我的第一个java 项目（半成品）

我的第一个java 项目（半成品）

这是一个小说项目，地址 github, 只有很少的接口，

以前有过nestjs 的开发记录，spring boot 的形式和nestjs差不多。controller， server， entity，这3层基本上就可以进行增删改查了。不过java的语法比较来说还是繁琐的。 光一个ArrayList 添加数据要一直new 对象，不能直接添加。

这个项目主要是学习spring boot 的基本用法和中间件的基本用法，redis， rabbitmq，es搜索。 都只做了简单的增加和查找， 其实我使用了ai来提需求和设计实现。 Ai 写的很详细， 容错重试什么的都有写上去， 不过目前对我来说实在是太复杂了。后面的话可能进行继续完善。

这篇文章就主要记录一下基础知识：

ElasticSearch

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@Configuration
public class EsConfiguration {
    @Value("${elasticsearch.host}")
    private String host;

    @Value("${elasticsearch.port}")
    private int port;


    @Bean
    public ElasticsearchClient elasticsearchClient() {
       RestClient restClient = RestClient.builder(
        new HttpHost(host, port, "http")
       ).build();

       RestClientTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());
       return new ElasticsearchClient(transport);
    }
}

es 保存

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// 保存到es 
public void saveToEs(NovelChapterEntity entity)  {
        try {
            ChapterESDoc doc = new ChapterESDoc();
            doc.setAuthorId(entity.getAuthorId());
            doc.setId(entity.getId());
            doc.setTitle(entity.getTitle());
            doc.setContent(entity.getContent());

            esClient.index( i -> i
                .index("chapter")
                .id(entity.getId().toString())
                .document(doc)
            );
        } catch (Exception e) {

        }
        
    }

es 查询

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public List<ChapterESDoc> searchChapterKeyword(String key) throws IOException {
        SearchResponse<ChapterESDoc> searchResponse = esClient.search(
                s -> s
                        .index("chapter")
                        .query(q -> q
                                .multiMatch(m -> m
                                        .fields("title", "content")
                                        .query(key))),
                ChapterESDoc.class);

        return searchResponse.hits().hits()
                .stream()
                .map(Hit::source)
                .collect(Collectors.toList());

    }

rabbitmq

配置

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@Configuration
public class RabbitConfiguration {
    public static final String EMAIL_QUEUE = "ppnovel-email.queue";
    public static final String EMAIL_EXCHANGE = "ppnovel-email.exchange";
    public static final String EMAIL_ROUTING_KEY = "ppnovel-email.send";

    public static final String CHAPTER_AUDIT_QUEUE = "ppnovel-chapter-audit.queue";
    public static final String CHAPTER_AUDIT_EXCHANGE = "ppnovel-chapter-audit.exchange";
    public static final String CHAPTER_AUDIT_ROUTING_KEY = "ppnovel-chapter-audit.send";

    @Bean
    public Queue emailQueue() {
        return new Queue(EMAIL_QUEUE, true);
    }

    @Bean
    public DirectExchange emailExchange() {
        return new DirectExchange(EMAIL_EXCHANGE);
    }

    @Bean
    public Binding emailBinding() {
        return BindingBuilder
                .bind(emailQueue())
                .to(emailExchange())
                .with(EMAIL_ROUTING_KEY);
    }

    @Bean
    public Queue chapterAuditQueue() {
        return new Queue(CHAPTER_AUDIT_QUEUE, true);
    }

    @Bean
    public DirectExchange chapterAuditExchange() {
        return new DirectExchange(CHAPTER_AUDIT_EXCHANGE);
    }

    @Bean
    public Binding chapterAuditBinding() {
        return BindingBuilder
            .bind(chapterAuditQueue())
            .to(chapterAuditExchange())
            .with(CHAPTER_AUDIT_ROUTING_KEY);
    }

    @Bean
    public MessageConverter messageConverter() {
        return new Jackson2JsonMessageConverter();
    }

    @Bean
    public RabbitTemplate rabbitTemplate(
            ConnectionFactory connectionFactory,
            MessageConverter messageConverter) {
        RabbitTemplate template = new RabbitTemplate(connectionFactory);
        template.setMessageConverter(messageConverter);
        return template;
    }
}

使用

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@RabbitListener(queues = RabbitConfiguration.EMAIL_QUEUE)
    public void handleEmail(EmailMessage msg, Channel channel, Message mqMessage) throws IOException {
        SimpleMailMessage message = new SimpleMailMessage();
        message.setFrom(mailFrom);
        message.setTo(msg.getTo());
        message.setSubject(msg.getSubject());
        message.setText(msg.getContent());
        try {


            javaMailSender.send(message);
            channel.basicAck(
                mqMessage.getMessageProperties().getDeliveryTag(),
                false
            );
            log.info("邮件发送成功: {}", msg.getTo());

        } catch (MailSendException e) {
            // 临时失败，重试
            channel.basicNack(
                mqMessage.getMessageProperties().getDeliveryTag(),
                false,
                true
            );
        } catch (Exception e) {
            // 不可恢复错误，丢弃或死信
            channel.basicReject(
                mqMessage.getMessageProperties().getDeliveryTag(),
                false
            );
        }
    }