如何使用Aggregator追加Exchange标头

Question

我正在编写一个Aggregator Strategy类，其中我需要旧交换的头部，而新交换应该相互附加，以便将集合头部传递给下一个处理器类。

我尝试过putAll newHeader，但它没有附加到旧的exchange。

Map<String, Object> newHeader = newExchange.getIn().getHeaders();
oldExchange.getIn().getHeaders().putAll(newHeader);
return oldExchange;

有什么建议吗？我如何才能做到这一点？

Answer 1

public class AggregateHeaders implements AggregationStrategy {
@Override
public Exchange aggregate(Exchange oldExchange, Exchange newExchange) {
    Map<String, Object> newHeaders = newExchange.getIn().getHeaders();
    oldExchange.getIn().getHeaders().putAll(newHeaders);
    return oldExchange;
}}

你的代码应该像预期的那样工作...

写了一个小测试

@Test
public void test() {
    DefaultCamelContext context = new DefaultCamelContext();
    AggregateHeaders aggregator = new AggregateHeaders();
    DefaultExchange newExchange = new DefaultExchange(context);
    newExchange.getIn().setHeader("newName", "newValue");
    DefaultExchange oldExchange = new DefaultExchange(context);
    oldExchange.getIn().setHeader("oldName", "oldValue");
    Exchange aggregated = aggregator.aggregate(oldExchange, newExchange);
    assertThat(aggregated.getIn().getHeader("oldName"), is("oldValue"));
    assertThat(aggregated.getIn().getHeader("newName"), is("newValue"));
}

另请参阅https://camel.apache.org/maven/current/camel-core/apidocs/org/apache/camel/Message.html#setHeaders(java.util.Map)

重要提示:如果要将邮件头从另一封邮件复制到此邮件，请使用getHeaders().putAll(other)复制邮件头，其中是其他邮件头。