java实现调用Http请求常用的几种方式

ゝ一纸荒年。 2023-10-07 15:53 48阅读 0赞

参考链接: [https://blog.csdn.net/riemann\_/article/details/90539829][https_blog.csdn.net_riemann_article_details_90539829].  
参考链接: [使用HttpURlConnection 发送POST请求上传文件（带参数）][HttpURlConnection _POST].

## 使用这些http客户端时注意tcp链接数的问题 ##

参考链接: [高并发下对接第三方请求时http请求的问题及处理方式][http].

## 通过Java.net.HttpURLConnection实现 ##

import java.io.*;
    import java.net.HttpURLConnection;
    import java.net.URL;
    import java.util.HashMap;
    import java.util.Map;
    import java.util.UUID;
    
    public class MyHttpUtil {
        
    
        private static final int TIME_OUT = 5 * 1000;             //超时时间
        private static final String GET = "GET";                  //GET请求
        private static final String POST = "POST";                //GET请求
        private static final String CHARSET = "UTF-8";            //编码格式
        private static final String PREFIX = "--";                //前缀
        private static final String LINE_END = "\r\n";            //换行
    
        /**
         * 对post参数进行编码处理
         */
        private static StringBuilder getStrParams(Map<String, String> strParams, String BOUNDARY) {
        
            StringBuilder strSb = new StringBuilder();
            for (Map.Entry<String, String> entry : strParams.entrySet()) {
        
                strSb.append(PREFIX)
                        .append(BOUNDARY)
                        .append(LINE_END)
                        .append("Content-Disposition: form-data; name=\"" + entry.getKey() + "\"" + LINE_END)
                        .append("Content-Type: text/plain; charset=" + CHARSET + LINE_END)
                        .append("Content-Transfer-Encoding: 8bit" + LINE_END)
                        .append(LINE_END)// 参数头设置完以后需要两个换行，然后才是参数内容
                        .append(entry.getValue())
                        .append(LINE_END);
            }
            return strSb;
        }
    
    
        public static String upload(String url, Map<String, String> strParams, File file) {
        
            String boundary = UUID.randomUUID().toString(); // 文件边界
            String filename = file.getName();
            StringBuffer result = new StringBuffer();
            HttpURLConnection connection = null;
            try {
        
                URL url1 = new URL(url);
                connection = (HttpURLConnection) url1.openConnection();
                connection.setRequestMethod(POST);
                connection.setDoOutput(true);
                connection.setDoInput(true);
                connection.setUseCaches(false);
                connection.setConnectTimeout(TIME_OUT);
                connection.setReadTimeout(TIME_OUT);
                connection.setRequestProperty("accept", "*/*");
                connection.setRequestProperty("connection", "Keep-Alive");
                connection.setRequestProperty("Charset", CHARSET);
                connection.setRequestProperty("Content-Type", "multipart/form-data" + ";boundary=" + boundary);
                connection.connect();
                try (DataOutputStream dos = new DataOutputStream(connection.getOutputStream());
                     InputStream is = new FileInputStream(file)) {
        
                    dos.writeBytes(getStrParams(strParams, boundary).toString());
                    dos.flush();
                    StringBuilder fileSb = new StringBuilder();
                    fileSb.append(PREFIX)
                            .append(boundary)
                            .append(LINE_END)
                            .append("Content-Disposition: form-data; name=\"file\"; filename=\""
                                    + filename + "\"" + LINE_END)
                            .append("Content-Transfer-Encoding: 8bit" + LINE_END)
                            .append(LINE_END);
                    dos.writeBytes(fileSb.toString());
                    dos.flush();
                    byte[] buffer = new byte[1024];
                    int len = 0;
                    while ((len = is.read(buffer)) != -1) {
        
                        dos.write(buffer, 0, len);
                    }
                    //请求结束标志
                    dos.writeBytes(LINE_END + PREFIX + boundary + PREFIX + LINE_END);
                    dos.flush();
                }
                try (BufferedReader reader = new BufferedReader(
                        new InputStreamReader(connection.getInputStream(), CHARSET))) {
        
                    String line;
                    while ((line = reader.readLine()) != null) {
        
                        result.append(line);
                    }
                    System.out.println(result.toString());
                }
            } catch (IOException e) {
        
                e.printStackTrace();
            } finally {
        
                connection.disconnect();
            }
            return result.toString();
        }
    
    
        public static String post(String url, String content) {
        
            StringBuffer result = new StringBuffer();
            HttpURLConnection connection = null;
            try {
        
                URL url1 = new URL(url);
                connection = (HttpURLConnection) url1.openConnection();
                //设置请求方式
                connection.setRequestMethod(POST);
                //DoOutput设置是否向httpUrlConnection输出，DoInput设置是否从httpUrlConnection读入，此外发送post请求必须设置这两个
                connection.setDoOutput(true);
                connection.setDoInput(true);
                // 设置是否允许缓存值
                connection.setUseCaches(false);
                //设置连接超时时间
                connection.setConnectTimeout(TIME_OUT);
                //设置读取超时时间
                connection.setReadTimeout(TIME_OUT);
                //设置通用的请求属性
                connection.setRequestProperty("accept", "*/*");
                connection.setRequestProperty("connection", "Keep-Alive");
                connection.setRequestProperty("Content-Type", "application/json;charset=utf-8");
                connection.connect();
                try (OutputStreamWriter out = new OutputStreamWriter(connection.getOutputStream(), CHARSET)) {
        
                    out.append(content);
                    out.flush();
                }
                try (BufferedReader reader = new BufferedReader(
                        new InputStreamReader(connection.getInputStream(), CHARSET))) {
        
                    String line;
                    while ((line = reader.readLine()) != null) {
        
                        result.append(line);
                    }
                    System.out.println(result.toString());
                }
            } catch (IOException e) {
        
                e.printStackTrace();
            } finally {
        
                connection.disconnect();
            }
            return result.toString();
        }
    
    
        public static String get(String url) {
        
            StringBuffer stringBuffer = new StringBuffer();
            HttpURLConnection connection = null;
            try {
        
                URL url1 = new URL(url);
                connection = (HttpURLConnection) url1.openConnection();
                //设置请求方式
                connection.setRequestMethod(GET);
                //设置连接超时时间
                connection.setReadTimeout(TIME_OUT);
                //开始连接
                connection.connect();
                try (BufferedReader bufferedReader = new BufferedReader(
                        new InputStreamReader(connection.getInputStream(), CHARSET))) {
        
                    String line;
                    while ((line = bufferedReader.readLine()) != null) {
        
                        stringBuffer.append(line);
                    }
                }
            } catch (IOException e) {
        
                e.printStackTrace();
            } finally {
        
                connection.disconnect();
            }
            System.out.println("GET请求返回值：" + stringBuffer.toString());
            return stringBuffer.toString();
        }
    
    }

总结：  
如果使用了HttpUrlConnection进行http请求  
1.最好在finally中加disconnet()，以防异常时候http连接未被关闭，造成tcp连接堆积  
2.并且要设置连接和读取超时时间，否则程序会一直卡在获取流这一步  
3.记得关闭IO流资源

## HttpClient ##

参考链接: [HttpClient用法–这一篇全了解][HttpClient].

链接: [实现HttpClient重试][HttpClient 1]

HttpClient是Apache Jakarta Common下的子项目，用来提供高效的、最新的、功能丰富的支持HTTP协议的客户端编程工具包，并且它支持HTTP协议最新的版本和建议。HttpClient已经应用在很多的项目中，比如Apache Jakarta上很著名的另外两个开源项目Cactus和HTMLUnit都使用了HttpClient。  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNjA0ODkw_size_16_color_FFFFFF_t_70]  
HttpClient相比传统JDK自带的URLConnection，增加了易用性和灵活性，它不仅使客户端发送Http请求变得容易，而且也方便开发人员测试接口（基于Http协议的），提高了开发的效率，也方便提高代码的健壮性。

### org.apache.commons.httpclient.HttpClient与org.apache.http.client.HttpClient的区别 ###

Commons的HttpClient项目现在是生命的尽头，不再被开发, 已被Apache HttpComponents项目HttpClient和HttpCore 模组取代，提供更好的性能和更大的灵活性。

### 基本使用方法 ###

<dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpclient</artifactId>
        <version>4.5.13</version>
    </dependency>
    <dependency>
        <groupId>org.apache.httpcomponents</groupId>
        <artifactId>httpmime</artifactId>
        <version>4.5.13</version>
    </dependency>

使用 HttpClient 发送请求主要分为一下几步骤：  
创建 CloseableHttpClient 对象或 CloseableHttpAsyncClient 对象  
创建 Http 请求对象  
调用 execute 方法执行请求，如果是异步请求在执行之前需调用 start 方法  
释放连接或放回线程池

参考链接: [HttpClient详细使用示例][HttpClient 2].

### ClosableHttpClient 同步请求 ###

import com.alibaba.fastjson.JSON;
    import com.zm.entity.User;
    import org.apache.http.HttpEntity;
    import org.apache.http.NameValuePair;
    import org.apache.http.ParseException;
    import org.apache.http.client.ClientProtocolException;
    import org.apache.http.client.config.RequestConfig;
    import org.apache.http.client.methods.CloseableHttpResponse;
    import org.apache.http.client.methods.HttpGet;
    import org.apache.http.client.methods.HttpPost;
    import org.apache.http.client.utils.URIBuilder;
    import org.apache.http.entity.ContentType;
    import org.apache.http.entity.StringEntity;
    import org.apache.http.entity.mime.MultipartEntityBuilder;
    import org.apache.http.impl.client.CloseableHttpClient;
    import org.apache.http.impl.client.HttpClientBuilder;
    import org.apache.http.message.BasicNameValuePair;
    import org.apache.http.util.EntityUtils;
    
    import java.io.File;
    import java.io.IOException;
    import java.io.UnsupportedEncodingException;
    import java.net.URI;
    import java.net.URISyntaxException;
    import java.net.URLEncoder;
    import java.nio.charset.Charset;
    import java.nio.charset.StandardCharsets;
    import java.util.ArrayList;
    import java.util.HashMap;
    import java.util.List;
    import java.util.Map;
    
    public class HttpClientUtil {
        
    
    
        public static void get(String url) {
        
            // 创建 Http 请求对象
            HttpGet httpGet = new HttpGet(url);
            RequestConfig requestConfig = RequestConfig.custom()
                    .setConnectionRequestTimeout(3000)//使用连接池来管理连接,从连接池获取连接的超时时间
                    .setSocketTimeout(5000)//请求超时,数据传输过程中数据包之间间隔的最大时间
                    .setConnectTimeout(5000)//连接超时,连接建立时间,三次握手完成时间
                    .build();
            httpGet.setConfig(requestConfig);
            try (// 获得Http客户端(创建 CloseableHttpClient 对象或 CloseableHttpAsyncClient 对象)
                 CloseableHttpClient httpClient = HttpClientBuilder.create().build();
                 // 调用 execute 方法执行请求，如果是异步请求在执行之前需调用 start 方法
                 CloseableHttpResponse response = httpClient.execute(httpGet)) {
        
                // 从响应模型中获取响应实体
                HttpEntity responseEntity = response.getEntity();
                System.out.println("响应状态为:" + response.getStatusLine());
                if (responseEntity != null) {
        
                    System.out.println("响应内容为:" + EntityUtils.toString(responseEntity, StandardCharsets.UTF_8));
                }
            } catch (ClientProtocolException e) {
        
                e.printStackTrace();
            } catch (ParseException e) {
        
                e.printStackTrace();
            } catch (IOException e) {
        
                e.printStackTrace();
            }
        }
    
        /**
         * get请求 参数转码
         *
         * @return
         * @throws UnsupportedEncodingException
         */
        public static String getParams(Map<String, String> params){
        
            StringBuilder strSb = new StringBuilder();
            boolean index = false;
            for (Map.Entry<String, String> entry : params.entrySet()) {
        
                if (index) {
        
                    strSb.append("&");
                }
                strSb.append(entry.getKey())
                        .append("=")
                        .append(encode(entry.getValue()));
                index = true;
            }
            return strSb.toString();
        }
    
        public static void get(String url, Map<String, String> params) {
        
            // 方式一：直接拼接URL
            String param = getParams(params);
            // 创建 Http 请求对象
            HttpGet httpGet = new HttpGet(url + "?" + param);
    
            // 方式二：使用URI获得HttpGet
    //        URI uri = null;
    //        try {
        
    //            // 将参数放入键值对类NameValuePair中,再放入集合中
    //            List<NameValuePair> param = new ArrayList<>();
    //            for (Map.Entry<String, String> entry : params.entrySet()) {
        
    //                param.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
    //            }
    //            // 设置uri信息,并将参数集合放入uri;
    //            uri = new URIBuilder().setScheme("http").setHost("localhost")
    //                    .setPort(8080).setPath("/Exception")
    //                    .setParameters(param).build();
    //
    //        } catch (URISyntaxException e) {
        
    //            e.printStackTrace();
    //        }
    //        // 创建Get请求
    //        HttpGet httpGet = new HttpGet(uri);
            
            RequestConfig requestConfig = RequestConfig.custom()
                    .setConnectionRequestTimeout(3000)//使用连接池来管理连接,从连接池获取连接的超时时间
                    .setSocketTimeout(5000)//请求超时,数据传输过程中数据包之间间隔的最大时间
                    .setConnectTimeout(5000)//连接超时,连接建立时间,三次握手完成时间
                    .build();
            httpGet.setConfig(requestConfig);
            try (// 获得Http客户端(创建 CloseableHttpClient 对象或 CloseableHttpAsyncClient 对象)
                 CloseableHttpClient httpClient = HttpClientBuilder.create().build();
                 // 调用 execute 方法执行请求，如果是异步请求在执行之前需调用 start 方法
                 CloseableHttpResponse response = httpClient.execute(httpGet)) {
        
                // 从响应模型中获取响应实体
                HttpEntity responseEntity = response.getEntity();
                System.out.println("响应状态为:" + response.getStatusLine());
                if (responseEntity != null) {
        
                    System.out.println("响应内容为:" + EntityUtils.toString(responseEntity, StandardCharsets.UTF_8));
                }
            } catch (ClientProtocolException e) {
        
                e.printStackTrace();
            } catch (ParseException e) {
        
                e.printStackTrace();
            } catch (IOException e) {
        
                e.printStackTrace();
            }
        }
    
        public static void post(String url, String params) {
        
            // 创建Post请求
            HttpPost httpPost = new HttpPost(url);
            // post请求是将参数放在请求体里面传过去的;这里将entity放入post请求体中
            httpPost.setEntity(new StringEntity(params, StandardCharsets.UTF_8));
            httpPost.setHeader("Content-Type", "application/json;charset=utf8");
            try (CloseableHttpClient httpClient = HttpClientBuilder.create().build();
                 CloseableHttpResponse response = httpClient.execute(httpPost)) {
        
                HttpEntity responseEntity = response.getEntity();
                System.out.println("响应状态为:" + response.getStatusLine());
                if (responseEntity != null) {
        
                    System.out.println("响应内容为:" + EntityUtils.toString(responseEntity, StandardCharsets.UTF_8));
                }
            } catch (ClientProtocolException e) {
        
                e.printStackTrace();
            } catch (ParseException e) {
        
                e.printStackTrace();
            } catch (IOException e) {
        
                e.printStackTrace();
            }
        }
    
        public static String encode(String str) {
        
            String encode = null;
            try {
        
                encode = URLEncoder.encode(str, "UTF-8");
            } catch (UnsupportedEncodingException e) {
        
                e.printStackTrace();
            }
            return encode;
        }
        
        public static void upload(String url, Map<String, String> params, File file) {
        
            HttpPost httpPost = new HttpPost(url);
            MultipartEntityBuilder multipartEntityBuilder = MultipartEntityBuilder.create();
            String filesKey = "file";
            // (多个文件的话，使用同一个key就行，后端用数组或集合进行接收即可)
            // 文件名其实是放在请求头的Content-Disposition里面进行传输的，如其值为form-data; name="files"; filename="头像.jpg"
            multipartEntityBuilder.addBinaryBody(filesKey, file, ContentType.DEFAULT_BINARY, encode(file.getName()));
            // 其它参数(注:自定义contentType，设置UTF-8是为了防止服务端拿到的参数出现乱码)
            ContentType contentType = ContentType.create("text/plain", Charset.forName("UTF-8"));
            for (Map.Entry<String, String> entry : params.entrySet()) {
        
                multipartEntityBuilder.addTextBody(entry.getKey(), entry.getValue(), contentType);
            }
            HttpEntity httpEntity = multipartEntityBuilder.build();
            httpPost.setEntity(httpEntity);
            try (CloseableHttpClient httpClient = HttpClientBuilder.create().build();
                 CloseableHttpResponse response = httpClient.execute(httpPost)) {
        
                HttpEntity responseEntity = response.getEntity();
                System.out.println("HTTPS响应状态为:" + response.getStatusLine());
                if (responseEntity != null) {
        
                    String responseStr = EntityUtils.toString(responseEntity, StandardCharsets.UTF_8);
                    System.out.println("HTTPS响应内容为:" + responseStr);
                }
            } catch (ParseException | IOException e) {
        
                e.printStackTrace();
            }
        }
        
    
    }

### CloseableHttpAsynClient 异步请求（了解） ###

链接: [异步请求CloseableHttpAsyncClient的使用][CloseableHttpAsyncClient].

## OkHttp ##

参考链接: [java使用OkHttp][java_OkHttp].  
参考链接: [Okhttp4 RequestBody.create()过时 解决办法][Okhttp4 RequestBody.create_].

使用 OkHttp 发送请求主要分为一下几步骤：  
创建 OkHttpClient 对象  
创建 Request 对象  
将 Request 对象封装为 Call  
通过 Call 来执行同步或异步请求，调用 execute 方法同步执行，调用 enqueue 方法异步执行

<dependency>
        <groupId>com.squareup.okhttp3</groupId>
        <artifactId>okhttp</artifactId>
        <version>4.9.1</version>
        <exclusions>
            <exclusion>
                <groupId>com.google.android</groupId>
                <artifactId>android</artifactId>
            </exclusion>
        </exclusions>
    </dependency>

import com.baomidou.mybatisplus.core.toolkit.StringUtils;
    import okhttp3.*;
    import java.io.File;
    import java.io.IOException;
    import java.io.UnsupportedEncodingException;
    import java.net.URLEncoder;
    import java.util.*;
    import java.util.concurrent.TimeUnit;
    
    public class OkHttpUtil {
        
        
        private static volatile OkHttpClient client;
    
        private static final String DEFAULT_MEDIA_TYPE = "application/json;charset=utf-8";
    
        private static final int CONNECT_TIMEOUT = 5;
    
        private static final int READ_TIMEOUT = 7;
        
        /**
         * 单例模式  获取类实例
         *
         * @return client
         */
        private static OkHttpClient getInstance() {
        
            if (client == null) {
        
                synchronized (OkHttpClient.class) {
        
                    if (client == null) {
        
                        client = new OkHttpClient.Builder()
                                .connectTimeout(CONNECT_TIMEOUT, TimeUnit.SECONDS)// 设置连接超时时间
                                .readTimeout(READ_TIMEOUT, TimeUnit.SECONDS)// 设置读取超时时间
                                .build();
                    }
                }
            }
            return client;
        }
    
        public static String get(String url) {
        
            try {
        
                Request request = new Request.Builder().url(url).build();
                Response response = getInstance().newCall(request).execute();
                return handleHttpResponse(response);
            } catch (Exception ex) {
        
                return StringUtils.EMPTY;
            }
        }
    
        public static String encode(String str) {
        
            String encode = null;
            try {
        
                encode = URLEncoder.encode(str, "UTF-8");
            } catch (UnsupportedEncodingException e) {
        
                e.printStackTrace();
            }
            return encode;
        }
    
        /**
         * get请求 参数转码
         *
         * @return
         * @throws UnsupportedEncodingException
         */
        public static String getParams(Map<String, String> params) {
        
            StringBuilder strSb = new StringBuilder();
            boolean index = false;
            for (Map.Entry<String, String> entry : params.entrySet()) {
        
                if (index) {
        
                    strSb.append("&");
                }
                strSb.append(entry.getKey())
                        .append("=")
                        .append(encode(entry.getValue()));
                index = true;
            }
            return strSb.toString();
        }
    
    
        public static String get(String url, Map<String, String> params) {
        
            try {
        
                url = url + "?" + getParams(params);
                System.out.println(url);
                Request request = new Request.Builder().url(url).build();
                Response response = getInstance().newCall(request).execute();
                return handleHttpResponse(response);
            } catch (Exception ex) {
        
                return StringUtils.EMPTY;
            }
        }
    
    
        public static String post(String url, String postBody) {
        
            try {
        
                MediaType mediaType = MediaType.Companion.parse(DEFAULT_MEDIA_TYPE);
                RequestBody stringBody = RequestBody.Companion.create(postBody, mediaType);
                Request request = new Request.Builder()
                        .url(url)
                        .post(stringBody)
                        .build();
                Response response = getInstance().newCall(request).execute();
                return handleHttpResponse(response);
            } catch (Exception ex) {
        
                return StringUtils.EMPTY;
            }
        }
    
        public static String upload(String url, Map<String, String> params, File file) throws IOException {
        
            MultipartBody.Builder builder = new MultipartBody.Builder();
            String fileName = file.getName();
            MediaType mediaType = MediaType.Companion.parse("multipart/form-data");
            RequestBody fileBody = RequestBody.Companion.create(file, mediaType);
            for (Map.Entry<String, String> entry : params.entrySet()) {
        
                builder.addFormDataPart(entry.getKey(), entry.getValue());  // 上传参数
            }
            RequestBody requestBody = builder
                    .setType(MultipartBody.FORM)
                    .addFormDataPart("file", fileName, fileBody)
                    .build();
            Request request = new Request.Builder()
                    .url(url)
                    .post(requestBody)
                    .build();
            Response response = getInstance().newCall(request).execute();
            return handleHttpResponse(response);
        }
    
    
        public static void main(String[] args) throws IOException {
        
            HashMap<String, String> map = new HashMap<>();
            map.put("name","小明");
            System.out.println(upload("http://127.0.0.1:8080/upload", map,new File("C:\\Users\\a\\Pictures\\1.jpg")));
    
        }
        
    
        private static String handleHttpResponse(Response response) throws IOException {
        
            if (response.body() == null) {
        
                throw new IOException("exception in OkHttpUtil,response body is null");
            }
            if (!response.isSuccessful()) {
        
               throw new RuntimeException("OkHttpUtil request failed");
            }
            return response.body().string();
        }
        
    }

## 文件和参数接收 ##

import com.zm.entity.User;
    import io.swagger.annotations.ApiOperation;
    import org.springframework.web.bind.annotation.PostMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    import org.springframework.web.bind.annotation.RestController;
    import org.springframework.web.multipart.MultipartFile;
    
    import java.io.File;
    import java.io.IOException;
    
    @RestController
    public class TestController {
        
    
        @PostMapping("/upload")
        @ApiOperation(value = "上传文件")
        public String upload(@RequestParam("file") MultipartFile file, User user) {
        
            System.out.println(user);
            String fileName = file.getOriginalFilename();// 文件名
            String filePath = "F:\\img\\";// 保存图片的地址
            File dest = new File(filePath + fileName);
            try {
        
                file.transferTo(dest);
                return "上传成功";
            } catch (IOException e) {
        
                e.printStackTrace();
            }
            return "上传失败！";
        }
    
    }

## RestTemplate ##

链接: [RestTemplate与ClosableHttpClient][RestTemplate_ClosableHttpClient].

Spring WebClient下封装了专门用于restful请求的RestTempate实际上内部就采用了ClosableHttpClient，对于有连接池的Client来说，最好使用单例模式，同时根据调用量配置合适的连接池大小以及配置各种超时时间等

待续。。。。。

https://www.jianshu.com/p/c852cbcf3d68

首先,明确两点:  
1.http连接池不是万能的,过多的长连接会占用服务器资源,导致其他服务受阻  
2.http连接池只适用于请求是经常访问同一主机(或同一个接口)的情况下  
3.并发数不高的情况下资源利用率低下

那么,当你的业务符合上面3点,那么你可以考虑使用http连接池来提高服务器性能  
使用http连接池的优点:  
1.复用http连接,省去了tcp的3次握手和4次挥手的时间,极大降低请求响应的时间  
2.自动管理tcp连接,不用人为地释放/创建连接

## Forest ##

SpringBoot整合Forest实现调用第三方接口

https://zhengqing.blog.csdn.net/article/details/108258130

轻量级 HTTP 客户端

https://www.oschina.net/p/forest?hmsr=aladdin1e1

[https_blog.csdn.net_riemann_article_details_90539829]: https://blog.csdn.net/riemann_/article/details/90539829
[HttpURlConnection _POST]: https://blog.csdn.net/u012246458/article/details/87188731
[http]: https://blog.csdn.net/qq_41604890/article/details/115511520
[HttpClient]: https://www.cnblogs.com/csnjava/p/14267191.html
[HttpClient 1]: https://joy-panda.blog.csdn.net/article/details/78143993
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNjA0ODkw_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20210314101749667.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNjA0ODkw,size_16,color_FFFFFF,t_70
[HttpClient 2]: https://blog.csdn.net/justry_deng/article/details/81042379
[CloseableHttpAsyncClient]: https://www.cnblogs.com/yz-yang/p/11596844.html
[java_OkHttp]: https://blog.csdn.net/qq_35890572/article/details/86003679
[Okhttp4 RequestBody.create_]: https://blog.csdn.net/qq_19306415/article/details/102954712
[RestTemplate_ClosableHttpClient]: https://blog.csdn.net/u010285974/article/details/100107061