Fix #1: use an InternalLogger instead of java.util.logging.Logger to log and output to stderr instead of outputting to java.util.logging

Author: cyrille-leclerc

src/main/java/com/cloudbees/syslog/sender/AbstractSyslogMessageSender.java

@@ -1,9 +1,7 @@
 package com.cloudbees.syslog.sender;
 
-import com.cloudbees.syslog.Facility;
-import com.cloudbees.syslog.Severity;
-import com.cloudbees.syslog.SyslogMessage;
-import com.cloudbees.syslog.MessageFormat;
+import com.cloudbees.syslog.*;
+import com.cloudbees.syslog.util.InternalLogger;
 
 import javax.annotation.Nonnull;
 import java.io.CharArrayWriter;
@@ -12,14 +10,13 @@
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicLong;
-import java.util.logging.Logger;
 
 /**
  * @author <a href="mailto:[email protected]">Cyrille Le Clerc</a>
  */
 public abstract class AbstractSyslogMessageSender implements SyslogMessageSender {
     protected final static Charset UTF_8 = Charset.forName("UTF-8");
-    protected final Logger logger = Logger.getLogger(getClass().getName());
+    protected final InternalLogger logger = InternalLogger.getLogger(getClass());
     // default values
     protected String defaultAppName;
     protected Facility defaultFacility = Facility.USER;

src/main/java/com/cloudbees/syslog/sender/UdpSyslogMessageSender.java

@@ -19,8 +19,14 @@
 import com.cloudbees.syslog.util.CachingReference;
 
 import javax.annotation.Nullable;
-import java.io.*;
-import java.net.*;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.OutputStreamWriter;
+import java.io.Writer;
+import java.net.DatagramPacket;
+import java.net.DatagramSocket;
+import java.net.InetAddress;
+import java.net.UnknownHostException;
 import java.util.logging.Level;
 
 /**

src/main/java/com/cloudbees/syslog/util/InternalLogger.java

@@ -0,0 +1,127 @@
+/*
+ * Copyright 2010-2014, CloudBees Inc.
+ *
+ * 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 com.cloudbees.syslog.util;
+
+import com.cloudbees.syslog.integration.jul.util.LevelHelper;
+
+import javax.annotation.Nullable;
+import java.text.DateFormat;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * Don't use {@link java.util.logging.Logger} as this code can be used as an Handler for java.util.logging and we would then have an infinite loop.
+ *
+ * @author <a href="mailto:[email protected]">Cyrille Le Clerc</a>
+ */
+public class InternalLogger {
+
+    private static Level level;
+
+    static {
+        try {
+            level = LevelHelper.findLevel(System.getProperty("com.cloudbees.syslog.debugLevel"));
+        } catch (RuntimeException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public static InternalLogger getLogger(@Nullable String name) {
+        return new InternalLogger(name);
+    }
+
+    public static InternalLogger getLogger(@Nullable Class clazz) {
+        return getLogger(clazz == null ? null : clazz.getName());
+    }
+
+    public static Level getLevel() {
+        return level;
+    }
+
+    public static void setLevel(Level level) {
+        InternalLogger.level = level;
+    }
+
+    private DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SSS");
+    private final String name;
+    /**
+     * use java.util.logger to find the logger level if not specified by system property.
+     */
+    private final Logger julLogger;
+
+    public InternalLogger(String name) {
+        this.name = name;
+        this.julLogger = Logger.getLogger(name);
+    }
+
+
+    public boolean isLoggable(Level level) {
+        if (level == null)
+            return false;
+
+        if (this.level == null)
+            return julLogger.isLoggable(level);
+
+        return level.intValue() >= this.level.intValue();
+    }
+
+    public void finest(@Nullable String msg) {
+        log(Level.FINEST, msg);
+    }
+
+    public void fine(@Nullable String msg) {
+        log(Level.FINE, msg);
+    }
+
+    public void finer(@Nullable String msg) {
+        log(Level.FINER, msg);
+    }
+
+    public void info(@Nullable String msg) {
+        log(Level.INFO, msg);
+    }
+
+    public void log(@Nullable Level level, @Nullable String msg) {
+        log(level, msg, null);
+    }
+
+    public void warn(@Nullable String msg) {
+        log(Level.WARNING, msg);
+    }
+
+    public void warn(@Nullable String msg, @Nullable Throwable t) {
+        log(Level.WARNING, msg, t);
+    }
+
+    /**
+     * synchronize for the {@link java.text.SimpleDateFormat}.
+     *
+     * @param level
+     * @param msg
+     * @param t
+     */
+    public synchronized void log(@Nullable Level level, @Nullable String msg, @Nullable Throwable t) {
+        if (!isLoggable(level))
+            return;
+        System.err.println(df.format(new Date()) + " [" + Thread.currentThread().getName() + "] " + name + " - " + level.getName() + ": " + msg);
+        if (t != null)
+            t.printStackTrace();
+
+    }
+
+}