001// *************************************************************************************************************************** 002// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file * 003// * distributed with this work for additional information regarding copyright ownership. The ASF licenses this file * 004// * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance * 005// * with the License. You may obtain a copy of the License at * 006// * * 007// * http://www.apache.org/licenses/LICENSE-2.0 * 008// * * 009// * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an * 010// * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the * 011// * specific language governing permissions and limitations under the License. * 012// *************************************************************************************************************************** 013package org.apache.juneau.rest; 014 015import static javax.servlet.http.HttpServletResponse.*; 016import static org.apache.juneau.internal.StringUtils.*; 017 018import java.text.*; 019import java.util.logging.*; 020 021import javax.servlet.http.*; 022 023import org.apache.juneau.internal.*; 024import org.apache.juneau.json.*; 025 026/** 027 * Logging utility class. 028 * 029 * <p> 030 * Subclasses can override these methods to tailor logging of HTTP requests. 031 * <br>Subclasses MUST implement a no-arg public constructor. 032 * 033 * <h5 class='section'>See Also:</h5> 034 * <ul> 035 * <li class='link'>{@doc juneau-rest-server.LoggingAndErrorHandling} 036 * </ul> 037 */ 038public class BasicRestLogger implements RestLogger { 039 040 private final JuneauLogger logger = JuneauLogger.getLogger(getClass()); 041 042 /** 043 * Returns the Java logger used for logging. 044 * 045 * <p> 046 * Subclasses can provide their own logger. 047 * The default implementation returns the logger created using <code>Logger.getLogger(getClass())</code>. 048 * 049 * @return The logger used for logging. 050 */ 051 protected Logger getLogger() { 052 return logger; 053 } 054 055 @Override /* RestLogger */ 056 public void setLevel(Level level) { 057 getLogger().setLevel(level); 058 } 059 060 /** 061 * Log a message to the logger. 062 * 063 * <p> 064 * Subclasses can override this method if they wish to log messages using a library other than Java Logging 065 * (e.g. Apache Commons Logging). 066 * 067 * @param level The log level. 068 * @param cause The cause. 069 * @param msg The message to log. 070 * @param args Optional {@link MessageFormat}-style arguments. 071 */ 072 @Override /* RestLogger */ 073 public void log(Level level, Throwable cause, String msg, Object...args) { 074 msg = format(msg, args); 075 getLogger().log(level, msg, cause); 076 } 077 078 /** 079 * Log a message. 080 * 081 * <p> 082 * Equivalent to calling <code>log(level, <jk>null</jk>, msg, args);</code> 083 * 084 * @param level The log level. 085 * @param msg The message to log. 086 * @param args Optional {@link MessageFormat}-style arguments. 087 */ 088 @Override /* RestLogger */ 089 public void log(Level level, String msg, Object...args) { 090 log(level, null, msg, args); 091 } 092 093 /** 094 * Same as {@link #log(Level, String, Object...)} excepts runs the arguments through {@link JsonSerializer#DEFAULT_READABLE}. 095 * 096 * <p> 097 * Serialization of arguments do not occur if message is not logged, so it's safe to use this method from within 098 * debug log statements. 099 * 100 * <h5 class='section'>Example:</h5> 101 * <p class='bcode w800'> 102 * logObjects(<jsf>DEBUG</jsf>, <js>"Pojo contents:\n{0}"</js>, myPojo); 103 * </p> 104 * 105 * @param level The log level. 106 * @param msg The message to log. 107 * @param args Optional {@link MessageFormat}-style arguments. 108 */ 109 @Override /* RestLogger */ 110 public void logObjects(Level level, String msg, Object...args) { 111 for (int i = 0; i < args.length; i++) 112 args[i] = SimpleJsonSerializer.DEFAULT_READABLE.toStringObject(args[i]); 113 log(level, null, msg, args); 114 } 115 116 /** 117 * Callback method for logging errors during HTTP requests. 118 * 119 * <p> 120 * Typically, subclasses will override this method and log errors themselves. 121 * 122 * <p> 123 * The default implementation simply logs errors to the <code>RestServlet</code> logger. 124 * 125 * <p> 126 * Here's a typical implementation showing how stack trace hashing can be used to reduce log file sizes... 127 * <p class='bcode w800'> 128 * <jk>protected void</jk> onError(HttpServletRequest req, HttpServletResponse res, RestException e, <jk>boolean</jk> noTrace) { 129 * String qs = req.getQueryString(); 130 * String msg = <js>"HTTP "</js> + req.getMethod() + <js>" "</js> + e.getStatus() + <js>" "</js> + req.getRequestURI() + (qs == <jk>null</jk> ? <js>""</js> : <js>"?"</js> + qs); 131 * <jk>int</jk> c = e.getOccurrence(); 132 * 133 * <jc>// REST_useStackTraceHashes is disabled, so we have to log the exception every time.</jc> 134 * <jk>if</jk> (c == 0) 135 * myLogger.log(Level.<jsf>WARNING</jsf>, <jsm>format</jsm>(<js>"[%s] %s"</js>, e.getStatus(), msg), e); 136 * 137 * <jc>// This is the first time we've countered this error, so log a stack trace 138 * // unless ?noTrace was passed in as a URL parameter.</jc> 139 * <jk>else if</jk> (c == 1 && ! noTrace) 140 * myLogger.log(Level.<jsf>WARNING</jsf>, <jsm>format</jsm>(<js>"[%h.%s.%s] %s"</js>, e.hashCode(), e.getStatus(), c, msg), e); 141 * 142 * <jc>// This error occurred before. 143 * // Only log the message, not the stack trace.</jc> 144 * <jk>else</jk> 145 * myLogger.log(Level.<jsf>WARNING</jsf>, <jsm>format</jsm>(<js>"[%h.%s.%s] %s, %s"</js>, e.hashCode(), e.getStatus(), c, msg, e.getLocalizedMessage())); 146 * } 147 * </p> 148 * 149 * @param req The servlet request object. 150 * @param res The servlet response object. 151 * @param e Exception indicating what error occurred. 152 */ 153 @Override /* RestLogger */ 154 public void onError(HttpServletRequest req, HttpServletResponse res, RestException e) { 155 if (shouldLog(req, res, e)) { 156 String qs = req.getQueryString(); 157 String msg = "HTTP " + req.getMethod() + " " + e.getStatus() + " " + req.getRequestURI() + (qs == null ? "" : "?" + qs); 158 int c = e.getOccurrence(); 159 if (shouldLogStackTrace(req, res, e)) { 160 msg = '[' + Integer.toHexString(e.hashCode()) + '.' + e.getStatus() + '.' + c + "] " + msg; 161 log(Level.WARNING, e, msg); 162 } else { 163 msg = '[' + Integer.toHexString(e.hashCode()) + '.' + e.getStatus() + '.' + c + "] " + msg + ", " + e.getLocalizedMessage(); 164 log(Level.WARNING, msg); 165 } 166 } 167 } 168 169 /** 170 * Returns <jk>true</jk> if the specified exception should be logged. 171 * 172 * <p> 173 * Subclasses can override this method to provide their own logic for determining when exceptions are logged. 174 * 175 * <p> 176 * The default implementation will return <jk>false</jk> if <js>"noTrace=true"</js> is passed in the query string 177 * or <code>No-Trace: true</code> is specified in the header. 178 * 179 * @param req The HTTP request. 180 * @param res The HTTP response. 181 * @param e The exception. 182 * @return <jk>true</jk> if exception should be logged. 183 */ 184 protected boolean shouldLog(HttpServletRequest req, HttpServletResponse res, RestException e) { 185 if (isNoTrace(req) && ! isDebug(req)) 186 return false; 187 return true; 188 } 189 190 /** 191 * Returns <jk>true</jk> if a stack trace should be logged for this exception. 192 * 193 * <p> 194 * Subclasses can override this method to provide their own logic for determining when stack traces are logged. 195 * 196 * <p> 197 * The default implementation will only log a stack trace if {@link RestException#getOccurrence()} returns 198 * <code>1</code> and the exception is not one of the following: 199 * <ul> 200 * <li>{@link HttpServletResponse#SC_UNAUTHORIZED} 201 * <li>{@link HttpServletResponse#SC_FORBIDDEN} 202 * <li>{@link HttpServletResponse#SC_NOT_FOUND} 203 * </ul> 204 * 205 * @param req The HTTP request. 206 * @param res The HTTP response. 207 * @param e The exception. 208 * @return <jk>true</jk> if stack trace should be logged. 209 */ 210 protected boolean shouldLogStackTrace(HttpServletRequest req, HttpServletResponse res, RestException e) { 211 if (e.getOccurrence() == 1) { 212 switch (e.getStatus()) { 213 case SC_UNAUTHORIZED: 214 case SC_FORBIDDEN: 215 case SC_NOT_FOUND: return false; 216 default: return true; 217 } 218 } 219 return false; 220 } 221 222 private static boolean isNoTrace(HttpServletRequest req) { 223 return contains(req.getHeader("No-Trace"), "true") || contains(req.getQueryString(), "noTrace=true"); 224 } 225 226 private static boolean isDebug(HttpServletRequest req) { 227 return contains(req.getHeader("Debug"), "true"); 228 } 229}