Initial commit (#302).

src/main/java/org/gitlab4j/api/models/GroupFilter.java

+package org.gitlab4j.api.models;
+
+import java.util.List;
+
+import org.gitlab4j.api.Constants.GroupOrderBy;
+import org.gitlab4j.api.Constants.SortOrder;
+import org.gitlab4j.api.GitLabApiForm;
+
+/**
+ *  This class is used to filter Projects when getting lists of projects for a specified group.
+ */
+public class GroupFilter {
+
+    private List<Integer> skipGroups;
+    private Boolean allAvailable;
+    private String search;
+    private GroupOrderBy orderBy;
+    private SortOrder sort;
+    private Boolean statistics;
+    private Boolean withCustomAttributes;
+    private Boolean owned;
+    private AccessLevel accessLevel;
+
+    /**
+     * Do not include the provided groups IDs.
+     *
+     * @param skipGroups List of group IDs to not include in the search
+     * @return the reference to this GroupFilter instance
+     */
+    public GroupFilter withSkipGroups(List<Integer> skipGroups) {
+        this.skipGroups = skipGroups;
+        return (this);  
+    }
+
+    /**
+     * Show all the groups you have access to (defaults to false for authenticated users, true for admin).
+     * Attributes owned and min_access_level have precedence
+     *
+     * @param allAvailable if true show all avauilable groups
+     * @return the reference to this GroupFilter instance
+     */
+    public GroupFilter withAllAvailabley(Boolean allAvailable) {
+        this.allAvailable = allAvailable;
+        return (this);       
+    }
+
+    /**
+     * Return list of groups matching the search criteria.
+     *
+     * @param search the search criteria
+     * @return the reference to this GroupFilter instance
+     */
+    public GroupFilter withSearch(String search) {
+        this.search = search;
+        return (this);
+    }
+
+    /**
+     * Return groups ordered by id, name, path, created_at, updated_at, or last_activity_at fields. Default is created_at.
+     *
+     * @param orderBy specifies what field to order by
+     * @return the reference to this GroupFilter instance
+     */
+    public GroupFilter withOrderBy(GroupOrderBy orderBy) {
+        this.orderBy = orderBy;
+        return (this);
+    }
+
+    /**
+     * Return groups sorted in asc or desc order. Default is desc.
+     *
+     * @param sort sort direction, ASC or DESC
+     * @return the reference to this GroupFilter instance
+     */
+    public GroupFilter withSortOder(SortOrder sort) {
+        this.sort = sort;
+        return (this);
+    }
+
+    /**
+     * Include group statistics (admins only).
+     *
+     * @param statistics if true, return statistics with the results
+     * @return the reference to this GroupFilter instance
+     */
+    public GroupFilter withStatistics(Boolean statistics) {
+        this.statistics = statistics;
+        return (this);
+    }
+
+    /**
+     *  Include custom attributes in response (admins only).
+     * 
+     * @param withCustomAttributes if true, include custom attributes in the response
+     * @return the reference to this GroupFilter instance
+     */
+    public GroupFilter withCustomAttributes(Boolean withCustomAttributes) {
+        this.withCustomAttributes = withCustomAttributes;
+        return (this);
+    }
+
+    /**
+     * Limit by groups explicitly owned by the current user
+     *
+     * @param owned if true, limit to groups explicitly owned by the current user
+     * @return the reference to this GroupFilter instance
+     */
+    public GroupFilter withOwned(Boolean owned) {
+        this.owned = owned;
+        return (this);
+    }
+
+    /**
+     * Limit to groups where current user has at least this access level.
+     *
+     * @param accessLevel limit to groups where current user has at least this access level
+     * @return the reference to this GroupFilter instance
+     */
+    public GroupFilter withMinAccessLevel(AccessLevel accessLevel) {
+        this.accessLevel = accessLevel;
+        return (this);
+    }
+
+    /**
+     * Get the query params specified by this filter.
+     *
+     * @return a GitLabApiForm instance holding the query parameters for this GroupFilter instance
+     */
+    public GitLabApiForm getQueryParams() {
+        return (new GitLabApiForm()
+            .withParam("skip_groups", skipGroups)
+            .withParam("all_available", allAvailable)
+            .withParam("search", search)
+            .withParam("order_by", orderBy)
+            .withParam("sort", sort)
+            .withParam("statistics", statistics)
+            .withParam("with_custom_attributes", withCustomAttributes)
+            .withParam("owned", owned)  
+            .withParam("min_access_level ", accessLevel)
+        );
+    }
+}