Java tutorial
/* * Copyright 2000-2018 Vaadin Ltd. * * 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.vaadin.client.communication; import java.util.Collection; import java.util.logging.Logger; import com.vaadin.client.ApplicationConnection; import com.vaadin.client.ConnectorMap; import com.vaadin.client.ServerConnector; import com.vaadin.client.metadata.Method; import com.vaadin.client.metadata.NoDataException; import com.vaadin.client.metadata.Type; import com.vaadin.shared.communication.ClientRpc; import com.vaadin.shared.communication.MethodInvocation; import elemental.json.JsonArray; /** * Client side RPC manager that can invoke methods based on RPC calls received * from the server. * * A GWT generator is used to create an implementation of this class at * run-time. * * @since 7.0 */ public class RpcManager { /** * Perform server to client RPC invocation. * * @param invocation * method to invoke */ public void applyInvocation(MethodInvocation invocation, ServerConnector connector) { Method method = getMethod(invocation); Collection<ClientRpc> implementations = connector.getRpcImplementations(invocation.getInterfaceName()); try { for (ClientRpc clientRpc : implementations) { method.invoke(clientRpc, invocation.getParameters()); } } catch (NoDataException e) { throw new IllegalStateException("There is no information about " + method.getSignature() + ". Did you remember to compile the right widgetset?", e); } } /** * Gets the method that an invocation targets. * * @param invocation * the method invocation to get the method for * * @since 7.4 * @return the method targeted by this invocation */ public static Method getMethod(MethodInvocation invocation) { // Implemented here instead of in MethodInovcation since it's in shared // and can't use our Method class. Type type = new Type(invocation.getInterfaceName(), null); Method method = type.getMethod(invocation.getMethodName()); return method; } private static String getSignature(MethodInvocation invocation) { return invocation.getInterfaceName() + "." + invocation.getMethodName(); } public Type[] getParameterTypes(MethodInvocation invocation) { Method method = getMethod(invocation); try { Type[] parameterTypes = method.getParameterTypes(); return parameterTypes; } catch (NoDataException e) { throw new IllegalStateException("There is no information about " + method.getSignature() + ". Did you remember to compile the right widgetset?", e); } } public MethodInvocation parseAndApplyInvocation(JsonArray rpcCall, ApplicationConnection connection) { ConnectorMap connectorMap = ConnectorMap.get(connection); String connectorId = rpcCall.getString(0); String interfaceName = rpcCall.getString(1); String methodName = rpcCall.getString(2); JsonArray parametersJson = rpcCall.getArray(3); ServerConnector connector = connectorMap.getConnector(connectorId); MethodInvocation invocation = new MethodInvocation(connectorId, interfaceName, methodName); if (connector instanceof HasJavaScriptConnectorHelper) { ((HasJavaScriptConnectorHelper) connector).getJavascriptConnectorHelper().invokeJsRpc(invocation, parametersJson); } else { if (connector == null) { throw new IllegalStateException( "Target connector (" + connector + ") not found for RCC to " + getSignature(invocation)); } parseMethodParameters(invocation, parametersJson, connection); getLogger().info("Server to client RPC call: " + invocation); applyInvocation(invocation, connector); } return invocation; } private void parseMethodParameters(MethodInvocation methodInvocation, JsonArray parametersJson, ApplicationConnection connection) { Type[] parameterTypes = getParameterTypes(methodInvocation); Object[] parameters = new Object[parametersJson.length()]; for (int j = 0; j < parametersJson.length(); ++j) { parameters[j] = JsonDecoder.decodeValue(parameterTypes[j], parametersJson.get(j), null, connection); } methodInvocation.setParameters(parameters); } private static Logger getLogger() { return Logger.getLogger(RpcManager.class.getName()); } }