001/* 002 * Copyright 2002-2017 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.aop.support; 018 019import java.io.Serializable; 020 021import org.springframework.lang.Nullable; 022 023/** 024 * Abstract superclass for expression pointcuts, 025 * offering location and expression properties. 026 * 027 * @author Rod Johnson 028 * @author Rob Harrop 029 * @since 2.0 030 * @see #setLocation 031 * @see #setExpression 032 */ 033@SuppressWarnings("serial") 034public abstract class AbstractExpressionPointcut implements ExpressionPointcut, Serializable { 035 036 @Nullable 037 private String location; 038 039 @Nullable 040 private String expression; 041 042 043 /** 044 * Set the location for debugging. 045 */ 046 public void setLocation(@Nullable String location) { 047 this.location = location; 048 } 049 050 /** 051 * Return location information about the pointcut expression 052 * if available. This is useful in debugging. 053 * @return location information as a human-readable String, 054 * or {@code null} if none is available 055 */ 056 @Nullable 057 public String getLocation() { 058 return this.location; 059 } 060 061 public void setExpression(@Nullable String expression) { 062 this.expression = expression; 063 try { 064 onSetExpression(expression); 065 } 066 catch (IllegalArgumentException ex) { 067 // Fill in location information if possible. 068 if (this.location != null) { 069 throw new IllegalArgumentException("Invalid expression at location [" + this.location + "]: " + ex); 070 } 071 else { 072 throw ex; 073 } 074 } 075 } 076 077 /** 078 * Called when a new pointcut expression is set. 079 * The expression should be parsed at this point if possible. 080 * <p>This implementation is empty. 081 * @param expression the expression to set 082 * @throws IllegalArgumentException if the expression is invalid 083 * @see #setExpression 084 */ 085 protected void onSetExpression(@Nullable String expression) throws IllegalArgumentException { 086 } 087 088 /** 089 * Return this pointcut's expression. 090 */ 091 @Override 092 @Nullable 093 public String getExpression() { 094 return this.expression; 095 } 096 097}