Java tutorial
/** * Ext4j UI Library Copyright 2014, Alain Ekambi, and individual contributors as * indicated by the @authors tag. See the copyright.txt in the distribution for * a full listing of individual contributors. * * 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.ait.ext4j.rebind; import java.io.IOException; import java.io.InputStream; import java.io.PrintWriter; import java.net.URL; import com.ait.ext4j.client.template.Template; import com.ait.ext4j.client.template.TemplateResource; 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.TreeLogger.Type; import com.google.gwt.core.ext.UnableToCompleteException; import com.google.gwt.core.ext.typeinfo.JClassType; import com.google.gwt.core.ext.typeinfo.NotFoundException; import com.google.gwt.core.ext.typeinfo.TypeOracle; import com.google.gwt.dev.resource.Resource; import com.google.gwt.dev.util.Name; import com.google.gwt.dev.util.Util; import com.google.gwt.safehtml.shared.SafeHtml; import com.google.gwt.safehtml.shared.SafeHtmlUtils; import com.google.gwt.user.rebind.ClassSourceFileComposerFactory; import com.google.gwt.user.rebind.SourceWriter; /** * Generator class for Templates */ public class TemplateGenerator extends Generator { private static final String TEMPLATE_SUFFIX = ".html"; private JClassType templatesInterface; /** * Given a TemplateResource interface, return the path to its .html file, * suitable for any classloader to find it as a resource. If the .html does * not exist or is empty see if the template was declared inline. If no * content is found we throw an exception. */ private String getTemplateContent(GeneratorContext context, TreeLogger logger, JClassType interfaceType) throws UnableToCompleteException { String templateHtmlFile = null; TemplateResource annotation = interfaceType.getAnnotation(TemplateResource.class); if (annotation == null) { // if the interface is defined as a nested class, use the name of // the // enclosing type if (interfaceType.getEnclosingType() != null) { interfaceType = interfaceType.getEnclosingType(); } templateHtmlFile = slashify(interfaceType.getQualifiedBinaryName()) + TEMPLATE_SUFFIX; logger.log(TreeLogger.INFO, "Template : " + templateHtmlFile); InputStream stream = getTemplateResource(context, logger, templateHtmlFile); if (stream == null) { logger.log(Type.ERROR, "No data could be loaded - no data at path " + interfaceType.getQualifiedBinaryName() + TEMPLATE_SUFFIX); throw new UnableToCompleteException(); } return sanitize(Util.readStreamAsString(stream)); } else { // first we look at the HTML File templateHtmlFile = annotation.source(); if (templateHtmlFile.length() > 0) { if (!templateHtmlFile.endsWith(TEMPLATE_SUFFIX)) { logger.log(TreeLogger.ERROR, "Template file name must end with " + TEMPLATE_SUFFIX); throw new UnableToCompleteException(); } if (annotation.value().length() != 0) { logger.log(Type.WARN, "Found both source file and inline template, using source file"); } templateHtmlFile = slashify(interfaceType.getPackage().getName()) + "/" + templateHtmlFile; InputStream stream = getTemplateResource(context, logger, templateHtmlFile); return sanitize(Util.readStreamAsString(stream)); } else if (annotation.value().length() > 0) { return annotation.value(); } else { logger.log(Type.ERROR, "Template annotation found with no contents, cannot generate method , this may cause other failures."); } } return null; } private static String slashify(String s) { return s.replace(".", "/").replace("$", "."); } private static String sanitize(String input) { return input.replace("\n", "").replace("'", "\\'").replace("\"", "\\\""); } @Override public String generate(TreeLogger logger, GeneratorContext context, String typeName) throws UnableToCompleteException { TypeOracle oracle = context.getTypeOracle(); this.templatesInterface = oracle.findType(Name.getSourceNameForClass(Template.class)); JClassType interfaceType; try { interfaceType = oracle.getType(typeName); } catch (NotFoundException e) { throw new RuntimeException(e); } if (interfaceType.isInterface() == null) { logger.log(TreeLogger.ERROR, typeName + " is not an interface type"); throw new UnableToCompleteException(); } if (!interfaceType.isAssignableTo(templatesInterface)) { logger.log(Type.ERROR, "This isn't a Template subtype..."); throw new UnableToCompleteException(); } String content = getTemplateContent(context, logger, interfaceType); String packageName = interfaceType.getPackage().getName(); String className = "Template_For_" + interfaceType.getQualifiedSourceName().replace(".", "_"); ClassSourceFileComposerFactory composer = new ClassSourceFileComposerFactory(packageName, className); composer.addImport(SafeHtml.class.getName()); composer.addImport(SafeHtmlUtils.class.getName()); composer.addImplementedInterface(Template.class.getName()); PrintWriter pw = context.tryCreate(logger, packageName, className); SourceWriter sw = composer.createSourceWriter(context, pw); sw.println(" public SafeHtml getContent(){"); sw.println(" return SafeHtmlUtils.fromSafeConstant(\"" + content + "\");"); sw.println(" }"); sw.println(""); sw.println(""); sw.println(" public SafeHtml getSafeContent(){"); sw.println(" return SafeHtmlUtils.fromString(\"" + content + "\");"); sw.println(" }"); sw.commit(logger); return composer.getCreatedClassName(); } protected InputStream getTemplateResource(GeneratorContext context, TreeLogger l, String markerPath) throws UnableToCompleteException { // look for a local file first String path = slashify(markerPath); l.log(Type.INFO, "Current resource path : " + markerPath); Resource res = context.getResourcesOracle().getResourceMap().get(path); // if not a local path, try an absolute one if (res == null) { l.log(Type.INFO, "Resource is Null trying with URL "); URL url = Thread.currentThread().getContextClassLoader().getResource(markerPath); if (url == null) { l.log(Type.INFO, "URL seems to be null here ... hmmmmss"); return null; } try { return url.openStream(); } catch (IOException e) { l.log(Type.ERROR, "IO Exception occured", e); throw new UnableToCompleteException(); } } try { return res.openContents(); } catch (Exception e) { l.log(Type.ERROR, "Exception occured reading " + path, e); throw new UnableToCompleteException(); } } }