Add convenience constructors

vaadin-spring/src/main/java/com/vaadin/flow/spring/data/filter/AndFilter.java

@@ -9,8 +9,26 @@
  * filters and verifying that all of them pass.
  */
 public class AndFilter extends Filter {
+
     private List<Filter> children;
 
+    /**
+     * Create an empty filter.
+     */
+    public AndFilter() {
+        // Empty constructor is needed for serialization
+    }
+
+    /**
+     * Create a filter with the given children.
+     * 
+     * @param children
+     *            the children of the filter
+     */
+    public AndFilter(Filter... children) {
+        setChildren(List.of(children));
+    }
+
     public List<Filter> getChildren() {
         return children;
     }
@@ -21,7 +39,7 @@ public void setChildren(List<Filter> children) {
 
     @Override
     public String toString() {
-        return "AndFilter [children=" + children + "]";
+        return getClass().getSimpleName()+" [children=" + children + "]";
     }
 
 }

vaadin-spring/src/main/java/com/vaadin/flow/spring/data/filter/OrFilter.java

@@ -12,6 +12,23 @@ public class OrFilter extends Filter {
 
     private List<Filter> children;
 
+    /**
+     * Create an empty filter.
+     */
+    public OrFilter() {
+        // Empty constructor is needed for serialization
+    }
+
+    /**
+     * Create a filter with the given children.
+     * 
+     * @param children
+     *            the children of the filter
+     */
+    public OrFilter(Filter... children) {
+        setChildren(List.of(children));
+    }
+
     public List<Filter> getChildren() {
         return children;
     }
@@ -22,7 +39,7 @@ public void setChildren(List<Filter> children) {
 
     @Override
     public String toString() {
-        return "OrFilter [children=" + children + "]";
+        return getClass().getSimpleName() + " [children=" + children + "]";
     }
 
 }

vaadin-spring/src/main/java/com/vaadin/flow/spring/data/filter/PropertyStringFilter.java

@@ -24,6 +24,32 @@ public enum Matcher {
     private String filterValue;
     private Matcher matcher;
 
+    /**
+     * Create an empty filter.
+     */
+    public PropertyStringFilter() {
+        // Empty constructor is needed for serialization
+    }
+
+    /**
+     * Create a filter with the given property, matcher and filter value.
+     * 
+     * @param propertyId
+     *            the property id, or a nested property path where each
+     *            property is separated by a dot
+     * @param matcher
+     *            the matcher to use when comparing the property value to the
+     *            filter value
+     * @param filterValue
+     *            the filter value to compare against
+     */
+    public PropertyStringFilter(String propertyId, Matcher matcher,
+            String filterValue) {
+        this.propertyId = propertyId;
+        this.matcher = matcher;
+        this.filterValue = filterValue;
+    }
+
     /**
      * Gets the property, or nested property path, to filter by. For example
      * {@code "name"} or {@code "address.city"}.
@@ -91,8 +117,8 @@ public void setMatcher(Matcher type) {
 
     @Override
     public String toString() {
-        return "PropertyStringFilter [propertyId=" + propertyId + ", matcher="
-                + matcher + ", filterValue=" + filterValue + "]";
+        return getClass().getSimpleName() + " [propertyId=" + propertyId
+                + ", matcher=" + matcher + ", filterValue=" + filterValue + "]";
     }
 
 }