Use a proper HTTP client when discovering federated IS to avoid 4xx's

src/main/java/io/kamax/mxisd/Mxisd.java

@@ -40,6 +40,7 @@ import io.kamax.mxisd.lookup.provider.BridgeFetcher;
 import io.kamax.mxisd.lookup.provider.RemoteIdentityServerFetcher;
 import io.kamax.mxisd.lookup.strategy.LookupStrategy;
 import io.kamax.mxisd.lookup.strategy.RecursivePriorityLookupStrategy;
+import io.kamax.mxisd.matrix.IdentityServerUtils;
 import io.kamax.mxisd.notification.NotificationHandlerSupplier;
 import io.kamax.mxisd.notification.NotificationHandlers;
 import io.kamax.mxisd.notification.NotificationManager;
@@ -86,6 +87,7 @@ public class Mxisd {
                 .setMaxConnTotal(Integer.MAX_VALUE)
                 .build();
 
+        IdentityServerUtils.setHttpClient(httpClient);
         srvFetcher = new RemoteIdentityServerFetcher(httpClient);
 
         store = new OrmLiteSqlStorage(cfg);

src/main/java/io/kamax/mxisd/lookup/provider/RemoteIdentityServerFetcher.java

@@ -25,6 +25,7 @@ import com.google.gson.JsonObject;
 import com.google.gson.JsonParseException;
 import io.kamax.matrix.json.GsonUtil;
 import io.kamax.mxisd.exception.InvalidResponseJsonException;
+import io.kamax.mxisd.http.IsAPIv1;
 import io.kamax.mxisd.http.io.identity.ClientBulkLookupRequest;
 import io.kamax.mxisd.lookup.SingleLookupReply;
 import io.kamax.mxisd.lookup.SingleLookupRequest;
@@ -73,7 +74,7 @@ public class RemoteIdentityServerFetcher implements IRemoteIdentityServerFetcher
 
         try {
             URIBuilder b = new URIBuilder(remote);
-            b.setPath("/_matrix/identity/api/v1/lookup");
+            b.setPath(IsAPIv1.Base + "/lookup");
             b.addParameter("medium", request.getType());
             b.addParameter("address", request.getThreePid());
             HttpGet req = new HttpGet(b.build());
@@ -116,7 +117,7 @@ public class RemoteIdentityServerFetcher implements IRemoteIdentityServerFetcher
         ClientBulkLookupRequest mappingRequest = new ClientBulkLookupRequest();
         mappingRequest.setMappings(mappings);
 
-        String url = remote + "/_matrix/identity/api/v1/bulk_lookup";
+        String url = remote + IsAPIv1.Base + "/bulk_lookup";
         try {
             HttpPost request = RestClientUtils.post(url, mappingRequest);
             try (CloseableHttpResponse response = client.execute(request)) {

src/main/java/io/kamax/mxisd/matrix/IdentityServerUtils.java

@@ -6,13 +6,17 @@ import com.google.gson.JsonParser;
 import io.kamax.mxisd.http.IsAPIv1;
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang.StringUtils;
+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.impl.client.CloseableHttpClient;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.xbill.DNS.*;
 
 import java.io.IOException;
-import java.net.HttpURLConnection;
 import java.net.MalformedURLException;
+import java.net.URI;
 import java.net.URL;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
@@ -21,31 +25,41 @@ import java.util.List;
 import java.util.Optional;
 
 // FIXME placeholder, this must go in matrix-java-sdk for 1.0
+// FIXME this class is just a mistake and should never have happened. Make sure to get rid of for v2.x
 public class IdentityServerUtils {
 
     private static Logger log = LoggerFactory.getLogger(IdentityServerUtils.class);
     private static JsonParser parser = new JsonParser();
 
+    private static CloseableHttpClient client;
+
+    public static void setHttpClient(CloseableHttpClient client) {
+        IdentityServerUtils.client = client;
+    }
+
     public static boolean isUsable(String remote) {
         if (StringUtils.isBlank(remote)) {
+            log.info("IS URL is blank, not usable");
             return false;
         }
 
-        try {
+        HttpGet req = new HttpGet(URI.create(remote + IsAPIv1.Base));
-            // FIXME use Apache HTTP client
+        req.setConfig(RequestConfig.custom()
-            HttpURLConnection rootSrvConn = (HttpURLConnection) new URL(remote + IsAPIv1.Base).openConnection();
+                .setConnectTimeout(2000)
-            // TODO turn this into a configuration property
+                .setConnectionRequestTimeout(2000)
-            rootSrvConn.setConnectTimeout(2000);
+                .build()
+        );
 
-            int status = rootSrvConn.getResponseCode();
+        try (CloseableHttpResponse res = client.execute(req)) {
+            int status = res.getStatusLine().getStatusCode();
             if (status != 200) {
                 log.info("Usability of {} as Identity server: answer status: {}", remote, status);
                 return false;
             }
 
-            JsonElement el = parser.parse(IOUtils.toString(rootSrvConn.getInputStream(), StandardCharsets.UTF_8));
+            JsonElement el = parser.parse(IOUtils.toString(res.getEntity().getContent(), StandardCharsets.UTF_8));
             if (!el.isJsonObject()) {
-                log.debug("IS {} did not send back a JSON object for single 3PID lookup");
+                log.debug("IS {} did not send back an empty JSON object as per spec, not a valid IS");
                 return false;
             }