Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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 org.apache.camel.maven; import java.io.UnsupportedEncodingException; import java.net.URLDecoder; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import javax.swing.text.ChangedCharSetException; import javax.swing.text.SimpleAttributeSet; import javax.swing.text.html.HTML; import javax.swing.text.html.parser.DTD; import javax.swing.text.html.parser.Parser; import javax.swing.text.html.parser.TagElement; import org.apache.commons.lang.StringEscapeUtils; /** * Parses Javadoc HTML to get Method Signatures from Method Sumary. Supports Java 6, 7 and 8 Javadoc formats. */ public class JavadocParser extends Parser { private static final String NON_BREAKING_SPACE = "\u00A0"; private static final String JAVA6_NON_BREAKING_SPACE = " "; private final String hrefPattern; private ParserState parserState; private String methodWithTypes; private StringBuilder methodTextBuilder = new StringBuilder(); private List<String> methods = new ArrayList<String>(); private Map<String, String> methodText = new HashMap<String, String>(); private String errorMessage; public JavadocParser(DTD dtd, String docPath) { super(dtd); this.hrefPattern = docPath + "#"; parserState = ParserState.INIT; } public void reset() { parserState = ParserState.INIT; methodWithTypes = null; methodTextBuilder = new StringBuilder(); methods.clear(); methodText.clear(); errorMessage = null; } @Override protected void startTag(TagElement tag) throws ChangedCharSetException { super.startTag(tag); final HTML.Tag htmlTag = tag.getHTMLTag(); if (htmlTag != null) { if (HTML.Tag.A.equals(htmlTag)) { final SimpleAttributeSet attributes = getAttributes(); final Object name = attributes.getAttribute(HTML.Attribute.NAME); if (name != null) { final String nameAttr = (String) name; if (parserState == ParserState.INIT && ("method_summary".equals(nameAttr) || "method.summary".equals(nameAttr))) { parserState = ParserState.METHOD_SUMMARY; } else if (parserState == ParserState.METHOD) { if (methodWithTypes == null) { final String hrefAttr = (String) attributes.getAttribute(HTML.Attribute.HREF); if (hrefAttr != null && hrefAttr.contains(hrefPattern)) { // unescape HTML String methodSignature = hrefAttr.substring(hrefAttr.indexOf('#') + 1); final int firstHyphen = methodSignature.indexOf('-'); if (firstHyphen != -1) { final int lastHyphen = methodSignature.lastIndexOf('-'); methodSignature = methodSignature.substring(0, firstHyphen) + "(" + methodSignature.substring(firstHyphen + 1, lastHyphen) + ")"; methodSignature = methodSignature.replaceAll("-", ","); } // support varargs if (methodSignature.contains("...)")) { methodSignature = methodSignature.replaceAll("\\.\\.\\.\\)", "[])"); } // map Java8 array types if (methodSignature.contains(":A")) { methodSignature = methodSignature.replaceAll(":A", "[]"); } methodWithTypes = unescapeHtml(methodSignature); } } else { final String title = (String) attributes.getAttribute(HTML.Attribute.TITLE); if (title != null) { // append package name to type name text methodTextBuilder.append(title.substring(title.lastIndexOf(' '))).append('.'); } } } } } else if (parserState == ParserState.METHOD_SUMMARY && HTML.Tag.CODE.equals(htmlTag)) { parserState = ParserState.METHOD; } } } private static String unescapeHtml(String htmlString) { String result = StringEscapeUtils.unescapeHtml(htmlString).replaceAll(NON_BREAKING_SPACE, " ") .replaceAll(JAVA6_NON_BREAKING_SPACE, " "); try { result = URLDecoder.decode(result, "UTF-8"); } catch (UnsupportedEncodingException ignored) { } return result; } @Override protected void handleEmptyTag(TagElement tag) { if (parserState == ParserState.METHOD && HTML.Tag.CODE.equals(tag.getHTMLTag())) { if (methodWithTypes != null) { // process collected method data methods.add(methodWithTypes); this.methodText.put(methodWithTypes, getArgSignature()); // clear the text builder for next method methodTextBuilder.delete(0, methodTextBuilder.length()); methodWithTypes = null; } parserState = ParserState.METHOD_SUMMARY; } else if (parserState == ParserState.METHOD_SUMMARY && HTML.Tag.TABLE.equals(tag.getHTMLTag())) { // end of method summary table parserState = ParserState.INIT; } } private String getArgSignature() { final String typeString = methodWithTypes.substring(methodWithTypes.indexOf('(') + 1, methodWithTypes.indexOf(')')); if (typeString.isEmpty()) { return "()"; } // unescape HTML method text String plainText = unescapeHtml(methodTextBuilder.toString()); // support varargs if (plainText.contains("...")) { plainText = plainText.replaceAll("\\.\\.\\.", "[]"); } return plainText.substring(plainText.indexOf('('), plainText.indexOf(')') + 1); } @Override protected void handleText(char[] text) { if (parserState == ParserState.METHOD && methodWithTypes != null) { methodTextBuilder.append(text); } } @Override protected void handleError(int ln, String msg) { if (msg.startsWith("exception ")) { this.errorMessage = "Exception parsing Javadoc line " + ln + ": " + msg; } } public String getErrorMessage() { return errorMessage; } public List<String> getMethods() { return methods; } public Map<String, String> getMethodText() { return methodText; } private static enum ParserState { INIT, METHOD_SUMMARY, METHOD } }