/*
* Copyright 2002-2008 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
*
* 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 org.springframework.core;
import java.io.PrintWriter;
import java.io.StringWriter;
import org.springframework.util.Assert;
/**
* Static factory to conceal the automatic choice of the ControlFlow
* implementation class.
*
* <p>This implementation always uses the efficient Java 1.4 StackTraceElement
* mechanism for analyzing control flows.
*
* @author Rod Johnson
* @author Juergen Hoeller
* @since 02.02.2004
*/
public abstract class ControlFlowFactory {
/**
* Return an appropriate {@link ControlFlow} instance.
*/
public static ControlFlow createControlFlow() {
return new Jdk14ControlFlow();
}
/**
* Utilities for cflow-style pointcuts. Note that such pointcuts are
* 5-10 times more expensive to evaluate than other pointcuts, as they require
* analysis of the stack trace (through constructing a new throwable).
* However, they are useful in some cases.
* <p>This implementation uses the StackTraceElement class introduced in Java 1.4.
* @see java.lang.StackTraceElement
*/
static class Jdk14ControlFlow implements ControlFlow {
private StackTraceElement[] stack;
public Jdk14ControlFlow() {
this.stack = new Throwable().getStackTrace();
}
/**
* Searches for class name match in a StackTraceElement.
*/
public boolean under(Class clazz) {
Assert.notNull(clazz, "Class must not be null");
String className = clazz.getName();
for (int i = 0; i < stack.length; i++) {
if (this.stack[i].getClassName().equals(className)) {
return true;
}
}
return false;
}
/**
* Searches for class name match plus method name match
* in a StackTraceElement.
*/
public boolean under(Class clazz, String methodName) {
Assert.notNull(clazz, "Class must not be null");
Assert.notNull(methodName, "Method name must not be null");
String className = clazz.getName();
for (int i = 0; i < this.stack.length; i++) {
if (this.stack[i].getClassName().equals(className) &&
this.stack[i].getMethodName().equals(methodName)) {
return true;
}
}
return false;
}
/**
* Leave it up to the caller to decide what matches.
* Caller must understand stack trace format, so there's less abstraction.
*/
public boolean underToken(String token) {
if (token == null) {
return false;
}
StringWriter sw = new StringWriter();
new Throwable().printStackTrace(new PrintWriter(sw));
String stackTrace = sw.toString();
return stackTrace.indexOf(token) != -1;
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder("Jdk14ControlFlow: ");
for (int i = 0; i < this.stack.length; i++) {
if (i > 0) {
sb.append("\n\t@");
}
sb.append(this.stack[i]);
}
return sb.toString();
}
}
}
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