Java tutorial
/** * This file is part of pwt. * * pwt is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser * General Public License as published by the Free Software Foundation, either version 3 of the * License, or (at your option) any later version. * * pwt 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 Lesser * General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License along with pwt. If not, * see <http://www.gnu.org/licenses/>. */ package fr.putnami.pwt.plugin.rest.rebind; import com.google.common.base.Objects; import com.google.common.collect.Lists; import com.google.common.collect.Sets; import com.google.gwt.core.client.GWT; 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.typeinfo.JClassType; import com.google.gwt.core.ext.typeinfo.JMethod; import com.google.gwt.core.ext.typeinfo.JParameter; import com.google.gwt.core.ext.typeinfo.JParameterizedType; import com.google.gwt.core.ext.typeinfo.JPrimitiveType; import com.google.gwt.core.ext.typeinfo.JType; import com.google.gwt.user.rebind.ClassSourceFileComposerFactory; import com.google.gwt.user.rebind.SourceWriter; import org.fusesource.restygwt.client.Method; import org.fusesource.restygwt.client.REST; import java.io.PrintWriter; import java.util.Arrays; import java.util.Collection; import java.util.Set; import fr.putnami.pwt.core.service.client.AbstractServiceBinder; import fr.putnami.pwt.core.service.client.CallbackAdapter; import fr.putnami.pwt.core.service.client.annotation.AsyncHandler; import fr.putnami.pwt.core.service.client.annotation.QuietCommand; import fr.putnami.pwt.plugin.rest.client.CompositeMethodCallback; import fr.putnami.pwt.plugin.rest.client.MethodCallbackAdapter; public class RestServiceBinderCreator { private final JClassType serviceType; private final JClassType serviceBinderType; private final JClassType handlerType; private String proxyModelQualifiedName; private Collection<JType> imports = Sets.newHashSet(); public RestServiceBinderCreator(JClassType serviceBinderType, JClassType serviceType, JClassType handlerType) { this.serviceBinderType = serviceBinderType; this.serviceType = serviceType; this.handlerType = handlerType; this.proxyModelQualifiedName = this.handlerType.getQualifiedSourceName() + "_" + this.serviceType.getSimpleSourceName() + "_ServiceBinder"; } public String create(TreeLogger logger, GeneratorContext context) { PrintWriter printWriter = this.getPrintWriter(logger, context); if (printWriter == null) { return this.proxyModelQualifiedName; } this.collectImports(); SourceWriter srcWriter = this.getSourceWriter(printWriter, context); srcWriter.indent(); srcWriter.println(); this.generateCreateService(srcWriter); srcWriter.println(); this.generateServiceImplementation(logger, srcWriter); this.generateServiceImplementationWithCallback(srcWriter); srcWriter.outdent(); srcWriter.commit(logger); return this.proxyModelQualifiedName; } private void generateCreateService(SourceWriter srcWriter) { srcWriter.println("private final %s restService = GWT.create(%s.class);", this.serviceType.getQualifiedSourceName(), this.serviceType.getQualifiedSourceName()); } private static class CallbackMethod { String successMethodName; String failureMethodName; @Override public int hashCode() { return Objects.hashCode(this.successMethodName, this.failureMethodName); } @Override public boolean equals(Object obj) { if (obj instanceof CallbackMethod) { CallbackMethod other = (CallbackMethod) obj; return Objects.equal(this.successMethodName, other.successMethodName) && Objects.equal(this.failureMethodName, other.failureMethodName); } return false; } } private Collection<CallbackMethod> listCallbackMethods(TreeLogger logger, JMethod serviceMethod) { Collection<CallbackMethod> callbackMethods = Sets.newHashSet(); for (JMethod handlerMethod : this.handlerType.getOverridableMethods()) { AsyncHandler serviceHandlerAnnotation = handlerMethod.getAnnotation(AsyncHandler.class); if (serviceHandlerAnnotation == null) { continue; } if (handlerMethod.getParameterTypes() == null || handlerMethod.getParameterTypes().length != 1) { logger.log(Type.WARN, "the service handler " + this.handlerType.getSimpleSourceName() + "." + handlerMethod.getName() + " skipped : shall have one parameter"); continue; } String methodName = serviceHandlerAnnotation.method(); if (AsyncHandler.DEFAULT_METHOD_NAME.equals(methodName)) { methodName = handlerMethod.getName(); methodName = methodName.replaceFirst("on", ""); if (methodName.lastIndexOf("Event") != -1) { methodName = methodName.substring(0, methodName.lastIndexOf("Event")); } else if (methodName.lastIndexOf("Thrown") != -1) { methodName = methodName.substring(0, methodName.lastIndexOf("Thrown")); } methodName = methodName.substring(0, 1).toLowerCase() + methodName.substring(1); } if (serviceMethod.getName().equals(methodName)) { JType paramType = handlerMethod.getParameterTypes()[0]; String paramQualifiedName = paramType.getQualifiedSourceName(); JType returnType = serviceMethod.getReturnType(); String returnQualifiedName = returnType.getQualifiedSourceName(); if (returnType instanceof JPrimitiveType) { returnQualifiedName = ((JPrimitiveType) returnType).getQualifiedBoxedSourceName(); } if (returnQualifiedName.equals(paramQualifiedName)) { CallbackMethod method = new CallbackMethod(); method.successMethodName = handlerMethod.getName(); callbackMethods.add(method); continue; } else if (Throwable.class.getCanonicalName().equals(paramQualifiedName)) { CallbackMethod method = new CallbackMethod(); method.failureMethodName = handlerMethod.getName(); callbackMethods.add(method); } } } return callbackMethods; } private void generateServiceImplementationWithCallback(SourceWriter srcWriter) { for (JMethod method : this.serviceBinderType.getMethods()) { JParameter[] methodParams = method.getParameters(); JParameter callbackParam = null; if (methodParams != null && methodParams.length > 0) { callbackParam = methodParams[methodParams.length - 1]; } if (callbackParam == null) { break; } this.writeStartMethod(srcWriter, method); this.writeMethodCallback(srcWriter, method, null, callbackParam); this.writeMethodCall(srcWriter, method, callbackParam); this.writeEndMethod(srcWriter, method); } } private void generateServiceImplementation(TreeLogger logger, SourceWriter srcWriter) { Set<String> addedMethods = Sets.newHashSet(); for (JMethod method : this.serviceType.getOverridableMethods()) { if (!addedMethods.contains(method.getName())) { addedMethods.add(method.getName()); this.writeStartMethod(srcWriter, method); this.writeMethodCallback(srcWriter, method, this.listCallbackMethods(logger, method), null); this.writeMethodCall(srcWriter, method, null); this.writeEndMethod(srcWriter, method); } } } private void writeStartMethod(SourceWriter srcWriter, JMethod method) { srcWriter.print("public %s %s(", this.typeAsString(method.getReturnType(), false), method.getName()); int i = 0; for (JParameter parameter : method.getParameters()) { if (i++ > 0) { srcWriter.print(", "); } srcWriter.print("%s $%d_%s", this.typeAsString(parameter.getType(), false), i, parameter.getName()); } srcWriter.println("){"); srcWriter.indent(); } private void writeMethodCall(SourceWriter srcWriter, JMethod method, JParameter callbackParam) { srcWriter.print("REST.<%s> withCallback(compositeCallback).call(restService).%s(", this.typeAsString(method.getReturnType(), true), method.getName()); int i = 0; for (JParameter parameter : method.getParameters()) { if (!parameter.equals(callbackParam)) { if (i++ > 0) { srcWriter.print(", "); } srcWriter.print("$%d_%s", i, parameter.getName()); } } srcWriter.println(");"); } private void writeEndMethod(SourceWriter srcWriter, JMethod method) { if (method.getReturnType().equals(JPrimitiveType.BOOLEAN)) { srcWriter.println("return false;"); } else if (method.getReturnType().equals(JPrimitiveType.BYTE) || method.getReturnType().equals(JPrimitiveType.CHAR) || method.getReturnType().equals(JPrimitiveType.DOUBLE) || method.getReturnType().equals(JPrimitiveType.FLOAT) || method.getReturnType().equals(JPrimitiveType.INT) || method.getReturnType().equals(JPrimitiveType.LONG) || method.getReturnType().equals(JPrimitiveType.SHORT)) { srcWriter.println("return 0;"); } else if (!method.getReturnType().equals(JPrimitiveType.VOID)) { srcWriter.println("return null;"); } srcWriter.outdent(); srcWriter.println("}"); } private void writeMethodCallback(SourceWriter srcWriter, JMethod method, Collection<CallbackMethod> callbackSuccess, JParameter callbackParam) { boolean quiet = method.getAnnotation(QuietCommand.class) != null; srcWriter.print("CompositeMethodCallback compositeCallback = new CompositeMethodCallback("); srcWriter.print("%s, ", quiet); srcWriter.println("Lists.newArrayList("); srcWriter.indent(); int i = 0; if (callbackParam != null) { srcWriter.print("$%d_%s", method.getParameters().length, callbackParam); i++; } if (callbackSuccess != null) { for (CallbackMethod callbackMethod : callbackSuccess) { if (i++ > 0) { srcWriter.print(", "); } srcWriter.println("new MethodCallbackAdapter<%s>(){", this.typeAsString(method.getReturnType(), true)); srcWriter.indent(); if (callbackMethod.successMethodName != null) { srcWriter.println("public void onSuccess(Method method, %s result){", this.typeAsString(method.getReturnType(), true)); srcWriter.indent(); srcWriter.println("getHandler().%s(result);", callbackMethod.successMethodName); srcWriter.outdent(); srcWriter.println("}"); } if (callbackMethod.failureMethodName != null) { srcWriter.println("public void onFailure(Method method, Throwable caught){", this.typeAsString(method.getReturnType(), true)); srcWriter.indent(); srcWriter.println("getHandler().%s(caught);", callbackMethod.failureMethodName); srcWriter.outdent(); srcWriter.println("}"); } srcWriter.outdent(); srcWriter.print("}"); } } srcWriter.outdent(); srcWriter.println("));"); } private String typeAsString(JType type, boolean translatePrimitives) { StringBuilder sb = new StringBuilder(); if (translatePrimitives && type instanceof JPrimitiveType) { sb.append(((JPrimitiveType) type).getQualifiedBoxedSourceName()); } else { sb.append(type.getSimpleSourceName()); if (type instanceof JParameterizedType) { JParameterizedType parameterizedType = (JParameterizedType) type; sb.append("<"); int i = 0; for (JType paramType : parameterizedType.getTypeArgs()) { if (i++ > 0) { sb.append(", "); } sb.append(this.typeAsString(paramType, false)); } sb.append(">"); } } return sb.toString(); } private void collectImports() { Collection<JType> toImports = Sets.newHashSet(); for (JMethod method : this.serviceType.getOverridableMethods()) { toImports.add(method.getReturnType()); for (JParameter parameter : method.getParameters()) { toImports.add(parameter.getType()); } } this.imports.addAll(toImports); for (JType importType : this.imports) { if (importType instanceof JParameterizedType) { JParameterizedType parameterizedType = (JParameterizedType) importType; for (JType paramType : parameterizedType.getTypeArgs()) { toImports.add(paramType); } } } this.imports.addAll(toImports); } private SourceWriter getSourceWriter(PrintWriter printWriter, GeneratorContext ctx) { String packageName = this.handlerType.getPackage().getName(); String className = this.proxyModelQualifiedName.indexOf('.') == -1 ? this.proxyModelQualifiedName : this.proxyModelQualifiedName.substring(this.proxyModelQualifiedName.lastIndexOf('.') + 1, this.proxyModelQualifiedName.length()); ClassSourceFileComposerFactory composerFactory = new ClassSourceFileComposerFactory(packageName, className); composerFactory.addImport(AbstractServiceBinder.class.getName()); composerFactory.addImport(Arrays.class.getName()); composerFactory.addImport(Lists.class.getName()); composerFactory.addImport(MethodCallbackAdapter.class.getName()); composerFactory.addImport(Method.class.getName()); composerFactory.addImport(CompositeMethodCallback.class.getName()); composerFactory.addImport(CallbackAdapter.class.getName()); composerFactory.addImport(REST.class.getName()); composerFactory.addImport(GWT.class.getName()); composerFactory.addImport(this.serviceType.getQualifiedSourceName()); composerFactory.addImport(this.serviceBinderType.getQualifiedSourceName()); for (JType jType : this.imports) { if (jType.isPrimitive() != null) { continue; } composerFactory.addImport(jType.getQualifiedSourceName()); } composerFactory.setSuperclass(AbstractServiceBinder.class.getSimpleName() + "<" + this.handlerType.getSimpleSourceName() + ", " + this.serviceType.getSimpleSourceName() + ">"); composerFactory.addImplementedInterface(this.serviceType.getSimpleSourceName()); composerFactory.addImplementedInterface(this.serviceBinderType.getSimpleSourceName()); return composerFactory.createSourceWriter(ctx, printWriter); } private PrintWriter getPrintWriter(TreeLogger logger, GeneratorContext ctx) { String packageName = this.proxyModelQualifiedName.indexOf('.') == -1 ? "" : this.proxyModelQualifiedName.substring(0, this.proxyModelQualifiedName.lastIndexOf('.')); String className = this.proxyModelQualifiedName.indexOf('.') == -1 ? this.proxyModelQualifiedName : this.proxyModelQualifiedName.substring(this.proxyModelQualifiedName.lastIndexOf('.') + 1, this.proxyModelQualifiedName.length()); return ctx.tryCreate(logger, packageName, className); } }