001/* 002 * Copyright 2002-2014 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.web.socket.sockjs.frame; 018 019import java.io.IOException; 020import java.io.InputStream; 021 022import org.springframework.lang.Nullable; 023 024/** 025 * Encode and decode messages to and from a SockJS message frame, 026 * essentially an array of JSON-encoded messages. For example: 027 * 028 * <pre class="code"> 029 * a["message1","message2"] 030 * </pre> 031 * 032 * @author Rossen Stoyanchev 033 * @since 4.0 034 */ 035public interface SockJsMessageCodec { 036 037 /** 038 * Encode the given messages as a SockJS message frame. Aside from applying standard 039 * JSON quoting to each message, there are some additional JSON Unicode escaping 040 * rules. See the "JSON Unicode Encoding" section of SockJS protocol (i.e. the 041 * protocol test suite). 042 * @param messages the messages to encode 043 * @return the content for a SockJS message frame (never {@code null}) 044 */ 045 String encode(String... messages); 046 047 /** 048 * Decode the given SockJS message frame. 049 * @param content the SockJS message frame 050 * @return an array of messages, or {@code null} if none 051 * @throws IOException if the content could not be parsed 052 */ 053 @Nullable 054 String[] decode(String content) throws IOException; 055 056 /** 057 * Decode the given SockJS message frame. 058 * @param content the SockJS message frame 059 * @return an array of messages, or {@code null} if none 060 * @throws IOException if the content could not be parsed 061 */ 062 @Nullable 063 String[] decodeInputStream(InputStream content) throws IOException; 064 065}