如何动态改变Retrofit的base url和rest版本详解

class HeaderInterceptor implements Interceptor {  private static final String ENCODING_GZIP = "gzip"; private static final String CONTENT_TYPE_JSON = "application/json;charset=UTF-8"; private static final String HEADER_CONTENT_TYPE = "Content-Type"; private static final String HEADER_ACCEPT_TYPE = "application/json"; private static final String HEADER_CONTENT_ENCODING = "Content-Encoding"; private final static String CHARSET = "UTF-8";  @Override public Response intercept(Chain chain) throws IOException {  Request originRequest = chain.request();  Request.Builder newBuilder = originRequest.newBuilder();  newBuilder.addHeader("Accept", HEADER_ACCEPT_TYPE);  newBuilder.addHeader("Accept-Charset", CHARSET);  newBuilder.addHeader("Accept-Encoding", ENCODING_GZIP);  newBuilder.addHeader("Accept-Language", Locale.getDefault().toString().replace("_", "-"));  newBuilder.addHeader(HEADER_CONTENT_TYPE, CONTENT_TYPE_JSON);  return chain.proceed(newBuilder.build()); }}

Request originRequest = chain.request();if (paramsMap != null) { HttpUrl originUrl = originRequest.url(); HttpUrl.Builder newBuilder = originUrl.newBuilder(); for (String key : paramsMap.keySet()) {  newBuilder.addEncodedQueryParameter(key, paramsMap.get(key)); } HttpUrl newUrl = newBuilder.build(); Request newRequest = originRequest.newBuilder().url(newUrl).build(); return chain.proceed(newRequest);}return chain.proceed(originRequest);

interface HostName { String CLOUD = "CLOUD"; String PRIVATE = "PRIVATE"; String DEV = "DEV";} interface HostValue { String CLOUD = "https://www.baidu.com"; String PRIVATE = "https://private.bidu.com"; String DEV = "https://dev.baidu.com";}

interface RestVersionCode { String EMPTY = "EMPTY"; String V1 = "V1"; String V2 = "V2"; String PRIVATE = "PRIVATE";} /** * path 前缀值 */interface RestVersionValue { String EMPTY = ""; String V1 = "rest/v1"; String V2 = "rest/v2"; String PRIVATE = "rest/private";}

interface BaiduApiService {  @GET("s") Observable<Response<Object>> search(@Query("wd")String wd);  @GET("s") @Headers({UrlConstants.Header.REST_VERSION_V1}) Observable<Response<Object>> searchChangePath(@Query("wd")String wd);  @GET("s") @Headers({UrlConstants.Header.HOST_DEV}) Observable<Response<Object>> searchChangeHost(@Query("wd")String wd);  @Headers({UrlConstants.Header.HOST_PRIVATE, UrlConstants.Header.REST_VERSION_PRIVATE}) @GET("s") Observable<Response<Object>> searchChangeHostPath(@Query("wd")String wd);}

interface Header { String SPLIT_COLON = ":"; String HOST = "HostName"; String HOST_CLOUD = HOST + SPLIT_COLON + HostName.CLOUD; String HOST_PRIVATE = HOST + SPLIT_COLON + HostName.PRIVATE; String HOST_DEV = HOST + SPLIT_COLON + HostName.DEV; String REST_VERSION = "RestVersion"; String REST_VERSION_V1 = REST_VERSION + SPLIT_COLON + RestVersionCode.V1; String REST_VERSION_V2 = REST_VERSION + SPLIT_COLON + RestVersionCode.V2; String REST_VERSION_PRIVATE = REST_VERSION + SPLIT_COLON + RestVersionCode.PRIVATE; String REST_VERSION_EMPTY = REST_VERSION + SPLIT_COLON + RestVersionCode.EMPTY;}

class RequestInterceptor implements Interceptor {  @Override public Response intercept(Chain chain) throws IOException {  Request originRequest = chain.request();  HttpUrl originUrl = originRequest.url();  HttpUrl.Builder newBuilder;   String hostType = originRequest.header(UrlConstants.Header.HOST);  System.out.println("hostType:" + hostType);  if (hostType != null && hostType.length() > 0) {   String hostValue = UrlManager.getInstance().getHost(hostType);   HttpUrl temp = HttpUrl.parse(hostValue);   if (temp == null) {    throw new IllegalArgumentException(hostType + "对应的host地址不合法:" + hostValue);   }   newBuilder = temp.newBuilder();  } else {   newBuilder = new HttpUrl.Builder()     .scheme(originUrl.scheme())     .host(originUrl.host())     .port(originUrl.port());  }  String restVersion = originRequest.header(UrlConstants.Header.REST_VERSION);  System.out.println("restVersion:" + restVersion);  if (restVersion == null) {   restVersion = UrlConstants.RestVersionCode.V2;  }  String restValue = UrlManager.getInstance().getRest(restVersion);  if (restValue.contains("/")) {   String[] paths = restValue.split("/");   for (String path : paths) {    newBuilder.addEncodedPathSegment(path);   }  } else {   newBuilder.addEncodedPathSegment(restValue);  }  for (int i = 0; i < originUrl.pathSegments().size(); i++) {   newBuilder.addEncodedPathSegment(originUrl.encodedPathSegments().get(i));  }   newBuilder.encodedPassword(originUrl.encodedPassword())    .encodedUsername(originUrl.encodedUsername())    .encodedQuery(originUrl.encodedQuery())    .encodedFragment(originUrl.encodedFragment());   HttpUrl newUrl = newBuilder.build();  System.out.println("newUrl:" + newUrl.toString());  Request newRequest = originRequest.newBuilder().url(newUrl).build();  return chain.proceed(newRequest); }}

private Map<String, String> hostMap;private Map<String, String> restMap; private UrlManager() { hostMap = new HashMap<>(16); for (UrlConstants.Host host : UrlConstants.Host.values()) {  hostMap.put(host.getName(), host.getValue()); } restMap = new HashMap<>(); for (UrlConstants.Rest rest : UrlConstants.Rest.values()) {  restMap.put(rest.getVersion(), rest.getValue()); }} //更新host 的值public void setHost(String name, String value) { if (hostMap.containsKey(name)) {  HttpUrl httpUrl = HttpUrl.parse(value);  if (httpUrl == null) {   throw new IllegalArgumentException("要存入的Host " + name + "对应的value:"     + value + "不合法!");  }  hostMap.put(name, value); } else {  throw new NoSuchElementException("没有找到已经定义的Host名称:" + name + ",请先在" +    "net.devwiki.manager.UrlConstants.Host中定义!"); }} //根据host 获取值public String getHost(String name) { if (!hostMap.containsKey(name)) {  throw new NoSuchElementException("没有找到已经定义的Host名称:" + name + ",请先在" +    "net.devwiki.manager.UrlConstants.Host中定义!"); } return hostMap.get(name);}

private static void testRequest() { BaiduRest rest = new BaiduRest();  testDefault(rest);  testChangeHost(rest);  testChangePath(rest);  testChangeHostPath(rest);}