从Apache Camel内的JSON主体访问数据 [英] Accessing Data from JSON body inside Apache Camel

问题描述

我正在使用一个API，该API基本上允许文件系统的导航.我试图通过API从返回的JSON中访问数据，以便对其执行功能.

I am working with an API which basically allows for the navigation of a file-system. I am trying to access data from within the returned JSON by the API in order to perform a function on it.

以下是我正在使用的用于访问API的代码.我试图用元帅来 将返回的JSON转换为Map.

Below is the code I am using the access the API. I have tried to use unmarshal to convert the JSON returned to a Map.

from("timer://foo?fixedRate=true&period=120000")
    .log("Checking for files")
    .setHeader("Authorization", simple(myHttp.getAuth()))
    .setHeader("CamelHttpMethod", constant("GET"))
    .to(myHttp.getFullRequest())
    .unmarshal(new JacksonDataFormat(Map.class)).log("${body}");

哪个数据返回给我:

{
    objects=[
    {
        name=file1.csv,
        type=file
    },
    {
        name=dir1,
        type=directory,
    },
    {
        name=dir2,
        type=directory
    },
    {
        name=dir3,
        type=directory
    },
    {
        name=dir4,
        type=directory
    }]
}

我想访问对象"下的数组，以便检查此目录内是否存在任何文件.到目前为止，我只尝试将数据记录在对象下，因此我使用了以下代码:

I want to access the array under "objects" in order to check whether any files exist inside this directory. So far, I only tried to log the data under objects and therefore I have used this code:

   .unmarshal(new JacksonDataFormat(Map.class)).log("${body.objects}");

使用$ {body.objects}，我仍然无法访问MAP中的数据.我希望这样的东西会被返回:

Using ${body.objects}, I'm still unable to access the data inside the MAP. I expected something like this to be returned:

        [{
            name=file1.csv,
            type=file
        },
        {
            name=dir1,
            type=directory,
        },
        {
            name=dir2,
            type=directory
        },
        {
            name=dir3,
            type=directory
        },
        {
            name=dir4,
            type=directory
        }]

但我收到此错误:

名称为:在bean上找不到对象的方法:{objects = [{name = file1.csv，type = file}，{name = dir1，type = directory，}，{name = dir2，type = directory}，类型为:java.util.LinkedHashMap的{name = dir3，type = directory}，{name = dir4，type = directory}]}.交换[ID-IT1289-1529914067957-0-1]

Method with name: objects not found on bean: {objects=[{name=file1.csv,type=file},{name=dir1,type=directory,},{name=dir2,type=directory},{name=dir3,type=directory},{name=dir4,type=directory}]} of type: java.util.LinkedHashMap. Exchange[ID-IT1289-1529914067957-0-1]

我使用了不正确的编组后是否正在访问返回的MAP?如果是这样，我必须使用什么正确的语法?

Am I accessing the returned MAP after using unmarshall incorrectly? What is the correct syntax I must I use if so?

我看过其他解组邮件的例子...但是我无法完全理解.我注意到许多示例使用具有JSON结构的类.这有必要吗?如果我的身体当前是类型:java.util.LinkedHashMap，我希望它应该不是访问问题，但是我似乎找不到方法.

I have seen other examples of unmarshalling... but I cannot understand completely. I've noticed many examples use a class with the structure of the JSON. Is this necessary? If my body is currently of type: java.util.LinkedHashMap, I expect it shouldn't be a problem to access but I cannot seem to find the way.

预先感谢

推荐答案

做到这一点的最佳方法是创建一个与您的Json Structure匹配的类.

The best way to do this is to create a class matching your Json Structure.

class RestResponse {
   List<FileNameType> objects;
   //Getters and Setters
}

class FileNameType {
  String name;
  String type;
  //Getters and setters.
}

然后像这样更改您的路线

Then change your route like this

from("timer://foo?fixedRate=true&period=120000")
    .log("Checking for files")
    .setHeader("Authorization", simple(myHttp.getAuth()))
    .setHeader("CamelHttpMethod", constant("GET"))
    .to(myHttp.getFullRequest())
    .unmarshal().json(JsonLibrary.Jackson, RestResponse.class)
    .to(....);

最后一部分我留为空白，您可以在此处添加一个处理器来验证您的逻辑.您可以从exchange.getIn().getBody()获取RestResponse对象.像这样的事情会做

The last part I have left it blank, here you can add a processor to verify your logic. You can get the RestResponse object from exchange.getIn().getBody(). Some thing like this will do

........
.unmarshal().json(JsonLibrary.Jackson, RestResponse.class)
.process(exchange -> {

              RestResponse response = exchange.getIn().getBody(RestResponse.class);
               // Do your logic here.

  })

您可能需要添加此依赖项

You might need to add this dependency

<dependency>
       <groupId>org.apache.camel</groupId>
       <artifactId>camel-jackson</artifactId>
       <version>yourcamelversion</version>
 </dependency>

这篇关于从Apache Camel内的JSON主体访问数据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！