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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
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 * This code 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 General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
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 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
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package jdk.javadoc.internal.doclets.toolkit.taglets;

import java.util.*;
import java.util.Map.Entry;

import javax.lang.model.element.Element;
import javax.lang.model.element.ExecutableElement;
import javax.lang.model.element.TypeElement;
import javax.lang.model.type.TypeMirror;

import com.sun.source.doctree.DocTree;
import jdk.javadoc.internal.doclets.toolkit.Content;
import jdk.javadoc.internal.doclets.toolkit.util.CommentHelper;
import jdk.javadoc.internal.doclets.toolkit.util.DocFinder;
import jdk.javadoc.internal.doclets.toolkit.util.DocFinder.Input;
import jdk.javadoc.internal.doclets.toolkit.util.Utils;

import static com.sun.source.doctree.DocTree.Kind.THROWS;

A taglet that represents the @throws tag.
 
This is NOT part of any supported API.
 If you write code that depends on this, you do so at your own risk.
 This code and its internal interfaces are subject to change or
 deletion without notice.
Author:
Jamie Ho/**
 * A taglet that represents the @throws tag.
 *
 *  <p><b>This is NOT part of any supported API.
 *  If you write code that depends on this, you do so at your own risk.
 *  This code and its internal interfaces are subject to change or
 *  deletion without notice.</b>
 *
 * @author Jamie Ho
 */
public class ThrowsTaglet extends BaseTaglet
    implements InheritableTaglet {

    public ThrowsTaglet() {
        super(THROWS.tagName, false, EnumSet.of(Site.CONSTRUCTOR, Site.METHOD));
    }

    @Override
    public void inherit(DocFinder.Input input, DocFinder.Output output) {
        Utils utils = input.utils;
        Element exception;
        CommentHelper ch = utils.getCommentHelper(input.element);
        if (input.tagId == null) {
            exception = ch.getException(utils.configuration, input.docTreeInfo.docTree);
            input.tagId = exception == null
                    ? ch.getExceptionName(input.docTreeInfo.docTree).getSignature()
                    : utils.getFullyQualifiedName(exception);
        } else {
            TypeElement element = input.utils.findClass(input.element, input.tagId);
            exception = (element == null) ? null : element;
        }

        for (DocTree dt : input.utils.getThrowsTrees(input.element)) {
            Element texception = ch.getException(utils.configuration, dt);
            if (texception != null && (input.tagId.equals(utils.getSimpleName(texception)) ||
                 (input.tagId.equals(utils.getFullyQualifiedName(texception))))) {
                output.holder = input.element;
                output.holderTag = dt;
                output.inlineTags = ch.getBody(input.utils.configuration, output.holderTag);
                output.tagList.add(dt);
            } else if (exception != null && texception != null &&
                    utils.isTypeElement(texception) && utils.isTypeElement(exception) &&
                    utils.isSubclassOf((TypeElement)texception, (TypeElement)exception)) {
                output.tagList.add(dt);
            }
        }
    }

    
Add links for exceptions that are declared but not documented.
/**
     * Add links for exceptions that are declared but not documented.
     */
    private Content linkToUndocumentedDeclaredExceptions(List<? extends TypeMirror> declaredExceptionTypes,
            Set<String> alreadyDocumented, TagletWriter writer) {
        Utils utils = writer.configuration().utils;
        Content result = writer.getOutputInstance();
        //Add links to the exceptions declared but not documented.
        for (TypeMirror declaredExceptionType : declaredExceptionTypes) {
            TypeElement klass = utils.asTypeElement(declaredExceptionType);
            if (klass != null &&
                !alreadyDocumented.contains(utils.getSimpleName(klass)) &&
                !alreadyDocumented.contains(utils.getFullyQualifiedName(klass))) {
                if (alreadyDocumented.isEmpty()) {
                    result.addContent(writer.getThrowsHeader());
                }
                result.addContent(writer.throwsTagOutput(declaredExceptionType));
                alreadyDocumented.add(utils.getSimpleName(klass));
            }
        }
        return result;
    }

    
Inherit throws documentation for exceptions that were declared but not
documented.
/**
     * Inherit throws documentation for exceptions that were declared but not
     * documented.
     */
    private Content inheritThrowsDocumentation(Element holder,
            List<? extends TypeMirror> declaredExceptionTypes, Set<String> alreadyDocumented,
            TagletWriter writer) {
        Utils utils = writer.configuration().utils;
        Content result = writer.getOutputInstance();
        if (utils.isExecutableElement(holder)) {
            Map<List<? extends DocTree>, ExecutableElement> declaredExceptionTags = new LinkedHashMap<>();
            for (TypeMirror declaredExceptionType : declaredExceptionTypes) {
                Input input = new DocFinder.Input(utils, holder, this,
                        utils.getTypeName(declaredExceptionType, false));
                DocFinder.Output inheritedDoc = DocFinder.search(writer.configuration(), input);
                if (inheritedDoc.tagList.isEmpty()) {
                    String typeName = utils.getTypeName(declaredExceptionType, true);
                    input = new DocFinder.Input(utils, holder, this, typeName);
                    inheritedDoc = DocFinder.search(writer.configuration(), input);
                }
                if (!inheritedDoc.tagList.isEmpty()) {
                    if (inheritedDoc.holder == null) {
                        inheritedDoc.holder = holder;
                    }
                    declaredExceptionTags.put(inheritedDoc.tagList, (ExecutableElement)inheritedDoc.holder);
                }
            }
            result.addContent(throwsTagsOutput(declaredExceptionTags, writer, alreadyDocumented, false));
        }
        return result;
    }

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    public Content getTagletOutput(Element holder, TagletWriter writer) {
        Utils utils = writer.configuration().utils;
        ExecutableElement execHolder = (ExecutableElement) holder;
        Map<List<? extends DocTree>, ExecutableElement> tagsMap = new LinkedHashMap<>();
        tagsMap.put(utils.getThrowsTrees(execHolder), execHolder);
        Content result = writer.getOutputInstance();
        HashSet<String> alreadyDocumented = new HashSet<>();
        if (!tagsMap.isEmpty()) {
            result.addContent(throwsTagsOutput(tagsMap, writer, alreadyDocumented, true));
        }
        result.addContent(inheritThrowsDocumentation(holder,
            execHolder.getThrownTypes(), alreadyDocumented, writer));
        result.addContent(linkToUndocumentedDeclaredExceptions(
            execHolder.getThrownTypes(), alreadyDocumented, writer));
        return result;
    }

    
Given an array of Tags representing this custom
tag, return its string representation.
Params:
throwTags – the array of ThrowsTags to convert.
writer – the TagletWriter that will write this tag.
alreadyDocumented – the set of exceptions that have already
       been documented.
allowDups – True if we allow duplicate throws tags to be documented.
Returns:
the Content representation of this Tag./**
     * Given an array of <code>Tag</code>s representing this custom
     * tag, return its string representation.
     * @param throwTags the array of <code>ThrowsTag</code>s to convert.
     * @param writer the TagletWriter that will write this tag.
     * @param alreadyDocumented the set of exceptions that have already
     *        been documented.
     * @param allowDups True if we allow duplicate throws tags to be documented.
     * @return the Content representation of this <code>Tag</code>.
     */
    protected Content throwsTagsOutput(Map<List<? extends DocTree>, ExecutableElement> throwTags,
        TagletWriter writer, Set<String> alreadyDocumented, boolean allowDups) {
        Utils utils = writer.configuration().utils;
        Content result = writer.getOutputInstance();
        if (!throwTags.isEmpty()) {
            for (Entry<List<? extends DocTree>, ExecutableElement> entry : throwTags.entrySet()) {
                CommentHelper ch = utils.getCommentHelper(entry.getValue());
                Element e = entry.getValue();
                for (DocTree dt : entry.getKey()) {
                    Element te = ch.getException(utils.configuration, dt);
                    String excName = ch.getExceptionName(dt).toString();
                    if ((!allowDups) &&
                        (alreadyDocumented.contains(excName) ||
                        (te != null && alreadyDocumented.contains(utils.getFullyQualifiedName(te))))) {
                        continue;
                    }
                    if (alreadyDocumented.isEmpty()) {
                        result.addContent(writer.getThrowsHeader());
                    }
                    result.addContent(writer.throwsTagOutput(e, dt));
                    alreadyDocumented.add(te != null
                            ? utils.getFullyQualifiedName(te)
                            : excName);
                }
            }
        }
        return result;
    }
}