BAEL-3321 Flogger Fluent Logging (#7872)

* Added Flogger maven dependency

* Implemented Flogger logging examples

* Finished implementing Flogger logging examples

* Changed Flogger Test to Integration tests

* Adding examples on optimisation

* Added support for Slf4j and Log4j backends

* Added support for Slf4j and Log4j backends, uncommended dependencies in pom, removed log4j config file

logging-modules/flogger/pom.xml

@@ -17,11 +17,50 @@
             <artifactId>flogger</artifactId>
             <version>0.4</version>
         </dependency>
+
         <dependency>
             <groupId>com.google.flogger</groupId>
             <artifactId>flogger-system-backend</artifactId>
             <version>0.4</version>
             <scope>runtime</scope>
         </dependency>
+
+        <dependency>
+            <groupId>com.google.flogger</groupId>
+            <artifactId>flogger-slf4j-backend</artifactId>
+            <version>0.4</version>
+        </dependency>
+
+        <dependency>
+            <groupId>com.google.flogger</groupId>
+            <artifactId>flogger-log4j-backend</artifactId>
+            <version>0.4</version>
+            <exclusions>
+                <exclusion>
+                    <groupId>com.sun.jmx</groupId>
+                    <artifactId>jmxri</artifactId>
+                </exclusion>
+                <exclusion>
+                    <groupId>com.sun.jdmk</groupId>
+                    <artifactId>jmxtools</artifactId>
+                </exclusion>
+                <exclusion>
+                    <groupId>javax.jms</groupId>
+                    <artifactId>jms</artifactId>
+                </exclusion>
+            </exclusions>
+        </dependency>
+
+        <dependency>
+            <groupId>log4j</groupId>
+            <artifactId>log4j</artifactId>
+            <version>1.2.17</version>
+        </dependency>
+        <dependency>
+            <groupId>log4j</groupId>
+            <artifactId>apache-log4j-extras</artifactId>
+            <version>1.2.17</version>
+        </dependency>
+
     </dependencies>
 </project>

logging-modules/flogger/src/test/java/com/baeldung/flogger/FloggerIntegrationTest.java

@@ -12,6 +12,10 @@ import java.util.stream.IntStream;
 import static com.google.common.flogger.LazyArgs.lazy;
 
 public class FloggerIntegrationTest {
+    static {
+//        System.setProperty("flogger.backend_factory", "com.google.common.flogger.backend.log4j.Log4jBackendFactory#getInstance");
+        System.setProperty("flogger.backend_factory", "com.google.common.flogger.backend.slf4j.Slf4jBackendFactory#getInstance");
+    }
     private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
     @Test
@@ -28,6 +32,16 @@ public class FloggerIntegrationTest {
         });
     }
 
+    @Test
+    public void givenAnObject_shouldLogTheObject() {
+        User user = new User();
+        logger.atInfo().log("The user is: %s", user); //correct
+
+        //The following ways of logging are not recommended
+        logger.atInfo().log("The user is: %s", user.toString());
+        logger.atInfo().log("The user is: %s" + user);
+    }
+
     @Test
     public void givenASimpleOperation_shouldLogTheResult() {
         int result = 45 / 3;
@@ -70,4 +84,13 @@ public class FloggerIntegrationTest {
         int s = 30;
         return String.format("%d seconds elapsed so far. %d items pending processing", s, items);
     }
+
+    private class User {
+        String name = "Test";
+
+        @Override
+        public String toString() {
+            return name;
+        }
+    }
 }