The remote endpoint was in state

3-16 14:59:13 109 ConsumeMessageThread_15 ERROR [] - The remote endpoint was in state [TEXT_FULL_WRITING] which is an invalid state for called method
java.lang.IllegalStateException: The remote endpoint was in state [TEXT_FULL_WRITING] which is an invalid state for called method
    at org.apache.tomcat.websocket.WsRemoteEndpointImplBase$StateMachine.checkState(WsRemoteEndpointImplBase.java:1206) ~[tomcat7-websocket.jar:7.0.90]
    at org.apache.tomcat.websocket.WsRemoteEndpointImplBase$StateMachine.textStart(WsRemoteEndpointImplBase.java:1169) ~[tomcat7-websocket.jar:7.0.90]
    at org.apache.tomcat.websocket.WsRemoteEndpointImplBase.sendString(WsRemoteEndpointImplBase.java:194) ~[tomcat7-websocket.jar:7.0.90]
    at org.apache.tomcat.websocket.WsRemoteEndpointBasic.sendText(WsRemoteEndpointBasic.java:37) ~[tomcat7-websocket.jar:7.0.90]

使用websocket 做实时聊天系统，在生产环境上有业务人员反馈收不到消息，查看日志发现有很多The remote endpoint was in state [TEXT_FULL_WRITING] which is an invalid state for called method,猜测很可能是它引起的。
产生原因：同时有多个线程调用了this.session.getBasicRemote().sendText(msg); 方法。
修改前：

public void sendMessage(String msg) {
            try {
                this.session.getBasicRemote().sendText(msg);
            } catch (IOException e) {
                this.sendMessage(new Response().failure(e.getMessage()));
            }
    }

修改后:

public void sendMessage(String msg) {
        synchronized(this.session) {
            try {
                this.session.getBasicRemote().sendText(msg);
            } catch (IOException e) {
                this.sendMessage(new Response().failure(e.getMessage()));
            }
        }
    }