jetty-jspc-maven-plugin/src/main/java/org/eclipse/jetty/jspc/plugin/JspcMojo.java - jetty - Git at Google

 //
 //  ========================================================================
 //  Copyright (c) 1995-2017 Mort Bay Consulting Pty. Ltd.
 //  ------------------------------------------------------------------------
 //  All rights reserved. This program and the accompanying materials
 //  are made available under the terms of the Eclipse Public License v1.0
 //  and Apache License v2.0 which accompanies this distribution.
 //
 //      The Eclipse Public License is available at
 //      http://www.eclipse.org/legal/epl-v10.html
 //
 //      The Apache License v2.0 is available at
 //      http://www.opensource.org/licenses/apache2.0.php
 //
 //  You may elect to redistribute this code under either of these licenses.
 //  ========================================================================
 //

 package org.eclipse.jetty.jspc.plugin;

 import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileFilter;
 import java.io.FileReader;
 import java.io.FileWriter;
 import java.io.IOException;
 import java.io.PrintWriter;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.URLClassLoader;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Set;

 import org.apache.jasper.JspC;
 import org.apache.jasper.servlet.JspCServletContext;
 import org.apache.jasper.servlet.TldScanner;
 import org.apache.maven.artifact.Artifact;
 import org.apache.maven.plugin.AbstractMojo;
 import org.apache.maven.plugin.MojoExecutionException;
 import org.apache.maven.plugin.MojoFailureException;
 import org.apache.maven.project.MavenProject;
 import org.apache.tomcat.JarScanner;
 import org.apache.tomcat.util.scan.StandardJarScanner;
 import org.codehaus.plexus.util.FileUtils;
 import org.codehaus.plexus.util.StringUtils;
 import org.eclipse.jetty.util.IO;
 import org.eclipse.jetty.util.resource.Resource;

 /**
  * This goal will compile jsps for a webapp so that they can be included in a
  * war.
  * <p>
  * At runtime, the plugin will use the jspc compiler to precompile jsps and tags.
  * </p>
  * <p>
  * Note that the same java compiler will be used as for on-the-fly compiled
  * jsps, which will be the Eclipse java compiler.
  * <p>
  * See <a
  * href="https://www.eclipse.org/jetty/documentation/current/jetty-jspc-maven-plugin.html">Usage
  * Guide</a> for instructions on using this plugin.
  * </p>
  * @goal jspc
  * @phase process-classes
  * @requiresDependencyResolution compile+runtime
  * @description Runs jspc compiler to produce .java and .class files
  */
 public class JspcMojo extends AbstractMojo
 {
     public static final String END_OF_WEBAPP = "</web-app>";
     public static final String PRECOMPILED_FLAG = "org.eclipse.jetty.jsp.precompiled";


     /**
      * JettyJspC
      *
      * Add some extra setters to standard JspC class to help configure it
      * for running in maven.
      *
      * TODO move all setters on the plugin onto this jspc class instead.
      */
     public static class JettyJspC extends JspC
     {

         private boolean scanAll;

         public void setClassLoader (ClassLoader loader)
         {
             this.loader = loader;
         }

        public void setScanAllDirectories (boolean scanAll)
        {
            this.scanAll = scanAll;
        }

        public boolean getScanAllDirectories ()
        {
            return this.scanAll;
        }


         @Override
         protected TldScanner newTldScanner(JspCServletContext context, boolean namespaceAware, boolean validate, boolean blockExternal)
         {
             if (context != null && context.getAttribute(JarScanner.class.getName()) == null)
             {
                 StandardJarScanner jarScanner = new StandardJarScanner();
                 jarScanner.setScanAllDirectories(getScanAllDirectories());
                 context.setAttribute(JarScanner.class.getName(), jarScanner);
             }

             return super.newTldScanner(context, namespaceAware, validate, blockExternal);
         }
     }


     /**
      * Whether or not to include dependencies on the plugin's classpath with &lt;scope&gt;provided&lt;/scope&gt;
      * Use WITH CAUTION as you may wind up with duplicate jars/classes.
      *
      * @since jetty-7.6.3
      * @parameter  default-value="false"
      */
     private boolean useProvidedScope;

     /**
      * The artifacts for the project.
      *
      * @since jetty-7.6.3
      * @parameter default-value="${project.artifacts}"
      * @readonly
      */
     private Set projectArtifacts;


     /**
      * The maven project.
      *
      * @parameter default-value="${project}"
      * @required
      * @readonly
      */
     private MavenProject project;


     /**
      * The artifacts for the plugin itself.
      *
      * @parameter default-value="${plugin.artifacts}"
      * @readonly
      */
     private List pluginArtifacts;


     /**
      * File into which to generate the &lt;servlet&gt; and
      * &lt;servlet-mapping&gt; tags for the compiled jsps
      *
      * @parameter default-value="${basedir}/target/webfrag.xml"
      */
     private String webXmlFragment;

     /**
      * Optional. A marker string in the src web.xml file which indicates where
      * to merge in the generated web.xml fragment. Note that the marker string
      * will NOT be preserved during the insertion. Can be left blank, in which
      * case the generated fragment is inserted just before the &lt;/web-app&gt;
      * line
      *
      * @parameter
      */
     private String insertionMarker;

     /**
      * Merge the generated fragment file with the web.xml from
      * webAppSourceDirectory. The merged file will go into the same directory as
      * the webXmlFragment.
      *
      * @parameter default-value="true"
      */
     private boolean mergeFragment;

     /**
      * The destination directory into which to put the compiled jsps.
      *
      * @parameter default-value="${project.build.outputDirectory}"
      */
     private String generatedClasses;

     /**
      * Controls whether or not .java files generated during compilation will be
      * preserved.
      *
      * @parameter default-value="false"
      */
     private boolean keepSources;


     /**
      * Root directory for all html/jsp etc files
      *
      * @parameter default-value="${basedir}/src/main/webapp"
      *
      */
     private String webAppSourceDirectory;


     /**
      * Location of web.xml. Defaults to src/main/webapp/web.xml.
      * @parameter default-value="${basedir}/src/main/webapp/WEB-INF/web.xml"
      */
     private String webXml;


     /**
      * The comma separated list of patterns for file extensions to be processed. By default
      * will include all .jsp and .jspx files.
      *
      * @parameter default-value="**\/*.jsp, **\/*.jspx"
      */
     private String includes;

     /**
      * The comma separated list of file name patters to exclude from compilation.
      *
      * @parameter default_value="**\/.svn\/**";
      */
     private String excludes;

     /**
      * The location of the compiled classes for the webapp
      *
      * @parameter default-value="${project.build.outputDirectory}"
      */
     private File classesDirectory;


     /**
      * Patterns of jars on the system path that contain tlds. Use | to separate each pattern.
      *
      * @parameter default-value=".*taglibs[^/]*\.jar|.*jstl[^/]*\.jar$
      */
     private String tldJarNamePatterns;


     /**
      * Source version - if not set defaults to jsp default (currently 1.7)
      * @parameter
      */
     private String sourceVersion;


     /**
      * Target version - if not set defaults to jsp default (currently 1.7)
      * @parameter
      */
     private String targetVersion;

     /**
      *
      * The JspC instance being used to compile the jsps.
      *
      * @parameter
      */
     private JettyJspC jspc;


     /**
      * Whether dirs on the classpath should be scanned as well as jars.
      * True by default. This allows for scanning for tlds of dependent projects that
      * are in the reactor as unassembled jars.
      *
      * @parameter default-value=true
      */
     private boolean scanAllDirectories;


     public void execute() throws MojoExecutionException, MojoFailureException
     {
         if (getLog().isDebugEnabled())
         {

             getLog().info("webAppSourceDirectory=" + webAppSourceDirectory);
             getLog().info("generatedClasses=" + generatedClasses);
             getLog().info("webXmlFragment=" + webXmlFragment);
             getLog().info("webXml="+webXml);
             getLog().info("insertionMarker="+ (insertionMarker == null || insertionMarker.equals("") ? END_OF_WEBAPP : insertionMarker));
             getLog().info("keepSources=" + keepSources);
             getLog().info("mergeFragment=" + mergeFragment);
             if (sourceVersion != null)
                 getLog().info("sourceVersion="+sourceVersion);
             if (targetVersion != null)
                 getLog().info("targetVersion="+targetVersion);
         }
         try
         {
             prepare();
             compile();
             cleanupSrcs();
             mergeWebXml();
         }
         catch (Exception e)
         {
             throw new MojoExecutionException("Failure processing jsps", e);
         }
     }

     public void compile() throws Exception
     {
         ClassLoader currentClassLoader = Thread.currentThread().getContextClassLoader();

         //set up the classpath of the webapp
         List<URL> webAppUrls = setUpWebAppClassPath();

         //set up the classpath of the container (ie jetty and jsp jars)
         Set<URL> pluginJars = getPluginJars();
         Set<URL> providedJars = getProvidedScopeJars(pluginJars);


         //Make a classloader so provided jars will be on the classpath
         List<URL> sysUrls = new ArrayList<URL>();
         sysUrls.addAll(providedJars);
         URLClassLoader sysClassLoader = new URLClassLoader((URL[])sysUrls.toArray(new URL[0]), currentClassLoader);

         //make a classloader with the webapp classpath
         URLClassLoader webAppClassLoader = new URLClassLoader((URL[]) webAppUrls.toArray(new URL[0]), sysClassLoader);
         StringBuffer webAppClassPath = new StringBuffer();

         for (int i = 0; i < webAppUrls.size(); i++)
         {
             if (getLog().isDebugEnabled())
                 getLog().debug("webappclassloader contains: " + webAppUrls.get(i));
             webAppClassPath.append(new File(webAppUrls.get(i).toURI()).getCanonicalPath());
             if (getLog().isDebugEnabled())
                 getLog().debug("added to classpath: " + ((URL) webAppUrls.get(i)).getFile());
             if (i+1<webAppUrls.size())
                 webAppClassPath.append(System.getProperty("path.separator"));
         }

         //Interpose a fake classloader as the webapp class loader. This is because the Apache JspC class
         //uses a TldScanner which ignores jars outside of the WEB-INF/lib path on the webapp classloader.
         //It will, however, look at all jars on the parents of the webapp classloader.
         URLClassLoader fakeWebAppClassLoader = new URLClassLoader(new URL[0], webAppClassLoader);
         Thread.currentThread().setContextClassLoader(fakeWebAppClassLoader);

         if (jspc == null)
             jspc = new JettyJspC();


         jspc.setWebXmlFragment(webXmlFragment);
         jspc.setUriroot(webAppSourceDirectory);
         jspc.setOutputDir(generatedClasses);
         jspc.setClassLoader(fakeWebAppClassLoader);
         jspc.setScanAllDirectories(scanAllDirectories);
         jspc.setCompile(true);
         if (sourceVersion != null)
             jspc.setCompilerSourceVM(sourceVersion);
         if (targetVersion != null)
             jspc.setCompilerTargetVM(targetVersion);

         // JspC#setExtensions() does not exist, so
         // always set concrete list of files that will be processed.
         String jspFiles = getJspFiles(webAppSourceDirectory);

         try
         {
             if (jspFiles == null | jspFiles.equals(""))
             {
                 getLog().info("No files selected to precompile");
             }
             else
             {
                 getLog().info("Compiling "+jspFiles+" from includes="+includes+" excludes="+excludes);
                 jspc.setJspFiles(jspFiles);
                 jspc.execute();
             }
         }
         finally
         {

             Thread.currentThread().setContextClassLoader(currentClassLoader);
         }
     }

     private String getJspFiles(String webAppSourceDirectory)
     throws Exception
     {
         List fileNames =  FileUtils.getFileNames(new File(webAppSourceDirectory),includes, excludes, false);
         return StringUtils.join(fileNames.toArray(new String[0]), ",");

     }

     /**
      * Until Jasper supports the option to generate the srcs in a different dir
      * than the classes, this is the best we can do.
      *
      * @throws Exception if unable to clean srcs
      */
     public void cleanupSrcs() throws Exception
     {
         // delete the .java files - depending on keepGenerated setting
         if (!keepSources)
         {
             File generatedClassesDir = new File(generatedClasses);

             if(generatedClassesDir.exists() && generatedClassesDir.isDirectory())
             {
                 delete(generatedClassesDir, new FileFilter()
                 {
                     public boolean accept(File f)
                     {
                         return f.isDirectory() || f.getName().endsWith(".java");
                     }
                 });
             }
         }
     }

     static void delete(File dir, FileFilter filter)
     {
         File[] files = dir.listFiles(filter);
         if (files != null)
         {
             for(File f: files)
             {
                 if(f.isDirectory())
                     delete(f, filter);
                 else
                     f.delete();
             }
         }
     }

     /**
      * Take the web fragment and put it inside a copy of the web.xml.
      *
      * You can specify the insertion point by specifying the string in the
      * insertionMarker configuration entry.
      *
      * If you dont specify the insertionMarker, then the fragment will be
      * inserted at the end of the file just before the &lt;/webapp&gt;
      *
      * @throws Exception if unable to merge the web xml
      */
     public void mergeWebXml() throws Exception
     {
         if (mergeFragment)
         {
             // open the src web.xml
             File webXml = getWebXmlFile();

             if (!webXml.exists())
             {
                 getLog().info(webXml.toString() + " does not exist, cannot merge with generated fragment");
                 return;
             }

             File fragmentWebXml = new File(webXmlFragment);
             File mergedWebXml = new File(fragmentWebXml.getParentFile(), "web.xml");

             try (BufferedReader webXmlReader = new BufferedReader(new FileReader(webXml));
                  PrintWriter mergedWebXmlWriter = new PrintWriter(new FileWriter(mergedWebXml)))
             {

                 if (!fragmentWebXml.exists())
                 {
                     getLog().info("No fragment web.xml file generated");
                     //just copy existing web.xml to expected position
                     IO.copy(webXmlReader, mergedWebXmlWriter);
                 }
                 else
                 {
                     // read up to the insertion marker or the </webapp> if there is no
                     // marker
                     boolean atInsertPoint = false;
                     boolean atEOF = false;
                     String marker = (insertionMarker == null
                             || insertionMarker.equals("") ? END_OF_WEBAPP : insertionMarker);
                     while (!atInsertPoint && !atEOF)
                     {
                         String line = webXmlReader.readLine();
                         if (line == null)
                             atEOF = true;
                         else if (line.indexOf(marker) >= 0)
                         {
                             atInsertPoint = true;
                         }
                         else
                         {
                             mergedWebXmlWriter.println(line);
                         }
                     }

                     if (atEOF && !atInsertPoint)
                         throw new IllegalStateException("web.xml does not contain insertionMarker "+insertionMarker);

                     //put in a context init-param to flag that the contents have been precompiled
                     mergedWebXmlWriter.println("<context-param><param-name>"+PRECOMPILED_FLAG+"</param-name><param-value>true</param-value></context-param>");


                     // put in the generated fragment
                     try (BufferedReader fragmentWebXmlReader =
                             new BufferedReader(new FileReader(fragmentWebXml)))
                     {
                         IO.copy(fragmentWebXmlReader, mergedWebXmlWriter);

                         // if we inserted just before the </web-app>, put it back in
                         if (marker.equals(END_OF_WEBAPP))
                             mergedWebXmlWriter.println(END_OF_WEBAPP);

                         // copy in the rest of the original web.xml file
                         IO.copy(webXmlReader, mergedWebXmlWriter);
                     }
                 }
             }
         }
     }

     private void prepare() throws Exception
     {
         // For some reason JspC doesn't like it if the dir doesn't
         // already exist and refuses to create the web.xml fragment
         File generatedSourceDirectoryFile = new File(generatedClasses);
         if (!generatedSourceDirectoryFile.exists())
             generatedSourceDirectoryFile.mkdirs();
     }

     /**
      * Set up the execution classpath for Jasper.
      *
      * Put everything in the classesDirectory and all of the dependencies on the
      * classpath.
      *
      * @returns a list of the urls of the dependencies
      * @throws Exception
      */
     private List<URL> setUpWebAppClassPath() throws Exception
     {
         //add any classes from the webapp
         List<URL> urls = new ArrayList<URL>();
         String classesDir = classesDirectory.getCanonicalPath();
         classesDir = classesDir + (classesDir.endsWith(File.pathSeparator) ? "" : File.separator);
         urls.add(Resource.toURL(new File(classesDir)));

         if (getLog().isDebugEnabled())
             getLog().debug("Adding to classpath classes dir: " + classesDir);

         //add the dependencies of the webapp (which will form WEB-INF/lib)
         for (Iterator<Artifact> iter = project.getArtifacts().iterator(); iter.hasNext();)
         {
             Artifact artifact = (Artifact)iter.next();

             // Include runtime and compile time libraries
             if (!Artifact.SCOPE_TEST.equals(artifact.getScope()) && !Artifact.SCOPE_PROVIDED.equals(artifact.getScope()))
             {
                 String filePath = artifact.getFile().getCanonicalPath();
                 if (getLog().isDebugEnabled())
                     getLog().debug("Adding to classpath dependency file: " + filePath);

                 urls.add(Resource.toURL(artifact.getFile()));
             }
         }
         return urls;
     }


     /**
      * @return
      * @throws MalformedURLException
      */
     private Set<URL> getPluginJars () throws MalformedURLException
     {
         HashSet<URL> pluginJars = new HashSet<>();
         for (Iterator<Artifact> iter = pluginArtifacts.iterator(); iter.hasNext(); )
         {
             Artifact pluginArtifact = iter.next();
             if ("jar".equalsIgnoreCase(pluginArtifact.getType()))
             {
                 if (getLog().isDebugEnabled()) { getLog().debug("Adding plugin artifact "+pluginArtifact);}
                 pluginJars.add(pluginArtifact.getFile().toURI().toURL());
             }
         }

         return pluginJars;
     }


     /**
      * @param pluginJars
      * @return
      * @throws MalformedURLException
      */
     private Set<URL>  getProvidedScopeJars (Set<URL> pluginJars) throws MalformedURLException
     {
         if (!useProvidedScope)
             return Collections.emptySet();

         HashSet<URL> providedJars = new HashSet<>();

         for ( Iterator<Artifact> iter = projectArtifacts.iterator(); iter.hasNext(); )
         {
             Artifact artifact = iter.next();
             if (Artifact.SCOPE_PROVIDED.equals(artifact.getScope()))
             {
                 //test to see if the provided artifact was amongst the plugin artifacts
                 URL jar = artifact.getFile().toURI().toURL();
                 if (!pluginJars.contains(jar))
                 {
                     providedJars.add(jar);
                     if (getLog().isDebugEnabled()) { getLog().debug("Adding provided artifact: "+artifact);}
                 }
                 else
                 {
                     if (getLog().isDebugEnabled()) { getLog().debug("Skipping provided artifact: "+artifact);}
                 }
             }
         }
         return providedJars;
     }


     private File getWebXmlFile ()
     throws IOException
     {
         File file = null;
         File baseDir = project.getBasedir().getCanonicalFile();
         File defaultWebAppSrcDir = new File (baseDir, "src/main/webapp").getCanonicalFile();
         File webAppSrcDir = new File (webAppSourceDirectory).getCanonicalFile();
         File defaultWebXml = new File (defaultWebAppSrcDir, "web.xml").getCanonicalFile();

         //If the web.xml has been changed from the default, try that
         File webXmlFile = new File (webXml).getCanonicalFile();
         if (webXmlFile.compareTo(defaultWebXml) != 0)
         {
             file = new File (webXml);
             return file;
         }

         //If the web app src directory has not been changed from the default, use whatever
         //is set for the web.xml location
         file = new File (webAppSrcDir, "web.xml");
         return file;
     }
 }
	//
	// ========================================================================
	// Copyright (c) 1995-2017 Mort Bay Consulting Pty. Ltd.
	// ------------------------------------------------------------------------
	// All rights reserved. This program and the accompanying materials
	// are made available under the terms of the Eclipse Public License v1.0
	// and Apache License v2.0 which accompanies this distribution.
	//
	// The Eclipse Public License is available at
	// http://www.eclipse.org/legal/epl-v10.html
	//
	// The Apache License v2.0 is available at
	// http://www.opensource.org/licenses/apache2.0.php
	//
	// You may elect to redistribute this code under either of these licenses.
	// ========================================================================
	//

	package org.eclipse.jetty.jspc.plugin;

	import java.io.BufferedReader;
	import java.io.File;
	import java.io.FileFilter;
	import java.io.FileReader;
	import java.io.FileWriter;
	import java.io.IOException;
	import java.io.PrintWriter;
	import java.net.MalformedURLException;
	import java.net.URL;
	import java.net.URLClassLoader;
	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.HashSet;
	import java.util.Iterator;
	import java.util.List;
	import java.util.Set;

	import org.apache.jasper.JspC;
	import org.apache.jasper.servlet.JspCServletContext;
	import org.apache.jasper.servlet.TldScanner;
	import org.apache.maven.artifact.Artifact;
	import org.apache.maven.plugin.AbstractMojo;
	import org.apache.maven.plugin.MojoExecutionException;
	import org.apache.maven.plugin.MojoFailureException;
	import org.apache.maven.project.MavenProject;
	import org.apache.tomcat.JarScanner;
	import org.apache.tomcat.util.scan.StandardJarScanner;
	import org.codehaus.plexus.util.FileUtils;
	import org.codehaus.plexus.util.StringUtils;
	import org.eclipse.jetty.util.IO;
	import org.eclipse.jetty.util.resource.Resource;

	/**
	* This goal will compile jsps for a webapp so that they can be included in a
	* war.
	* <p>
	* At runtime, the plugin will use the jspc compiler to precompile jsps and tags.
	* </p>
	* <p>
	* Note that the same java compiler will be used as for on-the-fly compiled
	* jsps, which will be the Eclipse java compiler.
	* <p>
	* See <a
	* href="https://www.eclipse.org/jetty/documentation/current/jetty-jspc-maven-plugin.html">Usage
	* Guide</a> for instructions on using this plugin.
	* </p>
	* @goal jspc
	* @phase process-classes
	* @requiresDependencyResolution compile+runtime
	* @description Runs jspc compiler to produce .java and .class files
	*/
	public class JspcMojo extends AbstractMojo
	{
	public static final String END_OF_WEBAPP = "</web-app>";
	public static final String PRECOMPILED_FLAG = "org.eclipse.jetty.jsp.precompiled";


	/**
	* JettyJspC
	*
	* Add some extra setters to standard JspC class to help configure it
	* for running in maven.
	*
	* TODO move all setters on the plugin onto this jspc class instead.
	*/
	public static class JettyJspC extends JspC
	{

	private boolean scanAll;

	public void setClassLoader (ClassLoader loader)
	{
	this.loader = loader;
	}

	public void setScanAllDirectories (boolean scanAll)
	{
	this.scanAll = scanAll;
	}

	public boolean getScanAllDirectories ()
	{
	return this.scanAll;
	}


	@Override
	protected TldScanner newTldScanner(JspCServletContext context, boolean namespaceAware, boolean validate, boolean blockExternal)
	{
	if (context != null && context.getAttribute(JarScanner.class.getName()) == null)
	{
	StandardJarScanner jarScanner = new StandardJarScanner();
	jarScanner.setScanAllDirectories(getScanAllDirectories());
	context.setAttribute(JarScanner.class.getName(), jarScanner);
	}

	return super.newTldScanner(context, namespaceAware, validate, blockExternal);
	}
	}


	/**
	* Whether or not to include dependencies on the plugin's classpath with <scope>provided</scope>
	* Use WITH CAUTION as you may wind up with duplicate jars/classes.
	*
	* @since jetty-7.6.3
	* @parameter default-value="false"
	*/
	private boolean useProvidedScope;

	/**
	* The artifacts for the project.
	*
	* @since jetty-7.6.3
	* @parameter default-value="${project.artifacts}"
	* @readonly
	*/
	private Set projectArtifacts;


	/**
	* The maven project.
	*
	* @parameter default-value="${project}"
	* @required
	* @readonly
	*/
	private MavenProject project;



	/**
	* The artifacts for the plugin itself.
	*
	* @parameter default-value="${plugin.artifacts}"
	* @readonly
	*/
	private List pluginArtifacts;


	/**
	* File into which to generate the <servlet> and
	* <servlet-mapping> tags for the compiled jsps
	*
	* @parameter default-value="${basedir}/target/webfrag.xml"
	*/
	private String webXmlFragment;

	/**
	* Optional. A marker string in the src web.xml file which indicates where
	* to merge in the generated web.xml fragment. Note that the marker string
	* will NOT be preserved during the insertion. Can be left blank, in which
	* case the generated fragment is inserted just before the </web-app>
	* line
	*
	* @parameter
	*/
	private String insertionMarker;

	/**
	* Merge the generated fragment file with the web.xml from
	* webAppSourceDirectory. The merged file will go into the same directory as
	* the webXmlFragment.
	*
	* @parameter default-value="true"
	*/
	private boolean mergeFragment;

	/**
	* The destination directory into which to put the compiled jsps.
	*
	* @parameter default-value="${project.build.outputDirectory}"
	*/
	private String generatedClasses;

	/**
	* Controls whether or not .java files generated during compilation will be
	* preserved.
	*
	* @parameter default-value="false"
	*/
	private boolean keepSources;


	/**
	* Root directory for all html/jsp etc files
	*
	* @parameter default-value="${basedir}/src/main/webapp"
	*
	*/
	private String webAppSourceDirectory;



	/**
	* Location of web.xml. Defaults to src/main/webapp/web.xml.
	* @parameter default-value="${basedir}/src/main/webapp/WEB-INF/web.xml"
	*/
	private String webXml;


	/**
	* The comma separated list of patterns for file extensions to be processed. By default
	* will include all .jsp and .jspx files.
	*
	* @parameter default-value="*\/.jsp, *\/.jspx"
	*/
	private String includes;

	/**
	* The comma separated list of file name patters to exclude from compilation.
	*
	* @parameter default_value="\/.svn\/";
	*/
	private String excludes;

	/**
	* The location of the compiled classes for the webapp
	*
	* @parameter default-value="${project.build.outputDirectory}"
	*/
	private File classesDirectory;


	/**
	* Patterns of jars on the system path that contain tlds. Use \| to separate each pattern.
	*
	* @parameter default-value=".taglibs[^/]\.jar\|.jstl[^/]\.jar$
	*/
	private String tldJarNamePatterns;


	/**
	* Source version - if not set defaults to jsp default (currently 1.7)
	* @parameter
	*/
	private String sourceVersion;


	/**
	* Target version - if not set defaults to jsp default (currently 1.7)
	* @parameter
	*/
	private String targetVersion;

	/**
	*
	* The JspC instance being used to compile the jsps.
	*
	* @parameter
	*/
	private JettyJspC jspc;


	/**
	* Whether dirs on the classpath should be scanned as well as jars.
	* True by default. This allows for scanning for tlds of dependent projects that
	* are in the reactor as unassembled jars.
	*
	* @parameter default-value=true
	*/
	private boolean scanAllDirectories;


	public void execute() throws MojoExecutionException, MojoFailureException
	{
	if (getLog().isDebugEnabled())
	{

	getLog().info("webAppSourceDirectory=" + webAppSourceDirectory);
	getLog().info("generatedClasses=" + generatedClasses);
	getLog().info("webXmlFragment=" + webXmlFragment);
	getLog().info("webXml="+webXml);
	getLog().info("insertionMarker="+ (insertionMarker == null \|\| insertionMarker.equals("") ? END_OF_WEBAPP : insertionMarker));
	getLog().info("keepSources=" + keepSources);
	getLog().info("mergeFragment=" + mergeFragment);
	if (sourceVersion != null)
	getLog().info("sourceVersion="+sourceVersion);
	if (targetVersion != null)
	getLog().info("targetVersion="+targetVersion);
	}
	try
	{
	prepare();
	compile();
	cleanupSrcs();
	mergeWebXml();
	}
	catch (Exception e)
	{
	throw new MojoExecutionException("Failure processing jsps", e);
	}
	}

	public void compile() throws Exception
	{
	ClassLoader currentClassLoader = Thread.currentThread().getContextClassLoader();

	//set up the classpath of the webapp
	List<URL> webAppUrls = setUpWebAppClassPath();

	//set up the classpath of the container (ie jetty and jsp jars)
	Set<URL> pluginJars = getPluginJars();
	Set<URL> providedJars = getProvidedScopeJars(pluginJars);


	//Make a classloader so provided jars will be on the classpath
	List<URL> sysUrls = new ArrayList<URL>();
	sysUrls.addAll(providedJars);
	URLClassLoader sysClassLoader = new URLClassLoader((URL[])sysUrls.toArray(new URL[0]), currentClassLoader);

	//make a classloader with the webapp classpath
	URLClassLoader webAppClassLoader = new URLClassLoader((URL[]) webAppUrls.toArray(new URL[0]), sysClassLoader);
	StringBuffer webAppClassPath = new StringBuffer();

	for (int i = 0; i < webAppUrls.size(); i++)
	{
	if (getLog().isDebugEnabled())
	getLog().debug("webappclassloader contains: " + webAppUrls.get(i));
	webAppClassPath.append(new File(webAppUrls.get(i).toURI()).getCanonicalPath());
	if (getLog().isDebugEnabled())
	getLog().debug("added to classpath: " + ((URL) webAppUrls.get(i)).getFile());
	if (i+1<webAppUrls.size())
	webAppClassPath.append(System.getProperty("path.separator"));
	}

	//Interpose a fake classloader as the webapp class loader. This is because the Apache JspC class
	//uses a TldScanner which ignores jars outside of the WEB-INF/lib path on the webapp classloader.
	//It will, however, look at all jars on the parents of the webapp classloader.
	URLClassLoader fakeWebAppClassLoader = new URLClassLoader(new URL[0], webAppClassLoader);
	Thread.currentThread().setContextClassLoader(fakeWebAppClassLoader);

	if (jspc == null)
	jspc = new JettyJspC();


	jspc.setWebXmlFragment(webXmlFragment);
	jspc.setUriroot(webAppSourceDirectory);
	jspc.setOutputDir(generatedClasses);
	jspc.setClassLoader(fakeWebAppClassLoader);
	jspc.setScanAllDirectories(scanAllDirectories);
	jspc.setCompile(true);
	if (sourceVersion != null)
	jspc.setCompilerSourceVM(sourceVersion);
	if (targetVersion != null)
	jspc.setCompilerTargetVM(targetVersion);

	// JspC#setExtensions() does not exist, so
	// always set concrete list of files that will be processed.
	String jspFiles = getJspFiles(webAppSourceDirectory);

	try
	{
	if (jspFiles == null \| jspFiles.equals(""))
	{
	getLog().info("No files selected to precompile");
	}
	else
	{
	getLog().info("Compiling "+jspFiles+" from includes="+includes+" excludes="+excludes);
	jspc.setJspFiles(jspFiles);
	jspc.execute();
	}
	}
	finally
	{

	Thread.currentThread().setContextClassLoader(currentClassLoader);
	}
	}

	private String getJspFiles(String webAppSourceDirectory)
	throws Exception
	{
	List fileNames = FileUtils.getFileNames(new File(webAppSourceDirectory),includes, excludes, false);
	return StringUtils.join(fileNames.toArray(new String[0]), ",");

	}

	/**
	* Until Jasper supports the option to generate the srcs in a different dir
	* than the classes, this is the best we can do.
	*
	* @throws Exception if unable to clean srcs
	*/
	public void cleanupSrcs() throws Exception
	{
	// delete the .java files - depending on keepGenerated setting
	if (!keepSources)
	{
	File generatedClassesDir = new File(generatedClasses);

	if(generatedClassesDir.exists() && generatedClassesDir.isDirectory())
	{
	delete(generatedClassesDir, new FileFilter()
	{
	public boolean accept(File f)
	{
	return f.isDirectory() \|\| f.getName().endsWith(".java");
	}
	});
	}
	}
	}

	static void delete(File dir, FileFilter filter)
	{
	File[] files = dir.listFiles(filter);
	if (files != null)
	{
	for(File f: files)
	{
	if(f.isDirectory())
	delete(f, filter);
	else
	f.delete();
	}
	}
	}

	/**
	* Take the web fragment and put it inside a copy of the web.xml.
	*
	* You can specify the insertion point by specifying the string in the
	* insertionMarker configuration entry.
	*
	* If you dont specify the insertionMarker, then the fragment will be
	* inserted at the end of the file just before the </webapp>
	*
	* @throws Exception if unable to merge the web xml
	*/
	public void mergeWebXml() throws Exception
	{
	if (mergeFragment)
	{
	// open the src web.xml
	File webXml = getWebXmlFile();

	if (!webXml.exists())
	{
	getLog().info(webXml.toString() + " does not exist, cannot merge with generated fragment");
	return;
	}

	File fragmentWebXml = new File(webXmlFragment);
	File mergedWebXml = new File(fragmentWebXml.getParentFile(), "web.xml");

	try (BufferedReader webXmlReader = new BufferedReader(new FileReader(webXml));
	PrintWriter mergedWebXmlWriter = new PrintWriter(new FileWriter(mergedWebXml)))
	{

	if (!fragmentWebXml.exists())
	{
	getLog().info("No fragment web.xml file generated");
	//just copy existing web.xml to expected position
	IO.copy(webXmlReader, mergedWebXmlWriter);
	}
	else
	{
	// read up to the insertion marker or the </webapp> if there is no
	// marker
	boolean atInsertPoint = false;
	boolean atEOF = false;
	String marker = (insertionMarker == null
	\|\| insertionMarker.equals("") ? END_OF_WEBAPP : insertionMarker);
	while (!atInsertPoint && !atEOF)
	{
	String line = webXmlReader.readLine();
	if (line == null)
	atEOF = true;
	else if (line.indexOf(marker) >= 0)
	{
	atInsertPoint = true;
	}
	else
	{
	mergedWebXmlWriter.println(line);
	}
	}

	if (atEOF && !atInsertPoint)
	throw new IllegalStateException("web.xml does not contain insertionMarker "+insertionMarker);

	//put in a context init-param to flag that the contents have been precompiled
	mergedWebXmlWriter.println("<context-param><param-name>"+PRECOMPILED_FLAG+"</param-name><param-value>true</param-value></context-param>");


	// put in the generated fragment
	try (BufferedReader fragmentWebXmlReader =
	new BufferedReader(new FileReader(fragmentWebXml)))
	{
	IO.copy(fragmentWebXmlReader, mergedWebXmlWriter);

	// if we inserted just before the </web-app>, put it back in
	if (marker.equals(END_OF_WEBAPP))
	mergedWebXmlWriter.println(END_OF_WEBAPP);

	// copy in the rest of the original web.xml file
	IO.copy(webXmlReader, mergedWebXmlWriter);
	}
	}
	}
	}
	}

	private void prepare() throws Exception
	{
	// For some reason JspC doesn't like it if the dir doesn't
	// already exist and refuses to create the web.xml fragment
	File generatedSourceDirectoryFile = new File(generatedClasses);
	if (!generatedSourceDirectoryFile.exists())
	generatedSourceDirectoryFile.mkdirs();
	}

	/**
	* Set up the execution classpath for Jasper.
	*
	* Put everything in the classesDirectory and all of the dependencies on the
	* classpath.
	*
	* @returns a list of the urls of the dependencies
	* @throws Exception
	*/
	private List<URL> setUpWebAppClassPath() throws Exception
	{
	//add any classes from the webapp
	List<URL> urls = new ArrayList<URL>();
	String classesDir = classesDirectory.getCanonicalPath();
	classesDir = classesDir + (classesDir.endsWith(File.pathSeparator) ? "" : File.separator);
	urls.add(Resource.toURL(new File(classesDir)));

	if (getLog().isDebugEnabled())
	getLog().debug("Adding to classpath classes dir: " + classesDir);

	//add the dependencies of the webapp (which will form WEB-INF/lib)
	for (Iterator<Artifact> iter = project.getArtifacts().iterator(); iter.hasNext();)
	{
	Artifact artifact = (Artifact)iter.next();

	// Include runtime and compile time libraries
	if (!Artifact.SCOPE_TEST.equals(artifact.getScope()) && !Artifact.SCOPE_PROVIDED.equals(artifact.getScope()))
	{
	String filePath = artifact.getFile().getCanonicalPath();
	if (getLog().isDebugEnabled())
	getLog().debug("Adding to classpath dependency file: " + filePath);

	urls.add(Resource.toURL(artifact.getFile()));
	}
	}
	return urls;
	}



	/**
	* @return
	* @throws MalformedURLException
	*/
	private Set<URL> getPluginJars () throws MalformedURLException
	{
	HashSet<URL> pluginJars = new HashSet<>();
	for (Iterator<Artifact> iter = pluginArtifacts.iterator(); iter.hasNext(); )
	{
	Artifact pluginArtifact = iter.next();
	if ("jar".equalsIgnoreCase(pluginArtifact.getType()))
	{
	if (getLog().isDebugEnabled()) { getLog().debug("Adding plugin artifact "+pluginArtifact);}
	pluginJars.add(pluginArtifact.getFile().toURI().toURL());
	}
	}

	return pluginJars;
	}



	/**
	* @param pluginJars
	* @return
	* @throws MalformedURLException
	*/
	private Set<URL> getProvidedScopeJars (Set<URL> pluginJars) throws MalformedURLException
	{
	if (!useProvidedScope)
	return Collections.emptySet();

	HashSet<URL> providedJars = new HashSet<>();

	for ( Iterator<Artifact> iter = projectArtifacts.iterator(); iter.hasNext(); )
	{
	Artifact artifact = iter.next();
	if (Artifact.SCOPE_PROVIDED.equals(artifact.getScope()))
	{
	//test to see if the provided artifact was amongst the plugin artifacts
	URL jar = artifact.getFile().toURI().toURL();
	if (!pluginJars.contains(jar))
	{
	providedJars.add(jar);
	if (getLog().isDebugEnabled()) { getLog().debug("Adding provided artifact: "+artifact);}
	}
	else
	{
	if (getLog().isDebugEnabled()) { getLog().debug("Skipping provided artifact: "+artifact);}
	}
	}
	}
	return providedJars;
	}



	private File getWebXmlFile ()
	throws IOException
	{
	File file = null;
	File baseDir = project.getBasedir().getCanonicalFile();
	File defaultWebAppSrcDir = new File (baseDir, "src/main/webapp").getCanonicalFile();
	File webAppSrcDir = new File (webAppSourceDirectory).getCanonicalFile();
	File defaultWebXml = new File (defaultWebAppSrcDir, "web.xml").getCanonicalFile();

	//If the web.xml has been changed from the default, try that
	File webXmlFile = new File (webXml).getCanonicalFile();
	if (webXmlFile.compareTo(defaultWebXml) != 0)
	{
	file = new File (webXml);
	return file;
	}

	//If the web app src directory has not been changed from the default, use whatever
	//is set for the web.xml location
	file = new File (webAppSrcDir, "web.xml");
	return file;
	}
	}