001/** 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.camel.language.simple.ast; 018 019import org.apache.camel.CamelExchangeException; 020import org.apache.camel.Exchange; 021import org.apache.camel.Expression; 022import org.apache.camel.NoTypeConversionAvailableException; 023import org.apache.camel.language.simple.types.SimpleParserException; 024import org.apache.camel.language.simple.types.SimpleToken; 025import org.apache.camel.language.simple.types.UnaryOperatorType; 026import org.apache.camel.util.ObjectHelper; 027 028/** 029 * Represents an unary expression in the AST 030 */ 031public class UnaryExpression extends BaseSimpleNode { 032 033 private UnaryOperatorType operator; 034 private SimpleNode left; 035 036 public UnaryExpression(SimpleToken token) { 037 super(token); 038 operator = UnaryOperatorType.asOperator(token.getText()); 039 } 040 041 @Override 042 public String toString() { 043 if (left != null) { 044 return left + token.getText(); 045 } else { 046 return token.getText(); 047 } 048 } 049 050 /** 051 * Accepts the left node to this operator 052 * 053 * @param left the left node to accept 054 */ 055 public void acceptLeft(SimpleNode left) { 056 this.left = left; 057 } 058 059 public UnaryOperatorType getOperator() { 060 return operator; 061 } 062 063 @Override 064 public Expression createExpression(String expression) { 065 ObjectHelper.notNull(left, "left node", this); 066 067 final Expression leftExp = left.createExpression(expression); 068 069 if (operator == UnaryOperatorType.INC) { 070 return createIncExpression(leftExp); 071 } else if (operator == UnaryOperatorType.DEC) { 072 return createDecExpression(leftExp); 073 } 074 075 throw new SimpleParserException("Unknown unary operator " + operator, token.getIndex()); 076 } 077 078 private Expression createIncExpression(final Expression leftExp) { 079 return new Expression() { 080 @Override 081 public <T> T evaluate(Exchange exchange, Class<T> type) { 082 Number num = leftExp.evaluate(exchange, Number.class); 083 if (num != null) { 084 long val = num.longValue(); 085 val++; 086 087 // convert value back to same type as input as we want to preserve type 088 Object left = leftExp.evaluate(exchange, Object.class); 089 try { 090 left = exchange.getContext().getTypeConverter().mandatoryConvertTo(left.getClass(), exchange, val); 091 } catch (NoTypeConversionAvailableException e) { 092 throw ObjectHelper.wrapRuntimeCamelException(e); 093 } 094 095 // and return the result 096 return exchange.getContext().getTypeConverter().convertTo(type, left); 097 } 098 // cannot convert the expression as a number 099 Exception cause = new CamelExchangeException("Cannot evaluate " + leftExp + " as a number", exchange); 100 throw ObjectHelper.wrapRuntimeCamelException(cause); 101 } 102 103 @Override 104 public String toString() { 105 return left + operator.toString(); 106 } 107 }; 108 } 109 110 private Expression createDecExpression(final Expression leftExp) { 111 return new Expression() { 112 @Override 113 public <T> T evaluate(Exchange exchange, Class<T> type) { 114 Number num = leftExp.evaluate(exchange, Number.class); 115 if (num != null) { 116 long val = num.longValue(); 117 val--; 118 119 // convert value back to same type as input as we want to preserve type 120 Object left = leftExp.evaluate(exchange, Object.class); 121 try { 122 left = exchange.getContext().getTypeConverter().mandatoryConvertTo(left.getClass(), exchange, val); 123 } catch (NoTypeConversionAvailableException e) { 124 throw ObjectHelper.wrapRuntimeCamelException(e); 125 } 126 127 // and return the result 128 return exchange.getContext().getTypeConverter().convertTo(type, left); 129 } 130 // cannot convert the expression as a number 131 Exception cause = new CamelExchangeException("Cannot evaluate " + leftExp + " as a number", exchange); 132 throw ObjectHelper.wrapRuntimeCamelException(cause); 133 } 134 135 @Override 136 public String toString() { 137 return left + operator.toString(); 138 } 139 }; 140 } 141 142}