Java tutorial
package com.fasterxml.jackson.databind.ser.impl; import java.util.*; import com.fasterxml.jackson.core.JsonGenerator; import com.fasterxml.jackson.databind.*; import com.fasterxml.jackson.databind.node.ObjectNode; import com.fasterxml.jackson.databind.jsonFormatVisitors.JsonObjectFormatVisitor; import com.fasterxml.jackson.databind.ser.*; /** * Simple {@link PropertyFilter} implementation that only uses property name * to determine whether to serialize property as is, or to filter it out. *<p> * Use of this class as the base implementation for any custom * {@link PropertyFilter} implementations is strongly encouraged, * because it can provide default implementation for any methods that may * be added in {@link PropertyFilter} (as unfortunate as additions may be). */ public abstract class SimpleBeanPropertyFilter implements BeanPropertyFilter, PropertyFilter // sub-classes must also implement java.io.Serializable { /* /********************************************************** /* Life-cycle /********************************************************** */ protected SimpleBeanPropertyFilter() { } /** * Factory method to construct filter that filters out all properties <b>except</b> * ones includes in set */ public static SimpleBeanPropertyFilter filterOutAllExcept(Set<String> properties) { return new FilterExceptFilter(properties); } public static SimpleBeanPropertyFilter filterOutAllExcept(String... propertyArray) { HashSet<String> properties = new HashSet<String>(propertyArray.length); Collections.addAll(properties, propertyArray); return new FilterExceptFilter(properties); } public static SimpleBeanPropertyFilter serializeAllExcept(Set<String> properties) { return new SerializeExceptFilter(properties); } public static SimpleBeanPropertyFilter serializeAllExcept(String... propertyArray) { HashSet<String> properties = new HashSet<String>(propertyArray.length); Collections.addAll(properties, propertyArray); return new SerializeExceptFilter(properties); } /** * Helper method to ease transition from {@link BeanPropertyWriter} into * {@link PropertyWriter} * * @since 2.3 */ @SuppressWarnings("deprecation") public static PropertyFilter from(final BeanPropertyFilter src) { return new PropertyFilter() { @Override public void serializeAsField(Object pojo, JsonGenerator jgen, SerializerProvider prov, PropertyWriter writer) throws Exception { src.serializeAsField(pojo, jgen, prov, (BeanPropertyWriter) writer); } @Override public void depositSchemaProperty(PropertyWriter writer, ObjectNode propertiesNode, SerializerProvider provider) throws JsonMappingException { src.depositSchemaProperty((BeanPropertyWriter) writer, propertiesNode, provider); } @Override public void depositSchemaProperty(PropertyWriter writer, JsonObjectFormatVisitor objectVisitor, SerializerProvider provider) throws JsonMappingException { src.depositSchemaProperty((BeanPropertyWriter) writer, objectVisitor, provider); } @Override public void serializeAsElement(Object elementValue, JsonGenerator jgen, SerializerProvider prov, PropertyWriter writer) throws Exception { // not needed; element filtering only available through new interfaces throw new UnsupportedOperationException(); } }; } /* /********************************************************** /* Methods for sub-classes /********************************************************** */ /** * Method called to determine whether property will be included * (if 'true' returned) or filtered out (if 'false' returned) */ protected abstract boolean include(BeanPropertyWriter writer); /** * @since 2.3 */ protected abstract boolean include(PropertyWriter writer); /** * Method that defines what to do with container elements; * default implementation simply writes them out. * * @since 2.3 */ protected boolean includeElement(Object elementValue) { return true; } /* /********************************************************** /* BeanPropertyFilter (deprecated) implementation /********************************************************** */ @Deprecated @Override public void serializeAsField(Object bean, JsonGenerator jgen, SerializerProvider provider, BeanPropertyWriter writer) throws Exception { if (include(writer)) { writer.serializeAsField(bean, jgen, provider); } else if (!jgen.canOmitFields()) { // since 2.3 writer.serializeAsOmittedField(bean, jgen, provider); } } @Deprecated @Override public void depositSchemaProperty(BeanPropertyWriter writer, ObjectNode propertiesNode, SerializerProvider provider) throws JsonMappingException { if (include(writer)) { writer.depositSchemaProperty(propertiesNode, provider); } } @Deprecated @Override public void depositSchemaProperty(BeanPropertyWriter writer, JsonObjectFormatVisitor objectVisitor, SerializerProvider provider) throws JsonMappingException { if (include(writer)) { writer.depositSchemaProperty(objectVisitor); } } /* /********************************************************** /* PropertyFilter implementation /********************************************************** */ @Override public void serializeAsField(Object pojo, JsonGenerator jgen, SerializerProvider provider, PropertyWriter writer) throws Exception { if (include(writer)) { writer.serializeAsField(pojo, jgen, provider); } else if (!jgen.canOmitFields()) { // since 2.3 writer.serializeAsOmittedField(pojo, jgen, provider); } } @Override public void serializeAsElement(Object elementValue, JsonGenerator jgen, SerializerProvider provider, PropertyWriter writer) throws Exception { if (includeElement(elementValue)) { writer.serializeAsElement(elementValue, jgen, provider); } } @Deprecated @Override public void depositSchemaProperty(PropertyWriter writer, ObjectNode propertiesNode, SerializerProvider provider) throws JsonMappingException { if (include(writer)) { writer.depositSchemaProperty(propertiesNode, provider); } } @Override public void depositSchemaProperty(PropertyWriter writer, JsonObjectFormatVisitor objectVisitor, SerializerProvider provider) throws JsonMappingException { if (include(writer)) { writer.depositSchemaProperty(objectVisitor); } } /* /********************************************************** /* Sub-classes /********************************************************** */ /** * Filter implementation which defaults to filtering out unknown * properties and only serializes ones explicitly listed. */ public static class FilterExceptFilter extends SimpleBeanPropertyFilter implements java.io.Serializable { private static final long serialVersionUID = 1L; /** * Set of property names to serialize. */ protected final Set<String> _propertiesToInclude; public FilterExceptFilter(Set<String> properties) { _propertiesToInclude = properties; } @Override protected boolean include(BeanPropertyWriter writer) { return _propertiesToInclude.contains(writer.getName()); } @Override protected boolean include(PropertyWriter writer) { return _propertiesToInclude.contains(writer.getName()); } } /** * Filter implementation which defaults to serializing all * properties, except for ones explicitly listed to be filtered out. */ public static class SerializeExceptFilter extends SimpleBeanPropertyFilter implements java.io.Serializable { private static final long serialVersionUID = 1L; /** * Set of property names to filter out. */ protected final Set<String> _propertiesToExclude; public SerializeExceptFilter(Set<String> properties) { _propertiesToExclude = properties; } @Override protected boolean include(BeanPropertyWriter writer) { return !_propertiesToExclude.contains(writer.getName()); } @Override protected boolean include(PropertyWriter writer) { return !_propertiesToExclude.contains(writer.getName()); } } }