sviolet.thistle.util.reflect.MethodCaller Maven / Gradle / Ivy
/*
* Copyright (C) 2015-2020 S.Violet
*
* 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.
*
* Project GitHub: https://github.com/shepherdviolet/thistle
* Email: [email protected]
*/
package sviolet.thistle.util.reflect;
import java.util.Collection;
import java.util.Set;
/**
* 方法调用者工具
*
* @author S.Violet
*/
public class MethodCaller {
/**
* 常用的startsWithSkips: Spring动态代理类
*/
public static final String STARTS_WITH_SKIPS_SPRING_PROXY = "org.springframework.cglib.proxy.Proxy$ProxyImpl$$";
/**
* 忽略调用链前3个元素
*/
private static final int SKIP_ELEMENTS = 3;
/**
* 获取方法调用者信息(类名/方法名)
*
* 在A方法内调用MethodCaller.getMethodCaller(null, null)方法时, 可以得到A方法的调用者(是谁调用了A方法).
*
* 使用equalSkips参数跳过一些类: 假如A方法还会被B/C两个方法调用(封装), 我们想要知道是谁调用了A/B/C方法, 可以在A方法中
* 调用MethodCaller.getMethodCaller(equalSkips, null)获取调用者, equalSkips配置B/C方法所在类的类名. 示例:
*
*
* //推荐用HashSet, 性能较好
* private final Set equalSkips = new HashSet<>(Arrays.asList(
* AClass.class.getName(),
* BClass.class.getName()
* ));
*
* public void method(){
* String callerClassName = MethodCaller.getMethodCaller(equalSkips, null).getClassName();
* }
*
*
* 使用startsWithSkips参数跳过一些类: 假如A方法还会被B/C两个方法调用(封装), 我们想要知道是谁调用了A/B/C方法, 可以在A方法中
* 调用MethodCaller.getMethodCaller(null, startsWithSkips)获取调用者, startsWithSkips配置B/C方法所在类的类名的前缀. 示例:
*
*
* //推荐用ArrayList, 性能较好
* private final Collection startsWithSkips = Arrays.asList(
* "org.springframework.cglib.proxy.Proxy$ProxyImpl$$",
* "com.company.packagename."
* );
*
* public void method(){
* String callerClassName = MethodCaller.getMethodCaller(null, startsWithSkips).getClassName();
* }
*
*
* 另外, equalSkips和startsWithSkips参数可以同时使用.
*
* 关于性能, new Throwable().getStackTrace()性能较差(和抛出一个异常的开销差不多),
* 但微微比Thread.currentThread().getStackTrace()好一点点, 实测性能如下:
* 3.31GHz CPU 单线程
* 线程堆栈15层时 10000次 耗时112.33ms
* 线程堆栈13层时 10000次 耗时93.37ms
* 线程堆栈 7层时 10000次 耗时62.29ms
* 线程堆栈 3层时 10000次 耗时37.60ms
*
*
* @param equalSkips 要跳过的类(equals方式匹配), 可为空, 推荐HashSet
* @param startsWithSkips 要跳过的类(startsWith方式匹配), 可为空, 推荐ArrayList
* @return 调用者信息, Nullable, 若返回空则表示找不到调用者
*/
public static MethodCaller getMethodCaller(Set equalSkips, Collection startsWithSkips) {
return getMethodCaller(equalSkips, startsWithSkips, SKIP_ELEMENTS);
}
static MethodCaller getMethodCaller(Set equalSkips, Collection startsWithSkips, int skipElements) {
//获取当前堆栈
StackTraceElement[] elements = new Throwable().getStackTrace();
//跳过头三个元素(getMethodCaller/public getMethodCaller/调用public getMethodCaller的方法)
if (elements != null && elements.length > skipElements) {
//遍历堆栈
int i = skipElements;
for (; i < elements.length; i++) {
//当前元素
StackTraceElement element = elements[i];
//如果类名与skipEquals中的一个相同, 则跳过该元素查找下一个
if (equalSkips != null && equalSkips.contains(element.getClassName())) {
continue;
}
//如果类名是skipStarts中的任意一个作为开头的, 则跳过该元素查找下一个
if (startsWithSkips != null && isStartsWithSkips(startsWithSkips, element)) {
continue;
}
//如果未跳过则当前元素就是调用者
return new MethodCaller(element, i, elements);
}
}
//找不到调用者
return null;
}
private static boolean isStartsWithSkips(Collection startsWithSkips, StackTraceElement element) {
String className = element.getClassName();
for (String skipStart : startsWithSkips) {
if (skipStart != null && className.startsWith(skipStart)) {
return true;
}
}
return false;
}
// ///////////////////////////////////////////////////////////////////////////////////////////////////////////////
private String callerClass;
private String callerMethodName;
private String callerFileName;
private int callerLineNumber;
private int callerIndex;
private StackTraceElement[] stackTraces;
private MethodCaller(StackTraceElement caller, int callerIndex, StackTraceElement[] stackTraces) {
this.callerClass = caller.getClassName();
this.callerMethodName = caller.getMethodName();
this.callerFileName = caller.getFileName();
this.callerLineNumber = caller.getLineNumber();
this.callerIndex = callerIndex;
this.stackTraces = stackTraces;
}
/**
* 调用点所在的类, 不为空
*/
public String getCallerClass() {
return callerClass;
}
/**
* 调用点的方法名, 不为空
*/
public String getCallerMethodName() {
return callerMethodName;
}
/**
* 调用点所在类对应的文件, 可为空
*/
public String getCallerFileName() {
return callerFileName;
}
/**
* 调用点所在行数
*/
public int getCallerLineNumber() {
return callerLineNumber;
}
/**
* 调用点在线程堆栈中的位置
*/
public int getCallerIndex() {
return callerIndex;
}
/**
* 调用线程堆栈
*/
public StackTraceElement[] getStackTraces() {
return stackTraces;
}
@Override
public String toString() {
return "MethodCaller{" +
"callerClass='" + callerClass + '\'' +
", callerMethodName='" + callerMethodName + '\'' +
'}';
}
}