refactor: some trick modification (#1135)

* refactor: some trick modification

* refactor: some trick modification

* fix: checkstyle
Signed-off-by: licho <lecho.sun@gmail.com>
Signed-off-by: licho <lecho.sun@gmail.com>

dlink-common/src/main/java/com/dlink/assertion/Asserts.java

@@ -32,6 +32,9 @@ import java.util.Map;
  */
 public class Asserts {
 
+    private Asserts() {
+    }
+
     public static boolean isNotNull(Object object) {
         return object != null;
     }
@@ -88,25 +91,19 @@ public class Asserts {
         }
     }
 
-    public static boolean isNullCollection(Collection collection) {
-        if (isNull(collection) || collection.size() == 0) {
-            return true;
-        }
-        return false;
+    public static boolean isNullCollection(Collection<?> collection) {
+        return isNull(collection) || collection.isEmpty();
     }
 
-    public static boolean isNotNullCollection(Collection collection) {
+    public static boolean isNotNullCollection(Collection<?> collection) {
         return !isNullCollection(collection);
     }
 
-    public static boolean isNullMap(Map map) {
-        if (isNull(map) || map.size() == 0) {
-            return true;
-        }
-        return false;
+    public static boolean isNullMap(Map<?, ?> map) {
+        return isNull(map) || map.size() == 0;
     }
 
-    public static boolean isNotNullMap(Map map) {
+    public static boolean isNotNullMap(Map<?, ?> map) {
         return !isNullMap(map);
     }
 
@@ -128,13 +125,13 @@ public class Asserts {
         }
     }
 
-    public static void checkNullCollection(Collection collection, String msg) {
+    public static void checkNullCollection(Collection<?> collection, String msg) {
         if (isNullCollection(collection)) {
             throw new RunTimeException(msg);
         }
     }
 
-    public static void checkNullMap(Map map, String msg) {
+    public static void checkNullMap(Map<?, ?> map, String msg) {
         if (isNullMap(map)) {
             throw new RunTimeException(msg);
         }

dlink-common/src/main/java/com/dlink/utils/SqlUtil.java

@@ -41,7 +41,7 @@ public class SqlUtil {
             return new String[0];
         }
 
-        String[] splits = sql.replaceAll(";\r\n", ";\n").split(sqlSeparator);
+        String[] splits = sql.replace(";\r\n", ";\n").split(sqlSeparator);
         String lastStatement = splits[splits.length - 1].trim();
         if (lastStatement.endsWith(SEMICOLON)) {
             splits[splits.length - 1] = lastStatement.substring(0, lastStatement.length() - 1);

dlink-executor/src/main/java/com/dlink/parser/SqlType.java

@@ -63,10 +63,7 @@ public enum SqlType {
     }
 
     public boolean isInsert() {
-        if (type.equals("INSERT")) {
-            return true;
-        }
-        return false;
+        return type.equals("INSERT");
     }
 
 }

dlink-executor/src/main/java/com/dlink/trans/Operations.java

@@ -26,6 +26,8 @@ import com.dlink.trans.ddl.SetOperation;
 import com.dlink.trans.ddl.ShowFragmentOperation;
 import com.dlink.trans.ddl.ShowFragmentsOperation;
 
+import java.util.Arrays;
+
 /**
  * Operations
  *
@@ -34,8 +36,10 @@ import com.dlink.trans.ddl.ShowFragmentsOperation;
  **/
 public class Operations {
 
-    private static Operation[] operations = {
-        new CreateAggTableOperation()
+    private Operations() {
+    }
+
+    private static final Operation[] ALL_OPERATIONS = {new CreateAggTableOperation()
             , new SetOperation()
             , new CreateCDCSourceOperation()
             , new ShowFragmentsOperation()
@@ -70,12 +74,15 @@ public class Operations {
     }
 
     public static Operation buildOperation(String statement) {
-        String sql = statement.replace("\n", " ").replaceAll("\\s{1,}", " ").trim().toUpperCase();
-        for (int i = 0; i < operations.length; i++) {
-            if (sql.startsWith(operations[i].getHandle())) {
-                return operations[i].create(statement);
-            }
-        }
-        return null;
+        String sql = statement.replace("\n", " ")
+                .replaceAll("\\s+", " ")
+                .trim()
+                .toUpperCase();
+
+        return Arrays.stream(ALL_OPERATIONS)
+                .filter(p -> sql.startsWith(p.getHandle()))
+                .findFirst()
+                .map(p -> p.create(statement))
+                .orElse(null);
     }
 }

dlink-gateway/src/main/java/com/dlink/gateway/GatewayType.java

@@ -29,12 +29,16 @@ import com.dlink.assertion.Asserts;
  **/
 public enum GatewayType {
 
-    LOCAL("l", "local"), STANDALONE("s", "standalone"),
-    YARN_SESSION("ys", "yarn-session"), YARN_APPLICATION("ya", "yarn-application"),
-    YARN_PER_JOB("ypj", "yarn-per-job"), KUBERNETES_SESSION("ks", "kubernetes-session"), KUBERNETES_APPLICATION("ka", "kubernetes-application");
+    LOCAL("l", "local"),
+    STANDALONE("s", "standalone"),
+    YARN_SESSION("ys", "yarn-session"),
+    YARN_APPLICATION("ya", "yarn-application"),
+    YARN_PER_JOB("ypj", "yarn-per-job"),
+    KUBERNETES_SESSION("ks", "kubernetes-session"),
+    KUBERNETES_APPLICATION("ka", "kubernetes-application");
 
-    private String value;
-    private String longValue;
+    private final String value;
+    private final String longValue;
 
     GatewayType(String value, String longValue) {
         this.value = value;
@@ -59,10 +63,7 @@ public enum GatewayType {
     }
 
     public boolean equalsValue(String type) {
-        if (Asserts.isEquals(value, type) || Asserts.isEquals(longValue, type)) {
-            return true;
-        }
-        return false;
+        return Asserts.isEquals(value, type) || Asserts.isEquals(longValue, type);
     }
 
     public static boolean isDeployCluster(String type) {