How to use

findOrCreateOverride

method

in

com.fasterxml.jackson.databind.cfg.ConfigOverrides

/**
 * Accessor for getting a mutable configuration override object for
 * given type, needed to add or change per-type overrides applied
 * to properties of given type.
 * Usage is through returned object by colling "setter" methods, which
 * directly modify override object and take effect directly.
 * For example you can do
 *<pre>
 *   mapper.configOverride(java.util.Date.class)
 *       .setFormat(JsonFormat.Value.forPattern("yyyy-MM-dd"));
 *<pre>
 * to change the default format to use for properties of type
 * {@link java.util.Date} (possibly further overridden by per-property
 * annotations)
 *
 * @since 2.8
 */
public MutableConfigOverride configOverride(Class<?> type) {
  return _configOverrides.findOrCreateOverride(type);
}

/**
 * Accessor for getting a mutable configuration override object for
 * given type, needed to add or change per-type overrides applied
 * to properties of given type.
 * Usage is through returned object by colling "setter" methods, which
 * directly modify override object and take effect directly.
 * For example you can do
 *<pre>
 *   mapper.configOverride(java.util.Date.class)
 *       .setFormat(JsonFormat.Value.forPattern("yyyy-MM-dd"));
 *<pre>
 * to change the default format to use for properties of type
 * {@link java.util.Date} (possibly further overridden by per-property
 * annotations)
 *
 * @since 2.8
 */
public MutableConfigOverride configOverride(Class<?> type) {
  return _configOverrides.findOrCreateOverride(type);
}

/**
 * Accessor for getting a mutable configuration override object for
 * given type, needed to add or change per-type overrides applied
 * to properties of given type.
 * Usage is through returned object by colling "setter" methods, which
 * directly modify override object and take effect directly.
 * For example you can do
 *<pre>
 *   mapper.configOverride(java.util.Date.class)
 *       .setFormat(JsonFormat.Value.forPattern("yyyy-MM-dd"));
 *<pre>
 * to change the default format to use for properties of type
 * {@link java.util.Date} (possibly further overridden by per-property
 * annotations)
 *
 * @since 2.8
 */
public MutableConfigOverride configOverride(Class<?> type) {
  return _propertyOverrides.findOrCreateOverride(type);
}

public Builder(XmlFactory f) {
  super(f);
  // 21-Jun-2017, tatu: Seems like there are many cases in XML where ability to coerce empty
  //    String into `null` (where it otherwise is an error) is very useful.
  enable(DeserializationFeature.ACCEPT_EMPTY_STRING_AS_NULL_OBJECT);
  _defaultUseWrapper = JacksonXmlAnnotationIntrospector.DEFAULT_USE_WRAPPER;
  _nameForTextElement = FromXmlParser.DEFAULT_UNNAMED_TEXT_PROPERTY;
  // as well as AnnotationIntrospector: note, however, that "use wrapper" may well
  // change later on
  annotationIntrospector(new JacksonXmlAnnotationIntrospector(_defaultUseWrapper));
  // Need to mangle Type Ids (to avoid invalid XML Name characters); one way is this:
  typeResolverProvider(new XmlTypeResolverProvider());
  // Some changes easiest to apply via Module
  addModule(new XmlModule());
  // 04-May-2018, tatu: Important! Let's also default `String` `null` handling to coerce
  //   to empty string -- this lets us induce `null` from empty tags first
  _configOverrides.findOrCreateOverride(String.class)
    .setNullHandling(JsonSetter.Value.forValueNulls(Nulls.AS_EMPTY));
}