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 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
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 *      http://www.apache.org/licenses/LICENSE-2.0
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package org.springframework.expression.spel.ast;

import java.math.BigDecimal;
import java.math.BigInteger;

import org.springframework.expression.EvaluationException;
import org.springframework.expression.Operation;
import org.springframework.expression.TypedValue;
import org.springframework.expression.spel.ExpressionState;
import org.springframework.expression.spel.SpelEvaluationException;
import org.springframework.expression.spel.SpelMessage;
import org.springframework.util.Assert;

Increment operator. Can be used in a prefix or postfix form. This will throw appropriate exceptions if the operand in question does not support increment.
Author:Andy Clement, Juergen Hoeller, Giovanni Dall'Oglio Risso
Since:3.2
/** * Increment operator. Can be used in a prefix or postfix form. This will throw * appropriate exceptions if the operand in question does not support increment. * * @author Andy Clement * @author Juergen Hoeller * @author Giovanni Dall'Oglio Risso * @since 3.2 */
public class OpInc extends Operator { private final boolean postfix; // false means prefix public OpInc(int pos, boolean postfix, SpelNodeImpl... operands) { super("++", pos, operands); this.postfix = postfix; Assert.notEmpty(operands, "Operands must not be empty"); } @Override public TypedValue getValueInternal(ExpressionState state) throws EvaluationException { SpelNodeImpl operand = getLeftOperand(); ValueRef valueRef = operand.getValueRef(state); TypedValue typedValue = valueRef.getValue(); Object value = typedValue.getValue(); TypedValue returnValue = typedValue; TypedValue newValue = null; if (value instanceof Number) { Number op1 = (Number) value; if (op1 instanceof BigDecimal) { newValue = new TypedValue(((BigDecimal) op1).add(BigDecimal.ONE), typedValue.getTypeDescriptor()); } else if (op1 instanceof Double) { newValue = new TypedValue(op1.doubleValue() + 1.0d, typedValue.getTypeDescriptor()); } else if (op1 instanceof Float) { newValue = new TypedValue(op1.floatValue() + 1.0f, typedValue.getTypeDescriptor()); } else if (op1 instanceof BigInteger) { newValue = new TypedValue(((BigInteger) op1).add(BigInteger.ONE), typedValue.getTypeDescriptor()); } else if (op1 instanceof Long) { newValue = new TypedValue(op1.longValue() + 1L, typedValue.getTypeDescriptor()); } else if (op1 instanceof Integer) { newValue = new TypedValue(op1.intValue() + 1, typedValue.getTypeDescriptor()); } else if (op1 instanceof Short) { newValue = new TypedValue(op1.shortValue() + (short) 1, typedValue.getTypeDescriptor()); } else if (op1 instanceof Byte) { newValue = new TypedValue(op1.byteValue() + (byte) 1, typedValue.getTypeDescriptor()); } else { // Unknown Number subtype -> best guess is double increment newValue = new TypedValue(op1.doubleValue() + 1.0d, typedValue.getTypeDescriptor()); } } if (newValue == null) { try { newValue = state.operate(Operation.ADD, returnValue.getValue(), 1); } catch (SpelEvaluationException ex) { if (ex.getMessageCode() == SpelMessage.OPERATOR_NOT_SUPPORTED_BETWEEN_TYPES) { // This means the operand is not incrementable throw new SpelEvaluationException(operand.getStartPosition(), SpelMessage.OPERAND_NOT_INCREMENTABLE, operand.toStringAST()); } throw ex; } } // set the name value try { valueRef.setValue(newValue.getValue()); } catch (SpelEvaluationException see) { // If unable to set the value the operand is not writable (e.g. 1++ ) if (see.getMessageCode() == SpelMessage.SETVALUE_NOT_SUPPORTED) { throw new SpelEvaluationException(operand.getStartPosition(), SpelMessage.OPERAND_NOT_INCREMENTABLE); } else { throw see; } } if (!this.postfix) { // The return value is the new value, not the original value returnValue = newValue; } return returnValue; } @Override public String toStringAST() { return getLeftOperand().toStringAST() + "++"; } @Override public SpelNodeImpl getRightOperand() { throw new IllegalStateException("No right operand"); } }