java: Fix findbugs errors on generated code.

mojo/public/tools/bindings/generators/java_templates/struct_definition.tmpl

 {% from "constant_definition.tmpl" import constant_def %}
 {% from "enum_definition.tmpl" import enum_def %}
 
 {%- macro inequality(kind, v1, v2) -%}
 {%-   if kind|is_reference_kind -%}
 {%-     if kind|is_array_kind -%}
 {%-       if kind.kind|is_reference_kind -%}
 !java.util.Arrays.deepEquals({{v1}}, {{v2}})
 {%-       else -%}
 !java.util.Arrays.equals({{v1}}, {{v2}})
@@ skipping 169 matching lines @@
      * @see Object#equals(Object)
      */
     @Override
     public boolean equals(Object object) {
         if (object == this)
             return true;
         if (object == null)
             return false;
         if (getClass() != object.getClass())
             return false;
+{% if struct.fields|length %}
         {{struct|name}} other = ({{struct|name}}) object;
-{% for field in struct.fields %}
+{%   for field in struct.fields %}
         if ({{inequality(field.kind, field|name, 'other.'~field|name)}})
             return false;
-{% endfor %}
+{%   endfor %}
+{% endif %}
         return true;
     }
 
     /**
      * @see Object#hashCode()
      */
     @Override
     public int hashCode() {
         final int prime = 31;
-        int result = 1;
+        int result = prime + getClass().hashCode();
 {% for field in struct.fields %}
         result = prime * result + {{hash(field.kind, field|name)}};
 {% endfor %}
         return result;
     }
 }
 {% endmacro %}