#502 Replaced usages of System.out with logger.

reader-writer-lock/src/main/java/com/iluwatar/reader/writer/lock/App.java

@@ -23,6 +23,9 @@
 
 package com.iluwatar.reader.writer.lock;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
@@ -48,6 +51,8 @@ import java.util.stream.IntStream;
  */
 public class App {
 
+  private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
+
   /**
    * Program entry point
    * 
@@ -71,7 +76,7 @@ public class App {
     try {
       executeService.awaitTermination(5, TimeUnit.SECONDS);
     } catch (InterruptedException e) {
-      System.out.println("Error waiting for ExecutorService shutdown");
+      LOGGER.error("Error waiting for ExecutorService shutdown");
     }
 
   }

reader-writer-lock/src/main/java/com/iluwatar/reader/writer/lock/Reader.java

@@ -22,6 +22,9 @@
  */
 package com.iluwatar.reader.writer.lock;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import java.util.concurrent.locks.Lock;
 
 /**
@@ -29,6 +32,8 @@ import java.util.concurrent.locks.Lock;
  */
 public class Reader implements Runnable {
 
+  private static final Logger LOGGER = LoggerFactory.getLogger(Reader.class);
+
   private Lock readLock;
 
   private String name;
@@ -55,8 +60,8 @@ public class Reader implements Runnable {
    * 
    */
   public void read() throws InterruptedException {
-    System.out.println(name + " begin");
+    LOGGER.info("{} begin", name);
     Thread.sleep(250);
-    System.out.println(name + " finish");
+    LOGGER.info("{} finish", name);
   }
 }

reader-writer-lock/src/main/java/com/iluwatar/reader/writer/lock/Writer.java

@@ -22,6 +22,9 @@
  */
 package com.iluwatar.reader.writer.lock;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import java.util.concurrent.locks.Lock;
 
 /**
@@ -29,6 +32,8 @@ import java.util.concurrent.locks.Lock;
  */
 public class Writer implements Runnable {
 
+  private static final Logger LOGGER = LoggerFactory.getLogger(Writer.class);
+
   private Lock writeLock;
 
   private String name;
@@ -55,8 +60,8 @@ public class Writer implements Runnable {
    * Simulate the write operation
    */
   public void write() throws InterruptedException {
-    System.out.println(name + " begin");
+    LOGGER.info("{} begin", name);
     Thread.sleep(250);
-    System.out.println(name + " finish");
+    LOGGER.info("{} finish", name);
   }
 }

reader-writer-lock/src/test/java/com/iluwatar/reader/writer/lock/ReaderAndWriterTest.java

@@ -31,13 +31,15 @@ import java.util.concurrent.TimeUnit;
 
 import org.junit.Test;
 import org.mockito.InOrder;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * @author hongshuwei@gmail.com
  */
 public class ReaderAndWriterTest extends StdOutTest {
 
-
+  private static final Logger LOGGER = LoggerFactory.getLogger(ReaderAndWriterTest.class);
 
   /**
    * Verify reader and writer can only get the lock to read and write orderly
@@ -60,7 +62,7 @@ public class ReaderAndWriterTest extends StdOutTest {
     try {
       executeService.awaitTermination(10, TimeUnit.SECONDS);
     } catch (InterruptedException e) {
-      System.out.println("Error waiting for ExecutorService shutdown");
+      LOGGER.error("Error waiting for ExecutorService shutdown", e);
     }
 
     final InOrder inOrder = inOrder(getStdOutMock());
@@ -91,7 +93,7 @@ public class ReaderAndWriterTest extends StdOutTest {
     try {
       executeService.awaitTermination(10, TimeUnit.SECONDS);
     } catch (InterruptedException e) {
-      System.out.println("Error waiting for ExecutorService shutdown");
+      LOGGER.error("Error waiting for ExecutorService shutdown", e);
     }
 
     final InOrder inOrder = inOrder(getStdOutMock());

reader-writer-lock/src/test/java/com/iluwatar/reader/writer/lock/ReaderTest.java

@@ -31,12 +31,16 @@ import java.util.concurrent.TimeUnit;
 
 import org.junit.Test;
 import org.mockito.InOrder;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * @author hongshuwei@gmail.com
  */
 public class ReaderTest extends StdOutTest {
 
+  private static final Logger LOGGER = LoggerFactory.getLogger(ReaderTest.class);
+
   /**
    * Verify that multiple readers can get the read lock concurrently
    */
@@ -57,7 +61,7 @@ public class ReaderTest extends StdOutTest {
     try {
       executeService.awaitTermination(10, TimeUnit.SECONDS);
     } catch (InterruptedException e) {
-      System.out.println("Error waiting for ExecutorService shutdown");
+      LOGGER.error("Error waiting for ExecutorService shutdown", e);
     }
 
     // Read operation will hold the read lock 250 milliseconds, so here we prove that multiple reads

reader-writer-lock/src/test/java/com/iluwatar/reader/writer/lock/WriterTest.java

@@ -31,12 +31,16 @@ import java.util.concurrent.TimeUnit;
 
 import org.junit.Test;
 import org.mockito.InOrder;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * @author hongshuwei@gmail.com
  */
 public class WriterTest extends StdOutTest {
 
+  private static final Logger LOGGER = LoggerFactory.getLogger(WriterTest.class);
+
   /**
    * Verify that multiple writers will get the lock in order.
    */
@@ -58,7 +62,7 @@ public class WriterTest extends StdOutTest {
     try {
       executeService.awaitTermination(10, TimeUnit.SECONDS);
     } catch (InterruptedException e) {
-      System.out.println("Error waiting for ExecutorService shutdown");
+      LOGGER.error("Error waiting for ExecutorService shutdown", e);
     }
     // Write operation will hold the write lock 250 milliseconds, so here we verify that when two
     // writer execute concurrently, the second writer can only writes only when the first one is