yegor256#28 fix CR comments

pom.xml

@@ -203,6 +203,7 @@
             <artifactId>slf4j-api</artifactId>
             <version>1.7.7</version>
             <scope>compile</scope>
+            <optional>true</optional>
         </dependency>
     </dependencies>
     <build>

src/main/java/org/takes/facets/slf4j/Slf4j.java

@@ -0,0 +1,145 @@
+/**
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2015 Yegor Bugayenko
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package org.takes.facets.slf4j;
+
+import lombok.EqualsAndHashCode;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Slf4j target.
+ *
+ * <p>The class is immutable and thread-safe.
+ * @author Dmitry Zaytsev (dmitry.zaytsev@gmail.com)
+ * @version $Id$
+ * @since 0.11.2
+ */
+@EqualsAndHashCode(of = "logger")
+@SuppressWarnings("PMD.LoggerIsNotStaticFinal")
+public final class Slf4j implements Target {
+    /**
+     * Default log level.
+     */
+    public static final Slf4j.Level DEFAULT_LEVEL = Slf4j.Level.DEBUG;
+
+    /**
+     * Log levels.
+     */
+    public enum Level {
+        /**
+         * Trace level.
+         */
+        TRACE,
+        /**
+         * Debug level.
+         */
+        DEBUG,
+        /**
+         * Info level.
+         */
+        INFO,
+        /**
+         * Warn level.
+         */
+        WARN,
+        /**
+         * Error level.
+         */
+        ERROR
+    };
+
+    /**
+     * Log level.
+     */
+    private final transient Slf4j.Level level;
+
+    /**
+     * Logger.
+     */
+    private transient Logger logger;
+
+    /**
+     * Ctor.
+     * @param clazz Logger class
+     */
+    public Slf4j(final Class<?> clazz) {
+        this(clazz, Slf4j.DEFAULT_LEVEL);
+    }
+
+    /**
+     * Ctor.
+     * @param name Logger name
+     */
+    public Slf4j(final String name) {
+        this(name, Slf4j.DEFAULT_LEVEL);
+    }
+
+    /**
+     * Ctor.
+     * @param clazz Logger class
+     * @param lvl Log level
+     */
+    public Slf4j(final Class<?> clazz, final Slf4j.Level lvl) {
+        this(clazz.getName(), lvl);
+    }
+
+    /**
+     * Ctor.
+     * @param name Logger name
+     * @param lvl Log level
+     */
+    public Slf4j(final String name, final Slf4j.Level lvl) {
+        this.level = lvl;
+        this.logger = LoggerFactory.getLogger(name);
+    }
+
+    /**
+     * Log message.
+     * @param format Format string
+     * @param param Parameters
+     */
+    @Override
+    public void log(final String format, final Object... param) {
+        switch (this.level) {
+            case TRACE:
+                this.logger.trace(format, param);
+                break;
+            case DEBUG:
+                this.logger.debug(format, param);
+                break;
+            case INFO:
+                this.logger.info(format, param);
+                break;
+            case WARN:
+                this.logger.warn(format, param);
+                break;
+            case ERROR:
+                this.logger.error(format, param);
+                break;
+            default:
+                throw new IllegalArgumentException("Unknown log level");
+        }
+    }
+}

src/main/java/org/takes/facets/slf4j/FtLogged.java → src/main/java/org/takes/facets/slf4j/Target.java

@@ -24,50 +24,19 @@
 
 package org.takes.facets.slf4j;
 
-import java.io.IOException;
-import lombok.EqualsAndHashCode;
-import org.takes.http.Exit;
-import org.takes.http.Front;
-
 /**
- * Logs Front.start() calls.
+ * Log target.
  *
- * <p>The class is immutable and thread-safe.
+ * <p>All implementations of this interface must be immutable and thread-safe.
  * @author Dmitry Zaytsev (dmitry.zaytsev@gmail.com)
  * @version $Id$
+ * @since 0.11
  */
-@EqualsAndHashCode(of = "origin", callSuper = false)
-public final class FtLogged extends LogWrap implements Front {
-    /**
-     * Original front.
-     */
-    private final transient Front origin;
-
+public interface Target {
     /**
-     * Ctor.
-     * @param front Original
+     * SLF4J parameterized logging.
+     * @param format Format string
+     * @param param Params
      */
-    public FtLogged(final Front front) {
-        this(front, LogWrap.DEFAULT_LEVEL);
-    }
-
-    /**
-     * Ctor.
-     * @param front Original
-     * @param lvl Log level
-     */
-    public FtLogged(final Front front, final LogWrap.Level lvl) {
-        super(front.getClass(), lvl);
-        this.origin = front;
-    }
-
-    @Override
-    public void start(final Exit exit) throws IOException {
-        this.log(
-            "[{}] #start([{}])",
-            this.origin,
-            exit
-        );
-        this.origin.start(exit);
-    }
+    void log(final String format, final Object... param);
 }