[update][plugin][streamwriter] Refactor code to enhance readability a…

…nd efficiency

 1. Replace `Thread.sleep` with `TimeUnit.SECONDS.sleep` to avoid busy-waiting.
2. Fix issue where `count` was not reset after sleeping.
3. Apply minor code improvements for better maintainability.

plugin/writer/streamwriter/src/main/java/com/wgzhao/addax/plugin/writer/streamwriter/StreamWriter.java

@@ -39,6 +39,7 @@
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.concurrent.TimeUnit;
 
 import static com.wgzhao.addax.common.spi.ErrorCode.CONFIG_ERROR;
 import static com.wgzhao.addax.common.spi.ErrorCode.ILLEGAL_VALUE;
@@ -132,12 +133,6 @@ private void validateParameter(String path, String fileName)
             }
         }
 
-        @Override
-        public void prepare()
-        {
-            //
-        }
-
         @Override
         public List<Configuration> split(int mandatoryNumber)
         {
@@ -149,12 +144,6 @@ public List<Configuration> split(int mandatoryNumber)
             return writerSplitConfigs;
         }
 
-        @Override
-        public void post()
-        {
-            //
-        }
-
         @Override
         public void destroy()
         {
@@ -166,7 +155,6 @@ public static class Task
             extends Writer.Task
     {
         private static final Logger LOG = LoggerFactory.getLogger(Task.class);
-        private static final String NULL_FLAG = "NULL";
         private static final String NEWLINE_FLAG = System.getProperty("line.separator", "\n");
 
         private String fieldDelimiter;
@@ -192,21 +180,15 @@ public void init()
             this.fileName = writerSliceConfig.getString(StreamKey.FILE_NAME, null);
             this.recordNumBeforeSleep = writerSliceConfig.getLong(StreamKey.RECORD_NUM_BEFORE_SLEEP, 0);
             this.sleepTime = writerSliceConfig.getLong(StreamKey.SLEEP_TIME, 0);
-            this.nullFormat = writerSliceConfig.getString(StreamKey.NULL_FORMAT, NULL_FLAG);
+            this.nullFormat = writerSliceConfig.getString(StreamKey.NULL_FORMAT, StreamKey.NULL_FLAG);
             if (recordNumBeforeSleep < 0) {
-                throw AddaxException.asAddaxException(ILLEGAL_VALUE, "recordNumber 不能为负值");
+                throw AddaxException.asAddaxException(ILLEGAL_VALUE, "recordNumber must be greater than 0");
             }
             if (sleepTime < 0) {
-                throw AddaxException.asAddaxException(ILLEGAL_VALUE, "sleep 不能为负值");
+                throw AddaxException.asAddaxException(ILLEGAL_VALUE, "sleep time must be greater than 0");
             }
         }
 
-        @Override
-        public void prepare()
-        {
-            //
-        }
-
         @Override
         public void startWrite(RecordReceiver recordReceiver)
         {
@@ -238,22 +220,15 @@ private void writeToFile(RecordReceiver recordReceiver, String path, String file
             String fileFullPath = buildFilePath(path, fileName);
             LOG.info("write to file : [{}]", fileFullPath);
             File newFile = new File(fileFullPath);
-            try {
-                if (!newFile.createNewFile()) {
-                    LOG.error("failed to create file {}", fileFullPath);
-                }
-            }
-            catch (IOException ioe) {
-                LOG.error("failed to create file {}", fileFullPath);
-            }
             try (BufferedWriter writer = new BufferedWriter(
                     new OutputStreamWriter(new FileOutputStream(newFile, true), StandardCharsets.UTF_8))) {
                 Record record;
                 int count = 0;
                 while ((record = recordReceiver.getFromReader()) != null) {
                     if (recordNumBeforeSleep > 0 && sleepTime > 0 && count == recordNumBeforeSleep) {
                         LOG.info("StreamWriter start to sleep ... recordNumBeforeSleep={},sleepTime={}", recordNumBeforeSleep, sleepTime);
-                        Thread.sleep(sleepTime * 1000L);
+                        TimeUnit.SECONDS.sleep(sleepTime);
+                        count=0;
                     }
                     writer.write(recordToString(record));
                     count++;
@@ -265,12 +240,6 @@ private void writeToFile(RecordReceiver recordReceiver, String path, String file
             }
         }
 
-        @Override
-        public void post()
-        {
-            //
-        }
-
         @Override
         public void destroy()
         {