java8 spring-boot を練習しながら facebook messenger bot を書いてみた

java8 + spring-boot で facebook messenger bot を書きました

http://qiita.com/amanoiverse/items/742a963be069e1902269 の fb messenger 版

• callback は https://...:443/fbmessengerbot に
• 必要情報は環境変数で
• jackson, httpclient, lombok 使用
• try catch はノーポリシー + 過剰な例外回避

controller

@RestController
@val
public class FBMessengerBotController {
    @Autowired
    FBMessengerBotService botService;

    @RequestMapping(value = "/fbmessengerbot", method = RequestMethod.GET)
    String verify(HttpServletRequest request) throws RuntimeException {
        return botService.verify(request);
    }
    @RequestMapping(value = "/fbmessengerbot", method = RequestMethod.POST)
    String message(HttpServletRequest request) throws RuntimeException {
        return botService.sentToMessenger(request);
    }
}

model

@Data
public class FBMessengerBotWebhook {
    String object;
    List<FBMessengerBotWebhookEntry> entry;
}
@Data
public class FBMessengerBotWebhookEntry {
    BigDecimal id;
    BigDecimal time;
    List<FBMessengerBotWebhookEntryMessaging> messaging;
}
@Data
public class FBMessengerBotWebhookEntryMessaging {
    Map<String, BigDecimal> sender;
    Map<String, BigDecimal> recipient;
    BigDecimal timestamp;
    FBMessengerBotWebhookEntryMessagingMessage message;
}
@Data
public class FBMessengerBotWebhookEntryMessagingMessage {
    String mid;
    BigDecimal seq;
    String text;
}

@Data
public class FBMessengerBotWebhookRecipient {
    Map<String, BigDecimal> recipient;
    Map<String, String> message;

}

service

@val
@Slf4j
@Service
public class FBMessengerBotService {
    final String FBMESSENGERBOT_VERIFY_TOKEN = System.getenv("FBMESSENGERBOT_VERIFY_TOKEN");
    final String FBMESSENGERBOT_ACCESS_TOKEN = System.getenv("FBMESSENGERBOT_ACCESS_TOKEN");
    final String FBMESSENGERBOT_ENDPOINT = "https://graph.facebook.com/v2.6/me/messages";

    public String verify(HttpServletRequest request) {
        try {
            val paramMap = request.getParameterMap();

            // debug
            val mapStream = paramMap.entrySet().stream();
            mapStream.forEach(e -> log.info(String.format("%s:%s", e.getKey(), String.join("", e.getValue()))));

            if (paramMap.get("hub.mode")[0].equals("subscribe")
                    && paramMap.get("hub.verify_token")[0].equals(FBMESSENGERBOT_VERIFY_TOKEN)) {
                return String.join("", paramMap.get("hub.challenge"));
            }
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        return "failed";
    }

    public String sentToMessenger(HttpServletRequest request) {
        try {
            val jb = new StringBuffer();
            request.getReader().lines().forEach(jb::append);
            log.info(jb.toString());

            val mapper = new ObjectMapper();
            val botResponse = mapper.readValue(jb.toString(), FBMessengerBotWebhook.class);
            log.error("!!!" + ToStringBuilder.reflectionToString(botResponse));
            botResponse.getEntry().forEach(e -> e.getMessaging().stream().forEach(this::sendMessage));
        } catch (UnrecognizedPropertyException ex) {
            ;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "ok";
    }

    void sendMessage(FBMessengerBotWebhookEntryMessaging messaging) {
        try {
            val message = messaging.getMessage();
            val text = message.getText();
            log.info(text);
            Stream<String> stream = Arrays.stream(text.split(""));
            val builder = new URIBuilder(FBMESSENGERBOT_ENDPOINT);
            builder.setParameter("access_token", FBMESSENGERBOT_ACCESS_TOKEN);
            val recipient = new FBMessengerBotWebhookRecipient();
            recipient.setRecipient(messaging.getSender());
            val post = new HttpPost(builder.build());
            post.setHeader("Content-Type", "application/json; charset=UTF-8");
            try (val httpclient = HttpClients.createDefault()) {
                stream.forEach(e -> sendOneRequest(httpclient, post, recipient, e));
            }
        } catch (IOException e) {
            e.printStackTrace();
        } catch (URISyntaxException e) {
            e.printStackTrace();
        }
    }

    void sendOneRequest(CloseableHttpClient client, HttpPost post, FBMessengerBotWebhookRecipient recipient,
            String oneString) {
        try {
            Map<String, String> message = new HashMap<>();
            message.put("text", oneString);
            recipient.setMessage(message);

            val mapper = new ObjectMapper();
            val json = mapper.writeValueAsString(recipient);
            log.info(json);

            post.setEntity(new StringEntity(json, StandardCharsets.UTF_8));
            val res = client.execute(post);

            Arrays.stream(res.getAllHeaders()).forEach(e -> log.info(e.toString()));
            try (val br = new BufferedReader(
                    new InputStreamReader(res.getEntity().getContent(), StandardCharsets.UTF_8))) {
                br.lines().forEach(e -> log.info(e.toString()));
            } catch (IOException e) {
                e.printStackTrace();
            }
            log.info("JSON:" + json);
            log.info("STATUSLINE:" + res.getStatusLine().toString());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

build.gradle

dependencies {
    compileOnly('org.projectlombok:lombok')
    compile('org.springframework.boot:spring-boot-starter-web')
    compile('com.fasterxml.jackson.core:jackson-databind:2.7.0')
    compile('com.fasterxml.jackson.core:jackson-annotations:2.7.0')
    compile('com.fasterxml.jackson.core:jackson-core:2.7.0')
    compile('org.apache.httpcomponents:httpasyncclient:4.1.1')
    compile('org.apache.httpcomponents:httpcore-nio:4.4.4')
}

task wrapper(type: Wrapper) {
    gradleVersion = '2.12'
}

• なんか、bot自身の発言でも callback が来るので、 json パースエラーを catch して握りつぶす。
• Organize Import すると、Unexpected error in organize imports. See log for details AST must not be null っていわれる(ここが一番はまった)。回避するには val を全部あきらめる。Organize Import ないと生きていけない。
  • lombok version は 1.6.8 かな。。。。過去の changelog で AST... についての修正的なのが書いてあるが、最新でもだめだった。
  • ということで、今後は val 全面的にやめようと思う。