Java tutorial
/* * Copyright 2016 The Netty Project * * The Netty Project licenses this file to you 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 io.netty.util.internal; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.PrintStream; import java.util.List; public final class ThrowableUtil { private ThrowableUtil() { } /** * Set the {@link StackTraceElement} for the given {@link Throwable}, using the {@link Class} and method name. */ public static <T extends Throwable> T unknownStackTrace(T cause, Class<?> clazz, String method) { cause.setStackTrace(new StackTraceElement[] { new StackTraceElement(clazz.getName(), method, null, -1) }); return cause; } /** * Gets the stack trace from a Throwable as a String. * * @param cause the {@link Throwable} to be examined * @return the stack trace as generated by {@link Throwable#printStackTrace(java.io.PrintWriter)} method. */ public static String stackTraceToString(Throwable cause) { ByteArrayOutputStream out = new ByteArrayOutputStream(); PrintStream pout = new PrintStream(out); cause.printStackTrace(pout); pout.flush(); try { return new String(out.toByteArray()); } finally { try { out.close(); } catch (IOException ignore) { // ignore as should never happen } } } public static boolean haveSuppressed() { return PlatformDependent.javaVersion() >= 7; } @SuppressJava6Requirement(reason = "Throwable addSuppressed is only available for >= 7. Has check for < 7.") public static void addSuppressed(Throwable target, Throwable suppressed) { if (!haveSuppressed()) { return; } target.addSuppressed(suppressed); } public static void addSuppressedAndClear(Throwable target, List<Throwable> suppressed) { addSuppressed(target, suppressed); suppressed.clear(); } public static void addSuppressed(Throwable target, List<Throwable> suppressed) { for (Throwable t : suppressed) { addSuppressed(target, t); } } }