Avoid some redundant unboxing and object creation (#21909)

core/src/main/java/org/elasticsearch/action/admin/cluster/allocation/NodeExplanation.java

@@ -106,7 +106,7 @@ public class NodeExplanation implements Writeable, ToXContent {
             }
             builder.endObject(); // end store
             builder.field("final_decision", finalDecision.toString());
-            builder.field("final_explanation", finalExplanation.toString());
+            builder.field("final_explanation", finalExplanation);
             builder.field("weight", nodeWeight);
             nodeDecision.toXContent(builder, params);
         }

core/src/main/java/org/elasticsearch/bootstrap/JNACLibrary.java

@@ -61,7 +61,7 @@ final class JNACLibrary {
 
         @Override
         protected List<String> getFieldOrder() {
-            return Arrays.asList(new String[] { "rlim_cur", "rlim_max" });
+            return Arrays.asList("rlim_cur", "rlim_max");
         }
     }
 

core/src/main/java/org/elasticsearch/bootstrap/JNAKernel32Library.java

@@ -149,7 +149,7 @@ final class JNAKernel32Library {
 
         @Override
         protected List<String> getFieldOrder() {
-            return Arrays.asList(new String[]{"BaseAddress", "AllocationBase", "AllocationProtect", "RegionSize", "State", "Protect", "Type"});
+            return Arrays.asList("BaseAddress", "AllocationBase", "AllocationProtect", "RegionSize", "State", "Protect", "Type");
         }
     }
 
@@ -261,10 +261,8 @@ final class JNAKernel32Library {
 
       @Override
       protected List<String> getFieldOrder() {
-          return Arrays.asList(new String[] {
-                  "PerProcessUserTimeLimit", "PerJobUserTimeLimit", "LimitFlags", "MinimumWorkingSetSize",
-                  "MaximumWorkingSetSize", "ActiveProcessLimit", "Affinity", "PriorityClass", "SchedulingClass"
-          });
+          return Arrays.asList("PerProcessUserTimeLimit", "PerJobUserTimeLimit", "LimitFlags", "MinimumWorkingSetSize",
+              "MaximumWorkingSetSize", "ActiveProcessLimit", "Affinity", "PriorityClass", "SchedulingClass");
       }
     }
 

core/src/main/java/org/elasticsearch/bootstrap/JavaVersion.java

@@ -33,9 +33,7 @@ public class JavaVersion implements Comparable<JavaVersion> {
     }
 
     private JavaVersion(List<Integer> version) {
-        if (version.size() >= 2
-                && version.get(0).intValue() == 1
-                && version.get(1).intValue() == 8) {
+        if (version.size() >= 2 && version.get(0) == 1 && version.get(1) == 8) {
             // for Java 8 there is ambiguity since both 1.8 and 8 are supported,
             // so we rewrite the former to the latter
             version = new ArrayList<>(version.subList(1, version.size()));

core/src/main/java/org/elasticsearch/bootstrap/Seccomp.java

@@ -172,7 +172,7 @@ final class Seccomp {
 
         @Override
         protected List<String> getFieldOrder() {
-            return Arrays.asList(new String[] { "len", "filter" });
+            return Arrays.asList("len", "filter");
         }
     }
 

core/src/main/java/org/elasticsearch/bootstrap/StartupException.java

@@ -104,7 +104,7 @@ final class StartupException extends RuntimeException {
                     continue;
                 }
 
-                consumer.accept("\tat " + line.toString());
+                consumer.accept("\tat " + line);
                 linesWritten++;
             }
         }