com.xceptance.xlt.api.validators.HtmlEndTagValidator Maven / Gradle / Ivy

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XLT (Xceptance LoadTest) is an extensive load and performance test tool developed and maintained by Xceptance.
There is a newer version: 8.1.0
/*
 * Copyright (c) 2005-2022 Xceptance Software Technologies GmbH
 *
 * Licensed 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.
 */
package com.xceptance.xlt.api.validators;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.junit.Assert;

import com.gargoylesoftware.htmlunit.html.HtmlPage;
import com.xceptance.xlt.api.htmlunit.LightWeightPage;
import com.xceptance.xlt.api.util.XltLogger;

/**
 * Checks that a page has at least one closing HTML tag. Does not check, that this tag is the only one. It uses a
 * regular expression.
 * 
 * HTML comments are permitted after the closing HTML tag. Anything else will be logged as warning.
 * 
 * 
 * It also assumes a lower-case closing HTML tag according to the HTML/XHTML standard.
 * 
 * 
 * @author René Schwietzke (Xceptance Software Technologies GmbH)
 */
public class HtmlEndTagValidator
{
    /**
     * Regular expression that matches the closing HTML tag followed by any content.
     */
    private static final String CL_HTML_REGEX = "(?ism)(\\s|)*(.*)$";
/**
* Regular expression used to check for regular trailing content.
*/
private static final String REGULAR_TRAILING_CONTENT_REGEX = "(?sm)(\\s|)*";
/**
* The pattern to be use on the page.
*/
private final Pattern pattern;
/**
* Pattern used to check for regular trailing content.
*/
private final Pattern trailingContentPattern;
/**
* Constructor.
* 
* Declared as private to prevent external instantiation.
* 
*/
private HtmlEndTagValidator()
{
pattern = Pattern.compile(CL_HTML_REGEX);
trailingContentPattern = Pattern.compile(REGULAR_TRAILING_CONTENT_REGEX);
}
/**
* Validates the specified HTML page.
*
* @param page
* the page to check
* @throws AssertionError
* if the page fails validation
*/
public void validate(final HtmlPage page)
{
final String content = page.getWebResponse().getContentAsString();
validate(content);
}
/**
* Validates the specified lightweight HTML page.
*
* @param page
* the page to check
* @throws AssertionError
* if the page fails validation
*/
public void validate(final LightWeightPage page)
{
final String content = page.getContent();
validate(content);
}
/**
* The validation as plain string method to be tested and used independently from the page.
*
* @param content
* a snippet of HTML code to be checked
*/
public void validate(final String content)
{
// parameter validation
Assert.assertNotNull("The page content is null", content);
Assert.assertTrue("The page is empty", content.length() > 0);
// try a small size first to save time
final String truncated = content.substring((int) (content.length() * 0.90));
Matcher matcher = pattern.matcher(truncated);
if (!matcher.find())
{
// try the long version
matcher = pattern.matcher(content);
Assert.assertTrue("html endtag not found", matcher.find());
}
final String trailingContent = matcher.group(2);
matcher = trailingContentPattern.matcher(trailingContent);
if (!matcher.matches())
{
XltLogger.runTimeLogger.warn("Only whitespace and XML comments are allowed after closing HTML tag.");
}
}
/**
* Returns the singleton instance.
*
* @return the singleton instance
*/
public static HtmlEndTagValidator getInstance()
{
return HtmlEndTagValidator_Singleton.instance;
}
/**
* Singleton implementation of {@link HtmlEndTagValidator}.
*/
private static class HtmlEndTagValidator_Singleton
{
/**
* Singleton instance.
*/
private static final HtmlEndTagValidator instance;
// static initializer (synchronized by class loader)
static
{
instance = new HtmlEndTagValidator();
}
}
}