如何在Groovy中获得REST响应？

@Grab('org.codehaus.groovy.modules.http-builder:http-builder:0.7.1')
import groovyx.net.http.HTTPBuilder
import static groovyx.net.http.ContentType.*

def http = new HTTPBuilder('http://api.example.com')
http.request(Method.GET, JSON) { req ->
    response.success = { resp, json ->
        // 处理成功响应
        println(resp.statusLine)
        println(json)
    }
    response.failure = { resp, json ->
        // 处理失败响应
        println(resp.statusLine)
        println(json)
    }
}

http.request(Method.GET, JSON) { req ->
    uri.path = '/api/resource'
    uri.query = [param1: 'value1', param2: 'value2']
    headers.'User-Agent' = 'Groovy HTTPBuilder'
    // ...
}

http.request(Method.GET, JSON) { req ->
    response.success = { resp, json ->
        println(resp.statusLine)
        println(json)
        // 解析JSON响应
        def result = json.result
        // ...
    }
}