# 在 CloudFront Functions 查看器请求中使用键值对
<a name="example_cloudfront_functions_kvs_key_value_pairs_section"></a>

以下代码示例演示了如何在 CloudFront Functions 查看器请求中使用键值对。

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#### [ JavaScript ]

**适用于 CloudFront Functions 的 JavaScript 运行时 2.0**  
 查看 GitHub，了解更多信息。查找完整示例，并了解如何在 [CloudFront Functions examples](https://github.com/aws-samples/amazon-cloudfront-functions/tree/main/kvs-key-value-pairs) 存储库中进行设置和运行。

```
import cf from 'cloudfront';

// This fails if there is no key value store associated with the function
const kvsHandle = cf.kvs();

// Remember to associate the KVS with your function before referencing KVS in your code.
// https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/kvs-with-functions-associate.html
async function handler(event) {
    const request = event.request;
    // Use the first segment of the pathname as key
    // For example http(s)://domain/<key>/something/else
    const pathSegments = request.uri.split('/')
    const key = pathSegments[1]
    try {
        // Replace the first path of the pathname with the value of the key
        // For example http(s)://domain/<value>/something/else
        pathSegments[1] = await kvsHandle.get(key);
        const newUri = pathSegments.join('/');
        console.log(`${request.uri} -> ${newUri}`)
        request.uri = newUri;
    } catch (err) {
        // No change to the pathname if the key is not found
        console.log(`${request.uri} | ${err}`);
    }
    return request;
}
```

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有关 AWS SDK 开发人员指南和代码示例的完整列表，请参阅 [将 CloudFront 与 AWS SDK 配合使用](sdk-general-information-section.md) 本主题还包括有关入门的信息以及有关先前的 SDK 版本的详细信息。