Java tutorial
/* * Copyright 2002-2017 the original author or authors. * * 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 * * https://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 org.springframework.aop.support; import java.io.Serializable; import org.springframework.lang.Nullable; /** * Abstract superclass for expression pointcuts, * offering location and expression properties. * * @author Rod Johnson * @author Rob Harrop * @since 2.0 * @see #setLocation * @see #setExpression */ @SuppressWarnings("serial") public abstract class AbstractExpressionPointcut implements ExpressionPointcut, Serializable { @Nullable private String location; @Nullable private String expression; /** * Set the location for debugging. */ public void setLocation(@Nullable String location) { this.location = location; } /** * Return location information about the pointcut expression * if available. This is useful in debugging. * @return location information as a human-readable String, * or {@code null} if none is available */ @Nullable public String getLocation() { return this.location; } public void setExpression(@Nullable String expression) { this.expression = expression; try { onSetExpression(expression); } catch (IllegalArgumentException ex) { // Fill in location information if possible. if (this.location != null) { throw new IllegalArgumentException("Invalid expression at location [" + this.location + "]: " + ex); } else { throw ex; } } } /** * Called when a new pointcut expression is set. * The expression should be parsed at this point if possible. * <p>This implementation is empty. * @param expression expression to set * @throws IllegalArgumentException if the expression is invalid * @see #setExpression */ protected void onSetExpression(@Nullable String expression) throws IllegalArgumentException { } /** * Return this pointcut's expression. */ @Override @Nullable public String getExpression() { return this.expression; } }