for #1963 implement MySQLComStmtClosePacket.

sharding-parser/sharding-parser-mysql/src/main/antlr4/imports/mysql/MySQLKeyword.tokens

+ACCOUNT=1
+ACTION=2
+ADMIN=3
+AFTER=4
+ALGORITHM=5
+ANALYZE=6
+AUDIT_ADMIN=7
+AUTO_INCREMENT=8
+AUTOCOMMIT=9
+AVG_ROW_LENGTH=10
+BEGIN=11
+BINLOG_ADMIN=12
+BTREE=13
+CASE=14
+CHAIN=15
+CHANGE=16
+CHAR=17
+CHARACTER=18
+CHARSET=19
+CHECKSUM=20
+CIPHER=21
+CLIENT=22
+COALESCE=23
+COLLATE=24
+COLUMNS=25
+COLUMN_FORMAT=26
+COMMENT=27
+COMPACT=28
+COMPRESSED=29
+COMPRESSION=30
+CONNECTION=31
+CONNECTION_ADMIN=32
+CONSISTENT=33
+CONVERT=34
+COPY=35
+CROSS=36
+CURRENT_TIMESTAMP=37
+DATA=38
+DATABASES=39
+DELAYED=40
+DELAY_KEY_WRITE=41
+DIRECTORY=42
+DISCARD=43
+DISK=44
+DISTINCTROW=45
+DOUBLE=46
+DUPLICATE=47
+DYNAMIC=48
+ELSE=49
+ENCRYPTION=50
+ENCRYPTION_KEY_ADMIN=51
+END=52
+ENGINE=53
+EVENT=54
+EXCEPT=55
+EXCHANGE=56
+EXCLUSIVE=57
+EXECUTE=58
+EXPIRE=59
+FILE=60
+FIREWALL_ADMIN=61
+FIREWALL_USER=62
+FIRST=63
+FIXED=64
+FOLLOWING=65
+FORCE=66
+FULL=67
+FULLTEXT=68
+GLOBAL=69
+GROUP_CONCAT=70
+GROUP_REPLICATION_ADMIN=71
+HASH=72
+HIGH_PRIORITY=73
+HISTORY=74
+IDENTIFIED=75
+IF=76
+IGNORE=77
+IMPORT_=78
+INNER=79
+INPLACE=80
+INSERT=81
+INSERT_METHOD=82
+INTERVAL=83
+INTO=84
+ISSUER=85
+JOIN=86
+KEYS=87
+KEY_BLOCK_SIZE=88
+LAST=89
+LEFT=90
+LESS=91
+LINEAR=92
+LIST=93
+LOCALTIME=94
+LOCALTIMESTAMP=95
+LOCK=96
+LOW_PRIORITY=97
+MATCH=98
+MAXVALUE=99
+MAX_CONNECTIONS_PER_HOUR=100
+MAX_QUERIES_PER_HOUR=101
+MAX_ROWS=102
+MAX_UPDATES_PER_HOUR=103
+MAX_USER_CONNECTIONS=104
+MEMORY=105
+MIN_ROWS=106
+MODIFY=107
+NATURAL=108
+NEVER=109
+NONE=110
+NOW=111
+OFFLINE=112
+OLD=113
+ONLINE=114
+ONLY=115
+OPTIMIZE=116
+OPTIONAL=117
+OUTER=118
+OVER=119
+PACK_KEYS=120
+PARSER=121
+PARTIAL=122
+PARTITIONING=123
+PARTITIONS=124
+PERSIST=125
+PERSIST_ONLY=126
+PRECEDING=127
+PRECISION=128
+PROCEDURE=129
+PROCESS=130
+PROXY=131
+QUICK=132
+RANGE=133
+REBUILD=134
+RECURSIVE=135
+REDUNDANT=136
+RELEASE=137
+RELOAD=138
+REMOVE=139
+RENAME=140
+REORGANIZE=141
+REPAIR=142
+REPEATABLE=143
+REPLACE=144
+REPLICATION=145
+REPLICATION_SLAVE_ADMIN=146
+REQUIRE=147
+RESTRICT=148
+RETAIN=149
+REUSE=150
+RIGHT=151
+ROLE_ADMIN=152
+ROUTINE=153
+ROW_FORMAT=154
+SAVEPOINT=155
+SELECT=156
+SEPARATOR=157
+SESSION=158
+SET_USER_ID=159
+SHARED=160
+SHOW=161
+SHUTDOWN=162
+SIMPLE=163
+SLAVE=164
+SNAPSHOT=165
+SPATIAL=166
+SQLDML=167
+SQLDQL=168
+SQL_BIG_RESULT=169
+SQL_BUFFER_RESULT=170
+SQL_CACHE=171
+SQL_CALC_FOUND_ROWS=172
+SQL_NO_CACHE=173
+SQL_SMALL_RESULT=174
+SSL=175
+STATS_AUTO_RECALC=176
+STATS_PERSISTENT=177
+STATS_SAMPLE_PAGES=178
+STORAGE=179
+STORED=180
+STRAIGHT_JOIN=181
+SUBJECT=182
+SUBPARTITION=183
+SUBPARTITIONS=184
+SUPER=185
+SYSTEM_VARIABLES_ADMIN=186
+TABLES=187
+TABLESPACE=188
+TEMPORARY=189
+THAN=190
+THEN=191
+TRIGGER=192
+UNBOUNDED=193
+UNCOMMITTED=194
+UNLOCK=195
+UNSIGNED=196
+UPDATE=197
+UPGRADE=198
+USAGE=199
+USE=200
+USING=201
+VALIDATION=202
+VALUE=203
+VALUES=204
+VERSION_TOKEN_ADMIN=205
+VIEW=206
+VIRTUAL=207
+WHEN=208
+WINDOW=209
+WITHOUT=210
+WRITE=211
+ZEROFILL=212
+VISIBLE=213
+INVISIBLE=214
+INSTANT=215
+ENFORCED=216
+FOR_GENERATOR=217
+'DO NOT MATCH ANY THING, JUST FOR GENERATOR'=217

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

@@ -24,6 +24,7 @@ import org.apache.shardingsphere.shardingproxy.transport.mysql.packet.MySQLPacke
 import org.apache.shardingsphere.shardingproxy.transport.mysql.packet.command.admin.MySQLOKCommandPacketExecutor;
 import org.apache.shardingsphere.shardingproxy.transport.mysql.packet.command.admin.MySQLUnsupportedCommandPacketExecutor;
 import org.apache.shardingsphere.shardingproxy.transport.mysql.packet.command.admin.initdb.MySQLComInitDbPacketExecutor;
+import org.apache.shardingsphere.shardingproxy.transport.mysql.packet.command.query.binary.close.MySQLComStmtClosePacketExecutor;
 import org.apache.shardingsphere.shardingproxy.transport.mysql.packet.command.query.binary.execute.MySQLQueryComStmtExecutePacketExecutor;
 import org.apache.shardingsphere.shardingproxy.transport.mysql.packet.command.query.binary.prepare.MySQLComStmtPreparePacketExecutor;
 import org.apache.shardingsphere.shardingproxy.transport.mysql.packet.command.query.text.fieldlist.MySQLComFieldListPacketExecutor;
@@ -58,7 +59,7 @@ public final class MySQLCommandPacketExecutorFactory {
             case COM_STMT_EXECUTE:
                 return new MySQLQueryComStmtExecutePacketExecutor();
             case COM_STMT_CLOSE:
-                return new MySQLComFieldListPacketExecutor();
+                return new MySQLComStmtClosePacketExecutor();
             case COM_PING:
                 return new MySQLOKCommandPacketExecutor();
             default:

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

@@ -29,6 +29,7 @@ import java.util.concurrent.atomic.AtomicInteger;
  *
  * @author zhangliang
  * @author zhangyonglun
+ * @author zhaojun
  */
 @NoArgsConstructor(access = AccessLevel.NONE)
 public final class MySQLBinaryStatementRegistry {
@@ -77,4 +78,17 @@ public final class MySQLBinaryStatementRegistry {
     public MySQLBinaryStatement getBinaryStatement(final int statementId) {
         return binaryStatements.get(statementId);
     }
+    
+    /**
+     * Remove expired cache statement.
+     *
+     * @param statementId statement ID
+     */
+    public void remove(final int statementId) {
+        MySQLBinaryStatement binaryStatement = getBinaryStatement(statementId);
+        if (null != binaryStatement) {
+            statementIdAssigner.remove(binaryStatement.getSql());
+            binaryStatements.remove(statementId);
+        }
+    }
 }

sharding-proxy/sharding-proxy-transport/sharding-proxy-transport-mysql/src/main/java/org/apache/shardingsphere/shardingproxy/transport/mysql/packet/command/query/binary/close/MySQLComStmtClosePacket.java

@@ -19,6 +19,7 @@ package org.apache.shardingsphere.shardingproxy.transport.mysql.packet.command.q
 
 import lombok.Getter;
 import org.apache.shardingsphere.shardingproxy.transport.mysql.packet.command.MySQLCommandPacket;
+import org.apache.shardingsphere.shardingproxy.transport.mysql.packet.command.query.binary.MySQLBinaryStatementRegistry;
 import org.apache.shardingsphere.shardingproxy.transport.mysql.payload.MySQLPacketPayload;
 
 /**
@@ -39,6 +40,7 @@ public final class MySQLComStmtClosePacket implements MySQLCommandPacket {
     
     @Override
     public void write(final MySQLPacketPayload payload) {
+        MySQLBinaryStatementRegistry.getInstance().remove(statementId);
     }
     
     @Override

sharding-proxy/sharding-proxy-transport/sharding-proxy-transport-mysql/src/main/java/org/apache/shardingsphere/shardingproxy/transport/mysql/packet/command/query/binary/close/MySQLComStmtClosePacketExecutor.java

@@ -22,6 +22,7 @@ import org.apache.shardingsphere.shardingproxy.transport.api.packet.CommandPacke
 import org.apache.shardingsphere.shardingproxy.transport.common.packet.CommandPacketExecutor;
 import org.apache.shardingsphere.shardingproxy.transport.mysql.packet.MySQLPacket;
 
+import java.sql.SQLException;
 import java.util.Collection;
 import java.util.Collections;
 
@@ -33,7 +34,8 @@ import java.util.Collections;
 public final class MySQLComStmtClosePacketExecutor implements CommandPacketExecutor<MySQLPacket> {
     
     @Override
-    public Collection<MySQLPacket> execute(final BackendConnection backendConnection, final CommandPacket commandPacket) {
+    public Collection<MySQLPacket> execute(final BackendConnection backendConnection, final CommandPacket commandPacket) throws SQLException {
+        commandPacket.execute();
         return Collections.emptyList();
     }
 }