org.milyn.validation.Validator Maven / Gradle / Ivy
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/*
* Milyn - Copyright (C) 2006 - 2010
*
* This library is free software; you can redistribute it and/or modify it under
* the terms of the GNU Lesser General Public License (version 2.1) as published
* by the Free Software Foundation.
*
* This library is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE.
*
* See the GNU Lesser General Public License for more details:
* http://www.gnu.org/licenses/lgpl.txt
*/
package org.milyn.validation;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.milyn.SmooksException;
import org.milyn.cdr.SmooksConfigurationException;
import org.milyn.cdr.SmooksResourceConfiguration;
import org.milyn.cdr.annotation.AppContext;
import org.milyn.cdr.annotation.Config;
import org.milyn.cdr.annotation.ConfigParam;
import org.milyn.container.ApplicationContext;
import org.milyn.container.ExecutionContext;
import org.milyn.delivery.annotation.Initialize;
import org.milyn.delivery.dom.DOMVisitAfter;
import org.milyn.delivery.sax.SAXElement;
import org.milyn.delivery.sax.SAXUtil;
import org.milyn.delivery.sax.SAXVisitAfter;
import org.milyn.delivery.sax.SAXVisitBefore;
import org.milyn.event.report.annotation.VisitAfterReport;
import org.milyn.event.report.annotation.VisitBeforeReport;
import org.milyn.payload.FilterResult;
import org.milyn.resource.URIResourceLocator;
import org.milyn.rules.RuleEvalResult;
import org.milyn.rules.RuleProvider;
import org.milyn.rules.RuleProviderAccessor;
import org.milyn.util.FreeMarkerTemplate;
import org.milyn.xml.DomUtils;
import org.w3c.dom.Element;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.util.*;
/**
*
*
* A Validator uses a predefined Rule that performs the actual validator for a Validator. This way a Validator does not know
* about the technology used for the validation and users can mix and max different rules as appropriate to the use case they
* have. For example, one problem might be solve nicely with a regular expression but another might be easier to sovle using
* a MVEL expression.
*
* Example configuration:
* {@code
*
*
*
*
* Options:
*
* - on
* The fragement that the validation will be performed upon.
*
* - rule
* Is the name of a previously defined in a rules element. The rule itself is identified by ruleProviderName.ruleName.
* So taking the above example addressing is the ruleProviderName and email is the rule name. In this case email
* identifies a regular expression but if you were to change the provider that might change and a differnet technology
* could be used to validate an email address.
*
* - onFail
* The onFail attribute in the validation configuration specified what action should be taken when a rule matches.
* This is all about reporting back valdiation failures.
*
*
*
*
* @author Daniel Bevenius
*
*/
@VisitBeforeReport(condition = "false")
@VisitAfterReport(summary = "Applied validation rule '${resource.parameters.name}'.")
public final class Validator implements SAXVisitBefore, SAXVisitAfter, DOMVisitAfter
{
private static Log logger = LogFactory.getLog(Validator.class);
/**
* The name of the rule that will be used by this validator.
*/
private String compositRuleName;
/**
* Rule provider name.
*/
private String ruleProviderName;
/**
* Rule name.
*/
private String ruleName;
/**
* Rule provider for this validator.
*/
private RuleProvider ruleProvider;
/**
* The validation failure level. Default is OnFail.ERROR.
*/
private OnFail onFail = OnFail.ERROR;
/**
* The Smooks {@link ApplicationContext}.
*/
@AppContext
private ApplicationContext appContext;
/**
* Config.
*/
@Config
private SmooksResourceConfiguration config;
/**
* Attribute name if the validation target is an attribute, otherwise null.
*/
private String targetAttribute;
/**
* Message bundle name for the ruleset.
*/
private String messageBundleBaseName;
/**
* The maximum number of failures permitted per {@link ValidationResult} instance..
*/
private int maxFails;
/**
* No-args constructor required by Smooks.
*/
public Validator() {}
/**
* Initialize the visitor instance.
*/
@Initialize
public void initialize() {
targetAttribute = config.getTargetAttribute();
}
/**
* Public constructor.
* @param compositRuleName The name of the rule that will be used by this validator.
* @param onFail The failure level.
*/
public Validator(final String compositRuleName, final OnFail onFail)
{
setCompositRuleName(compositRuleName);
this.onFail = onFail;
}
public void visitBefore(final SAXElement element, final ExecutionContext executionContext) throws SmooksException
{
if(targetAttribute == null) {
// The selected text is not an attribute, which means it's the element text,
// which means we need to turn on text accumulation for SAX...
element.accumulateText();
}
}
public void visitAfter(final SAXElement element, final ExecutionContext executionContext) throws SmooksException
{
if(targetAttribute != null) {
OnFailResultImpl result = _validate(element.getAttribute(targetAttribute), executionContext);
if(result != null) {
result.setFailFragmentPath(SAXUtil.getXPath(element) + "/@" + targetAttribute);
assertValidationException(result, executionContext);
}
} else {
OnFailResultImpl result = _validate(element.getTextContent(), executionContext);
if(result != null) {
result.setFailFragmentPath(SAXUtil.getXPath(element));
assertValidationException(result, executionContext);
}
}
}
public void visitAfter(final Element element, final ExecutionContext executionContext) throws SmooksException
{
if(targetAttribute != null) {
OnFailResultImpl result = _validate(element.getAttribute(targetAttribute), executionContext);
if(result != null) {
result.setFailFragmentPath(DomUtils.getXPath(element) + "/@" + targetAttribute);
assertValidationException(result, executionContext);
}
} else {
OnFailResultImpl result = _validate(element.getTextContent(), executionContext);
if(result != null) {
result.setFailFragmentPath(DomUtils.getXPath(element));
assertValidationException(result, executionContext);
}
}
}
private void assertValidationException(OnFailResultImpl result, ExecutionContext executionContext) {
if (onFail == OnFail.FATAL) {
throw new ValidationException("A FATAL validation failure has occured " + result, result);
}
ValidationResult validationResult = getValidationResult(executionContext);
if(validationResult != null && validationResult.getNumFailures() > maxFails) {
throw new ValidationException("The maximum number of allowed validation failures (" + maxFails + ") has been exceeded.", result);
}
}
/**
* Validate will lookup the configured RuleProvider and validate the text against the
* rule specfied by the composite rule name.
*
* @param text The selected data to perform the evaluation on.
* @param executionContext The Smooks {@link org.milyn.container.ExecutionContext}.
*
* @throws ValidationException A FATAL Validation failure has occured, or the maximum number of
* allowed failures has been exceeded.
*/
void validate(final String text, final ExecutionContext executionContext) throws ValidationException
{
OnFailResultImpl result = _validate(text, executionContext);
if(result != null) {
assertValidationException(result, executionContext);
}
}
/**
* Validate will lookup the configured RuleProvider and validate the text against the
* rule specfied by the composite rule name.
*
* @param text The selected data to perform the evaluation on.
* @param executionContext The Smooks {@link org.milyn.container.ExecutionContext}.
*
* @throws ValidationException A FATAL Validation failure has occured, or the maximum number of
* allowed failures has been exceeded.
*/
private OnFailResultImpl _validate(final String text, final ExecutionContext executionContext) throws ValidationException
{
if(ruleProvider == null) {
setRuleProvider(executionContext);
}
final RuleEvalResult result = ruleProvider.evaluate(ruleName, text, executionContext);
if(logger.isDebugEnabled()) {
logger.debug(result);
}
if (!result.matched())
{
ValidationResult validationResult = getValidationResult(executionContext);
OnFailResultImpl onFailResult = new OnFailResultImpl();
onFailResult.setRuleResult(result);
onFailResult.setBeanContext(executionContext.getBeanContext().getBeanMap());
validationResult.addResult(onFailResult, onFail);
return onFailResult;
}
return null;
}
private ValidationResult getValidationResult(ExecutionContext executionContext) {
ValidationResult validationResult = (ValidationResult) FilterResult.getResult(executionContext, ValidationResult.class);
// Create a new ValidationResult if one was not available in the execution context.
// This would be the case for example if one as not specified to Smooks filter method.
if (validationResult == null) {
validationResult = new ValidationResult();
}
return validationResult;
}
private synchronized void setRuleProvider(ExecutionContext executionContext) {
if(ruleProvider != null) {
return;
}
ruleProvider = RuleProviderAccessor.get(appContext, ruleProviderName);
if(ruleProvider == null) {
throw new SmooksException("Unknown rule provider '" + ruleProviderName + "'.");
}
// Configure the base bundle name for validation failure messages...
setMessageBundleBaseName();
// Configure the maxFails per ValidationResult instance...
String maxFailsConfig = executionContext.getConfigParameter(OnFailResult.MAX_FAILS);
if(maxFailsConfig != null) {
try {
maxFails = Integer.parseInt(maxFailsConfig.trim());
} catch(NumberFormatException e) {
throw new SmooksConfigurationException("Invalid config value '" + maxFailsConfig.trim() + "' for global parameter '" + OnFailResult.MAX_FAILS + "'. Must be a valid Integer value.");
}
} else {
maxFails = Integer.MAX_VALUE;
}
}
private void setMessageBundleBaseName() {
String ruleSource = ruleProvider.getSrc();
File srcFile = new File(ruleSource);
String srcFileName = srcFile.getName();
int indexOfExt = srcFileName.lastIndexOf('.');
File parentFolder = srcFile.getParentFile();
if(indexOfExt != -1) {
messageBundleBaseName = srcFileName.substring(0, indexOfExt);
} else {
messageBundleBaseName = ruleSource;
}
if(parentFolder != null) {
messageBundleBaseName = parentFolder.getPath() + "/i18n/" + messageBundleBaseName;
} else {
messageBundleBaseName = "i18n/" + messageBundleBaseName;
}
messageBundleBaseName = messageBundleBaseName.replace('\\', '/');
}
@Override
public String toString()
{
return String.format("%s [rule=%s, onFail=%s]", getClass().getSimpleName(), compositRuleName, onFail);
}
@ConfigParam (name="name")
public void setCompositRuleName(final String compositRuleName)
{
this.compositRuleName = compositRuleName;
this.ruleProviderName = RuleProviderAccessor.parseRuleProviderName(compositRuleName);
this.ruleName = RuleProviderAccessor.parseRuleName(compositRuleName);
}
public String getCompositRuleName()
{
return compositRuleName;
}
@ConfigParam (defaultVal = "ERROR")
public void setOnFail(final OnFail onFail)
{
this.onFail = onFail;
}
public OnFail getOnFail()
{
return onFail;
}
public Validator setAppContext(ApplicationContext appContext) {
this.appContext = appContext;
return this;
}
private class OnFailResultImpl implements OnFailResult {
private String failFragmentPath;
private RuleEvalResult ruleResult;
public Map beanContext;
public void setFailFragmentPath(String failFragmentPath) {
this.failFragmentPath = failFragmentPath;
}
public String getFailFragmentPath() {
return failFragmentPath;
}
public void setRuleResult(RuleEvalResult ruleResult) {
this.ruleResult = ruleResult;
}
public RuleEvalResult getFailRuleResult() {
return ruleResult;
}
public void setBeanContext(Map beanContext) {
// Need to create a shallow copy as the context data may change.
// Even this is not foolproof, as internal bean data can also be
// overwritten by the bean context!!
this.beanContext = new HashMap();
this.beanContext.putAll(beanContext);
}
public String getMessage() {
return getMessage(Locale.getDefault());
}
public String getMessage(Locale locale) {
if(ruleResult.getEvalException() != null) {
return ruleResult.getEvalException().getMessage();
}
String message = getMessage(locale, ruleName);
// If no ResouceBundle was configured then use this instances toString
if (message == null) {
return toString();
}
if (message.startsWith("ftl:")) {
// TODO: Is there a way to optimize this e.g. attach the compiled template
// to the bundle as an object and then get back using ResourceBundle.getObject??
// I timed it and it was able to create and apply 10000 templates in about 2500 ms
// on an "average" spec machine, so it's not toooooo bad, and it's only done on demand :)
FreeMarkerTemplate template = new FreeMarkerTemplate(message.substring("ftl:".length()));
beanContext.put("ruleResult", ruleResult);
beanContext.put("path", failFragmentPath);
message = template.apply(beanContext);
}
return message;
}
private String getMessage(final Locale locale, final String messageName) {
final ResourceBundle bundle = getMessageBundle(locale);
if (messageName == null || bundle == null)
return null;
return bundle.getString(messageName);
}
/**
* @param locale The Locale to look up.
* @return {@link ResourceBundle} for the Locale and message bundle base name. Or null if no bundle exists.
*/
private ResourceBundle getMessageBundle(final Locale locale) {
try {
return ResourceBundle.getBundle(messageBundleBaseName, locale, new ResourceBundleClassLoader());
} catch (final MissingResourceException e) {
logger.warn("Failed to load Validation rule message bundle '" + messageBundleBaseName + "'. This resource must be on the classpath!", e);
}
return null;
}
@Override
public String toString() {
return "[" + failFragmentPath + "] " + ruleResult.toString();
}
}
private class ResourceBundleClassLoader extends ClassLoader {
@Override
public InputStream getResourceAsStream(String name) {
try {
return new URIResourceLocator().getResource(name);
} catch (IOException e) {
return null;
}
}
}
}