java - Apache Camel : I can't get an object out of the body and transform it

Question

如果这样做的话:body -> string -> user

    .to("direct:httpClient")
    .process(new Processor() {
        @Override
        public void process(Exchange exchange) throws JsonProcessingException {
            String body = exchange.getIn().getBody(String.class);
            User[] users = jacksonDataFormat.getObjectMapper().readValue(body, User[].class);
        }
    })

此选项效果很好，但如果您这样做:

User [] body = exchange.getIn().getBody(User[].class);

body -> 用户，它不起作用。用户始终为空。

为了清楚起见:

from("timer://test?period=2000")
                .setHeader(Exchange.HTTP_METHOD).constant(HttpMethod.GET)
                .setHeader(Exchange.CONTENT_TYPE, constant("application/json"))
                .convertBodyTo(User[].class)
                .to("http://localhost:8085/api/user")
                .process(exchange -> System.out.println(exchange.getIn().getBody(String.class)))

控制台输出:

[
   {
      "name":"BLA"
   },
   {
      "name":"BLA"
   },
   {
      "name":"BLA"
   }
]

如果是这样:

from("timer://test?period=2000")
                .setHeader(Exchange.HTTP_METHOD).constant(HttpMethod.GET)
                .setHeader(Exchange.CONTENT_TYPE, constant("application/json"))
                .convertBodyTo(User[].class)
                .to("http://localhost:8085/api/user")
                .process(exchange -> System.out.println(exchange.getIn().getBody(User[].class)))

控制台输出:空

原因是什么？我该如何解决这个问题？

Answer 1

如果您希望Camel处理JSON字符串到Java对象的过程，您可以将其添加为编码器 - https://camel.apache.org/components/latest/dataformats/jacksonxml-dataformat.html