Replace plain string with constants (#2308)

Author: zhaomin1423

seatunnel-common/src/main/java/org/apache/seatunnel/common/Constants.java

@@ -41,6 +41,10 @@ public final class Constants {
 
     public static final String CHECKPOINT_ID = "checkpoint.id";
 
+    public static final String UUID = "uuid";
+
+    public static final String NOW = "now";
+
     private Constants() {
     }
 }

seatunnel-common/src/main/java/org/apache/seatunnel/common/utils/VariablesSubstitute.java

@@ -17,6 +17,8 @@
 
 package org.apache.seatunnel.common.utils;
 
+import org.apache.seatunnel.common.Constants;
+
 import org.apache.commons.lang3.text.StrSubstitutor;
 
 import java.time.ZonedDateTime;
@@ -40,8 +42,8 @@ public static String substitute(String text, String timeFormat) {
         final String formattedDate = df.format(ZonedDateTime.now());
 
         final Map<String, String> valuesMap = new HashMap<>(3);
-        valuesMap.put("uuid", UUID.randomUUID().toString());
-        valuesMap.put("now", formattedDate);
+        valuesMap.put(Constants.UUID, UUID.randomUUID().toString());
+        valuesMap.put(Constants.NOW, formattedDate);
         valuesMap.put(timeFormat, formattedDate);
         return substitute(text, valuesMap);
     }

seatunnel-connectors-v2/connector-file/connector-file-base/src/main/java/org/apache/seatunnel/connectors/seatunnel/file/sink/writer/FileSinkTransactionFileNameGenerator.java

@@ -17,6 +17,7 @@
 
 package org.apache.seatunnel.connectors.seatunnel.file.sink.writer;
 
+import org.apache.seatunnel.common.Constants;
 import org.apache.seatunnel.common.utils.VariablesSubstitute;
 import org.apache.seatunnel.connectors.seatunnel.file.config.Constant;
 import org.apache.seatunnel.connectors.seatunnel.file.config.FileFormat;
@@ -57,8 +58,8 @@ public String generateFileName(String transactionId) {
         final String formattedDate = df.format(ZonedDateTime.now());
 
         final Map<String, String> valuesMap = new HashMap<>(4);
-        valuesMap.put("uuid", UUID.randomUUID().toString());
-        valuesMap.put("now", formattedDate);
+        valuesMap.put(Constants.UUID, UUID.randomUUID().toString());
+        valuesMap.put(Constants.NOW, formattedDate);
         valuesMap.put(timeFormat, formattedDate);
         valuesMap.put(Constant.TRANSACTION_EXPRESSION, transactionId);
         String substitute = VariablesSubstitute.substitute(fileNameExpression, valuesMap);