#28 SLF4J logging

pom.xml

@@ -198,6 +198,12 @@
             <artifactId>javax.el-api</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-api</artifactId>
+            <version>1.7.7</version>
+            <scope>compile</scope>
+        </dependency>
     </dependencies>
     <build>
         <plugins>

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

@@ -0,0 +1,75 @@
+/**
+ * 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 java.io.IOException;
+import java.net.Socket;
+import lombok.EqualsAndHashCode;
+import org.takes.http.Back;
+
+/**
+ * Logs Back.accept() calls.
+ *
+ * <p>The class is immutable and thread-safe.
+ * @author Dmitry Zaytsev (dmitry.zaytsev@gmail.com)
+ * @version $Id$
+ */
+@EqualsAndHashCode(of = "origin", callSuper = false)
+public final class BkLogged extends LogWrap implements Back {
+    /**
+     * Original back.
+     */
+    private final transient Back origin;
+
+    /**
+     * Ctor.
+     * @param back Original
+     */
+    public BkLogged(final Back back) {
+        this(back, LogWrap.Level.TRACE);
+    }
+
+    /**
+     * Ctor.
+     * @param back Original
+     * @param lvl Log level
+     */
+    public BkLogged(final Back back, final LogWrap.Level lvl) {
+        super(back.getClass(), lvl);
+        this.origin = back;
+    }
+
+    @Override
+    public void accept(final Socket socket) throws IOException {
+        final long started = System.currentTimeMillis();
+        this.origin.accept(socket);
+        this.log(
+            "[%s] #accept(%s) in [%d] ms",
+            this.origin,
+            socket,
+            System.currentTimeMillis() - started
+        );
+    }
+}

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

@@ -0,0 +1,73 @@
+/**
+ * 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 java.io.IOException;
+import lombok.EqualsAndHashCode;
+import org.takes.http.Exit;
+import org.takes.http.Front;
+
+/**
+ * Logs Front.start() calls.
+ *
+ * <p>The class is immutable and thread-safe.
+ * @author Dmitry Zaytsev (dmitry.zaytsev@gmail.com)
+ * @version $Id$
+ */
+@EqualsAndHashCode(of = "origin", callSuper = false)
+public final class FtLogged extends LogWrap implements Front {
+    /**
+     * Original front.
+     */
+    private final transient Front origin;
+
+    /**
+     * Ctor.
+     * @param front Original
+     */
+    public FtLogged(final Front front) {
+        this(front, LogWrap.Level.TRACE);
+    }
+
+    /**
+     * 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(
+            "[%s] #start(%s)",
+            this.origin,
+            exit
+        );
+        this.origin.start(exit);
+    }
+}

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

@@ -0,0 +1,115 @@
+/**
+ * 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 org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Wrap slf4j functionality.
+ *
+ * <p>The class is immutable and thread-safe.
+ * @author Dmitry Zaytsev (dmitry.zaytsev@gmail.com)
+ * @version $Id$
+ * @since 0.11
+ */
+@SuppressWarnings({ "PMD.CyclomaticComplexity", "PMD.LoggerIsNotStaticFinal" })
+public class LogWrap {
+    /**
+     * Log levels.
+     */
+    public enum Level {
+        /**
+         * Trace level.
+         */
+        TRACE,
+        /**
+         * Debug level.
+         */
+        DEBUG,
+        /**
+         * Info level.
+         */
+        INFO,
+        /**
+         * Warn level.
+         */
+        WARN,
+        /**
+         * Severe level.
+         */
+        SEVERE
+    };
+
+    /**
+     * Log level.
+     */
+    private final transient LogWrap.Level level;
+
+    /**
+     * Logger.
+     */
+    private final transient Logger logger;
+
+    /**
+     * Ctor.
+     * @param clazz Logger class
+     * @param lvl Log level
+     */
+    public LogWrap(final Class<?> clazz, final LogWrap.Level lvl) {
+        this.level = lvl;
+        this.logger = LoggerFactory.getLogger(clazz);
+    }
+
+    /**
+     * Log message.
+     * @param format Format string
+     * @param param Parameters
+     */
+    // @checkstyle JavadocLocationCheck (1 line)
+    // @checkstyle CyclomaticComplexityCheck (1 line)
+    public final void log(final String format, final Object... param) {
+        if (this.level == LogWrap.Level.TRACE
+            && this.logger.isTraceEnabled()) {
+            this.logger.trace(String.format(format, param));
+        } else if (
+            this.level == LogWrap.Level.DEBUG
+                && this.logger.isDebugEnabled()) {
+            this.logger.debug(String.format(format, param));
+        } else if (
+            this.level == LogWrap.Level.INFO
+                && this.logger.isInfoEnabled()) {
+            this.logger.trace(String.format(format, param));
+        } else if (
+            this.level == LogWrap.Level.WARN
+                && this.logger.isWarnEnabled()) {
+            this.logger.warn(String.format(format, param));
+        } else if (
+            this.level == LogWrap.Level.SEVERE
+                && this.logger.isErrorEnabled()) {
+            this.logger.error(String.format(format, param));
+        }
+    }
+}

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

@@ -0,0 +1,107 @@
+/**
+ * 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 java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Iterator;
+import lombok.EqualsAndHashCode;
+import org.takes.Request;
+import org.takes.Response;
+import org.takes.facets.auth.Identity;
+import org.takes.facets.auth.Pass;
+
+/**
+ * Logs Pass methods calls..
+ *
+ * <p>The class is immutable and thread-safe.
+ * @author Dmitry Zaytsev (dmitry.zaytsev@gmail.com)
+ * @version $Id$
+ */
+@EqualsAndHashCode(of = "origin", callSuper = false)
+public final class PsLogged extends LogWrap implements Pass {
+    /**
+     * Original pass.
+     */
+    private final transient Pass origin;
+
+    /**
+     * Ctor.
+     * @param pass Original
+     */
+    public PsLogged(final Pass pass) {
+        this(pass, LogWrap.Level.TRACE);
+    }
+
+    /**
+     * Ctor.
+     * @param pass Original
+     * @param lvl Log level
+     */
+    public PsLogged(final Pass pass, final LogWrap.Level lvl) {
+        super(pass.getClass(), lvl);
+        this.origin = pass;
+    }
+
+    @Override
+    public Iterator<Identity> enter(final Request request) throws IOException {
+        final long started = System.currentTimeMillis();
+        final Iterator<Identity> iterator = this.origin.enter(request);
+        final Collection<Identity> resp = new ArrayList<Identity>(1);
+        final StringBuilder sbr = new StringBuilder("[");
+        if (iterator.hasNext()) {
+            final Identity next = iterator.next();
+            sbr.append(next);
+            sbr.append(',');
+            resp.add(next);
+        }
+        sbr.append(']');
+        this.log(
+            "[%s] #enter(%s) return [%s] in [%d] ms",
+            this.origin,
+            request,
+            sbr.toString(),
+            System.currentTimeMillis() - started
+        );
+        return resp.iterator();
+    }
+
+    @Override
+    public Response exit(final Response response, final Identity identity)
+        throws IOException {
+        final long started = System.currentTimeMillis();
+        final Response resp = this.origin.exit(response, identity);
+        this.log(
+            "[%s] #exit(%s,%s) return [%s] in [%d] ms",
+            this.origin,
+            response,
+            identity,
+            resp,
+            System.currentTimeMillis() - started
+        );
+        return resp;
+    }
+}