Java tutorial
/* * Copyright 2013, The gwtquery team. * * 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.cgxlib.xq.rebind; /* * #%L * CGXlib * %% * Copyright (C) 2016 CGXlib (http://www.cgxlib.com) * %% * 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. * #L% Code is originally from gwtquery, and modified by CGXlib team. */ import com.cgxlib.xq.client.builders.JsniBundle.LibrarySource; import com.cgxlib.xq.client.builders.JsniBundle.MethodSource; import com.google.gwt.core.ext.Generator; import com.google.gwt.core.ext.GeneratorContext; import com.google.gwt.core.ext.TreeLogger; import com.google.gwt.core.ext.UnableToCompleteException; import com.google.gwt.core.ext.typeinfo.JClassType; import com.google.gwt.core.ext.typeinfo.JMethod; import com.google.gwt.core.ext.typeinfo.TypeOracle; import com.google.gwt.user.rebind.ClassSourceFileComposerFactory; import com.google.gwt.user.rebind.SourceWriter; import org.apache.commons.io.output.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.PrintWriter; import java.net.HttpURLConnection; import java.net.URL; import java.util.zip.GZIPInputStream; import java.util.zip.InflaterInputStream; /** * Generates an implementation of a user-defined interface <code>T</code> that * extends {@link JsniBundle}. * <p/> * The generated implementation includes hand-written external js-files into * jsni methods so as those files can take advantage of gwt compiler optimizations. */ public class JsniBundleGenerator extends Generator { public String generate(TreeLogger logger, GeneratorContext context, String requestedClass) throws UnableToCompleteException { TypeOracle oracle = context.getTypeOracle(); JClassType clazz = oracle.findType(requestedClass); String packageName = clazz.getPackage().getName(); String className = clazz.getName().replace('.', '_') + "_Impl"; String fullName = packageName + "." + className; PrintWriter pw = context.tryCreate(logger, packageName, className); if (pw != null) { ClassSourceFileComposerFactory fact = new ClassSourceFileComposerFactory(packageName, className); if (clazz.isInterface() != null) { fact.addImplementedInterface(requestedClass); } else { fact.setSuperclass(requestedClass); } SourceWriter sw = fact.createSourceWriter(context, pw); if (sw != null) { for (JMethod method : clazz.getMethods()) { LibrarySource librarySource = method.getAnnotation(LibrarySource.class); String value, prepend, postpend; String replace[]; if (librarySource != null) { value = librarySource.value(); prepend = librarySource.prepend(); postpend = librarySource.postpend(); replace = librarySource.replace(); } else { MethodSource methodSource = method.getAnnotation(MethodSource.class); if (methodSource != null) { value = methodSource.value(); prepend = methodSource.prepend(); postpend = methodSource.postpend(); replace = methodSource.replace(); } else { continue; } } try { // Read the javascript content String content = getContent(logger, packageName.replace(".", "/"), value); // Adjust javascript so as we can introduce it in a JSNI comment block without // breaking java syntax. String jsni = parseJavascriptSource(content); for (int i = 0; i < replace.length - 1; i += 2) { jsni = jsni.replaceAll(replace[i], replace[i + 1]); } pw.println(method.toString().replace("abstract", "native") + "/*-{"); pw.println(prepend); pw.println(jsni); pw.println(postpend); pw.println("}-*/;"); } catch (Exception e) { logger.log(TreeLogger.ERROR, "Error parsing javascript source: " + value + " " + e.getMessage()); throw new UnableToCompleteException(); } } } sw.commit(logger); } return fullName; } /** * Get the content of a javascript source. It supports remote sources hosted in CDN's. */ private String getContent(TreeLogger logger, String path, String src) throws UnableToCompleteException { HttpURLConnection connection = null; InputStream in = null; try { if (!src.matches("(?i)https?://.*")) { String file = path + "/" + src; logger.log(TreeLogger.INFO, getClass().getSimpleName() + " - importing external javascript: " + file); in = this.getClass().getClassLoader().getResourceAsStream(file); if (in == null) { logger.log(TreeLogger.ERROR, "Unable to read javascript file: " + file); } } else { logger.log(TreeLogger.INFO, getClass().getSimpleName() + " - downloading external javascript: " + src); URL url = new URL(src); connection = (HttpURLConnection) url.openConnection(); connection.setRequestProperty("Accept-Encoding", "gzip, deflate"); connection.setRequestProperty("Host", url.getHost()); connection.setConnectTimeout(3000); connection.setReadTimeout(3000); int status = connection.getResponseCode(); if (status != HttpURLConnection.HTTP_OK) { logger.log(TreeLogger.ERROR, "Server Error: " + status + " " + connection.getResponseMessage()); throw new UnableToCompleteException(); } String encoding = connection.getContentEncoding(); in = connection.getInputStream(); if ("gzip".equalsIgnoreCase(encoding)) { in = new GZIPInputStream(in); } else if ("deflate".equalsIgnoreCase(encoding)) { in = new InflaterInputStream(in); } } return inputStreamToString(in); } catch (IOException e) { logger.log(TreeLogger.ERROR, "Error: " + e.getMessage()); throw new UnableToCompleteException(); } finally { if (connection != null) { connection.disconnect(); } } } /** * Adapt a java-script block which could produce a syntax error when * embedding it in a JSNI block. * <p/> * The objective is to replace any 'c' comment-ending occurrence to avoid closing * JSNI comment blocks prematurely. * <p/> * A Regexp based parser is not reliable, this approach is better and faster. */ // Note: this comment is intentionally using c++ style to allow writing the '*/' sequence. // // - Remove C comments: /* ... */ // - Remove C++ comments: // ... // - Escape certain strings: '...*/...' to '...*' + '/...' // - Rewrite inline regex: /...*/igm to new RegExp('...*' + 'igm'); private String parseJavascriptSource(String js) throws Exception { boolean isJS = true; boolean isSingQuot = false; boolean isDblQuot = false; boolean isSlash = false; boolean isCComment = false; boolean isCPPComment = false; boolean isRegex = false; boolean isOper = false; StringBuilder ret = new StringBuilder(); String tmp = ""; Character last = 0; Character prev = 0; for (int i = 0, l = js.length(); i < l; i++) { Character c = js.charAt(i); String out = c.toString(); if (isJS) { isDblQuot = c == '"'; isSingQuot = c == '\''; isSlash = c == '/'; isJS = !isDblQuot && !isSingQuot && !isSlash; if (!isJS) { out = tmp = ""; isCPPComment = isCComment = isRegex = false; } } else if (isSingQuot) { isJS = !(isSingQuot = last == '\\' || c != '\''); if (isJS) out = escapeQuotedString(tmp, c); else tmp += c; } else if (isDblQuot) { isJS = !(isDblQuot = last == '\\' || c != '"'); if (isJS) out = escapeQuotedString(tmp, c); else tmp += c; } else if (isSlash) { if (!isCPPComment && !isCComment && !isRegex && !isOper) { isCPPComment = c == '/'; isCComment = c == '*'; isOper = !isCPPComment && !isCComment && !"=(&|?:;},".contains("" + prev); isRegex = !isCPPComment && !isCComment && !isOper; } if (isOper) { isJS = !(isSlash = isOper = false); out = "" + last + c; } else if (isCPPComment) { isJS = !(isSlash = isCPPComment = c != '\n'); if (isJS) out = "\n"; } else if (isCComment) { isSlash = isCComment = !(isJS = (last == '*' && c == '/')); if (isJS) out = ""; } else if (isRegex) { isJS = !(isSlash = isRegex = (last == '\\' || c != '/')); if (isJS) { String mod = ""; while (++i < l) { c = js.charAt(i); if ("igm".contains("" + c)) mod += c; else break; } out = escapeInlineRegex(tmp, mod) + c; } else { tmp += c; } } else { isJS = true; } } if (isJS) { ret.append(out); } if (last != ' ') { prev = last; } last = prev == '\\' && c == '\\' ? 0 : c; } return ret.toString(); } private String escapeQuotedString(String s, Character quote) { return quote + s.replace("*/", "*" + quote + " + " + quote + "/") + quote; } private String escapeInlineRegex(String s, String mod) { if (s.endsWith("*")) { return "new RegExp('" + s.replace("\\", "\\\\") + "','" + mod + "')"; } else { return '/' + s + '/' + mod; } } private String inputStreamToString(InputStream in) throws IOException { ByteArrayOutputStream bytes = new ByteArrayOutputStream(); byte[] buffer = new byte[4096]; int read = in.read(buffer); while (read != -1) { bytes.write(buffer, 0, read); read = in.read(buffer); } in.close(); return bytes.toString(); } }