RestTemplateUtils网络请求工具类（建造者模式）

太过爱你忘了你带给我的痛 2023-06-19 02:59 23阅读 0赞

import com.google.common.base.Strings;
    import org.apache.http.entity.ContentType;
    import org.springframework.boot.configurationprocessor.json.JSONException;
    import org.springframework.boot.configurationprocessor.json.JSONObject;
    import org.springframework.http.HttpEntity;
    import org.springframework.http.HttpHeaders;
    import org.springframework.http.MediaType;
    import org.springframework.util.LinkedMultiValueMap;
    import org.springframework.util.MultiValueMap;
    import org.springframework.web.client.RestTemplate;
    
    import java.util.HashMap;
    import java.util.Objects;
    
    public final class RestTemplateUtils {
    
        private static RestTemplate restTemplate = new RestTemplate();
    
        private HttpEntity httpEntity;
    
        /**
         * 构造函数已经私有化，只能通过create方法构造HttpContent
         *
         * @return HttpContent
         */
        public static RestTemplateUtils create() {
            return new RestTemplateUtils();
        }
    
        /**
         * get请求返回模板对象
         *
         * @param url   url
         * @param clazz T.class
         * @param <T>   T
         * @return T
         */
        public static <T> T getForObj(String url, Class<T> clazz) {
            return RestTemplateUtils.restTemplate.getForObject(url, clazz);
        }
    
        /**
         * get请求返回模板对象
         *
         * @param url   url
         * @param clazz t.class
         * @param <T>   模板
         * @return T
         */
        public <T> T postForObj(String url, Class<T> clazz) {
            this.build();
            return restTemplate.postForObject(url, this.httpEntity, clazz);
        }
    
        /**
         * header
         */
        private HttpHeaders httpHeaders;
    
        private String contentType;
    
        /**
         * body
         */
        private HashMap<String, Object> params;
    
        private RestTemplateUtils() {
        }
    
        /**
         * 添加Header内容
         *
         * @param headerName  key
         * @param headerValue value
         * @return HttpContent
         */
        public RestTemplateUtils addHeader(String headerName, String headerValue) {
            if (Objects.isNull(httpHeaders)) {
                httpHeaders = new HttpHeaders();
            }
            httpHeaders.add(headerName, headerValue);
            return this;
        }
    
        /**
         * 设置请求体
         *
         * @param key   key
         * @param value value
         * @return HttpContent
         */
        public RestTemplateUtils addBody(String key, Object value) {
            if (Objects.isNull(params)) {
                params = new HashMap<>();
            }
            params.put(key, value);
            return this;
        }
    
        /**
         * 设置content-Type
         *
         * @param contentType string
         * @return HttpContent
         */
        public RestTemplateUtils setContentType(String contentType) {
            if (Strings.isNullOrEmpty(contentType)) {
                throw new RuntimeException("content-Type can not be empty,please check your mediaType and try again ~");
            }
            this.contentType = contentType;
            if (Objects.isNull(httpHeaders)) {
                httpHeaders = new HttpHeaders();
            }
            httpHeaders.setContentType(MediaType.parseMediaType(contentType));
            return this;
        }
    
        /**
         * 构建HttpEntity对象
         * 不设置Content-Type默认application/json
         */
        private void build() {
            if (Objects.isNull(this.params)) {
                throw new RuntimeException("body must be not empty,please add body and try again ~");
            }
            if (Objects.isNull(contentType) || ContentType.APPLICATION_JSON.getMimeType().equals(contentType)) {
                this.setContentType(ContentType.APPLICATION_JSON.getMimeType());
                JSONObject jsonObject = new JSONObject();
                for (String s : params.keySet()) {
                    try {
                        jsonObject.put(s, params.get(s));
                    } catch (JSONException e) {
                        e.printStackTrace();
                    }
                }
                String body = jsonObject.toString();
                this.httpEntity = new HttpEntity<>(body, httpHeaders);
            } else if (ContentType.APPLICATION_FORM_URLENCODED.getMimeType().equals(contentType)) {
                MultiValueMap<String, Object> formData = new LinkedMultiValueMap<>();
                for (String s : params.keySet()) {
                    formData.add(s, params.get(s));
                }
                this.httpEntity = new HttpEntity<>(formData, httpHeaders);
            } else {
                throw new RuntimeException("sorry this tool only support content-Type include {application/json,multipart/form-data}");
            }
        }
    }

使用教程：

JSONObject json = RestTemplateUtils
     .create() //创建一个实例
     .setContentType("xxx") //设置Content-Type,不设置默认为：application/json,多次设置，以最后一次为准
     .addHeader("headerKey","headerVal") //添加header，可以多次添加
     .addBody("bodyKey","bodyVal") //添加body，可以多次添加
     .postForObj("url",JSONObject.class); //发送post请求