cn.webfuse.core.kit.ExceptionKits Maven / Gradle / Ivy
/*
* Copyright [2018] [https://github.com/vipshop/vjtools]
*
* Further modifications copyright (c) 2019 by webfuse.cn
*
* 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 cn.webfuse.core.kit;
import cn.webfuse.core.exception.UncheckedException;
import cn.webfuse.core.kit.text.StringBuilderWriter;
import com.google.common.base.Throwables;
import org.apache.commons.lang3.ClassUtils;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.exception.ExceptionUtils;
import java.io.PrintWriter;
import java.lang.reflect.UndeclaredThrowableException;
/**
* 关于异常的工具类.
*
* 1. Checked/Uncheked及Wrap(如ExecutionException)的转换.
*
* 2. 打印Exception的辅助函数. (其中一些来自Common Lang ExceptionUtils)
*
* 3. 查找Cause(其中一些来自Guava Throwables)
*
* 4. StackTrace性能优化相关，尽量使用静态异常避免异常生成时获取StackTrace(Netty)
*
* copy from vjtools
*/
public class ExceptionKits {
private static final StackTraceElement[] EMPTY_STACK_TRACE = new StackTraceElement[0];
///// Checked/Unchecked及Wrap(如ExecutionException)的转换/////
/**
* 将CheckedException转换为RuntimeException重新抛出, 可以减少函数签名中的CheckExcetpion定义.
*
* CheckedException会用UndeclaredThrowableException包裹，RunTimeException和Error则不会被转变.
*
* copy from Commons Lange 3.5 ExceptionUtils.
*
* 虽然unchecked()里已直接抛出异常，但仍然定义返回值，方便欺骗Sonar。因此本函数也改变了一下返回值
*
* 示例代码:
*
*
* try{ ... }catch(Exception e){ throw unchecked(t); }
*
*
* @see ExceptionUtils#wrapAndThrow(Throwable)
*/
public static RuntimeException unchecked(Throwable t) {
if (t instanceof RuntimeException) {
throw (RuntimeException) t;
}
if (t instanceof Error) {
throw (Error) t;
}
throw new UncheckedException(t);
}
/**
* 如果是著名的包裹类，从cause中获得真正异常. 其他异常则不变.
*
* Future中使用的ExecutionException 与 反射时定义的InvocationTargetException， 真正的异常都封装在Cause中
*
* 前面 unchecked() 使用的UncheckedException同理.
*/
public static Throwable unwrap(Throwable t) {
if (t instanceof UncheckedException || t instanceof java.util.concurrent.ExecutionException
|| t instanceof java.lang.reflect.InvocationTargetException
|| t instanceof UndeclaredThrowableException) {
return t.getCause();
}
return t;
}
/**
* 组合unwrap与unchecked，用于处理反射/Callable的异常
*/
public static RuntimeException unwrapAndUnchecked(Throwable t) {
throw unchecked(unwrap(t));
}
////// 输出内容相关 //////
/**
* 将StackTrace[]转换为String, 供Logger或e.printStackTrace()外的其他地方使用.
*
* 为了使用StringBuilderWriter，没有用Throwables#getStackTraceAsString(Throwable)
*/
public static String stackTraceText(Throwable t) {
StringBuilderWriter stringWriter = new StringBuilderWriter();
t.printStackTrace(new PrintWriter(stringWriter)); // NOSONAR
return stringWriter.toString();
}
/**
* 拼装 短异常类名: 异常信息.
*
* 与Throwable.toString()相比使用了短类名
*
* @see ExceptionUtils#getMessage(Throwable)
*/
public static String toStringWithShortName(Throwable t) {
return ExceptionUtils.getMessage(t);
}
/**
* 拼装 短异常类名: 异常信息 <-- RootCause的短异常类名: 异常信息
*/
public static String toStringWithRootCause(Throwable t) {
if (t == null) {
return StringUtils.EMPTY;
}
final String clsName = ClassUtils.getShortClassName(t, null);
final String message = StringUtils.defaultString(t.getMessage());
Throwable cause = getRootCause(t);
StringBuilder sb = new StringBuilder(128).append(clsName).append(": ").append(message);
if (cause != t) {
sb.append("; <---").append(toStringWithShortName(cause));
}
return sb.toString();
}
////////// Cause 相关 /////////
/**
* 获取异常的Root Cause.
*
* 如无底层Cause, 则返回自身
*
* @see Throwables#getRootCause(Throwable)
*/
public static Throwable getRootCause(Throwable t) {
return Throwables.getRootCause(t);
}
/**
* 获取某种类型的cause，如果没有则返回空
*
* copy from Jodd ExceptionUtil
*/
public static T findCause(Throwable throwable, Class cause) {
while (throwable != null) {
if (throwable.getClass().equals(cause)) {
return (T) throwable;
}
throwable = throwable.getCause();
}
return null;
}
/**
* 判断异常是否由某些底层的异常引起.
*/
@SuppressWarnings("unchecked")
public static boolean isCausedBy(Throwable throwable,
Class... causeExceptionClasses) {
Throwable cause = throwable;
while (cause != null) {
for (Class causeClass : causeExceptionClasses) {
if (causeClass.isInstance(cause)) {
return true;
}
}
cause = cause.getCause();
}
return false;
}
/////////// StackTrace 性能优化相关////////
/**
* copy from Netty, 为静态异常设置StackTrace.
*
* 对某些已知且经常抛出的异常, 不需要每次创建异常类并很消耗性能的并生成完整的StackTrace. 此时可使用静态声明的异常.
*
* 如果异常可能在多个地方抛出，使用本函数设置抛出的类名和方法名.
*
*
* private static RuntimeException TIMEOUT_EXCEPTION = ExceptionUtil.setStackTrace(new RuntimeException("Timeout"),
* MyClass.class, "mymethod");
*
*/
public static T setStackTrace(T throwable, Class throwClass, String throwClazz) {
throwable.setStackTrace(
new StackTraceElement[]{new StackTraceElement(throwClass.getName(), throwClazz, null, -1)});
return throwable;
}
/**
* 清除StackTrace. 假设StackTrace已生成, 但把它打印出来也有不小的消耗.
*
* 如果不能控制StackTrace的生成，也不能控制它的打印端(如logger)，可用此方法暴力清除Trace.
*
* 但Cause链依然不能清除, 只能清除每一个Cause的StackTrace.
*/
public static T clearStackTrace(T throwable) {
Throwable cause = throwable;
while (cause != null) {
cause.setStackTrace(EMPTY_STACK_TRACE);
cause = cause.getCause();
}
return throwable;
}
}