Prefer valueOf() to create Number values

Update Long/Integer constructor calls with `valueOf` which can make use
of global caches.

Closes gh-4688

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/metrics/Metric.java

@@ -92,7 +92,7 @@ public class Metric<T extends Number> {
 	 */
 	public Metric<Long> increment(int amount) {
 		return new Metric<Long>(this.getName(),
-				new Long(this.getValue().longValue() + amount));
+				Long.valueOf(this.getValue().longValue() + amount));
 	}
 
 	/**

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/metrics/repository/InMemoryMetricRepository.java

@@ -57,7 +57,7 @@ public class InMemoryMetricRepository implements MetricRepository, MultiMetricRe
 							metric.increment(amount).getValue(), timestamp);
 				}
 				else {
-					return new Metric<Long>(metricName, new Long(amount), timestamp);
+					return new Metric<Long>(metricName, Long.valueOf(amount), timestamp);
 				}
 			}
 		});

spring-boot-actuator/src/test/java/org/springframework/boot/actuate/metrics/reader/MetricRegistryMetricReaderTests.java

@@ -64,12 +64,12 @@ public class MetricRegistryMetricReaderTests {
 
 			@Override
 			public Number getValue() {
-				return new Integer(5);
+				return Integer.valueOf(5);
 			}
 
 		});
 		Metric<Integer> metric = (Metric<Integer>) this.metricReader.findOne("test");
-		assertThat(metric.getValue(), equalTo(new Integer(5)));
+		assertThat(metric.getValue(), equalTo(Integer.valueOf(5)));
 		this.metricRegistry.remove("test");
 		assertThat(this.metricReader.findOne("test"), is(nullValue()));
 	}

spring-boot-actuator/src/test/java/org/springframework/boot/actuate/metrics/util/InMemoryRepositoryTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2013 the original author or authors.
+ * Copyright 2012-2015 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -127,7 +127,7 @@ public class InMemoryRepositoryTests {
 		for (Future<Boolean> future : all) {
 			assertTrue(future.get(1, TimeUnit.SECONDS));
 		}
-		assertEquals(new Integer(0), repository.findOne("foo"));
+		assertEquals(Integer.valueOf(0), repository.findOne("foo"));
 	}
 
 }