avoid serializing empty lists

Author: karussell

client-hc/src/main/java/com/graphhopper/api/GHMatrixBatchRequester.java

@@ -89,29 +89,24 @@ public MatrixResponse route(GHMRequest ghRequest) {
             outArraysList.add("weights");
         }
 
-        ArrayNode outArrayListJson = objectMapper.createArrayNode();
-        for (String str : outArraysList) {
-            outArrayListJson.add(str);
-        }
-
         boolean hasElevation = false;
         if (ghRequest.identicalLists) {
-            requestJson.putArray("points").addAll(createPointList(ghRequest.getFromPoints()));
-            requestJson.putArray("point_hints").addAll(createStringList(ghRequest.getFromPointHints()));
-            requestJson.putArray("curbsides").addAll(createStringList(ghRequest.getFromCurbsides()));
+            createPointArray(requestJson, "points", ghRequest.getFromPoints());
+            createStringArray(requestJson, "point_hints", ghRequest.getFromPointHints());
+            createStringArray(requestJson, "curbsides", ghRequest.getFromCurbsides());
         } else {
-            ArrayNode fromPointList = createPointList(ghRequest.getFromPoints());
-            ArrayNode toPointList = createPointList(ghRequest.getToPoints());
-            requestJson.putArray("from_points").addAll(fromPointList);
-            requestJson.putArray("from_point_hints").addAll(createStringList(ghRequest.getFromPointHints()));
-            requestJson.putArray("to_points").addAll(toPointList);
-            requestJson.putArray("to_point_hints").addAll(createStringList(ghRequest.getToPointHints()));
-            requestJson.putArray("from_curbsides").addAll(createStringList(ghRequest.getFromCurbsides()));
-            requestJson.putArray("to_curbsides").addAll(createStringList(ghRequest.getToPointHints()));
+            createPointArray(requestJson, "from_points", ghRequest.getFromPoints());
+            createStringArray(requestJson, "from_point_hints", ghRequest.getFromPointHints());
+
+            createPointArray(requestJson, "to_points", ghRequest.getToPoints());
+            createStringArray(requestJson, "to_point_hints", ghRequest.getToPointHints());
+
+            createStringArray(requestJson, "from_curbsides", ghRequest.getFromCurbsides());
+            createStringArray(requestJson, "to_curbsides", ghRequest.getToCurbsides());
         }
 
-        requestJson.putArray("snap_preventions").addAll(createStringList(ghRequest.getSnapPreventions()));
-        requestJson.putArray("out_arrays").addAll(outArrayListJson);
+        createStringArray(requestJson, "snap_preventions", ghRequest.getSnapPreventions());
+        createStringArray(requestJson, "out_arrays", outArraysList);
         requestJson.put("vehicle", ghRequest.getVehicle());
         requestJson.put("elevation", hasElevation);
         requestJson.put("fail_fast", ghRequest.getFailFast());
@@ -222,22 +217,26 @@ protected String postJson(String url, JsonNode data) throws IOException {
         }
     }
 
-    private ArrayNode createStringList(List<String> list) {
+    private void createStringArray(ObjectNode requestJson, String name, List<String> stringList) {
+        if (stringList.isEmpty())
+            return;
         ArrayNode outList = objectMapper.createArrayNode();
-        for (String str : list) {
+        for (String str : stringList) {
             outList.add(str);
         }
-        return outList;
+        requestJson.putArray(name).addAll(outList);
     }
 
-    private ArrayNode createPointList(List<GHPoint> list) {
+    private void createPointArray(ObjectNode requestJson, String name, List<GHPoint> pList) {
+        if (pList.isEmpty())
+            return;
         ArrayNode outList = objectMapper.createArrayNode();
-        for (GHPoint p : list) {
+        for (GHPoint p : pList) {
             ArrayNode entry = objectMapper.createArrayNode();
             entry.add(p.lon);
             entry.add(p.lat);
             outList.add(entry);
         }
-        return outList;
+        requestJson.putArray(name).addAll(outList);
     }
 }

client-hc/src/test/java/com/graphhopper/api/GraphHopperWebIT.java

@@ -24,6 +24,7 @@
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
+import java.util.concurrent.atomic.AtomicInteger;
 
 import static org.junit.Assert.*;
 
@@ -341,6 +342,28 @@ protected String postJson(String url, JsonNode data) throws IOException {
         assertEquals("xy", req.getVehicle());
     }
 
+    @Test
+    public void doNotIncludeEmptyCurbsidesList() {
+        final AtomicInteger counter = new AtomicInteger(0);
+        final GraphHopperMatrixWeb ghMatrix = new GraphHopperMatrixWeb(new GHMatrixBatchRequester() {
+            @Override
+            protected String postJson(String url, JsonNode data) throws IOException {
+                assertFalse(data.has("curbsides"));
+                assertTrue(data.has("points"));
+                counter.incrementAndGet();
+                return "";
+            }
+        });
+        GHMRequest req = new GHMRequest();
+        req.addPoint(new GHPoint(49.6724, 11.3494));
+        req.addPoint(new GHPoint(49.6550, 11.4180));
+        try {
+            ghMatrix.route(req);
+        } catch (Exception ex) {
+        }
+        assertEquals(1, counter.get());
+    }
+
     @Test
     public void testUnknownInstructionSign() throws IOException {
         // Actual path for the request: point=48.354413%2C8.676335&point=48.35442%2C8.676345