Add ExpectedExceptions for proxy

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

@@ -31,6 +31,7 @@ import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.Bac
 import org.apache.shardingsphere.proxy.backend.communication.jdbc.connection.ConnectionStatusHandler;
 import org.apache.shardingsphere.proxy.frontend.command.executor.CommandExecutor;
 import org.apache.shardingsphere.proxy.frontend.command.executor.QueryCommandExecutor;
+import org.apache.shardingsphere.proxy.frontend.exception.ExpectedExceptions;
 import org.apache.shardingsphere.proxy.frontend.spi.DatabaseProtocolFrontendEngine;
 
 import java.sql.SQLException;
@@ -77,7 +78,7 @@ public final class CommandExecutorTask implements Runnable {
             context.writeAndFlush(databaseProtocolFrontendEngine.getCommandExecuteEngine().getErrorPacket(ex));
             Optional<DatabasePacket<?>> databasePacket = databaseProtocolFrontendEngine.getCommandExecuteEngine().getOtherPacket();
             databasePacket.ifPresent(context::writeAndFlush);
-            if (!isExpectedException(ex)) {
+            if (!ExpectedExceptions.isExpected(ex.getClass())) {
                 log.error("Exception occur: ", ex);
             }
         } finally {
@@ -88,11 +89,6 @@ public final class CommandExecutorTask implements Runnable {
         }
     }
     
-    // TODO finish expected exception
-    private boolean isExpectedException(final Exception ex) {
-        return ex instanceof RuntimeException;
-    }
-    
     private boolean executeCommand(final ChannelHandlerContext context, final PacketPayload payload, final BackendConnection backendConnection) throws SQLException {
         CommandExecuteEngine commandExecuteEngine = databaseProtocolFrontendEngine.getCommandExecuteEngine();
         CommandPacketType type = commandExecuteEngine.getCommandPacketType(payload);

shardingsphere-proxy/shardingsphere-proxy-frontend/shardingsphere-proxy-frontend-core/src/main/java/org/apache/shardingsphere/proxy/frontend/exception/ExpectedExceptions.java

+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.shardingsphere.proxy.frontend.exception;
+
+import lombok.AccessLevel;
+import lombok.NoArgsConstructor;
+import org.apache.shardingsphere.infra.config.exception.ShardingSphereConfigurationException;
+import org.apache.shardingsphere.infra.exception.ShardingSphereException;
+import org.apache.shardingsphere.proxy.backend.exception.BackendException;
+import org.apache.shardingsphere.proxy.backend.text.sctl.exception.ShardingCTLException;
+import org.apache.shardingsphere.sql.parser.exception.SQLParsingException;
+
+import java.util.Collection;
+import java.util.HashSet;
+
+/**
+ * Expected exceptions.
+ */
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
+public final class ExpectedExceptions {
+    
+    private static final Collection<Class<? extends Exception>> EXCEPTIONS = new HashSet<>();
+    
+    static {
+        EXCEPTIONS.add(ShardingSphereException.class);
+        EXCEPTIONS.add(ShardingSphereConfigurationException.class);
+        EXCEPTIONS.add(SQLParsingException.class);
+        EXCEPTIONS.add(ShardingCTLException.class);
+        EXCEPTIONS.add(BackendException.class);
+    }
+    
+    /**
+     * Judge whether expected exception.
+     * @param exceptionClass exception class
+     * @return is expected exception or not
+     */
+    public static boolean isExpected(final Class<?> exceptionClass) {
+        return EXCEPTIONS.contains(exceptionClass);
+    }
+}

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

@@ -63,9 +63,9 @@ public final class PostgreSQLCommandExecuteEngine implements CommandExecuteEngin
     
     @Override
     public DatabasePacket<?> getErrorPacket(final Exception cause) {
-        PostgreSQLErrorResponsePacket errorResponsePacket = new PostgreSQLErrorResponsePacket();
-        errorResponsePacket.addField(PostgreSQLErrorResponsePacket.FIELD_TYPE_MESSAGE, cause.getMessage());
-        return errorResponsePacket;
+        PostgreSQLErrorResponsePacket result = new PostgreSQLErrorResponsePacket();
+        result.addField(PostgreSQLErrorResponsePacket.FIELD_TYPE_MESSAGE, cause.getMessage());
+        return result;
     }
     
     @Override