本文代码详见：/honghailiang/RetrofitUpLoadImage
一、再次膜拜下Retrofit
Retrofit无论从性能还是使用方便性上都很屌！！！，本文不去介绍其运作原理（虽然很想搞明白），后面会出专题文章解析Retrofit的内部原理；本文只是从使用上解析Retrofit实现多图片/文件、图文上传的功能。文件上传相关可参考Multipart/form-data文件上传简介 及Apache FileUpload文件上传功能 。
二、概念介绍
1）注解@Multipart
从字面上理解就是与多媒体文件相关的，没错，图片、文件等的上传都要用到该注解，其中每个部分需要使用@Part来注解。。看其注释
/*** Denotes that the request body is multi-part. Parts should be declared as parameters and* annotated with {@link Part @Part}.*/
2）注解@PartMap
当然可以理解为使用@PartMap注释，传递多个Part，以实现多文件上传。注释
/*** Denotes name and value parts of a multi-part request.* <p>* Values of the map on which this annotation exists will be processed in one of two ways:* <ul>* <li>If the type is {@link okhttp3.RequestBody RequestBody} the value will be used* directly with its content type.</li>* <li>Other object types will be converted to an appropriate representation by using* {@linkplain Converter a converter}.</li>* </ul>* <p>* <pre><code>* @Multipart* @POST("/upload")* Call<ResponseBody> upload(*@Part("file") RequestBody file,*@PartMap Map<String, RequestBody> params);* </code></pre>* <p>* A {@code null} value for the map, as a key, or as a value is not allowed.** @see Multipart* @see Part*/
3）RequestBody
从上面注释中就可以看到参数类型是RequestBody，其就是请求体。文件上传就需要参数为RequestBody。官方使用说明如下http://square.github.io/retrofit/
Multipart parts use one of Retrofit's converters or they can implement RequestBody to handle their own serialization.
四、基本实现
了解了以上概念，下面就一一实现
1）接口定义
public interface IHttpService {@Multipart@POST("file/upLoad.do")Call<BaseBean> upLoadAgree(@PartMap Map<String, RequestBody>params);}
BaseBean是根据服务端返回数据进行定义的，这个使用时可以根据自有Server定义。
2）Retrofit实现
/*** Created by DELL on /3/16.* 上传文件用（包含图片）*/public class RetrofitHttpUpLoad {/*** 超时时间60s*/private static final long DEFAULT_TIMEOUT = 60;private volatile static RetrofitHttpUpLoad mInstance;public Retrofit mRetrofit;public IHttpService mHttpService;private static Map<String, RequestBody> params;private RetrofitHttpUpLoad() {mRetrofit = new Retrofit.Builder().baseUrl(UrlConfig.ROOT_URL).client(genericClient()).addConverterFactory(GsonConverterFactory.create()).build();mHttpService = mRetrofit.create(IHttpService.class);}public static RetrofitHttpUpLoad getInstance() {if (mInstance == null) {synchronized (RetrofitHttpUpLoad.class) {if (mInstance == null)mInstance = new RetrofitHttpUpLoad();params = new HashMap<String, RequestBody>();}}return mInstance;}/*** 添加统一超时时间,http日志打印** @return*/private OkHttpClient genericClient() {HttpLoggingInterceptor logging = new HttpLoggingInterceptor();logging.setLevel(HttpLoggingInterceptor.Level.BODY);OkHttpClient httpClient = new OkHttpClient.Builder().addInterceptor(logging).connectTimeout(DEFAULT_TIMEOUT, TimeUnit.SECONDS).writeTimeout(DEFAULT_TIMEOUT, TimeUnit.SECONDS).readTimeout(DEFAULT_TIMEOUT, TimeUnit.SECONDS).build();return httpClient;}/*** 将call加入队列并实现回调** @param call 调入的call* @param retrofitCallBack 回调* @param method 调用方法标志，回调用* @param <T> 泛型参数*/public <T> void addToEnqueue(Call<T> call, final RetrofitCallBack retrofitCallBack, final int method) {final Context context = MyApplication.getContext();call.enqueue(new Callback<T>() {@Overridepublic void onResponse(Call<T> call, Response<T> response) {LogUtil.d("retrofit back code ====" + response.code());if (null != response.body()) {if (response.code() == 200) {LogUtil.d("retrofit back body ====" + new Gson().toJson(response.body()));retrofitCallBack.onResponse(response, method);} else {LogUtil.d("toEnqueue, onResponse Fail:" + response.code());ToastUtil.makeShortText(context, "网络连接错误" + response.code());retrofitCallBack.onFailure(response, method);}} else {LogUtil.d("toEnqueue, onResponse Fail m:" + response.message());ToastUtil.makeShortText(context, "网络连接错误" + response.message());retrofitCallBack.onFailure(response, method);}}@Overridepublic void onFailure(Call<T> call, Throwable t) {LogUtil.d("toEnqueue, onResponse Fail unKnown:" + t.getMessage());t.printStackTrace();ToastUtil.makeShortText(context, "网络连接错误" + t.getMessage());retrofitCallBack.onFailure(null, method);}});}/*** 添加参数* 根据传进来的Object对象来判断是String还是File类型的参数*/public RetrofitHttpUpLoad addParameter(String key, Object o) {if (o instanceof String) {RequestBody body = RequestBody.create(MediaType.parse("text/plain;charset=UTF-8"), (String) o);params.put(key, body);} else if (o instanceof File) {RequestBody body = RequestBody.create(MediaType.parse("multipart/form-data;charset=UTF-8"), (File) o);params.put(key + "\"; filename=\"" + ((File) o).getName() + "", body);}return this;}/*** 构建RequestBody*/public Map<String, RequestBody> bulider() {return params;}public void clear(){params.clear();}}
其中定义了Retrofit实例、还用拦截器定义了统一的超时时间和日志打印；将call加入队列并实现回调。最重要的就是添加参数：
/*** 添加参数* 根据传进来的Object对象来判断是String还是File类型的参数*/public RetrofitHttpUpLoad addParameter(String key, Object o) {if (o instanceof String) {RequestBody body = RequestBody.create(MediaType.parse("text/plain;charset=UTF-8"), (String) o);params.put(key, body);} else if (o instanceof File) {RequestBody body = RequestBody.create(MediaType.parse("multipart/form-data;charset=UTF-8"), (File) o);params.put(key + "\"; filename=\"" + ((File) o).getName() + "", body);}return this;}
这里就是根据传入的参数，返回不同的RequestBody, 注意文件的key值。
3）使用
private void upLoadAgree() {showWaitDialog();RetrofitHttpUpLoad retrofitHttpUpLoad = RetrofitHttpUpLoad.getInstance();retrofitHttpUpLoad.clear();if (!StringUtil.isEmpty(pathImage[0])){retrofitHttpUpLoad = retrofitHttpUpLoad.addParameter("pic1",new File(pathImage[0]));}if (!StringUtil.isEmpty(pathImage[1])){retrofitHttpUpLoad = retrofitHttpUpLoad.addParameter("pic2", new File(pathImage[1]));}if (!StringUtil.isEmpty(pathImage[2])){retrofitHttpUpLoad = retrofitHttpUpLoad.addParameter("zip", new File(pathImage[2]));}Map<String, RequestBody> params = retrofitHttpUpLoad.addParameter("status", "4").addParameter("pickupId", tv_orderquality_pid.getText().toString()).addParameter("cause", reason).addParameter("connectname", et_orderquality_lxrname.getText().toString()).addParameter("connectphone", et_orderquality_lxrphone.getText().toString()).addParameter("details", et_orderquality_xqms.getText().toString()).bulider();retrofitHttpUpLoad.addToEnqueue(retrofitHttpUpLoad.mHttpService.upLoadAgree(params),this, HttpStaticApi.HTTP_UPLOADAGREE);}
需要注意的是要对图片及文件路径进行判空操作，否则会报异常W/System.err: java.io.FileNotFoundException: /: open failed: EISDIR (Is a directory)
五、报文日志
其中图片报文有省略
D/OkHttp: --> POST http://192.168.xxx.xxx:8880/xxx/nocheck/file/agree.do http/1.1D/OkHttp: Content-Type: multipart/form-data; boundary=f3e7369a-ead9-46e2-9ddd-448442fd5108D/OkHttp: Content-Length: 300580D/OkHttp: --f3e7369a-ead9-46e2-9ddd-448442fd5108D/OkHttp: Content-Disposition: form-data; name="pic2"; filename="90079.jpg"D/OkHttp: Content-Transfer-Encoding: binaryD/OkHttp: Content-Type: multipart/form-data;charset=UTF-8D/OkHttp: Content-Length: 149456D/OkHttp: ??????JFIF????H??H????????C??D/OkHttp: "##! %*5-%'2( .?/279<<<$-BFA:F5;<9????CD/OkHttp: 9& &99999999999999999999999999999999999999999999999999?????8"????????????????????????????????????????????????????????????????????|???/n?s??y?]8ug?7?R??????h?tΘa?T?T<?U???z???+3C?w??tdf??=<??????fN??s??x??hhzd??X~?X??i?{~/?<^??~=zX??\??4?U?ɡ)I???????????????????$??@??? iM?"J?R2?f?MK5x#w?????r?I?3?Y??l???V?Bj??>{??t?u????]????g>?o??o???dM?U??????J?R??<?+?;??????????OG>????=?5?L?9?&???_/\?yu??~|*,???My?r????????='?d?=?t*??*?Y??(????????????????YB i?Jlv??d?"l????Y??4??X?7???;??sY?\κ+?N??;?L??&?(?MJ???@w~~???a?qs??m7??y???Ns?\?C?g??>???N%??N??gs?Q??c????Z?t???x??{??^_}s?s??gO?????N?|}?;??y?y?ǎ｜?v??N?l???????????*k5?(?????????1$?B??j?+,?l???hN??U?<sgb?g?x?S??;;c?,??7?0Z?J?I?r??X?9?t?'\?1W+D/OkHttp: [?? ????=/X???n??T*4?u??<?????s?q??????c???\?6?YV?p????oB%??|?s??????????{??g??k?}?t??d{]^W???v?WB?x???|z9?>V?{ǒ>?o??Y????xk?k7???{w????b?!JQjRQ%RH?%8?H??Q??Ys?{???u??(?`?b\??k?cC:u#???d?C??&??W.CXd?e??N??n????.?%v?,.zW?>??&??+??r??S'?.n?[V??q??oGL?,:?S??????/?o<???,?B???;??????^[?#Lm??7.Q?6sONz??fwN?D/OkHttp: ???,?\????D/OkHttp: ???U<???1?Z???=??pn?~q??[-?P??=?j?va?R???4X*???nv?H??j?j?p??`h#-???qiA?U?????x?&v?b?R??o?.??H[M5??Y??5?>%Y?j????x?2.m??=??GG???D/OkHttp: \?D??(?JK9<J???JE?jl??pWD/OkHttp: ??}??i?6??R??:!J??FT?!e???D/OkHttp: ????:??5????%??`?|???;z?G??[?P???N=???T??X?-?okNe???Y??f8?`:?P???x?1?I?g?0?)?fe*P?qU?~?jSY%??gɡR?(?$A?|y?}??s?2?<?/??4?s??@-?,??AZ?az?,??bl?.??WD??????q?X?u}?+G?z?h8=?w[`?j??g&q?c????????<|??|? 1????q^???D/OkHttp: 5??)x???:*dK??|?KPz5v?4?+?>eO?4??i?P2F?&\9???? -V?esf~&F?Q??S?\???8{??*B?1qVO????-S??!?????????*6??D/OkHttp: 3?5W?r?x??+?\?r???6??C??Ms,H?AE??=q??????(??f?=,????Z??+????L??<??v_i-?m|????6??L???=?4?Y?{?W??9=??\AW???~??{@!?^ Z6??,?k>|??CD/OkHttp: aZ??-?ы??R?K???1?6`'??F%/4wZ?Cn????[?]?el??U&[???1db-4????????~er!?4??>ji?]??AV?[v??e??`θo???帏!(??Pk?XCI??Glk-p??p?B?b???ae???d?]-|"??*??`??l??Tmn`???D/OkHttp: R?G??h?DETp???i???^????u?E??1?wW%?<????????3e??V????**m??9V??O?R??f?b?D/OkHttp: ??j%)^?$??g?\?Qm^`??D/OkHttp: ??[*?\?@/T@,?|@\$F?????v_??uA???:?9>%B????1 =?D]{?"??*^??q1??i??B?bs?L_???? e??W?2??pDR?Q??M?? ?{????7S?????Dzcb\??????0?????u? h???e??7X??)?s{??DIqf???QdM??V?????r??MTk?=??+?>b0?b???i?\?lI??H?P??,?Pn[]??.?`.X?=A?I?P?@?<~??Px??.???9?(??:=??5E?n?!l??? 5???ee_??'[????p?d??1?)g?s<????kop?вd?19m?ft??ab????????j?5/pT?M?xBb??8???z??????wX??V??|~x????????c?Rsx???D???ixH??ud?50??MΘ7???<?^I???i?`?????f?A?????????;?U?H????a~?W臸?@O?'u\-???????CN,????-???@?+"n?:y???G|S??C?F5?????Ix?????)?????b22???jRj????j?,K?K"￥</?G?w/*?W????sn??L????n?n????? k????"?*??~?9??<4?,c?d>?EG??iB??0+??i?Y??D???p???????S|.?2???# &??"v?Y??P??O?#EK???,J?6U?>a???;?-rM??@???^b??@??K?????PI??4?qM|??V??h[Ld??R????or?U?M??)_?J?^S?41n}?@n|??D/OkHttp: --f3e7369a-ead9-46e2-9ddd-448442fd5108D/OkHttp: Content-Disposition: form-data; name="cause"D/OkHttp: Content-Transfer-Encoding: binaryD/OkHttp: Content-Type: text/plain;charset=UTF-8D/OkHttp: Content-Length: 33D/OkHttp: 对货物数量、质量有异议D/OkHttp: --f3e7369a-ead9-46e2-9ddd-448442fd5108D/OkHttp: Content-Disposition: form-data; name="details"D/OkHttp: Content-Transfer-Encoding: binaryD/OkHttp: Content-Type: text/plain;charset=UTF-8D/OkHttp: Content-Length: 9D/OkHttp: 哈哈哈D/OkHttp: --f3e7369a-ead9-46e2-9ddd-448442fd5108D/OkHttp: Content-Disposition: form-data; name="status"D/OkHttp: Content-Transfer-Encoding: binaryD/OkHttp: Content-Type: text/plain;charset=UTF-8D/OkHttp: Content-Length: 1D/OkHttp: 4D/OkHttp: --f3e7369a-ead9-46e2-9ddd-448442fd5108D/OkHttp: Content-Disposition: form-data; name="pickupId"D/OkHttp: Content-Transfer-Encoding: binaryD/OkHttp: Content-Type: text/plain;charset=UTF-8D/OkHttp: Content-Length: 6D/OkHttp: 105329D/OkHttp: --f3e7369a-ead9-46e2-9ddd-448442fd5108D/OkHttp: Content-Disposition: form-data; name="connectphone"D/OkHttp: Content-Transfer-Encoding: binaryD/OkHttp: Content-Type: text/plain;charset=UTF-8D/OkHttp: Content-Length: 11D/OkHttp: 13xxxxxxxxxD/OkHttp: --f3e7369a-ead9-46e2-9ddd-448442fd5108D/OkHttp: Content-Disposition: form-data; name="connectname"D/OkHttp: Content-Transfer-Encoding: binaryD/OkHttp: Content-Type: text/plain;charset=UTF-8D/OkHttp: Content-Length: 3D/OkHttp: 111D/OkHttp: --f3e7369a-ead9-46e2-9ddd-448442fd5108--D/OkHttp: --> END POST (300580-byte body)
六、代码托管
/honghailiang/RetrofitUpLoadImage
七、效果图：
八、服务端代码
FileItemFactory factory = new DiskFileItemFactory();ServletFileUpload upload = new ServletFileUpload(factory);File directory = null;List<FileItem> items = new ArrayList<FileItem>();InputStream is = null;FileOutputStream fos = null;try {items = upload.parseRequest(request);// 得到所有的文件Iterator<FileItem> it = items.iterator();while (it.hasNext()) {FileItem fItem = (FileItem) it.next();String fName = "";Object fValue = null;if (fItem.isFormField()) { // 普通文本框的值fName = fItem.getFieldName();fValue = fItem.getString("UTF-8");if("pickupId".equals(fName)){pickupAppeal.setPickupId(fValue.toString());}else if("cause".equals(fName)){pickupAppeal.setCause(fValue.toString());}else if("connectname".equals(fName)){pickupAppeal.setConnectname(fValue.toString());}else if("connectphone".equals(fName)){pickupAppeal.setConnectphone(fValue.toString());}else if("details".equals(fName)){pickupAppeal.setDetails(fValue.toString());}else if("status".equals(fName)){String status = fValue.toString();BigDecimal big = new BigDecimal(status);pickupAppeal.setStatus(big);}//map.put(fName, fValue);} else { // 获取上传文件的值fName = fItem.getFieldName();fValue = fItem.getInputStream();String name = fItem.getName();if (name != null && !("".equals(name))) {name = name.substring(name.lastIndexOf(File.separator) + 1);int lenN =name.indexOf(".");String suf = name.substring(lenN, name.length());String day = DateUtil.format(Calendar.getInstance().getTime(), "yyyy-MM-dd");String path = PATH+File.separator+day;directory = new File(path);if (!directory.exists()) {directory.mkdirs();}String preFile =UUID.randomUUID().toString().replace("-", "");String filePath = path + File.separator+preFile+suf;String serverPath = day+ File.separator+preFile+suf;map.put(fName, serverPath);map.put(fName+"m", name);is = fItem.getInputStream();fos = new FileOutputStream(filePath);byte[] buffer = new byte[1024];int len = 0;while ((len = is.read(buffer, 0, 1024)) != -1) {fos.write(buffer, 0, len);}fos.flush();}}}} catch (Exception e) {pLog.error("接收参数错误：" + e.getMessage());resultInfo.setStatus(ComStatus.RESULTINFO_STATUS_FAILE);resultInfo.setMessage(ComStatus.RESULTINFO_MESSAGE_FAILE);resultInfo.setData(map);resReslt.setResData(resultInfo);} finally {try {if (null != fos) {fos.close();}if (null != is) {is.close();}} catch (IOException e) {e.printStackTrace();}}
