test/refactor: use lambda instead of anonymous class

Author: oldratlee

src/test/java/com/alibaba/ttl/log4j2/Log4j2TtlThreadContextMapTest.java

@@ -50,13 +50,10 @@ public void test_log4j2_ThreadContext() throws Exception {
     }
 
     private static Runnable createTask(final Logger logger) {
-        final Runnable task = new Runnable() {
-            @Override
-            public void run() {
-                // Log in thread pool
-                ThreadContext.put("task", "" + START_TIME_STAMP);
-                logger.info("Log in Runnable!");
-            }
+        final Runnable task = () -> {
+            // Log in thread pool
+            ThreadContext.put("task", "" + START_TIME_STAMP);
+            logger.info("Log in Runnable!");
         };
         return TtlRunnable.get(task);
     }

src/test/java/com/alibaba/ttl/log4j2/Slf4jMdcDemo.java

@@ -38,13 +38,10 @@ public static void main(String[] args) throws Exception {
     }
 
     private static Runnable createTask() {
-        final Runnable task = new Runnable() {
-            @Override
-            public void run() {
-                // Log in thread pool
-                MDC.put("task", new Date().toString());
-                logger.info("Log in Runnable!");
-            }
+        final Runnable task = () -> {
+            // Log in thread pool
+            MDC.put("task", new Date().toString());
+            logger.info("Log in Runnable!");
         };
         return TtlRunnable.get(task);
     }

src/test/java/com/alibaba/ttl/log4j2/Slf4jMdcTest.java

@@ -46,13 +46,10 @@ public void test_slf4j_MDC() throws Exception {
     }
 
     private static Runnable createTask(final Logger logger) {
-        final Runnable task = new Runnable() {
-            @Override
-            public void run() {
-                // Log in thread pool
-                MDC.put("task", "" + START_TIME_STAMP);
-                logger.info("Log in Runnable!");
-            }
+        final Runnable task = () -> {
+            // Log in thread pool
+            MDC.put("task", "" + START_TIME_STAMP);
+            logger.info("Log in Runnable!");
         };
         return TtlRunnable.get(task);
     }