WireMock匹配路径无对应返回文件时实现自定义404响应问询

可以实现，以下是两种常用的实现方案：

方案一：单Mapping模板判断（适用WireMock 2.31+版本） #

首先确保WireMock启动时已开启响应模板能力（添加启动参数--global-response-templating，或在单个Mapping中单独指定transformers），调整你的现有Mapping配置如下：

{
  "mappings": [
    {
      "name": "Retrieve Items",
      "request": {
        "headers": {
          "accept": {
            "caseInsensitive": true,
            "equalTo": "application/json"
          }
        },
        "method": "GET",
        "urlPathPattern": "/api/items/[0-9a-fA-F]{8}(-[0-9a-fA-F]{4}){3}-[0-9a-fA-F]{12}"
      },
      "response": {
        "transformers": ["response-template"],
        "failOnMissingBodyFile": false,
        "body": "{% set itemFile = 'items-api/responses/retrieve/' ~ request.pathSegments.[2] ~ '.json' %}{% if fileExists(itemFile) %}{{ readBodyFile(itemFile) }}{% else %}{\n  \"timestamp\": {{ now }},\n  \"status\": 404,\n  \"error\": \"Not Found\",\n  \"message\": null,\n  \"path\": \"{{ request.path }}\"\n}{% endif %}",
        "headers": {
          "content-type": "application/json"
        },
        "status": "{% set itemFile = 'items-api/responses/retrieve/' ~ request.pathSegments.[2] ~ '.json' %}{% if fileExists(itemFile) %}200{% else %}404{% endif %}"
      }
    }
  ]
}

配置说明：

• failOnMissingBodyFile: false：要求WireMock找不到指定响应文件时不要直接返回默认错误提示，继续执行模板渲染
• 内置函数fileExists会判断__files目录下对应UUID的JSON文件是否存在
• 响应状态码和响应体都会根据文件是否存在动态渲染，匹配你需要的返回逻辑

方案二：双Mapping优先级兜底（兼容所有支持响应模板的WireMock版本） #

如果使用的WireMock版本较低不支持fileExists语法，可以通过两个不同优先级的Mapping实现：

{
  "mappings": [
    {
      "name": "Retrieve Items - Exists",
      "priority": 1,
      "request": {
        "headers": {
          "accept": {
            "caseInsensitive": true,
            "equalTo": "application/json"
          }
        },
        "method": "GET",
        "urlPathPattern": "/api/items/[0-9a-fA-F]{8}(-[0-9a-fA-F]{4}){3}-[0-9a-fA-F]{12}"
      },
      "response": {
        "bodyFileName": "items-api/responses/retrieve/{{ request.pathSegments.[2] }}.json",
        "transformers": ["response-template"],
        "headers": {
          "content-type": "application/json"
        },
        "status": 200
      }
    },
    {
      "name": "Retrieve Items - Not Found",
      "priority": 10,
      "request": {
        "headers": {
          "accept": {
            "caseInsensitive": true,
            "equalTo": "application/json"
          }
        },
        "method": "GET",
        "urlPathPattern": "/api/items/[0-9a-fA-F]{8}(-[0-9a-fA-F]{4}){3}-[0-9a-fA-F]{12}"
      },
      "response": {
        "transformers": ["response-template"],
        "jsonBody": {
          "timestamp": "{{ now }}",
          "status": 404,
          "error": "Not Found",
          "message": null,
          "path": "{{ request.path }}"
        },
        "headers": {
          "content-type": "application/json"
        },
        "status": 404
      }
    }
  ]
}

配置说明：

• 优先级数值越小，Mapping匹配优先级越高
• 请求会先匹配优先级为1的Mapping，如果对应UUID的JSON文件存在，直接返回200和文件内容
• 如果文件不存在，优先级为1的Mapping会匹配失败，WireMock会继续匹配更低优先级的Mapping，最终命中第二个配置返回自定义404结构

内容的提问来源于stack exchange，提问作者user4695271