add sortkey support in QueryRequest

- required for paging with Gerrit < 2.9

Author: uwolfer

src/main/java/com/google/gerrit/extensions/api/changes/Changes.java

@@ -67,6 +67,7 @@ public abstract class QueryRequest {
     private String query;
     private int limit;
     private int start;
+    private String sortkey; // server version < 2.9, needed for change list paging
     private EnumSet<ListChangesOption> options = EnumSet.noneOf(ListChangesOption.class);
 
     public abstract List<ChangeInfo> get() throws RestApiException;
@@ -86,6 +87,12 @@ public QueryRequest withStart(int start) {
       return this;
     }
 
+    // server version < 2.9, needed for change list paging
+    public QueryRequest withSortkey(String sortkey) {
+      this.sortkey = sortkey;
+      return this;
+    }
+
     public QueryRequest withOption(ListChangesOption options) {
       this.options.add(options);
       return this;
@@ -113,6 +120,11 @@ public int getStart() {
       return start;
     }
 
+    // server version < 2.9, needed for change list paging
+    public String getSortkey() {
+      return sortkey;
+    }
+
     public EnumSet<ListChangesOption> getOptions() {
       return options;
     }

src/main/java/com/urswolfer/gerrit/client/rest/http/changes/ChangesRestClient.java

@@ -81,6 +81,10 @@ private List<ChangeInfo> get(QueryRequest queryRequest) throws RestApiException
         if (queryRequest.getStart() > 0) {
             query = UrlUtils.appendToUrlQuery(query, "S=" + queryRequest.getStart());
         }
+        // server version < 2.9, needed for change list paging
+        if (!Strings.isNullOrEmpty(queryRequest.getSortkey())) {
+            query = UrlUtils.appendToUrlQuery(query, "N=" + queryRequest.getSortkey());
+        }
         for (ListChangesOption option : queryRequest.getOptions()) {
             query = UrlUtils.appendToUrlQuery(query, "o=" + option);
         }

src/test/java/com/urswolfer/gerrit/client/rest/http/changes/ChangesRestClientTest.java

@@ -70,6 +70,9 @@ public Iterator<ChangesQueryTestCase[]> getChangesQueryTestCases() {
                 queryParameter(
                         new TestQueryRequest().withStart(50)
                 ).expectUrl("/changes/?S=50"),
+                queryParameter(
+                        new TestQueryRequest().withSortkey("003460ab0001ae15")
+                ).expectUrl("/changes/?N=003460ab0001ae15"),
                 queryParameter(
                         new TestQueryRequest().withQuery("is:open")
                                 .withLimit(10)
@@ -195,6 +198,7 @@ private static final class TestQueryRequest {
         private String query = null;
         private Integer limit = null;
         private Integer start = null;
+        private String sortkey = null;
         private EnumSet<ListChangesOption> options = EnumSet.noneOf(ListChangesOption.class);
 
         public TestQueryRequest withQuery(String query) {
@@ -212,6 +216,11 @@ public TestQueryRequest withStart(int start) {
             return this;
         }
 
+        public TestQueryRequest withSortkey(String sortkey) {
+            this.sortkey = sortkey;
+            return this;
+        }
+
         public TestQueryRequest withOption(ListChangesOption options) {
             this.options.add(options);
             return this;
@@ -227,6 +236,9 @@ public Changes.QueryRequest apply(Changes.QueryRequest queryRequest) {
             if (start != null) {
                 queryRequest.withStart(start);
             }
+            if (sortkey != null) {
+                queryRequest.withSortkey(sortkey);
+            }
             if (!options.isEmpty()) {
                 queryRequest.withOptions(options);
             }