| /* |
| * 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 javax.el; |
| |
| import java.util.HashMap; |
| import java.util.List; |
| import java.util.Map; |
| |
| public class LambdaExpression { |
| |
| private final List<String> formalParameters; |
| private final ValueExpression expression; |
| private final Map<String,Object> nestedArguments = new HashMap<>(); |
| private ELContext context = null; |
| |
| public LambdaExpression(List<String> formalParameters, |
| ValueExpression expression) { |
| this.formalParameters = formalParameters; |
| this.expression = expression; |
| |
| } |
| |
| public void setELContext(ELContext context) { |
| this.context = context; |
| } |
| |
| @SuppressWarnings("null") // args[i] can't be null due to earlier checks |
| public Object invoke(ELContext context, Object... args) |
| throws ELException { |
| |
| if (context == null) { |
| throw new NullPointerException(); |
| } |
| |
| int formalParamCount = 0; |
| if (formalParameters != null) { |
| formalParamCount = formalParameters.size(); |
| } |
| |
| int argCount = 0; |
| if (args != null) { |
| argCount = args.length; |
| } |
| |
| if (formalParamCount > argCount) { |
| throw new ELException(Util.message(context, |
| "lambdaExpression.tooFewArgs", |
| Integer.valueOf(argCount), |
| Integer.valueOf(formalParamCount))); |
| } |
| |
| // Build the argument map |
| // Start with the arguments from any outer expressions so if there is |
| // any overlap the local arguments have priority |
| Map<String,Object> lambdaArguments = new HashMap<>(); |
| lambdaArguments.putAll(nestedArguments); |
| for (int i = 0; i < formalParamCount; i++) { |
| lambdaArguments.put(formalParameters.get(i), args[i]); |
| } |
| |
| context.enterLambdaScope(lambdaArguments); |
| |
| try { |
| Object result = expression.getValue(context); |
| // Make arguments from this expression available to any nested |
| // expression |
| if (result instanceof LambdaExpression) { |
| ((LambdaExpression) result).nestedArguments.putAll( |
| lambdaArguments); |
| } |
| return result; |
| } finally { |
| context.exitLambdaScope(); |
| } |
| } |
| |
| public java.lang.Object invoke(Object... args) { |
| return invoke (context, args); |
| } |
| } |