Move proxy.frontend.command package (apache#7297)

* Update javadoc

* Update javadoc

* Add generic of MySQLProtocolFrontendEngine

* Add generic of DatabasePacketCodecEngine

* Move proxy.frontend.command package

shardingsphere-db-protocol/shardingsphere-db-protocol-core/src/main/java/org/apache/shardingsphere/db/protocol/codec/DatabasePacketCodecEngine.java

@@ -29,7 +29,7 @@
  * 
  * @param <T> type of database packet
  */
-public interface DatabasePacketCodecEngine<T extends DatabasePacket> {
+public interface DatabasePacketCodecEngine<T extends DatabasePacket<?>> {
 
     /**
      * Judge is valid header or not.

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-core/src/main/java/org/apache/shardingsphere/proxy/frontend/command/CommandExecutorTask.java

@@ -29,8 +29,6 @@
 import org.apache.shardingsphere.infra.hook.SPIRootInvokeHook;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.ConnectionStateHandler;
-import org.apache.shardingsphere.proxy.frontend.api.CommandExecutor;
-import org.apache.shardingsphere.proxy.frontend.api.QueryCommandExecutor;
 import org.apache.shardingsphere.proxy.frontend.engine.CommandExecuteEngine;
 import org.apache.shardingsphere.proxy.frontend.spi.DatabaseProtocolFrontendEngine;
 

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-core/src/test/java/org/apache/shardingsphere/proxy/frontend/command/CommandExecutorTaskTest.java

@@ -27,8 +27,6 @@
 import org.apache.shardingsphere.db.protocol.payload.PacketPayload;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.ConnectionStateHandler;
-import org.apache.shardingsphere.proxy.frontend.api.CommandExecutor;
-import org.apache.shardingsphere.proxy.frontend.api.QueryCommandExecutor;
 import org.apache.shardingsphere.proxy.frontend.context.FrontendContext;
 import org.apache.shardingsphere.proxy.frontend.engine.CommandExecuteEngine;
 import org.apache.shardingsphere.proxy.frontend.spi.DatabaseProtocolFrontendEngine;
@@ -94,7 +92,7 @@ public final class CommandExecutorTaskTest {
     @SneakyThrows
     public void assertRunNeedFlushByFalse() {
         when(backendConnection.getConnectionSize()).thenReturn(1);
-        when(queryCommandExecutor.execute()).thenReturn(Collections.EMPTY_LIST);
+        when(queryCommandExecutor.execute()).thenReturn(Collections.emptyList());
         when(executeEngine.getCommandPacket(eq(payload), eq(commandPacketType), eq(backendConnection))).thenReturn(commandPacket);
         when(executeEngine.getCommandExecutor(eq(commandPacketType), eq(commandPacket), eq(backendConnection))).thenReturn(queryCommandExecutor);
         when(executeEngine.getCommandPacketType(eq(payload))).thenReturn(commandPacketType);

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-core/src/test/java/org/apache/shardingsphere/proxy/frontend/fixture/DatabaseProtocolFrontendEngineFixture.java

@@ -37,7 +37,7 @@ public FrontendContext getFrontendContext() {
     }
 
     @Override
-    public DatabasePacketCodecEngine getCodecEngine() {
+    public DatabasePacketCodecEngine<?> getCodecEngine() {
         return null;
     }
 
@@ -53,6 +53,5 @@ public CommandExecuteEngine getCommandExecuteEngine() {
 
     @Override
     public void release(final BackendConnection backendConnection) {
-
     }
 }

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-mysql/src/main/java/org/apache/shardingsphere/proxy/frontend/mysql/MySQLProtocolFrontendEngine.java

@@ -38,7 +38,7 @@ public final class MySQLProtocolFrontendEngine implements DatabaseProtocolFronte
 
     private final MySQLCommandExecuteEngine commandExecuteEngine = new MySQLCommandExecuteEngine();
 
-    private final DatabasePacketCodecEngine codecEngine = new MySQLPacketCodecEngine();
+    private final DatabasePacketCodecEngine<?> codecEngine = new MySQLPacketCodecEngine();
 
     @Override
     public String getDatabaseType() {

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-mysql/src/main/java/org/apache/shardingsphere/proxy/frontend/mysql/command/MySQLCommandExecuteEngine.java

@@ -32,8 +32,8 @@
 import org.apache.shardingsphere.infra.config.properties.ConfigurationPropertyKey;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
 import org.apache.shardingsphere.proxy.backend.schema.ProxySchemaContexts;
-import org.apache.shardingsphere.proxy.frontend.api.CommandExecutor;
-import org.apache.shardingsphere.proxy.frontend.api.QueryCommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.CommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.QueryCommandExecutor;
 import org.apache.shardingsphere.proxy.frontend.engine.CommandExecuteEngine;
 import org.apache.shardingsphere.proxy.frontend.mysql.MySQLErrPacketFactory;
 

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-mysql/src/main/java/org/apache/shardingsphere/proxy/frontend/mysql/command/MySQLCommandExecutorFactory.java

@@ -30,7 +30,7 @@
 import org.apache.shardingsphere.db.protocol.mysql.packet.command.query.text.query.MySQLComQueryPacket;
 import org.apache.shardingsphere.db.protocol.packet.CommandPacket;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
-import org.apache.shardingsphere.proxy.frontend.api.CommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.CommandExecutor;
 import org.apache.shardingsphere.proxy.frontend.mysql.command.admin.initdb.MySQLComInitDbExecutor;
 import org.apache.shardingsphere.proxy.frontend.mysql.command.admin.ping.MySQLComPingExecutor;
 import org.apache.shardingsphere.proxy.frontend.mysql.command.admin.quit.MySQLComQuitExecutor;

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-mysql/src/main/java/org/apache/shardingsphere/proxy/frontend/mysql/command/admin/initdb/MySQLComInitDbExecutor.java

@@ -25,7 +25,7 @@
 import org.apache.shardingsphere.db.protocol.packet.DatabasePacket;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
 import org.apache.shardingsphere.proxy.backend.schema.ProxySchemaContexts;
-import org.apache.shardingsphere.proxy.frontend.api.CommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.CommandExecutor;
 import org.apache.shardingsphere.sql.parser.sql.common.util.SQLUtil;
 
 import java.util.Collection;

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-mysql/src/main/java/org/apache/shardingsphere/proxy/frontend/mysql/command/admin/ping/MySQLComPingExecutor.java

@@ -19,7 +19,7 @@
 
 import org.apache.shardingsphere.db.protocol.mysql.packet.generic.MySQLOKPacket;
 import org.apache.shardingsphere.db.protocol.packet.DatabasePacket;
-import org.apache.shardingsphere.proxy.frontend.api.CommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.CommandExecutor;
 
 import java.util.Collection;
 import java.util.Collections;

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-mysql/src/main/java/org/apache/shardingsphere/proxy/frontend/mysql/command/admin/quit/MySQLComQuitExecutor.java

@@ -19,7 +19,7 @@
 
 import org.apache.shardingsphere.db.protocol.mysql.packet.generic.MySQLOKPacket;
 import org.apache.shardingsphere.db.protocol.packet.DatabasePacket;
-import org.apache.shardingsphere.proxy.frontend.api.CommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.CommandExecutor;
 
 import java.util.Collection;
 import java.util.Collections;

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-mysql/src/main/java/org/apache/shardingsphere/proxy/frontend/mysql/command/generic/MySQLUnsupportedCommandExecutor.java

@@ -22,7 +22,7 @@
 import org.apache.shardingsphere.db.protocol.mysql.packet.command.MySQLCommandPacketType;
 import org.apache.shardingsphere.db.protocol.mysql.packet.generic.MySQLErrPacket;
 import org.apache.shardingsphere.db.protocol.packet.DatabasePacket;
-import org.apache.shardingsphere.proxy.frontend.api.CommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.CommandExecutor;
 
 import java.util.Collection;
 import java.util.Collections;

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-mysql/src/main/java/org/apache/shardingsphere/proxy/frontend/mysql/command/query/binary/close/MySQLComStmtCloseExecutor.java

@@ -20,7 +20,7 @@
 import lombok.RequiredArgsConstructor;
 import org.apache.shardingsphere.db.protocol.mysql.packet.command.query.binary.close.MySQLComStmtClosePacket;
 import org.apache.shardingsphere.db.protocol.packet.DatabasePacket;
-import org.apache.shardingsphere.proxy.frontend.api.CommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.CommandExecutor;
 
 import java.util.Collection;
 import java.util.Collections;

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-mysql/src/main/java/org/apache/shardingsphere/proxy/frontend/mysql/command/query/binary/execute/MySQLComStmtExecuteExecutor.java

@@ -39,7 +39,7 @@
 import org.apache.shardingsphere.proxy.backend.response.query.QueryResponse;
 import org.apache.shardingsphere.proxy.backend.response.update.UpdateResponse;
 import org.apache.shardingsphere.proxy.backend.schema.ProxySchemaContexts;
-import org.apache.shardingsphere.proxy.frontend.api.QueryCommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.QueryCommandExecutor;
 import org.apache.shardingsphere.proxy.frontend.mysql.MySQLErrPacketFactory;
 import org.apache.shardingsphere.sql.parser.sql.common.statement.SQLStatement;
 

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-mysql/src/main/java/org/apache/shardingsphere/proxy/frontend/mysql/command/query/binary/prepare/MySQLComStmtPrepareExecutor.java

@@ -29,7 +29,7 @@
 import org.apache.shardingsphere.infra.context.SchemaContext;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
 import org.apache.shardingsphere.proxy.backend.schema.ProxySchemaContexts;
-import org.apache.shardingsphere.proxy.frontend.api.CommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.CommandExecutor;
 import org.apache.shardingsphere.sql.parser.sql.common.statement.SQLStatement;
 import org.apache.shardingsphere.sql.parser.sql.common.statement.dml.SelectStatement;
 

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-mysql/src/main/java/org/apache/shardingsphere/proxy/frontend/mysql/command/query/binary/reset/MySQLComStmtResetExecutor.java

@@ -21,7 +21,7 @@
 import org.apache.shardingsphere.db.protocol.mysql.packet.command.query.binary.reset.MySQLComStmtResetPacket;
 import org.apache.shardingsphere.db.protocol.mysql.packet.generic.MySQLOKPacket;
 import org.apache.shardingsphere.db.protocol.packet.DatabasePacket;
-import org.apache.shardingsphere.proxy.frontend.api.CommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.CommandExecutor;
 
 import java.util.Collection;
 import java.util.Collections;

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-mysql/src/main/java/org/apache/shardingsphere/proxy/frontend/mysql/command/query/text/fieldlist/MySQLComFieldListPacketExecutor.java

@@ -28,7 +28,7 @@
 import org.apache.shardingsphere.proxy.backend.response.BackendResponse;
 import org.apache.shardingsphere.proxy.backend.response.error.ErrorResponse;
 import org.apache.shardingsphere.proxy.backend.schema.ProxySchemaContexts;
-import org.apache.shardingsphere.proxy.frontend.api.CommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.CommandExecutor;
 import org.apache.shardingsphere.proxy.frontend.mysql.MySQLErrPacketFactory;
 import org.apache.shardingsphere.sql.parser.sql.common.statement.SQLStatement;
 

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-mysql/src/main/java/org/apache/shardingsphere/proxy/frontend/mysql/command/query/text/query/MySQLComQueryPacketExecutor.java

@@ -40,7 +40,7 @@
 import org.apache.shardingsphere.proxy.backend.schema.ProxySchemaContexts;
 import org.apache.shardingsphere.proxy.backend.text.TextProtocolBackendHandler;
 import org.apache.shardingsphere.proxy.backend.text.TextProtocolBackendHandlerFactory;
-import org.apache.shardingsphere.proxy.frontend.api.QueryCommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.QueryCommandExecutor;
 import org.apache.shardingsphere.proxy.frontend.mysql.MySQLErrPacketFactory;
 
 import java.sql.SQLException;
@@ -72,7 +72,7 @@ public MySQLComQueryPacketExecutor(final MySQLComQueryPacket comQueryPacket, fin
     }
 
     @Override
-    public Collection<DatabasePacket<?>> execute() throws SQLException {
+    public Collection<DatabasePacket<?>> execute() {
         if (ProxySchemaContexts.getInstance().getSchemaContexts().isCircuitBreak()) {
             return Collections.singletonList(new MySQLErrPacket(1, CommonErrorCode.CIRCUIT_BREAK_MODE));
         }

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-postgresql/src/main/java/org/apache/shardingsphere/proxy/frontend/postgresql/PostgreSQLProtocolFrontendEngine.java

@@ -39,7 +39,7 @@ public final class PostgreSQLProtocolFrontendEngine implements DatabaseProtocolF
 
     private final PostgreSQLCommandExecuteEngine commandExecuteEngine = new PostgreSQLCommandExecuteEngine();
 
-    private final DatabasePacketCodecEngine codecEngine = new PostgreSQLPacketCodecEngine();
+    private final DatabasePacketCodecEngine<?> codecEngine = new PostgreSQLPacketCodecEngine();
 
     @Override
     public String getDatabaseType() {

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-postgresql/src/main/java/org/apache/shardingsphere/proxy/frontend/postgresql/command/PostgreSQLCommandExecuteEngine.java

@@ -34,8 +34,8 @@
 import org.apache.shardingsphere.infra.config.properties.ConfigurationPropertyKey;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
 import org.apache.shardingsphere.proxy.backend.schema.ProxySchemaContexts;
-import org.apache.shardingsphere.proxy.frontend.api.CommandExecutor;
-import org.apache.shardingsphere.proxy.frontend.api.QueryCommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.CommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.QueryCommandExecutor;
 import org.apache.shardingsphere.proxy.frontend.engine.CommandExecuteEngine;
 
 import java.sql.SQLException;

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-postgresql/src/main/java/org/apache/shardingsphere/proxy/frontend/postgresql/command/PostgreSQLCommandExecutorFactory.java

@@ -26,7 +26,7 @@
 import org.apache.shardingsphere.db.protocol.postgresql.packet.command.query.binary.parse.PostgreSQLComParsePacket;
 import org.apache.shardingsphere.db.protocol.postgresql.packet.command.query.text.PostgreSQLComQueryPacket;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
-import org.apache.shardingsphere.proxy.frontend.api.CommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.CommandExecutor;
 import org.apache.shardingsphere.proxy.frontend.postgresql.command.generic.PostgreSQLComTerminationExecutor;
 import org.apache.shardingsphere.proxy.frontend.postgresql.command.generic.PostgreSQLUnsupportedCommandExecutor;
 import org.apache.shardingsphere.proxy.frontend.postgresql.command.query.binary.bind.PostgreSQLComBindExecutor;

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-postgresql/src/main/java/org/apache/shardingsphere/proxy/frontend/postgresql/command/generic/PostgreSQLComTerminationExecutor.java

@@ -18,7 +18,7 @@
 package org.apache.shardingsphere.proxy.frontend.postgresql.command.generic;
 
 import org.apache.shardingsphere.db.protocol.packet.DatabasePacket;
-import org.apache.shardingsphere.proxy.frontend.api.CommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.CommandExecutor;
 
 import java.util.Collection;
 import java.util.Collections;

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-postgresql/src/main/java/org/apache/shardingsphere/proxy/frontend/postgresql/command/generic/PostgreSQLUnsupportedCommandExecutor.java

@@ -19,7 +19,7 @@
 
 import org.apache.shardingsphere.db.protocol.packet.DatabasePacket;
 import org.apache.shardingsphere.db.protocol.postgresql.packet.generic.PostgreSQLErrorResponsePacket;
-import org.apache.shardingsphere.proxy.frontend.api.CommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.CommandExecutor;
 
 import java.util.Collection;
 import java.util.Collections;

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-postgresql/src/main/java/org/apache/shardingsphere/proxy/frontend/postgresql/command/query/binary/bind/PostgreSQLComBindExecutor.java

@@ -41,7 +41,7 @@
 import org.apache.shardingsphere.proxy.backend.response.query.QueryResponse;
 import org.apache.shardingsphere.proxy.backend.response.update.UpdateResponse;
 import org.apache.shardingsphere.proxy.backend.schema.ProxySchemaContexts;
-import org.apache.shardingsphere.proxy.frontend.api.QueryCommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.QueryCommandExecutor;
 import org.apache.shardingsphere.proxy.frontend.postgresql.PostgreSQLErrPacketFactory;
 import org.apache.shardingsphere.sql.parser.sql.common.statement.SQLStatement;
 

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-postgresql/src/main/java/org/apache/shardingsphere/proxy/frontend/postgresql/command/query/binary/describe/PostgreSQLComDescribeExecutor.java

@@ -18,7 +18,7 @@
 package org.apache.shardingsphere.proxy.frontend.postgresql.command.query.binary.describe;
 
 import org.apache.shardingsphere.db.protocol.packet.DatabasePacket;
-import org.apache.shardingsphere.proxy.frontend.api.CommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.CommandExecutor;
 
 import java.util.Collection;
 import java.util.Collections;

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-postgresql/src/main/java/org/apache/shardingsphere/proxy/frontend/postgresql/command/query/binary/execute/PostgreSQLComExecuteExecutor.java

@@ -18,7 +18,7 @@
 package org.apache.shardingsphere.proxy.frontend.postgresql.command.query.binary.execute;
 
 import org.apache.shardingsphere.db.protocol.packet.DatabasePacket;
-import org.apache.shardingsphere.proxy.frontend.api.CommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.CommandExecutor;
 
 import java.util.Collection;
 import java.util.Collections;

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-postgresql/src/main/java/org/apache/shardingsphere/proxy/frontend/postgresql/command/query/binary/parse/PostgreSQLComParseExecutor.java

@@ -25,7 +25,7 @@
 import org.apache.shardingsphere.infra.context.SchemaContext;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
 import org.apache.shardingsphere.proxy.backend.schema.ProxySchemaContexts;
-import org.apache.shardingsphere.proxy.frontend.api.CommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.CommandExecutor;
 import org.apache.shardingsphere.sql.parser.sql.common.statement.SQLStatement;
 
 import java.util.Collection;

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-postgresql/src/main/java/org/apache/shardingsphere/proxy/frontend/postgresql/command/query/binary/sync/PostgreSQLComSyncExecutor.java

@@ -18,7 +18,7 @@
 package org.apache.shardingsphere.proxy.frontend.postgresql.command.query.binary.sync;
 
 import org.apache.shardingsphere.db.protocol.packet.DatabasePacket;
-import org.apache.shardingsphere.proxy.frontend.api.CommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.CommandExecutor;
 
 import java.util.Collection;
 import java.util.Collections;

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-postgresql/src/main/java/org/apache/shardingsphere/proxy/frontend/postgresql/command/query/text/PostgreSQLComQueryExecutor.java

@@ -37,7 +37,7 @@
 import org.apache.shardingsphere.proxy.backend.schema.ProxySchemaContexts;
 import org.apache.shardingsphere.proxy.backend.text.TextProtocolBackendHandler;
 import org.apache.shardingsphere.proxy.backend.text.TextProtocolBackendHandlerFactory;
-import org.apache.shardingsphere.proxy.frontend.api.QueryCommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.QueryCommandExecutor;
 import org.apache.shardingsphere.proxy.frontend.postgresql.PostgreSQLErrPacketFactory;
 
 import java.sql.ResultSetMetaData;
@@ -69,7 +69,7 @@ public PostgreSQLComQueryExecutor(final PostgreSQLComQueryPacket comQueryPacket,
     }
 
     @Override
-    public Collection<DatabasePacket<?>> execute() throws SQLException {
+    public Collection<DatabasePacket<?>> execute() {
         if (ProxySchemaContexts.getInstance().getSchemaContexts().isCircuitBreak()) {
             return Collections.singletonList(new PostgreSQLErrorResponsePacket());
         }

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-postgresql/src/test/java/org/apache/shardingsphere/proxy/frontend/postgresql/command/PostgreSQLCommandExecuteEngineTest.java

@@ -20,7 +20,7 @@
 import io.netty.channel.ChannelHandlerContext;
 import lombok.SneakyThrows;
 import org.apache.shardingsphere.db.protocol.postgresql.packet.generic.PostgreSQLReadyForQueryPacket;
-import org.apache.shardingsphere.proxy.frontend.api.QueryCommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.QueryCommandExecutor;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.Mock;

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-spi/src/main/java/org/apache/shardingsphere/proxy/frontend/api/CommandExecutor.java → shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-spi/src/main/java/org/apache/shardingsphere/proxy/frontend/command/CommandExecutor.java

@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 
-package org.apache.shardingsphere.proxy.frontend.api;
+package org.apache.shardingsphere.proxy.frontend.command;
 
 import org.apache.shardingsphere.db.protocol.packet.DatabasePacket;
 

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-spi/src/main/java/org/apache/shardingsphere/proxy/frontend/api/QueryCommandExecutor.java → shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-spi/src/main/java/org/apache/shardingsphere/proxy/frontend/command/QueryCommandExecutor.java

@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 
-package org.apache.shardingsphere.proxy.frontend.api;
+package org.apache.shardingsphere.proxy.frontend.command;
 
 import org.apache.shardingsphere.db.protocol.packet.DatabasePacket;
 
@@ -27,21 +27,21 @@
 public interface QueryCommandExecutor extends CommandExecutor {
 
     /**
-     * Judge is query SQL or not.
+     * Judge whether query response.
      *
-     * @return is query SQL or not
+     * @return is query response or not
      */
     boolean isQueryResponse();
 
     /**
-     * Judge is update response.
+     * Judge whether update response.
      *
      * @return is update response or not
      */
     boolean isUpdateResponse();
 
     /**
-     * Judge is error response.
+     * Judge whether error response.
      *
      * @return is error response or not
      */

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-spi/src/main/java/org/apache/shardingsphere/proxy/frontend/engine/CommandExecuteEngine.java

@@ -23,8 +23,8 @@
 import org.apache.shardingsphere.db.protocol.packet.DatabasePacket;
 import org.apache.shardingsphere.db.protocol.payload.PacketPayload;
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.BackendConnection;
-import org.apache.shardingsphere.proxy.frontend.api.CommandExecutor;
-import org.apache.shardingsphere.proxy.frontend.api.QueryCommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.CommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.command.QueryCommandExecutor;
 
 import java.sql.SQLException;
 import java.util.Optional;

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-spi/src/main/java/org/apache/shardingsphere/proxy/frontend/spi/DatabaseProtocolFrontendEngine.java

@@ -41,7 +41,7 @@ public interface DatabaseProtocolFrontendEngine extends DatabaseTypeAwareSPI {
      * 
      * @return database packet codec engine
      */
-    DatabasePacketCodecEngine getCodecEngine();
+    DatabasePacketCodecEngine<?> getCodecEngine();
 
     /**
      * Get authentication engine.