| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF 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 org.apache.tomcat.util.log; |
| |
| import java.io.IOException; |
| import java.io.PrintStream; |
| import java.util.EmptyStackException; |
| import java.util.Stack; |
| |
| /** |
| * This helper class may be used to do sophisticated redirection of |
| * System.out and System.err on a per Thread basis. |
| * |
| * A stack is implemented per Thread so that nested startCapture |
| * and stopCapture can be used. |
| * |
| * @author Remy Maucherat |
| * @author Glenn L. Nielsen |
| */ |
| public class SystemLogHandler extends PrintStream { |
| |
| |
| // ----------------------------------------------------------- Constructors |
| |
| |
| /** |
| * Construct the handler to capture the output of the given steam. |
| */ |
| public SystemLogHandler(PrintStream wrapped) { |
| super(wrapped); |
| out = wrapped; |
| } |
| |
| |
| // ----------------------------------------------------- Instance Variables |
| |
| |
| /** |
| * Wrapped PrintStream. |
| */ |
| private final PrintStream out; |
| |
| |
| /** |
| * Thread <-> CaptureLog associations. |
| */ |
| private static final ThreadLocal<Stack<CaptureLog>> logs = new ThreadLocal<>(); |
| |
| |
| /** |
| * Spare CaptureLog ready for reuse. |
| */ |
| private static final Stack<CaptureLog> reuse = new Stack<>(); |
| |
| |
| // --------------------------------------------------------- Public Methods |
| |
| |
| /** |
| * Start capturing thread's output. |
| */ |
| public static void startCapture() { |
| CaptureLog log = null; |
| if (!reuse.isEmpty()) { |
| try { |
| log = reuse.pop(); |
| } catch (EmptyStackException e) { |
| log = new CaptureLog(); |
| } |
| } else { |
| log = new CaptureLog(); |
| } |
| Stack<CaptureLog> stack = logs.get(); |
| if (stack == null) { |
| stack = new Stack<>(); |
| logs.set(stack); |
| } |
| stack.push(log); |
| } |
| |
| |
| /** |
| * Stop capturing thread's output and return captured data as a String. |
| */ |
| public static String stopCapture() { |
| Stack<CaptureLog> stack = logs.get(); |
| if (stack == null || stack.isEmpty()) { |
| return null; |
| } |
| CaptureLog log = stack.pop(); |
| if (log == null) { |
| return null; |
| } |
| String capture = log.getCapture(); |
| log.reset(); |
| reuse.push(log); |
| return capture; |
| } |
| |
| |
| // ------------------------------------------------------ Protected Methods |
| |
| |
| /** |
| * Find PrintStream to which the output must be written to. |
| */ |
| protected PrintStream findStream() { |
| Stack<CaptureLog> stack = logs.get(); |
| if (stack != null && !stack.isEmpty()) { |
| CaptureLog log = stack.peek(); |
| if (log != null) { |
| PrintStream ps = log.getStream(); |
| if (ps != null) { |
| return ps; |
| } |
| } |
| } |
| return out; |
| } |
| |
| |
| // ---------------------------------------------------- PrintStream Methods |
| |
| |
| @Override |
| public void flush() { |
| findStream().flush(); |
| } |
| |
| @Override |
| public void close() { |
| findStream().close(); |
| } |
| |
| @Override |
| public boolean checkError() { |
| return findStream().checkError(); |
| } |
| |
| @Override |
| protected void setError() { |
| //findStream().setError(); |
| } |
| |
| @Override |
| public void write(int b) { |
| findStream().write(b); |
| } |
| |
| @Override |
| public void write(byte[] b) |
| throws IOException { |
| findStream().write(b); |
| } |
| |
| @Override |
| public void write(byte[] buf, int off, int len) { |
| findStream().write(buf, off, len); |
| } |
| |
| @Override |
| public void print(boolean b) { |
| findStream().print(b); |
| } |
| |
| @Override |
| public void print(char c) { |
| findStream().print(c); |
| } |
| |
| @Override |
| public void print(int i) { |
| findStream().print(i); |
| } |
| |
| @Override |
| public void print(long l) { |
| findStream().print(l); |
| } |
| |
| @Override |
| public void print(float f) { |
| findStream().print(f); |
| } |
| |
| @Override |
| public void print(double d) { |
| findStream().print(d); |
| } |
| |
| @Override |
| public void print(char[] s) { |
| findStream().print(s); |
| } |
| |
| @Override |
| public void print(String s) { |
| findStream().print(s); |
| } |
| |
| @Override |
| public void print(Object obj) { |
| findStream().print(obj); |
| } |
| |
| @Override |
| public void println() { |
| findStream().println(); |
| } |
| |
| @Override |
| public void println(boolean x) { |
| findStream().println(x); |
| } |
| |
| @Override |
| public void println(char x) { |
| findStream().println(x); |
| } |
| |
| @Override |
| public void println(int x) { |
| findStream().println(x); |
| } |
| |
| @Override |
| public void println(long x) { |
| findStream().println(x); |
| } |
| |
| @Override |
| public void println(float x) { |
| findStream().println(x); |
| } |
| |
| @Override |
| public void println(double x) { |
| findStream().println(x); |
| } |
| |
| @Override |
| public void println(char[] x) { |
| findStream().println(x); |
| } |
| |
| @Override |
| public void println(String x) { |
| findStream().println(x); |
| } |
| |
| @Override |
| public void println(Object x) { |
| findStream().println(x); |
| } |
| |
| } |