用 Camel 的表达语言获取和格式化昨天的日期 [英] Get and format yesterday's date in Camel's expression language

问题描述

我在 Camel 的路径中使用日期:

I am using the date in a path in Camel:

fileName=${date:now:dd-MM-yyyy}

但我现在需要的是 - 1 天.这可能吗?

but what I need is now - 1 day. Is that possible?

推荐答案

好吧，不直接.简单语言中的 date: 对象只能获取当前时间(或您放置在标头中的某个时间值 - 您可以在 java 或类似语言中执行此操作.

Well, not directly. The date: object in the simple language can only grab the current time (or some time value you have placed inside a header - which you could do in java or similar.

但你也可以这样做.创建一个类:

But you could also do like this. Create a class:

public class YesterdayBean{
    public String getYesterday(){
        Calendar cal = Calendar.getInstance();
        DateFormat dateFormat = new SimpleDateFormat("dd-MM-yyyy");
        cal.add(Calendar.DATE, -1); 
        return dateFormat.format(cal.getTime());  
    }
}

将它作为 bean 连接到您的 Camel(或 spring，如果您使用它)注册表.如果您不确定如何执行此操作，请查找 registry 和 bean.

Wire it to your Camel (or spring, if you use that) registry as a bean. If you are unsure how to do that, lookup registry and the "using" section of bean.

假设您在注册表中将 bean 命名为昨天"，带弹簧:

Let's say you named the bean "yesterday" in the registry, with spring:

<bean id="yesterday" class="some.package.YesterdayBean"/>

然后将它与文件组件一起使用.

then just use it with the file component.

.to("file:fo/bar?fileName=${bean:yesterday}")

如果这只是您需要的一个地方，并且您正在使用 Java DSL，您也可以使用 Java 处理器预先创建日期并将其放在标题中.

If this is just one single place you need it, and you are using Java DSL, you could also just pre-create the date with a java processor and place it in a header.

像这样:

from("file:somewhere")
        .process(new Processor(){
            public void process(Exchange ex){
                Calendar cal = Calendar.getInstance();
                cal.add(Calendar.DATE, -1); 
                ex.getIn().setHeader("yesterday",cal.getTime());
            }
        })
       .to("file:target?fileName=${date:header.yesterday:dd-MM-yyyy}");
}

这篇关于用 Camel 的表达语言获取和格式化昨天的日期的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！