org.springframework.web.socket.support.ExceptionWebSocketHandlerDecorator.java Source code

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Here is the source code for org.springframework.web.socket.support.ExceptionWebSocketHandlerDecorator.java

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/*
 * Copyright 2002-2013 the original author or authors.
 *
 * Licensed 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.springframework.web.socket.support;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.web.socket.CloseStatus;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.WebSocketMessage;
import org.springframework.web.socket.WebSocketSession;

/**
 * An exception handling {@link WebSocketHandlerDecorator}. Traps all {@link Throwable}
 * instances that escape from the decorated handler and closes the session with
 * {@link CloseStatus#SERVER_ERROR}.
 *
 * @author Rossen Stoyanchev
 * @since 4.0
 */
public class ExceptionWebSocketHandlerDecorator extends WebSocketHandlerDecorator {

    private Log logger = LogFactory.getLog(ExceptionWebSocketHandlerDecorator.class);

    public ExceptionWebSocketHandlerDecorator(WebSocketHandler delegate) {
        super(delegate);
    }

    @Override
    public void afterConnectionEstablished(WebSocketSession session) {
        try {
            getDelegate().afterConnectionEstablished(session);
        } catch (Throwable ex) {
            tryCloseWithError(session, ex, logger);
        }
    }

    public static void tryCloseWithError(WebSocketSession session, Throwable exception, Log logger) {
        logger.error("Closing due to exception for " + session, exception);
        if (session.isOpen()) {
            try {
                session.close(CloseStatus.SERVER_ERROR);
            } catch (Throwable t) {
                // ignore
            }
        }
    }

    @Override
    public void handleMessage(WebSocketSession session, WebSocketMessage<?> message) {
        try {
            getDelegate().handleMessage(session, message);
        } catch (Throwable ex) {
            tryCloseWithError(session, ex, logger);
        }
    }

    @Override
    public void handleTransportError(WebSocketSession session, Throwable exception) {
        try {
            getDelegate().handleTransportError(session, exception);
        } catch (Throwable ex) {
            tryCloseWithError(session, ex, logger);
        }
    }

    @Override
    public void afterConnectionClosed(WebSocketSession session, CloseStatus closeStatus) {
        try {
            getDelegate().afterConnectionClosed(session, closeStatus);
        } catch (Throwable t) {
            logger.error("Unhandled error for " + this, t);
        }
    }

}