其中的中文编码并不是在发送之前就将数据进行编码，而是在请求时进行设置的，不需要手动编码。

1、Hutool中

import cn.hutool.http.HttpRequest;
import cn.hutool.http.HttpUtil;
import java.util.LinkedHashMap;
import java.util.Map;

public static void main(String[] args) throws Exception {
        Map<String, Object> map = new LinkedHashMap<>();
        ;
        map.put("param1", "1");
        map.put("param2", "2");
        map.put("param3", "3");
        map.put("param4", "中文");
        //设置表单数据的编码集
        String params = HttpUtil.toParams(map, "GBK");
        HttpRequest post = HttpUtil.createPost("url");
        String body = post.body(params).execute().body();
        System.out.println(body);
    }

2、HttpClient中

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.methods.PostMethod;
import org.apache.commons.httpclient.params.HttpMethodParams;

public static void main(String[] args) throws Exception {
        String info = null;
        try {
            HttpClient httpclient = new HttpClient();
            PostMethod post = new PostMethod("url");
            post.getParams().setParameter(HttpMethodParams.HTTP_CONTENT_CHARSET, "gbk");
            post.addParameter("param1", "1");
            post.addParameter("param2", "2");
            post.addParameter("param3", "3");
            post.addParameter("param4", "中文");
            httpclient.executeMethod(post);
            info = new String(post.getResponseBody(), "gbk");
            System.out.println(info);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

3、Groovy中的HTTPBuilder

import groovyx.net.http.ContentType
import groovyx.net.http.EncoderRegistry
import groovyx.net.http.HTTPBuilder
import groovyx.net.http.Method

static void main(String[] args) {
        Map<String, Object> map = new LinkedHashMap<>();
        map.put("param1", "1");
        map.put("param2", "2");
        map.put("param3", "3");
        map.put("param4", "中文");

        def data = null
        def http = new HTTPBuilder("url")
        http.ignoreSSLIssues()
        //设置表单数据的编码集
        http.setEncoderRegistry(new EncoderRegistry().setCharset("GBK"))
        http.request(Method.POST, ContentType.TEXT) { req ->
            requestContentType = ContentType.URLENC
            uri.query = map
            response.success = { resp, reader ->
                data = reader.text
            }
        }
    }