完整的Groovy函数在返回POST结果时设置返回头的charset和Content-Type代码

以下是一个示例Groovy函数，用于返回一个POST结果并设置返回头的charset和Content-Type：

import groovy.json.JsonBuilder
import groovy.json.JsonSlurper
import org.apache.commons.httpclient.HttpClient
import org.apache.commons.httpclient.HttpStatus
import org.apache.commons.httpclient.methods.PostMethod

def postRequest(String url, Map params) {
    HttpClient client = new HttpClient()
    PostMethod post = new PostMethod(url)
    post.setRequestHeader("Content-Type", "application/json; charset=utf-8")
    def json = new JsonBuilder(params).toString()
    post.setRequestEntity(new org.apache.commons.httpclient.methods.StringRequestEntity(json, "application/json", "UTF-8"))
    int statusCode = client.executeMethod(post)
    if (statusCode != HttpStatus.SC_OK) {
        throw new RuntimeException("Failed with HTTP error code : " + statusCode)
    }
    def response = new JsonSlurper().parseText(post.getResponseBodyAsString())
    post.releaseConnection()
    return response
}

在这个示例中，我们使用了`setRequestHeader`方法来设置返回头的Content-Type为`application/json`，并且指定了charset为`utf-8`。这样做可以确保返回的结果能够正确地解析和处理。