Java 11 migraiton: mute-idiom

mute-idiom/src/main/java/com/iluwatar/mute/App.java

@@ -25,7 +25,7 @@ package com.iluwatar.mute;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.sql.SQLException;
+import java.util.Optional;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -52,9 +52,8 @@ public class App {
    * Program entry point.
    *
    * @param args command line args.
-   * @throws Exception if any exception occurs
    */
-  public static void main(String[] args) throws Exception {
+  public static void main(String[] args) {
 
     useOfLoggedMute();
 
@@ -68,17 +67,17 @@ public class App {
    * exception occurs.
    */
   private static void useOfMute() {
-    ByteArrayOutputStream out = new ByteArrayOutputStream();
+    var out = new ByteArrayOutputStream();
     Mute.mute(() -> out.write("Hello".getBytes()));
   }
 
-  private static void useOfLoggedMute() throws SQLException {
+  private static void useOfLoggedMute() {
-    Resource resource = null;
+    Optional<Resource> resource = Optional.empty();
     try {
-      resource = acquireResource();
+      resource = Optional.of(acquireResource());
-      utilizeResource(resource);
+      utilizeResource(resource.get());
     } finally {
-      closeResource(resource);
+      resource.ifPresent(App::closeResource);
     }
   }
 
@@ -86,14 +85,14 @@ public class App {
    * All we can do while failed close of a resource is to log it.
    */
   private static void closeResource(Resource resource) {
-    Mute.loggedMute(() -> resource.close());
+    Mute.loggedMute(resource::close);
   }
 
-  private static void utilizeResource(Resource resource) throws SQLException {
+  private static void utilizeResource(Resource resource) {
     LOGGER.info("Utilizing acquired resource: {}", resource);
   }
 
-  private static Resource acquireResource() throws SQLException {
+  private static Resource acquireResource() {
     return new Resource() {
 
       @Override

mute-idiom/src/test/java/com/iluwatar/mute/AppTest.java

@@ -27,12 +27,11 @@ import org.junit.jupiter.api.Test;
 
 /**
  * Tests that Mute idiom example runs without errors.
- *
  */
 public class AppTest {
 
   @Test
-  public void test() throws Exception {
+  public void test() {
-    App.main(null);
+    App.main(new String[]{});
   }
 }

mute-idiom/src/test/java/com/iluwatar/mute/MuteTest.java

@@ -23,17 +23,15 @@
 
 package com.iluwatar.mute;
 
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
 import org.junit.jupiter.api.Test;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.io.ByteArrayOutputStream;
-import java.io.IOException;
-import java.io.PrintStream;
-
-import static org.junit.jupiter.api.Assertions.assertThrows;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-
 /**
  * Test for the mute-idiom pattern
  */
@@ -50,9 +48,7 @@ public class MuteTest {
 
   @Test
   public void muteShouldRethrowUnexpectedExceptionAsAssertionError() {
-    assertThrows(AssertionError.class, () -> {
+    assertThrows(AssertionError.class, () -> Mute.mute(this::methodThrowingException));
-      Mute.mute(this::methodThrowingException);
-    });
   }
 
   @Test
@@ -62,7 +58,7 @@ public class MuteTest {
 
   @Test
   public void loggedMuteShouldLogExceptionTraceBeforeSwallowingIt() {
-    ByteArrayOutputStream stream = new ByteArrayOutputStream();
+    var stream = new ByteArrayOutputStream();
     System.setErr(new PrintStream(stream));
 
     Mute.loggedMute(this::methodThrowingException);