for #1941, refactor PostgreSQLCommandPacket

sharding-proxy/sharding-proxy-transport/sharding-proxy-transport-mysql/src/main/java/org/apache/shardingsphere/shardingproxy/transport/mysql/packet/command/MySQLCommandPacket.java

@@ -23,7 +23,7 @@ import org.apache.shardingsphere.shardingproxy.transport.mysql.packet.MySQLPacke
 import org.apache.shardingsphere.shardingproxy.transport.mysql.payload.MySQLPacketPayload;
 
 /**
- * MySQL command packet.
+ * Command packet for MySQL.
  *
  * @author zhangliang
  */

sharding-proxy/sharding-proxy-transport/sharding-proxy-transport-postgresql/src/main/java/org/apache/shardingsphere/shardingproxy/transport/postgresql/packet/command/PostgreSQLCommandPacket.java

@@ -21,9 +21,9 @@ import org.apache.shardingsphere.shardingproxy.transport.api.packet.CommandPacke
 import org.apache.shardingsphere.shardingproxy.transport.postgresql.packet.PostgreSQLPacket;
 
 /**
- * PostgreSQL command packet.
+ * Command packet for PostgreSQL.
  *
  * @author zhangyonglun
  */
-public interface PostgreSQLCommandPacket extends PostgreSQLPacket, CommandPacket {
+public abstract class PostgreSQLCommandPacket implements PostgreSQLPacket, CommandPacket {
 }

sharding-proxy/sharding-proxy-transport/sharding-proxy-transport-postgresql/src/main/java/org/apache/shardingsphere/shardingproxy/transport/postgresql/packet/command/admin/PostgreSQLUnsupportedCommandPacket.java

@@ -28,7 +28,7 @@ import org.apache.shardingsphere.shardingproxy.transport.postgresql.payload.Post
  * @author zhangyonglun
  */
 @RequiredArgsConstructor
-public final class PostgreSQLUnsupportedCommandPacket implements PostgreSQLCommandPacket {
+public final class PostgreSQLUnsupportedCommandPacket extends PostgreSQLCommandPacket {
     
     @Getter
     private final char messageType;

sharding-proxy/sharding-proxy-transport/sharding-proxy-transport-postgresql/src/main/java/org/apache/shardingsphere/shardingproxy/transport/postgresql/packet/command/query/binary/bind/PostgreSQLComBindPacket.java

@@ -28,21 +28,22 @@ import org.apache.shardingsphere.shardingproxy.transport.postgresql.payload.Post
 
 import java.sql.SQLException;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 
 /**
- * PostgreSQL command bind packet.
+ * Command bind packet for PostgreSQL.
  *
  * @author zhangyonglun
  */
 @Getter
-public final class PostgreSQLComBindPacket implements PostgreSQLCommandPacket {
+public final class PostgreSQLComBindPacket extends PostgreSQLCommandPacket {
     
     private final String statementId;
     
     private final PostgreSQLBinaryStatement binaryStatement;
     
-    private List<Object> parameters;
+    private final List<Object> parameters;
     
     private final boolean binaryRowData;
     
@@ -57,6 +58,8 @@ public final class PostgreSQLComBindPacket implements PostgreSQLCommandPacket {
         binaryStatement = BinaryStatementRegistry.getInstance().get(connectionId).getBinaryStatement(statementId);
         if (null != binaryStatement && null != binaryStatement.getSql()) {
             parameters = getParameters(payload);
+        } else {
+            parameters = Collections.emptyList();
         }
         int resultFormatsLength = payload.readInt2();
         binaryRowData = resultFormatsLength > 0;

sharding-proxy/sharding-proxy-transport/sharding-proxy-transport-postgresql/src/main/java/org/apache/shardingsphere/shardingproxy/transport/postgresql/packet/command/query/binary/bind/PostgreSQLComBindPacketExecutor.java

@@ -46,7 +46,7 @@ import java.util.LinkedList;
 import java.util.List;
 
 /**
- * PostgreSQL command bind packet executor.
+ * Command bind packet executor for PostgreSQL.
  *
  * @author zhangyonglun
  * @author zhangliang

sharding-proxy/sharding-proxy-transport/sharding-proxy-transport-postgresql/src/main/java/org/apache/shardingsphere/shardingproxy/transport/postgresql/packet/command/query/binary/describe/PostgreSQLComDescribePacket.java

@@ -23,12 +23,12 @@ import org.apache.shardingsphere.shardingproxy.transport.postgresql.packet.comma
 import org.apache.shardingsphere.shardingproxy.transport.postgresql.payload.PostgreSQLPacketPayload;
 
 /**
- * PostgreSQL command describe packet.
+ * Command describe packet for PostgreSQL.
  *
  * @author zhangyonglun
  */
 @Getter
-public final class PostgreSQLComDescribePacket implements PostgreSQLCommandPacket {
+public final class PostgreSQLComDescribePacket extends PostgreSQLCommandPacket {
     
     public PostgreSQLComDescribePacket(final PostgreSQLPacketPayload payload) {
         payload.readInt4();

sharding-proxy/sharding-proxy-transport/sharding-proxy-transport-postgresql/src/main/java/org/apache/shardingsphere/shardingproxy/transport/postgresql/packet/command/query/binary/describe/PostgreSQLComDescribePacketExecutor.java

@@ -26,7 +26,7 @@ import java.util.Collection;
 import java.util.Collections;
 
 /**
- * PostgreSQL command describe packet executor.
+ * Command describe packet executor for PostgreSQL.
  *
  * @author zhangyonglun
  * @author zhangliang

sharding-proxy/sharding-proxy-transport/sharding-proxy-transport-postgresql/src/main/java/org/apache/shardingsphere/shardingproxy/transport/postgresql/packet/command/query/binary/execute/PostgreSQLComExecutePacket.java

@@ -22,11 +22,11 @@ import org.apache.shardingsphere.shardingproxy.transport.postgresql.packet.comma
 import org.apache.shardingsphere.shardingproxy.transport.postgresql.payload.PostgreSQLPacketPayload;
 
 /**
- * PostgreSQL command execute packet.
+ * Command execute packet for PostgreSQL.
  *
  * @author zhangyonglun
  */
-public final class PostgreSQLComExecutePacket implements PostgreSQLCommandPacket {
+public final class PostgreSQLComExecutePacket extends PostgreSQLCommandPacket {
     
     public PostgreSQLComExecutePacket(final PostgreSQLPacketPayload payload) {
         payload.readInt4();

sharding-proxy/sharding-proxy-transport/sharding-proxy-transport-postgresql/src/main/java/org/apache/shardingsphere/shardingproxy/transport/postgresql/packet/command/query/binary/execute/PostgreSQLComExecutePacketExecutor.java

@@ -26,7 +26,7 @@ import java.util.Collection;
 import java.util.Collections;
 
 /**
- * PostgreSQL command execute packet executor.
+ * Command execute packet executor for PostgreSQL.
  *
  * @author zhangyonglun
  * @author zhangliang

sharding-proxy/sharding-proxy-transport/sharding-proxy-transport-postgresql/src/main/java/org/apache/shardingsphere/shardingproxy/transport/postgresql/packet/command/query/binary/parse/PostgreSQLComParsePacket.java

@@ -30,12 +30,12 @@ import java.util.ArrayList;
 import java.util.List;
 
 /**
- * PostgreSQL command parse packet.
+ * Command parse packet for PostgreSQL.
  *
  * @author zhangyonglun
  */
 @Getter
-public final class PostgreSQLComParsePacket implements PostgreSQLCommandPacket {
+public final class PostgreSQLComParsePacket extends PostgreSQLCommandPacket {
     
     private final ConnectionScopeBinaryStatementRegistry binaryStatementRegistry;
     

sharding-proxy/sharding-proxy-transport/sharding-proxy-transport-postgresql/src/main/java/org/apache/shardingsphere/shardingproxy/transport/postgresql/packet/command/query/binary/sync/PostgreSQLComSyncPacket.java

@@ -22,11 +22,11 @@ import org.apache.shardingsphere.shardingproxy.transport.postgresql.packet.comma
 import org.apache.shardingsphere.shardingproxy.transport.postgresql.payload.PostgreSQLPacketPayload;
 
 /**
- * PostgreSQL command sync packet.
+ * Command sync packet for PostgreSQL.
  *
  * @author zhangyonglun
  */
-public final class PostgreSQLComSyncPacket implements PostgreSQLCommandPacket {
+public final class PostgreSQLComSyncPacket extends PostgreSQLCommandPacket {
     
     public PostgreSQLComSyncPacket(final PostgreSQLPacketPayload payload) {
         payload.readInt4();

sharding-proxy/sharding-proxy-transport/sharding-proxy-transport-postgresql/src/main/java/org/apache/shardingsphere/shardingproxy/transport/postgresql/packet/command/query/binary/sync/PostgreSQLComSyncPacketExecutor.java

@@ -26,7 +26,7 @@ import java.util.Collection;
 import java.util.Collections;
 
 /**
- * PostgreSQL command sync packet executor.
+ * Command sync packet executor for PostgreSQL.
  *
  * @author zhangyonglun
  * @author zhangliang

sharding-proxy/sharding-proxy-transport/sharding-proxy-transport-postgresql/src/main/java/org/apache/shardingsphere/shardingproxy/transport/postgresql/packet/command/query/text/PostgreSQLComQueryPacket.java

@@ -23,12 +23,12 @@ import org.apache.shardingsphere.shardingproxy.transport.postgresql.packet.comma
 import org.apache.shardingsphere.shardingproxy.transport.postgresql.payload.PostgreSQLPacketPayload;
 
 /**
- * PostgreSQL command query packet.
+ * Command query packet for PostgreSQL.
  *
  * @author zhangyonglun
  */
 @Getter
-public final class PostgreSQLComQueryPacket implements PostgreSQLCommandPacket {
+public final class PostgreSQLComQueryPacket extends PostgreSQLCommandPacket {
     
     private final String sql;
     

sharding-proxy/sharding-proxy-transport/sharding-proxy-transport-postgresql/src/main/java/org/apache/shardingsphere/shardingproxy/transport/postgresql/packet/command/query/text/PostgreSQLComQueryPacketExecutor.java

@@ -42,7 +42,7 @@ import java.util.LinkedList;
 import java.util.List;
 
 /**
- * PostgreSQL command query packet executor.
+ * Command query packet executor for PostgreSQL.
  *
  * @author zhangyonglun
  * @author zhangliang

sharding-proxy/sharding-proxy-transport/sharding-proxy-transport-postgresql/src/main/java/org/apache/shardingsphere/shardingproxy/transport/postgresql/packet/generic/PostgreSQLComTerminationPacket.java

@@ -22,11 +22,11 @@ import org.apache.shardingsphere.shardingproxy.transport.postgresql.packet.comma
 import org.apache.shardingsphere.shardingproxy.transport.postgresql.payload.PostgreSQLPacketPayload;
 
 /**
- * PostgreSQL command termination packet.
+ * Command termination packet for PostgreSQL.
  *
  * @author zhangyonglun
  */
-public final class PostgreSQLComTerminationPacket implements PostgreSQLCommandPacket {
+public final class PostgreSQLComTerminationPacket extends PostgreSQLCommandPacket {
     
     public PostgreSQLComTerminationPacket(final PostgreSQLPacketPayload payload) {
         payload.readInt4();

sharding-proxy/sharding-proxy-transport/sharding-proxy-transport-postgresql/src/main/java/org/apache/shardingsphere/shardingproxy/transport/postgresql/packet/generic/PostgreSQLComTerminationPacketExecutor.java

@@ -26,7 +26,7 @@ import java.util.Collection;
 import java.util.Collections;
 
 /**
- * PostgreSQL command termination packet executor.
+ * Command termination packet executor for PostgreSQL.
  * 
  * @author zhangliang
  */