be invoked, otherwise it will not.</li>
*
* <li>programmatic - Defaults to true. If true and the action is Validateable call validate(),
* and any method that starts with "validate".
* </li>
*
* <li>declarative - Defaults to true. Perform validation based on xml or annotations.</li>
*
* </ul>
*
* <!-- END SNIPPET: parameters -->
*
* <p><u>Extending the interceptor:</u></p>
*
* <!-- START SNIPPET: extending -->
*
* There are no known extension points for this interceptor.
*
* <!-- END SNIPPET: extending -->
*
* <p><u>Example code:</u></p>
*
* <pre>
* <!-- START SNIPPET: example -->
*
* <action name="someAction" class="com.examples.SomeAction">
* <interceptor-ref name="params"/>
* <interceptor-ref name="validation"/>
* <interceptor-ref name="workflow"/>
* <result name="success">good_result.ftl</result>
* </action>
*
* <-- in the following case myMethod of the action class will not
* get validated -->
* <action name="someAction" class="com.examples.SomeAction">
* <interceptor-ref name="params"/>
* <interceptor-ref name="validation">
* <param name="excludeMethods">myMethod</param>
* </interceptor-ref>
* <interceptor-ref name="workflow"/>
* <result name="success">good_result.ftl</result>
* </action>
*
* <-- in the following case only annotated methods of the action class will
* be validated -->
* <action name="someAction" class="com.examples.SomeAction">
* <interceptor-ref name="params"/>
* <interceptor-ref name="validation">
* <param name="validateAnnotatedMethodOnly">true</param>
* </interceptor-ref>
* <interceptor-ref name="workflow"/>
* <result name="success">good_result.ftl</result>
* </action>
*
*
* <!-- END SNIPPET: example -->
* </pre>
*
* @author Jason Carreira
* @author Rainer Hermanns
* @author <a href='mailto:the_mindstorm[at]evolva[dot]ro'>Alexandru Popescu</a>
* @see ActionValidatorManager
* @see org.apache.struts2.interceptor.DefaultWorkflowInterceptor
*/
public class ValidationInterceptor extends MethodFilterInterceptor {
private static final Logger LOG = LogManager.getLogger(ValidationInterceptor.class);
private final static String VALIDATE_PREFIX = "validate";
private final static String ALT_VALIDATE_PREFIX = "validateDo";
private boolean validateAnnotatedMethodOnly;
private ActionValidatorManager actionValidatorManager;
private boolean alwaysInvokeValidate = true;
private boolean programmatic = true;
private boolean declarative = true;
@Inject
public void setActionValidatorManager(ActionValidatorManager mgr) {
this.actionValidatorManager = mgr;
}
/**
* Determines if {@link Validateable}'s <code>validate()</code> should be called,
* as well as methods whose name that start with "validate". Defaults to "true".
*
* @param programmatic <tt>true</tt> then <code>validate()</code> is invoked.
*/
public void setProgrammatic(boolean programmatic) {
this.programmatic = programmatic;
}
/**
* Determines if validation based on annotations or xml should be performed. Defaults
* to "true".
*
* @param declarative <tt>true</tt> then perform validation based on annotations or xml.
*/
public void setDeclarative(boolean declarative) {
this.declarative = declarative;
}
/**
* Determines if {@link Validateable}'s <code>validate()</code> should always
* be invoked. Default to "true".
*
* @param alwaysInvokeValidate <tt>true</tt> then <code>validate()</code> is always invoked.
*/
public void setAlwaysInvokeValidate(String alwaysInvokeValidate) {
this.alwaysInvokeValidate = Boolean.parseBoolean(alwaysInvokeValidate);
}
/**
* Gets if <code>validate()</code> should always be called or only per annotated method.
*
* @return <tt>true</tt> to only validate per annotated method, otherwise <tt>false</tt> to always validate.
*/
public boolean isValidateAnnotatedMethodOnly() {
return validateAnnotatedMethodOnly;
}
/**
* Determine if <code>validate()</code> should always be called or only per annotated method.
* Default to <tt>false</tt>.
*
* @param validateAnnotatedMethodOnly <tt>true</tt> to only validate per annotated method, otherwise <tt>false</tt> to always validate.
*/
public void setValidateAnnotatedMethodOnly(boolean validateAnnotatedMethodOnly) {
this.validateAnnotatedMethodOnly = validateAnnotatedMethodOnly;
}
/**
* Gets the current action and its context and delegates to {@link ActionValidatorManager} proper validate method.
*
* @param invocation the execution state of the Action.
* @throws Exception if an error occurs validating the action.
*/
protected void doBeforeInvocation(ActionInvocation invocation) throws Exception {
Object action = invocation.getAction();
ActionProxy proxy = invocation.getProxy();
//the action name has to be from the url, otherwise validators that use aliases, like
//MyActio-someaction-validator.xml will not be found, see WW-3194
//UPDATE: see WW-3753
String context = this.getValidationContext(proxy);
String method = proxy.getMethod();
if (LOG.isDebugEnabled()) {
LOG.debug("Validating {}/{} with method {}.", invocation.getProxy().getNamespace(), invocation.getProxy().getActionName(), method);
}
if (declarative) {
if (validateAnnotatedMethodOnly) {
actionValidatorManager.validate(action, context, method);
} else {
actionValidatorManager.validate(action, context);
}
}
if (action instanceof Validateable && programmatic) {
// keep exception that might occured in validateXXX or validateDoXXX
Exception exception = null;
Validateable validateable = (Validateable) action;
LOG.debug("Invoking validate() on action {}", validateable);
try {
PrefixMethodInvocationUtil.invokePrefixMethod(invocation, new String[]{VALIDATE_PREFIX, ALT_VALIDATE_PREFIX});
}
catch(Exception e) {
// If any exception occurred while doing reflection, we want
// validate() to be executed
LOG.warn("an exception occured while executing the prefix method", e);
exception = e;
}
if (alwaysInvokeValidate) {
validateable.validate();
}
if (exception != null) {
// rethrow if something is wrong while doing validateXXX / validateDoXXX
throw exception;
}
}
}
@Override
protected String doIntercept(ActionInvocation invocation) throws Exception {
doBeforeInvocation(invocation);
return invocation.invoke();
}
/**
* <p>
* Returns the context that will be used by the
* {@link ActionValidatorManager} to associate the action invocation with
* the appropriate {@link ValidatorConfig ValidatorConfigs}.
* </p>
*
* <p>
* The context returned is used in the pattern
* <i>ActionClass-context-validation.xml</i>
* </p>
*
* <p>
* The default context is the action name from the URL, but the method can
* be overridden to implement custom contexts.
* </p>
*
* <p>
* This can be useful in cases in which a single action and a single model
* require vastly different validation based on some condition.
* </p>
*
* @param proxy action proxy
* @return the context (action name)
*/
protected String getValidationContext(ActionProxy proxy) {
// This method created for WW-3753
return proxy.getActionName();
}
}