Make the page number to be 1 when the value equal to 0.

apm-collector/apm-collector-ui/collector-ui-jetty-provider/src/main/java/org/apache/skywalking/apm/collector/ui/utils/PaginationUtils.java

@@ -28,7 +28,7 @@ public enum PaginationUtils {
 
     public Page exchange(Pagination paging) {
         int limit = paging.getPageSize();
-        int from = paging.getPageSize() * (paging.getPageNum() - 1);
+        int from = paging.getPageSize() * ((paging.getPageNum() == 0 ? 1 : paging.getPageNum()) - 1);
 
         return new Page(from, limit);
     }

apm-collector/apm-collector-ui/collector-ui-jetty-provider/src/test/java/org/apache/skywalking/apm/collector/ui/utils/PaginationUtilsTestCase.java

@@ -37,6 +37,13 @@ public class PaginationUtilsTestCase {
         Assert.assertEquals(0, page.getFrom());
         Assert.assertEquals(10, page.getLimit());
 
+        pagination = new Pagination();
+        pagination.setPageSize(10);
+
+        page = PaginationUtils.INSTANCE.exchange(pagination);
+        Assert.assertEquals(0, page.getFrom());
+        Assert.assertEquals(10, page.getLimit());
+
         pagination = new Pagination();
         pagination.setPageSize(10);
         pagination.setPageNum(2);