versioned_docs/version-2.4.1/developer/spi/custom-parameter-data.md

---
title: Custom Parameter Data
keywords: ["ParameterData"]
description: Custom Parameter Data
---

This paper describes how to customize the extension of  `org.apache.shenyu.plugin.base.condition.data.ParameterData`.

* Create a new class `CustomParameterData`, implements `org.apache.shenyu.plugin.base.condition.data.ParameterData`, add annotation `org.apache.shenyu.spi.Join`.

```java
/**
 * This is custom parameter data.
 */
@Join
public class CustomParameterData implements ParameterData {
    
    @Override
    public String builder(final String paramName, final ServerWebExchange exchange) {
        // custom parameter data
    }
}
```


* In `org.apache.shenyu.plugin.base.condition.data.ParameterData` file, add key-value as following:

```shell title="script"
${spi name} = ${custom class path}
``` 

`${spi name}` represents the name of `spi` and `${custom class path}` represents the fully qualified name of the class. Such as:


```shell title="script"
custom=org.apache.shenyu.examples.http.condition.data.CustomParameterData
```

* Add enum in `org.apache.shenyu.common.enums.ParamTypeEnum` class:

```java

    /**
     * custom param type enum.
     */
    CUSTOM("custom", true),
```


* In the `Apache ShenYu` gateway management system --> BasicConfig --> Dictionary,  find the dictionary code as `PARAM_TYPE`, add a new piece of data, pay attention to the dictionary name: `${spi name}`.

<img src="/img/shenyu/custom/custom_parameter_data_en.png" width="70%" height="60%" />

> DictionaryType: `paramType`;
>
> DictionaryCode: `PARAM_TYPE`;
>
> DictionaryName: `${spi name}`, input your custom spi name;
>
> DictionaryValue: When used, the value of the drop-down box, do not repeat with the existing;
>
> DictionaryDescribe: desc your custom match strategy;
>
> Sort: to sort;
>
> Status: open or close.


* When adding selectors or rules, you can use custom parameter data:


<img src="/img/shenyu/custom/use_custom_parameter_data_en.png" width="80%" height="70%" />