io.spring.isomorphic.CommentController.java Source code

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Here is the source code for io.spring.isomorphic.CommentController.java

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/*
 * Copyright 2002-2015 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 io.spring.isomorphic;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.MediaType;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.mvc.method.annotation.SseEmitter;

@Controller
public class CommentController {

    private CommentRepository commentRepository;
    private final List<SseEmitter> sseEmitters = new ArrayList<>();

    @Autowired
    CommentController(CommentRepository commentRepository) {
        this.commentRepository = commentRepository;
    }

    @RequestMapping(value = "/", produces = "application/json")
    @ResponseBody
    Iterable<Comment> jsonFindAll() {
        return this.commentRepository.findAll();
    }

    @RequestMapping(value = "/", method = RequestMethod.POST, produces = "application/json")
    @ResponseBody
    Comment jsonCreate(Comment comment) throws IOException {
        Comment newComment = this.commentRepository.save(comment);
        for (SseEmitter sseEmitter : this.sseEmitters) {
            // Servlet containers don't always detect ghost connection, so we must catch exceptions ...
            try {
                sseEmitter.send(newComment, MediaType.APPLICATION_JSON);
            } catch (Exception e) {
            }
        }
        return comment;
    }

    @RequestMapping("/")
    String render(Model model) {
        model.addAttribute("title", "Layout example");
        model.addAttribute("comments", this.commentRepository.findAll());
        return "index";
    }

    @RequestMapping("/sse/updates")
    SseEmitter subscribeUpdates() {
        SseEmitter sseEmitter = new SseEmitter();
        this.sseEmitters.add(sseEmitter);
        sseEmitter.onCompletion(() -> {
            this.sseEmitters.remove(sseEmitter);
        });
        return sseEmitter;
    }

}