记Java调用第三方接口封装实现

深碍√TFBOYSˉ_ 2024-03-27 17:02 145阅读 0赞

## 介绍 ##

在Java项目中，会遇到很多调用第三方接口的地方，比如接入微信，其他公司的系统，需要传token或者签名。由于接入调用接口很多，每个接口内部都需要手动设置token或者其他数据，这就显得很麻烦。而且发送http请求还需要自己创建request对象。下面介绍2中封装方式，

一、利用feign功能封装请求，所有接口和服务之间调用是一样的，只需要执行后面的url，参数类，请求方式等。内部需要传输的token信息，在自定的拦截器中设置，自定义的拦截器需要实现RequestInterceptor接口。在这里面设置公共的请求参数。比较推荐的。

二、自己封装一个通用的请求类，里面自己创建Request对象，发送完http请求之后拿到返回的json对象在封装返回类，借助于ObjectMapper类。

## 一、借助feign实现调用 ##

1.  写一个feign的接口调用类，因为调用服务和接收服务不在一个注册中心，所以需要指定url，并实现拦截器

自定义的feign接口

import org.springframework.cloud.openfeign.FeignClient;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.PathVariable;
    import org.springframework.web.bind.annotation.PostMapping;
    import org.springframework.web.bind.annotation.RequestBody;
    import org.springframework.web.bind.annotation.RequestMapping;
    
    @FeignClient(
        url = "${e-sign.apiHost}",        // 这个值在配置文件中配置好
        value = "authFeign"               // 这个是自定义的服务名称，没有用
    )
    @RequestMapping(
        headers = {"X-Tsign-Open-Auth-Mode=Signature"}    // 设置请求的header
    )
    public interface EAuthFeign {
        
    // 写封装的参数和请求路径
        @PostMapping({"/v3/oauth2/index"})
        EResponse<String> applyAuth(@RequestBody EApplyAuthDTO params);
    }

配置文件内容

e-sign:
      projectId: 111111
      projectSecret: fasdfads
      apiHost: https://ss.sign.cn
      callbackHost: https://call.baidu.com
      redirectHost: https://web.baidu.com

自定义拦截器，这个是feign的拦截器，只需要标记被扫描到就行，会自动加载。写了这个类后，这个类所在的项目所有的feign都会被这个拦截器控制

import common.exception.E;
    import esign.config.ESignConfig;
    import feign.RequestInterceptor;
    import feign.RequestTemplate;
    import java.net.URLDecoder;
    import java.nio.charset.StandardCharsets;
    import java.security.InvalidKeyException;
    import java.security.MessageDigest;
    import java.security.NoSuchAlgorithmException;
    import java.util.Collection;
    import java.util.Map;
    import javax.crypto.Mac;
    import javax.crypto.spec.SecretKeySpec;
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Component;
    import sun.misc.BASE64Encoder;
    
    @Component
    public class EAuthFeignRequestInterceptor implements RequestInterceptor {
        private static final Logger log = LoggerFactory.getLogger(EAuthFeignRequestInterceptor.class);
        @Autowired
        private ESignConfig eSignConfig;
        private static final BASE64Encoder encodeBase64 = new BASE64Encoder();
    
        public EAuthFeignRequestInterceptor() {
        }
    
        public void apply(RequestTemplate template) {
            String host = this.eSignConfig.getApiHost();
            String url = template.url();
            String target = template.feignTarget().url();
            boolean b = target.equals(host);
    // 这个判断就是为了防止所有的feign都走这个拦截器，限制只有第三方接口才能进入下面的逻辑
            if (b) {
                template.header("X-Tsign-Open-App-Id", new String[]{this.eSignConfig.getProjectId()});
                Map<String, Collection<String>> headers = template.headers();
                Collection<String> authMode = (Collection)headers.get("X-Tsign-Open-Auth-Mode");
                boolean isSign = authMode != null && authMode.contains("Signature");
                if (isSign) {
                    template.header("X-Tsign-Open-Ca-Timestamp", new String[]{String.valueOf(System.currentTimeMillis())});
                    template.header("Accept", new String[]{"*/*"});
                    template.header("Content-Type", new String[]{"application/json;charset=UTF-8"});
    
                    try {
                        this.setMd5AndSignature(template);
                    } catch (Exception var10) {
                        log.error("发送请求失败, url:{}, params:{}", url, new String(template.body()));
                        throw new E("发送请求失败");
                    }
                } else {
                    template.header("X-Tsign-Open-Authorization-Version", new String[]{"v2"});
                }
    
                log.info("发送请求, url:{}, params:{}", url, template.body() == null ? "" : new String(template.body()));
            }
        }
    
        public void setMd5AndSignature(RequestTemplate template) {
            byte[] body = template.body();
            String url = template.url();
            String method = template.method();
            String contentMD5 = doContentMD5(body);
            if ("GET".equals(method) || "DELETE".equals(method)) {
                contentMD5 = "";
                url = URLDecoder.decode(url);
            }
    
            String message = appendSignDataString(method, "*/*", contentMD5, "application/json;charset=UTF-8", "", "", url);
            log.info("接口,url:{}, 签名字符串:{}", url, message);
            String reqSignature = doSignatureBase64(message, this.eSignConfig.getProjectSecret());
            template.header("Content-MD5", new String[]{contentMD5});
            template.header("X-Tsign-Open-Ca-Signature", new String[]{reqSignature});
        }
    
        private static String doContentMD5(byte[] body) {
            if (body == null) {
                return "";
            } else {
                byte[] md5Bytes = null;
                MessageDigest md5 = null;
                String contentMD5 = null;
    
                try {
                    md5 = MessageDigest.getInstance("MD5");
                    md5.update(body);
                    byte[] md5Bytes = md5.digest();
                    contentMD5 = encodeBase64.encode(md5Bytes);
                    return contentMD5;
                } catch (NoSuchAlgorithmException var5) {
                    log.error("不支持此算法", var5);
                    throw new E("不支持此算法");
                }
            }
        }
    
        private static String doSignatureBase64(String message, String secret) {
            String algorithm = "HmacSHA256";
            String digestBase64 = null;
    
            try {
                Mac hmacSha256 = Mac.getInstance(algorithm);
                byte[] keyBytes = secret.getBytes(StandardCharsets.UTF_8);
                byte[] messageBytes = message.getBytes(StandardCharsets.UTF_8);
                hmacSha256.init(new SecretKeySpec(keyBytes, 0, keyBytes.length, algorithm));
                byte[] digestBytes = hmacSha256.doFinal(messageBytes);
                digestBase64 = encodeBase64.encode(digestBytes);
                return digestBase64;
            } catch (NoSuchAlgorithmException var8) {
                log.error("不支持此算法", var8);
                throw new E("不支持此算法");
            } catch (InvalidKeyException var9) {
                log.error("无效的密钥规范", var9);
                throw new E("无效的密钥规范");
            }
        }
    
        private static String appendSignDataString(String method, String accept, String contentMD5, String contentType, String date, String headers, String url) {
            StringBuilder sb = new StringBuilder();
            sb.append(method).append("\n").append(accept).append("\n").append(contentMD5).append("\n").append(contentType).append("\n").append(date).append("\n");
            if ("".equals(headers)) {
                sb.append(headers).append(url);
            } else {
                sb.append(headers).append("\n").append(url);
            }
    
            return new String(sb);
        }
    }

配置类

@Configuration
    @ConfigurationProperties(
        prefix = "e-sign"
    )
    public class ESignConfig {
        private static final Logger log = LoggerFactory.getLogger(ESignConfig.class);
        private String projectId;
        private String projectSecret;
        private String apiHost;
        private String callbackHost;
        private String redirectHost;
    }

上边几个类就可以封装对外请求了。自己服务根据要求可以另外处理

## 二、自己封装请求类 ##

通用请求返回结果类

package com.service;
    
    import com.alibaba.fastjson.JSONObject;
    import com.common.dto.coop.HttpDTO;
    import com.common.vo.coop.ThirdResultVO;
    import com.cooperation.generator.ThirdTokenGenerator;
    import com.cooperation.template.TokenTemplate;
    import lombok.extern.slf4j.Slf4j;
    import okhttp3.*;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    import org.springframework.util.Assert;
    
    import java.io.IOException;
    import java.net.MalformedURLException;
    import java.net.URL;
    import java.util.Objects;
    import java.util.concurrent.TimeUnit;
    
    /**
     * 基于okhttp的请求客户端的service
     *
     * @author aaa 2022-04-28
     */
    @Slf4j
    @Service
    public class HttpService2 {
    
        @Autowired
        private TokenTemplate tokenTemplate;
    
        /**
         * 获取接口调用返回值
         *
         * @param param 请求参数
         * @author aaa 2022-04-28
         */
        public ThirdResultVO getInterfaceResult(HttpDTO param) {
    
            // 参数转换成json
            JSONObject json = Objects.isNull(param.getObj()) ? new JSONObject()
                    : JSONObject.parseObject(JSONObject.toJSONString(param.getObj()));
    
            // 如果需要token，将token放在参数中
            if (param.getNeedToken()) {
    
                String token = tokenTemplate.getToken(new ThirdTokenGenerator());
    
                json.put("token", token);
            }
    
            // 发起请求，获得响应
            Response response = doRequest(param.getUrl(), json);
    
            // 处理返回值
            ThirdResultVO ThirdResult = handleReturn(response);
    
            // 如果为null，响应有问题，不能转成返回值类型
            Assert.notNull(ThirdResult, "接口调用异常");
    
            return ThirdResult;
        }
    
        /**
         * 处理返回值
         *
         * @param response 请求响应
         * @author aaa 2022-04-28
         */
        private ThirdResultVO handleReturn(Response response) {
            // 如果响应为空，返回null
            if (Objects.isNull(response)) {
                return null;
            }
    
            try {
                // 如果响应体为空，返回null
                if (Objects.isNull(response.body())) {
                    return null;
                }
    
                // 响应体的字节数组
                byte[] bytes = response.body().bytes();
                log.info("调用接口返回数据--:{}", new String(bytes));
                // 转换成返回值类型
                return JSONObject.parseObject(bytes, ThirdResultVO.class);
    
            } catch (Exception e) {
                log.info("处理返回值失败:{}", e.getMessage(), e);
            }
    
            return null;
        }
    
        /**
         * 发送请求
         *
         * @param url        请求地址
         * @param jsonObject 参数DTO
         * @author aaa 2022-04-28
         */
        private Response doRequest(String url, JSONObject jsonObject) {
    
            // 获得表单请求对象
            Request formRequest = getFormRequest(url, jsonObject);
    
            // 调用接口 请求入参
            log.info("调用接口请求入参--:url：{} , jsonObject :{}",url, JSONObject.toJSONString(jsonObject));
    
            // 获得okhttp请求工具
            OkHttpClient requestClient = getRequestClient();
    
            // 获得请求调用对象
            Call call = requestClient.newCall(formRequest);
    
            // 发起请求，获得响应
            Response execute = null;
            try {
                execute = call.execute();
            } catch (IOException e) {
                log.info("调用接口失败：{}", e.getMessage(), e);
            }
    
            return execute;
        }
    
        /**
         * 获得表单请求
         *
         * @param url        请求地址
         * @param jsonObject 参数DTO
         * @author aaa 2022-04-28
         */
        private Request getFormRequest(String url, JSONObject jsonObject) {
    
            // 获得请求构造器
            Request.Builder requestBuilder = new Request.Builder();
    
            // 设置表单请求的请求头
            try {
                requestBuilder.addHeader("content-type", "application/x-www-form-urlencoded").post(getFormBody(jsonObject)).url(new URL(url));
            } catch (MalformedURLException e) {
                log.info("url转换失败：{}", e.getMessage(), e);
            }
    
            // 返回请求对象
            return requestBuilder.build();
        }
    
        /**
         * 获取请求客户端
         *
         * @author aaa 2022-04-28
         */
        private OkHttpClient getRequestClient() {
            return new OkHttpClient.Builder()
                    .readTimeout(2L, TimeUnit.MINUTES)
                    .build();
        }
    
        /**
         * 获取form表单请求的body
         *
         * @param jsonObject 请求参数DTO
         * @author aaa 2022-04-28
         */
        private FormBody getFormBody(JSONObject jsonObject) {
    
            // 获取表单请求构造器
            FormBody.Builder fb = new FormBody.Builder();
    
            // 设置请求参数
            jsonObject.keySet().forEach(item -> fb.addEncoded(item, jsonObject.getString(item)));
    
            // 返回body
            return fb.build();
        }
    }

通用请求参数类

@Data
    @Accessors(chain = true)
    @EqualsAndHashCode(callSuper = false)
    public class HttpDTO implements Serializable {
    
        private static final long serialVersionUID = 1L;
    
        @NotNull(message = "请求路径不能为空")
        @NotBlank(message = "请求路径不能为空")
        @ApiModelProperty(value = "请求路径url")
        private String url;
    
        @ApiModelProperty(value = "参数")
        private Object obj;
    
        @NotNull(message = "是否需要token 不能为空")
        @ApiModelProperty(value = "是否需要token：true是，false否")
        private Boolean needToken;
    }

请求调用示例

public List<String> getSkuCode(String classifyCode) {
    
            ResultVO interfaceResult = httpService.getInterfaceResult(new HttpDTO()
                    .setUrl(Constant.HOST.concat(Constant.GOODS_GET_SKUS_BY_CLASSID_URI))
                    .setNeedToken(true)
                    .setObj(new DeLiGetSkusByClassId3DTO().setCode(classifyCode3).setIsAll(1)));
    
            log.info(interfaceResult.getResultMessage());
    
            return JSONArray.parseArray(interfaceResult.getResult(), String.class);
        }

上边的请求返回，从结果里取出result字符串，再转一下list，这可以放在后面的请求方法中，传一个返回的类class。使用objectMapper转一下。

private ObjectMapper mapper = new ObjectMapper();
    
    
    public <T, RR> Response<RR> api(ApiDTO<T> jsonParams, Class<RR> responseResult) {
            String json = JSONObject.toJSONString(jsonParams);
            log.info("三方api.do, requestParams:{}", json);
            String responseStr = this.thirdFileAgentFeign.api(json);
            // 构建返回类型
            JavaType javaType1 = this.mapper.getTypeFactory().constructParametricType(YZResponse.class, new Class[]{responseResult});
    
            try {
                // 这个代码块就看这里返回带泛型的类
                return (Response)this.mapper.readValue(responseStr, javaType1);
            } catch (JsonProcessingException e) {
                log.error("反序列化返回值异常, responseStr:{}, errInfo:{}", new Object[]{responseStr, var7.getMessage(), e});
                throw new E("反序列化返回值异常");
            }
        }

第二种返回类型

import com.fasterxml.jackson.core.type.TypeReference;
    
    public static <T> T toObj(String json, Class<T> type) {
            try {
                return MAPPER.readValue(json, type);
            } catch (IOException e) {
                log.error("toObj error", e);
                throw E.of(BaseExceptionEnum.FORMAT_ERROR);
            }
        }
    
    public static <T> T toObj(String json, TypeReference<T> typeReference) {
            try {
                return mapper.readValue(json, typeReference);
            } catch (IOException e) {
                log.error("toObj error", e);
                throw E.of(BaseExceptionEnum.FORMAT_ERROR);
            }
        }

泛型返回处理可以参考RestTemplate里面的postForObject()

Class<?> deserializationView = ((MappingJacksonInputMessage)inputMessage).getDeserializationView();
                    if (deserializationView != null) {
                        // 部分代码，构建一个reader
                        ObjectReader objectReader = this.objectMapper.readerWithView(deserializationView).forType(javaType);
                        if (isUnicode) {
                        // 返回class类型的对象
                            return objectReader.readValue(inputMessage.getBody());
                        }
    
                        Reader reader = new InputStreamReader(inputMessage.getBody(), charset);
                        return objectReader.readValue(reader);
                    }

具体可以学习一下ObjectMapper的用法

请求接口返回结果类

@Accessors(chain = true)
    @EqualsAndHashCode(callSuper = false)
    public class ResultVO implements Serializable {
    
        private static final long serialVersionUID = 1L;
    
        @ApiModelProperty(value = "接口返回成功与否")
        private Boolean success;
    
        @ApiModelProperty(value = "返回数据描述")
        private String resultMessage;
    
        @ApiModelProperty(value = "平台业务代码标记")
        private String resultCode;
    
    // 返回的json结果，再处理成返回对象
        @ApiModelProperty(value = "业务数据")
        private String result;
    }

## 三、调用第三方生成token，可以使用策略类实现 ##

策略接口类

public interface TokenGeneratorStrategy {
        /**
         * 获取token
         *
         * @author aaa 2022-04-26
         */
        String getToken();
    
        /**
         * 获取token缓存key
         *
         * @author aaa 2022-04-26
         */
        String getTokenCacheKey();
    
        /**
         * 获取token过期时间,采用redis单位
         *
         * @author aaa 2022-04-26
         */
        Duration getTokenExpireTime();
    
    }

获取token的实现类

package com.generator;
    
    import com.alibaba.fastjson.JSONObject;
    import com.common.constant.ThirdConstant;
    import com.common.constant.MallCacheKeyConstant;
    import com.common.constant.MallCommonConstant;
    import com.common.dto.coop.HttpDTO;
    import com.common.vo.coop.ThirdResultVO;
    import com.common.vo.coop.ThirdTokenVO;
    import com.cooperation.dto.ThirdTokenDTO;
    import com.cooperation.service.HttpService;
    import com.cooperation.strategy.TokenGeneratorStrategy;
    import com.common.exception.E;
    import lombok.extern.slf4j.Slf4j;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    import org.springframework.util.DigestUtils;
    
    import java.nio.charset.StandardCharsets;
    import java.time.Duration;
    import java.time.LocalDate;
    import java.time.LocalDateTime;
    import java.time.LocalTime;
    import java.time.format.DateTimeFormatter;
    import java.util.Objects;
    
    /**
     * 三方生成token
     *
     */
    @Slf4j
    @Service
    public class ThirdTokenGenerator implements TokenGeneratorStrategy {
    
        @Autowired
        private HttpService httpService;
    
        @Override
        public String getToken() {
    
            // 获取当前时间,转换成yyyy/MM/dd格式
            DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
            String format = LocalDateTime.now().format(dateTimeFormatter);
    
            // 签名规则：client_secret+timestamp+client_id+username+password+scope+client_secret将上面字符串MD5 加密后转为小写。
            String sign = ThirdConstant.CLIENT_SECRET
                    .concat(format)
                    .concat(ThirdConstant.CLIENT_ID)
                    .concat(ThirdConstant.USERNAME)
                    .concat(ThirdConstant.PASSWORD)
                    .concat(ThirdConstant.CLIENT_SECRET);
    
            // md5 加密
            String signMd5 = DigestUtils.md5DigestAsHex(sign.getBytes(StandardCharsets.UTF_8)).toLowerCase();
    
            ThirdTokenDTO ThirdTokenDto = new ThirdTokenDTO().setClient_id(ThirdConstant.CLIENT_ID).setClient_secret(ThirdConstant.CLIENT_SECRET)
                    .setUsername(ThirdConstant.USERNAME).setPassword(ThirdConstant.PASSWORD)
                    .setTimestamp(format).setSign(signMd5);
    
            // 接口调用
            ThirdResultVO interfaceResult = httpService.getInterfaceResult(
                    new HttpDTO()
                            .setUrl(ThirdConstant.HOST.concat(ThirdConstant.TOKEN_URI))
                            .setObj(ThirdTokenDto)
                            .setNeedToken(false));
    
    
            ThirdTokenVO ThirdToken = new ThirdTokenVO();
            try {
                ThirdToken = JSONObject.parseObject(interfaceResult.getResult(), ThirdTokenVO.class);
            } catch (Exception e) {
                log.info("token 返回值处理异常：{}", e.getMessage(), e);
            }
            if (Objects.isNull(ThirdToken)) {
                log.error("获取三方token为空----{}", interfaceResult);
                throw new E("获取三方token异常信息--" + interfaceResult.getResultMessage());
            }
    
            return ThirdToken.getAccess_token();
        }
    
        @Override
        public String getTokenCacheKey() {
            return MallCacheKeyConstant.COOP_Third_TOKEN + MallCommonConstant.DEFAULT_KEY;
        }
    
        /**
         * 三方有效时间一小时,这里的过期时间采用50分钟
         */
        @Override
        public Duration getTokenExpireTime() {
    
            // 当前时间到12点的时间
            Duration nowTo12 = Duration.between(LocalDateTime.now(), LocalDateTime.of(LocalDate.now(), LocalTime.MAX));
    
            // 50分钟
            Duration fiftyMin = Duration.ofSeconds(50 * 60L);
    
            // 如果当前时间到12点的时间超过50分钟，返回50分钟
            if (nowTo12.compareTo(fiftyMin) > 0) {
                return fiftyMin;
            }
    
            // 否则返回当前时间到12点的时间
            return nowTo12;
        }
    
    }

## 总结 ##

以上就是 2中方式请求第三方封装结果。