In this PR, I removed some redundant code under common and adjusted some formats.

bitsail-common/src/main/java/com/bytedance/bitsail/common/BitSailException.java

@@ -34,8 +34,8 @@
 public class BitSailException extends RuntimeException {
   private static final long serialVersionUID = 1L;
 
-  private ErrorCode errorCode;
-  private String errorMessage;
+  private final ErrorCode errorCode;
+  private final String errorMessage;
 
   public BitSailException(ErrorCode errorCode, String errorMessage) {
     super(errorCode.toString() + " - " + errorMessage);

bitsail-common/src/main/java/com/bytedance/bitsail/common/configuration/BitSailConfiguration.java

@@ -857,11 +857,11 @@ private boolean isPathMap(final String path) {
   }
 
   private int getIndex(final String index) {
-    return Integer.valueOf(index.replace("[", "").replace("]", ""));
+    return Integer.parseInt(index.replace("[", "").replace("]", ""));
   }
 
   private boolean isSuitForRoot(final Object object) {
-    return null != object && (object instanceof List || object instanceof Map);
+    return (object instanceof List || object instanceof Map);
 
   }
 
@@ -916,7 +916,7 @@ private Map<String, String> flatten(Map<String, Object> in) {
   }
 
   private Map<String, String> flatten(Map.Entry<String, Object> in) {
-    if (!Map.class.isInstance(in.getValue())) {
+    if (!(in.getValue() instanceof Map)) {
       return Collections.singletonMap(in.getKey(), in.getValue().toString());
     }
 
@@ -930,6 +930,7 @@ private Map<String, String> flatten(Map.Entry<String, Object> in) {
   }
 
   private enum ConfigType {
+    //Basic data type enumeration
     Boolean, Character, Double, Float, Integer, List, Long, Map, String
   }
 }

bitsail-common/src/main/java/com/bytedance/bitsail/common/configuration/BitSailSystemConfiguration.java

@@ -100,10 +100,6 @@ private static String getConfigDirectory() {
     } else if (new File(RUNTIME_FILE_DIR).exists()) {
       confDir = RUNTIME_FILE_DIR;
     }
-//    else {
-//      throw BITSAILException.asBITSAILException(CommonErrorCode.CONFIG_ERROR, "No system configuration found.");
-//
-//    }
     return confDir;
   }
 

bitsail-common/src/main/java/com/bytedance/bitsail/common/util/HttpManager.java

@@ -101,9 +101,8 @@ public static CloseableHttpResponse sendPost(String url, String jsonStr, Map<Str
     }
     StringEntity entity = new StringEntity(jsonStr, "UTF-8");
     httpPost.setEntity(entity);
-    CloseableHttpResponse response = closeableHttpClient
+    return closeableHttpClient
         .execute(httpPost);
-    return response;
   }
 
   public static WrappedResponse sendPost(String url, Map<String, String> headers, Map<String, Object> body, ContentType contentType) throws IOException {
@@ -227,8 +226,7 @@ public static WrappedResponse wrapAndClose(CloseableHttpResponse response) throw
       int statusCode = response.getStatusLine().getStatusCode();
       String responseString = EntityUtils.toString(response.getEntity(), "UTF-8");
       EntityUtils.consume(response.getEntity());
-      WrappedResponse wrappedResponse = new WrappedResponse(statusCode, responseString);
-      return wrappedResponse;
+      return new WrappedResponse(statusCode, responseString);
     } finally {
       response.close();
     }

bitsail-common/src/main/java/com/bytedance/bitsail/common/util/Pair.java

@@ -77,8 +77,8 @@ private static boolean equals(Object x, Object y) {
   @Override
   @SuppressWarnings("unchecked")
   public boolean equals(Object other) {
-    return other instanceof Pair && equals(first, ((Pair) other).first) &&
-        equals(second, ((Pair) other).second);
+    return other instanceof Pair && equals(first, ((Pair<?, ?>) other).first) &&
+        equals(second, ((Pair<?, ?>) other).second);
   }
 
   /**

bitsail-common/src/main/java/com/bytedance/bitsail/common/util/timelimit/SimpleTimeLimiter.java

@@ -122,7 +122,11 @@ private static boolean declaresInterruptedEx(Method method) {
     return false;
   }
 
-  // TODO: replace with version in common.reflect if and when it's open-sourced
+  /**
+   *
+   * TODO: replace with version in common.reflect if and when it's open-sourced
+   *
+   */
   private static <T> T newProxy(
       Class<T> interfaceType, InvocationHandler handler) {
     Object object = Proxy.newProxyInstance(interfaceType.getClassLoader(),
@@ -164,7 +168,12 @@ public Object call() throws Exception {
     return newProxy(interfaceType, handler);
   }
 
-  // TODO: should this actually throw only ExecutionException?
+
+  /**
+   *
+   * TODO: should this actually throw only ExecutionException?
+   *
+   */
   @Override
   public <T> T callWithTimeout(Callable<T> callable, long timeoutDuration,
                                TimeUnit timeoutUnit, boolean amInterruptible) throws Exception {