FileDocCategorySizeDatePackage
TagFileProcessor.javaAPI DocApache Tomcat 6.0.1427841Fri Jul 20 04:20:32 BST 2007org.apache.jasper.compiler

TagFileProcessor

public class TagFileProcessor extends Object
1. Processes and extracts the directive info in a tag file. 2. Compiles and loads tag files used in a JSP file.
author
Kin-man Chung

Fields Summary
private Vector
tempVector
Constructors Summary
Methods Summary
private java.lang.ClassloadTagFile(Compiler compiler, java.lang.String tagFilePath, javax.servlet.jsp.tagext.TagInfo tagInfo, PageInfo parentPageInfo)
Compiles and loads a tagfile.


        JspCompilationContext ctxt = compiler.getCompilationContext();
        JspRuntimeContext rctxt = ctxt.getRuntimeContext();
        JspServletWrapper wrapper = (JspServletWrapper) rctxt
                .getWrapper(tagFilePath);

        synchronized (rctxt) {
            if (wrapper == null) {
                wrapper = new JspServletWrapper(ctxt.getServletContext(), ctxt
                        .getOptions(), tagFilePath, tagInfo, ctxt
                        .getRuntimeContext(), ctxt.getTagFileJarUrl(tagFilePath));
                rctxt.addWrapper(tagFilePath, wrapper);

                // Use same classloader and classpath for compiling tag files
                wrapper.getJspEngineContext().setClassLoader(
                        (URLClassLoader) ctxt.getClassLoader());
                wrapper.getJspEngineContext().setClassPath(ctxt.getClassPath());
            } else {
                // Make sure that JspCompilationContext gets the latest TagInfo
                // for the tag file. TagInfo instance was created the last
                // time the tag file was scanned for directives, and the tag
                // file may have been modified since then.
                wrapper.getJspEngineContext().setTagInfo(tagInfo);
            }

            Class tagClazz;
            int tripCount = wrapper.incTripCount();
            try {
                if (tripCount > 0) {
                    // When tripCount is greater than zero, a circular
                    // dependency exists. The circularily dependant tag
                    // file is compiled in prototype mode, to avoid infinite
                    // recursion.

                    JspServletWrapper tempWrapper = new JspServletWrapper(ctxt
                            .getServletContext(), ctxt.getOptions(),
                            tagFilePath, tagInfo, ctxt.getRuntimeContext(),
                            ctxt.getTagFileJarUrl(tagFilePath));
                    tagClazz = tempWrapper.loadTagFilePrototype();
                    tempVector.add(tempWrapper.getJspEngineContext()
                            .getCompiler());
                } else {
                    tagClazz = wrapper.loadTagFile();
                }
            } finally {
                wrapper.decTripCount();
            }

            // Add the dependants for this tag file to its parent's
            // dependant list. The only reliable dependency information
            // can only be obtained from the tag instance.
            try {
                Object tagIns = tagClazz.newInstance();
                if (tagIns instanceof JspSourceDependent) {
                    Iterator iter = ((List) ((JspSourceDependent) tagIns)
                            .getDependants()).iterator();
                    while (iter.hasNext()) {
                        parentPageInfo.addDependant((String) iter.next());
                    }
                }
            } catch (Exception e) {
                // ignore errors
            }

            return tagClazz;
        }
public voidloadTagFiles(Compiler compiler, Node.Nodes page)
Implements a phase of the translation that compiles (if necessary) the tag files used in a JSP files. The directives in the tag files are assumed to have been proccessed and encapsulated as TagFileInfo in the CustomTag nodes.


        tempVector = new Vector();
        page.visit(new TagFileLoaderVisitor(compiler));
public static javax.servlet.jsp.tagext.TagInfoparseTagFileDirectives(ParserController pc, java.lang.String name, java.lang.String path, javax.servlet.jsp.tagext.TagLibraryInfo tagLibInfo)
Parses the tag file, and collects information on the directives included in it. The method is used to obtain the info on the tag file, when the handler that it represents is referenced. The tag file is not compiled here.

param
pc the current ParserController used in this compilation
param
name the tag name as specified in the TLD
param
tagfile the path for the tagfile
param
tagLibInfo the TagLibraryInfo object associated with this TagInfo
return
a TagInfo object assembled from the directives in the tag file.


        ErrorDispatcher err = pc.getCompiler().getErrorDispatcher();

        Node.Nodes page = null;
        try {
            page = pc.parseTagFileDirectives(path);
        } catch (FileNotFoundException e) {
            err.jspError("jsp.error.file.not.found", path);
        } catch (IOException e) {
            err.jspError("jsp.error.file.not.found", path);
        }

        TagFileDirectiveVisitor tagFileVisitor = new TagFileDirectiveVisitor(pc
                .getCompiler(), tagLibInfo, name, path);
        page.visit(tagFileVisitor);
        tagFileVisitor.postCheck();

        return tagFileVisitor.getTagInfo();
public voidremoveProtoTypeFiles(java.lang.String classFileName)
Removed the java and class files for the tag prototype generated from the current compilation.

param
classFileName If non-null, remove only the class file with with this name.

        Iterator iter = tempVector.iterator();
        while (iter.hasNext()) {
            Compiler c = (Compiler) iter.next();
            if (classFileName == null) {
                c.removeGeneratedClassFiles();
            } else if (classFileName.equals(c.getCompilationContext()
                    .getClassFileName())) {
                c.removeGeneratedClassFiles();
                tempVector.remove(c);
                return;
            }
        }