java - Camel 'OUT' 消息未从处理器中的 'IN' 填充

Question

试图弄清楚如何在处理器中将正文从我的 IN 消息传播到我的 OUT。见下文。请注意，我正在使用流缓存并且我的原始输入是一个流。

public void process(Exchange exchange) throws Exception {

    log.debug("In msg:"  + exchange.getIn().getBody(String.class));
    log.debug("Out msg:"  + exchange.getOut().getBody(String.class));

    exchange.setOut(exchange.getIn());

    log.debug("In msg:"  + exchange.getIn().getBody(String.class));
    log.debug("Out msg:"  + exchange.getOut().getBody(String.class));
}

输出是:

In msg: "My Payload"
Out msg: null
In msg: (empty string)
Out msg: (empty string)

我期望的是:

In msg: "My Payload"
Out msg: null
In msg: "My Payload"
Out msg: "My Payload"

那个空字符串是从哪里来的？

Answer 1

根据引用 docs 的 Claus 评论:

Consider using getIn() As shown above you most often need to alter the existing IN message, than creating a totally new OUT message. And therefore it's often easier just to adjust the IN message directly.