added generic filter support

account/src/main/java/de/muehlencord/shared/account/business/AbstractController.java

@@ -22,6 +22,8 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Date;
 import java.util.List;
+import java.util.Locale;
+import java.util.Map;
 import javax.ejb.Lock;
 import javax.ejb.LockType;
 import javax.ejb.TransactionAttribute;
@@ -32,11 +34,14 @@ import javax.persistence.TypedQuery;
 import javax.persistence.criteria.CriteriaBuilder;
 import javax.persistence.criteria.CriteriaQuery;
 import javax.persistence.criteria.Order;
+import javax.persistence.criteria.Path;
+import javax.persistence.criteria.Predicate;
 import javax.persistence.criteria.Root;
 import javax.persistence.metamodel.IdentifiableType;
 import javax.persistence.metamodel.Metamodel;
 import javax.persistence.metamodel.SingularAttribute;
 import javax.transaction.Transactional;
+import org.apache.shiro.util.StringUtils;
 
 /**
  *
@@ -58,6 +63,130 @@ public abstract class AbstractController<T> {
         this.entityClass = clazz;
     }
 
+    protected Predicate getFilterCondition(CriteriaBuilder cb, Root<T> root, Map<String, Object> filters) {
+        return getFilterCondition(cb, root, filters, null);
+    }
+
+    protected Predicate getFilterCondition(CriteriaBuilder cb, Root<T> root, Map<String, Object> filters, Map<String, Object> excludeFilters) {
+        Predicate filterCondition = null;
+        filterCondition = getFilterCondition(filterCondition, cb, root, filters, true);
+        filterCondition = getFilterCondition(filterCondition, cb, root, excludeFilters, false);
+        return filterCondition;
+    }
+
+    protected Predicate addFilterCondition(CriteriaBuilder cb, Predicate filterCondition, Predicate addCondition) {
+        if (addCondition == null) {
+            return filterCondition;
+        }
+        if (filterCondition == null) {
+            filterCondition = addCondition;
+        } else {
+            filterCondition = cb.and(filterCondition, addCondition);
+        }
+        return filterCondition;
+    }
+
+    /**
+     * extends the given filterCondition by the addtional filters
+     *
+     * @param filterCondition the current filter condition
+     * @param cb the criteria builder to use
+     * @param root the root of the object to search for
+     * @param filters the filters to apply
+     * @param include if set to true, the filter is used as include filter
+     * (equals, in). If set to false, the filter is inverted and used as exclude
+     * filter (not equals, not in etc)
+     * @return
+     */
+    protected Predicate getFilterCondition(Predicate filterCondition, CriteriaBuilder cb, Root<T> root, Map<String, Object> filters, boolean include) {
+        String wildCard = "%";
+        if (filters != null) {
+            for (Map.Entry<String, Object> filter : filters.entrySet()) {
+                if (!"".equals(filter.getValue())) {
+                    Path<String> path = getPathElement(root, filter);
+
+                    // check for differnt types 
+                    // 1st String, either from Enum Status or from other free text string
+                    if (String.class.equals(filter.getValue().getClass())) {
+                        switch (filter.getKey()) {
+                            default:
+                                String filterValue = filter.getValue().toString();
+                                Predicate predicate;
+                                if (filterValue.equals("{NULL}")) {
+                                    if (include) {
+                                        predicate = cb.isNull(path);
+                                    } else {
+                                        predicate = cb.isNotNull(path);
+                                    }
+                                } else {
+                                    filterValue = filterValue.trim();
+                                    filterValue = filterValue.replace("?", "_");
+                                    filterValue = filterValue.replace("*", "%");
+
+                                    String[] values = filterValue.split("\\s+"); // split by whitespaces
+                                    Predicate[] partSearchPredicates = new Predicate[values.length];
+                                    for (int i = 0; i < values.length; i++) {
+                                        String value = wildCard + values[i] + wildCard;
+                                        if (include) {
+                                            partSearchPredicates[i] = cb.like(cb.upper(path), value.toUpperCase(Locale.US), '\\');
+                                        } else {
+                                            partSearchPredicates[i] = cb.notLike(cb.upper(path), value.toUpperCase(Locale.US), '\\');
+                                        }
+                                    }
+                                    predicate = cb.and(partSearchPredicates); // all parts must be available
+                                }
+                                filterCondition = addFilterCondition(cb, filterCondition, predicate);
+                        }
+                    } // 2nd for arrays, received from e.g. project selections
+                    else if (filter.getValue().getClass().isArray()) {
+                        Predicate condition = null;
+                        Object[] values = (Object[]) filter.getValue();
+                        if (values.length > 0) {
+                            for (Object value : values) {
+                                if (include) {
+                                    Predicate equalPredicate = cb.equal(path, value);
+                                    if (condition == null) {
+                                        condition = equalPredicate;
+                                    } else {
+                                        condition = cb.or(condition, equalPredicate);
+                                    }
+                                } else {
+                                    Predicate equalPredicate = cb.notEqual(path, value);
+                                    if (condition == null) {
+                                        condition = equalPredicate;
+                                    } else {
+                                        condition = cb.and(condition, equalPredicate);
+                                    }
+                                }
+                            }
+                            filterCondition = addFilterCondition(cb, filterCondition, condition);
+                        }
+                    } else { // at last object comparison
+                        if (include) {
+                            filterCondition = addFilterCondition(cb, filterCondition, cb.equal(path, filter.getValue()));
+                        } else {
+                            filterCondition = addFilterCondition(cb, filterCondition, cb.notEqual(path, filter.getValue()));
+                        }
+                    }
+                }
+            }
+        }
+        return filterCondition;
+    }
+
+    private Path<String> getPathElement(Root<T> root, Map.Entry<String, Object> filter) {
+        String[] pathElements = StringUtils.split(filter.getKey(), '.');
+        Path<String> path = null;
+        for (String element : pathElements) {
+            if (path == null) {
+                path = root.get(element);
+            } else {
+                path = path.get(element);
+            }
+        }
+        return path;
+    }
+
     public void applyUpdateableChanges(Updateable updateable, boolean onCreate) throws ControllerException {
         if (onCreate) {
             updateable.setCreatedBy(account.getUsername());
@@ -130,6 +259,23 @@ public abstract class AbstractController<T> {
         return query.getResultList();
     }
 
+    @Lock(LockType.READ)
+    public List<T> find(Map<String, Object> filters, List<String> orderFields) {
+        final CriteriaBuilder cb = em.getCriteriaBuilder();
+        final CriteriaQuery<T> criteria = cb.createQuery(entityClass);
+
+        final Root<T> r = criteria.from(entityClass);
+        Predicate filterCondition = getFilterCondition(cb, r, filters);
+        if (filterCondition != null) {
+            criteria.where(filterCondition);
+        }
+        List<Order> orderList = new ArrayList<>();
+        orderFields.stream().forEachOrdered(field -> orderList.add(cb.asc(r.get(field))));
+        final TypedQuery<T> query = em.createQuery(criteria.orderBy(orderList));
+
+        return query.getResultList();
+    }
+
     /**
      * returns null, if the list is empty or null itself. Returns the one
      * element if there is exactly one element in the list. Otherwise an