AJ-470: code review, optimize code;

Author: chengyitian

src/com/xxdb/DBConnection.java

@@ -617,18 +617,24 @@ public DBConnection(boolean asynchronousTask, boolean useSSL, boolean compress,
         this.mutex_ = new ReentrantLock();
     }
 
+    /**
+     * This method has been deprecated since 'Java API 1.30.22.4' and will be disabled in the next version: 'Java API 1.30.22.4'.
+     * @param asynchronousTask
+     * @param useSSL
+     * @param compress
+     * @param usePython
+     * @param isUrgent
+     * @param isReverseStreaming
+     * @param sqlStd
+     */
     @Deprecated
     public DBConnection(boolean asynchronousTask, boolean useSSL, boolean compress, boolean usePython, boolean isUrgent, boolean isReverseStreaming, SqlStdEnum sqlStd){
         this.conn_ = new DBConnectionImpl(asynchronousTask, useSSL, compress, usePython, isUrgent, isReverseStreaming, sqlStd);
         this.mutex_ = new ReentrantLock();
     }
 
     public static DBConnection internalCreateEnableReverseStreamingDBConnection(boolean asynchronousTask, boolean useSSL, boolean compress, boolean usePython, boolean isUrgent, SqlStdEnum sqlStd) {
-        DBConnection dbConnection = new DBConnection();
-        dbConnection.conn_ = dbConnection.createEnableReverseStreamingDBConnectionImpl(asynchronousTask, useSSL, compress, usePython, isUrgent, sqlStd);
-        dbConnection.mutex_ = new ReentrantLock();
-
-        return dbConnection;
+        return new DBConnection(asynchronousTask, useSSL, compress, usePython, isUrgent, true, sqlStd);
     }
 
     public boolean isBusy() {

src/com/xxdb/data/BasicDecimal128Vector.java

@@ -451,10 +451,7 @@ public void Append(Scalar value) throws Exception{
         if (scale_ < 0)
             throw new RuntimeException("Please set scale first.");
 
-        if(value.getDataType() == DT_DECIMAL128)
-            add(value.getString());
-        else
-            add(value.getNumber().toString());
+        add(value.getString());
     }
 
     @Override

src/com/xxdb/data/BasicDecimal32Vector.java

@@ -334,10 +334,7 @@ public void Append(Scalar value) throws Exception{
             throw new RuntimeException("Please set scale first.");
         }
 
-        if(value.getDataType() == DT_DECIMAL32)
-            add(value.getString());
-        else
-            add(value.getNumber().doubleValue());
+        add(value.getString());
     }
 
     @Override

src/com/xxdb/data/BasicDecimal64Vector.java

@@ -339,10 +339,7 @@ public void Append(Scalar value) throws Exception{
         if (scale_ < 0)
             throw new RuntimeException("Please set scale first.");
 
-        if(value.getDataType() == DT_DECIMAL64)
-            add(value.getString());
-        else
-            add(value.getNumber().doubleValue());
+        add(value.getString());
     }
 
     @Override