request pagination

src/main/java/org/traccar/api/resource/UserResource.java

@@ -18,6 +18,7 @@
 import com.warrenstrange.googleauth.GoogleAuthenticator;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.ws.rs.DELETE;
+import jakarta.ws.rs.DefaultValue;
 import jakarta.ws.rs.PathParam;
 import jakarta.ws.rs.core.Context;
 import org.traccar.api.BaseObjectResource;
@@ -31,6 +32,7 @@
 import org.traccar.storage.StorageException;
 import org.traccar.storage.query.Columns;
 import org.traccar.storage.query.Condition;
+import org.traccar.storage.query.Pagination;
 import org.traccar.storage.query.Request;
 
 import jakarta.annotation.security.PermitAll;
@@ -61,18 +63,22 @@ public UserResource() {
     }
 
     @GET
-    public Collection<User> get(@QueryParam("userId") long userId) throws StorageException {
+    public Collection<User> get(@QueryParam("userId") long userId, @QueryParam("skip") @DefaultValue("0") int skip, @QueryParam("limit") @DefaultValue("0") int limit) throws StorageException {
         if (userId > 0) {
             permissionsService.checkUser(getUserId(), userId);
             return storage.getObjects(baseClass, new Request(
                     new Columns.All(),
-                    new Condition.Permission(User.class, userId, ManagedUser.class).excludeGroups()));
+                    new Condition.Permission(User.class, userId, ManagedUser.class).excludeGroups(),
+                    null,
+                    new Pagination(skip, limit)));
         } else if (permissionsService.notAdmin(getUserId())) {
             return storage.getObjects(baseClass, new Request(
                     new Columns.All(),
                     new Condition.Permission(User.class, getUserId(), ManagedUser.class).excludeGroups()));
         } else {
-            return storage.getObjects(baseClass, new Request(new Columns.All()));
+            return storage.getObjects(baseClass, new Request(
+            		new Columns.All(),
+                    new Pagination(skip, limit)));
         }
     }
 

src/main/java/org/traccar/database/CommandsManager.java

@@ -33,6 +33,7 @@
 import org.traccar.storage.query.Columns;
 import org.traccar.storage.query.Condition;
 import org.traccar.storage.query.Order;
+import org.traccar.storage.query.Pagination;
 import org.traccar.storage.query.Request;
 
 import jakarta.annotation.Nullable;
@@ -108,7 +109,8 @@ public Collection<Command> readQueuedCommands(long deviceId, int count) {
             var commands = storage.getObjects(QueuedCommand.class, new Request(
                     new Columns.All(),
                     new Condition.Equals("deviceId", deviceId),
-                    new Order("id", false, count)));
+                    new Order("id", false),
+                    new Pagination(0, count)));
             Map<Event, Position> events = new HashMap<>();
             for (var command : commands) {
                 storage.removeObject(QueuedCommand.class, new Request(

src/main/java/org/traccar/handler/FilterHandler.java

@@ -34,6 +34,7 @@
 import org.traccar.storage.query.Columns;
 import org.traccar.storage.query.Condition;
 import org.traccar.storage.query.Order;
+import org.traccar.storage.query.Pagination;
 import org.traccar.storage.query.Request;
 
 import jakarta.inject.Inject;
@@ -99,7 +100,8 @@ private Position getPrecedingPosition(long deviceId, Date date) throws StorageEx
                 new Condition.And(
                         new Condition.Equals("deviceId", deviceId),
                         new Condition.Compare("fixTime", "<=", "time", date)),
-                new Order("fixTime", true, 1)));
+                new Order("fixTime", true),
+                new Pagination(0, 1)));
     }
 
     private boolean filterInvalid(Position position) {

src/main/java/org/traccar/helper/model/UserUtil.java

@@ -23,6 +23,7 @@
 import org.traccar.storage.StorageException;
 import org.traccar.storage.query.Columns;
 import org.traccar.storage.query.Order;
+import org.traccar.storage.query.Pagination;
 import org.traccar.storage.query.Request;
 
 import java.util.Date;
@@ -36,7 +37,8 @@ private UserUtil() {
     public static boolean isEmpty(Storage storage) throws StorageException {
         return storage.getObjects(User.class, new Request(
                 new Columns.Include("id"),
-                new Order("id", false, 1))).isEmpty();
+                new Order("id", false),
+                new Pagination(0, 1))).isEmpty();
     }
 
     public static String getDistanceUnit(Server server, User user) {

src/main/java/org/traccar/reports/SummaryReportProvider.java

@@ -33,6 +33,7 @@
 import org.traccar.storage.query.Columns;
 import org.traccar.storage.query.Condition;
 import org.traccar.storage.query.Order;
+import org.traccar.storage.query.Pagination;
 import org.traccar.storage.query.Request;
 
 import jakarta.inject.Inject;
@@ -72,7 +73,8 @@ private Position getEdgePosition(long deviceId, Date from, Date to, boolean end)
                 new Condition.And(
                         new Condition.Equals("deviceId", deviceId),
                         new Condition.Between("fixTime", "from", from, "to", to)),
-                new Order("fixTime", end, 1)));
+                new Order("fixTime", end),
+                new Pagination(0, 1)));
     }
 
     private Collection<SummaryReportItem> calculateDeviceResult(

src/main/java/org/traccar/storage/DatabaseStorage.java

@@ -25,6 +25,7 @@
 import org.traccar.storage.query.Columns;
 import org.traccar.storage.query.Condition;
 import org.traccar.storage.query.Order;
+import org.traccar.storage.query.Pagination;
 import org.traccar.storage.query.Request;
 
 import jakarta.inject.Inject;
@@ -68,6 +69,7 @@ public <T> List<T> getObjects(Class<T> clazz, Request request) throws StorageExc
         query.append(" FROM ").append(getStorageName(clazz));
         query.append(formatCondition(request.getCondition()));
         query.append(formatOrder(request.getOrder()));
+        query.append(formatPagination(request.getPagination()));
         try {
             QueryBuilder builder = QueryBuilder.create(config, dataSource, objectMapper, query.toString());
             for (Map.Entry<String, Object> variable : getConditionVariables(request.getCondition()).entrySet()) {
@@ -307,14 +309,25 @@ private String formatOrder(Order order) {
             if (order.getDescending()) {
                 result.append(" DESC");
             }
-            if (order.getLimit() > 0) {
-                if (databaseType.equals("Microsoft SQL Server")) {
+        }
+        return result.toString();
+    }
+
+    private String formatPagination(Pagination pagination) {
+        StringBuilder result = new StringBuilder();
+        if (pagination != null) {
+        	if(pagination.getSkip() > 0) {
+        		result.append(" OFFSET ");
+                result.append(pagination.getSkip());
+        	}
+            if (pagination.getLimit() > 0) {
+            	if (databaseType.equals("Microsoft SQL Server")) {
                     result.append(" OFFSET 0 ROWS FETCH FIRST ");
-                    result.append(order.getLimit());
+                    result.append(pagination.getLimit());
                     result.append(" ROWS ONLY");
                 } else {
                     result.append(" LIMIT ");
-                    result.append(order.getLimit());
+                    result.append(pagination.getLimit());
                 }
             }
         }

src/main/java/org/traccar/storage/query/Order.java

@@ -19,18 +19,16 @@ public class Order {
 
     private final String column;
     private final boolean descending;
-    private final int limit;
 
     public Order(String column) {
-        this(column, false, 0);
+        this(column, false);
     }
 
-    public Order(String column, boolean descending, int limit) {
+    public Order(String column, boolean descending) {
         this.column = column;
         this.descending = descending;
-        this.limit = limit;
     }
-
+        
     public String getColumn() {
         return column;
     }
@@ -39,8 +37,4 @@ public boolean getDescending() {
         return descending;
     }
 
-    public int getLimit() {
-        return limit;
-    }
-
 }

src/main/java/org/traccar/storage/query/Pagination.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2022 Anton Tananaev (anton@traccar.org)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.traccar.storage.query;
+
+public class Pagination {
+
+    private final int limit;
+    private final int skip;
+
+    public Pagination(int skip, int limit) {
+        this.skip = skip;
+        this.limit = limit;
+    }
+
+    public int getSkip() {
+        return skip;
+    }
+
+    public int getLimit() {
+        return limit;
+    }
+
+}

src/main/java/org/traccar/storage/query/Request.java

@@ -20,27 +20,37 @@ public class Request {
     private final Columns columns;
     private final Condition condition;
     private final Order order;
+    private final Pagination pagination;
 
     public Request(Columns columns) {
-        this(columns, null, null);
+        this(columns, null, null, null);
     }
 
     public Request(Condition condition) {
-        this(null, condition, null);
+        this(null, condition, null, null);
     }
 
     public Request(Columns columns, Condition condition) {
-        this(columns, condition, null);
+        this(columns, condition, null, null);
     }
 
     public Request(Columns columns, Order order) {
-        this(columns, null, order);
+        this(columns, null, order, null);
+    }
+
+    public Request(Columns columns, Pagination pagination) {
+        this(columns, null, null, pagination);
+    }
+
+    public Request(Columns columns, Order order, Pagination pagination) {
+        this(columns, null, order, pagination);
     }
 
-    public Request(Columns columns, Condition condition, Order order) {
+    public Request(Columns columns, Condition condition, Order order, Pagination pagination) {
         this.columns = columns;
         this.condition = condition;
         this.order = order;
+        this.pagination = pagination;
     }
 
     public Columns getColumns() {
@@ -54,5 +64,9 @@ public Condition getCondition() {
     public Order getOrder() {
         return order;
     }
+
+    public Pagination getPagination() {
+    	return pagination;
+    }
 
 }