Uploaded image for project: 'Forge'
  1. Forge
  2. FORGE-481

JavaParser.parse gets confused on inner classes

XMLWordPrintable

    • Icon: Bug Bug
    • Resolution: Done
    • Icon: Major Major
    • 1.0.2.Final
    • None
    • None
    • None

      While developing the AeroGear scaffold, I discovered that if I do...

               // Generate ObjectMapperProviderTemplate.jv
               JavaClass objectMapperProvider = JavaParser.parse(JavaClass.class,
                        this.objectMapperProviderTemplate.render(context));
               objectMapperProvider.setPackage(serviceBean.getPackage());
               result.add(ScaffoldUtil.createOrOverwrite(this.prompt, java.getJavaResource(objectMapperProvider),
                        objectMapperProvider.toString(),
                        true));
      

      ...with a ObjectMapperProviderTemplate.jv of...

      import java.io.IOException;
      import java.lang.reflect.Method;
      
      import javax.persistence.Entity;
      import javax.persistence.EntityManager;
      import javax.persistence.PersistenceContext;
      import javax.ws.rs.ext.ContextResolver;
      import javax.ws.rs.ext.Provider;
      
      import org.codehaus.jackson.JsonGenerator;
      import org.codehaus.jackson.JsonParser;
      import org.codehaus.jackson.JsonProcessingException;
      import org.codehaus.jackson.map.DeserializationConfig;
      import org.codehaus.jackson.map.DeserializationContext;
      import org.codehaus.jackson.map.JsonSerializer;
      import org.codehaus.jackson.map.ObjectMapper;
      import org.codehaus.jackson.map.SerializationConfig;
      import org.codehaus.jackson.map.SerializerProvider;
      import org.codehaus.jackson.map.deser.BeanDeserializer;
      import org.codehaus.jackson.map.deser.CustomDeserializerFactory;
      import org.codehaus.jackson.map.deser.StdDeserializerProvider;
      import org.codehaus.jackson.map.introspect.BasicBeanDescription;
      import org.codehaus.jackson.map.ser.BeanSerializer;
      import org.codehaus.jackson.map.ser.CustomSerializerFactory;
      import org.codehaus.jackson.type.JavaType;
      
      /**
       * Custom JSON ObjectMapper that knows how to lookup JPA entities based on ids.
       */
      
      @Provider
      public class ObjectMapperProvider implements ContextResolver<ObjectMapper> {
      	private final ObjectMapper mapper;
      
      	@PersistenceContext
      	private EntityManager entityManager;
      
      	public ObjectMapperProvider() {
      
      		this.mapper = new ObjectMapper();
      
      		// Serialize
      
      		CustomSerializerFactory serializer = new CustomSerializerFactory() {
      
      			@Override
      			protected JsonSerializer<Object> constructBeanSerializer(
      					SerializationConfig config, BasicBeanDescription beanDesc) {
      
      				BeanSerializer beanSerializer = (BeanSerializer) super
      						.constructBeanSerializer(config, beanDesc);
      				return new JpaSerializer(beanSerializer);
      			}
      		};
      		this.mapper.setSerializerFactory(serializer);
      
      		// Deserialize
      
      		this.mapper.setDeserializerProvider(new StdDeserializerProvider(
      				new CustomDeserializerFactory() {
      
      					protected BeanDeserializer constructBeanDeserializerInstance(
      							DeserializationConfig config, JavaType type,
      							BasicBeanDescription beanDesc) {
      
      						return new JpaDeserializer(type);
      					}
      				}));
      	}
      
      	@Override
      	public ObjectMapper getContext(Class<?> type) {
      		return this.mapper;
      	}
      
      	//
      	// Inner classes
      	//
      
      	private class JpaSerializer extends JsonSerializer<Object> {
      
      		private BeanSerializer delegate;
      
      		private Method serializeFields;
      
      		public JpaSerializer(BeanSerializer delegate) {
      			this.delegate = delegate;
      			try {
      				this.serializeFields = BeanSerializer.class.getDeclaredMethod(
      						"serializeFields", Object.class, JsonGenerator.class,
      						SerializerProvider.class);
      			} catch (Exception e) {
      				throw new RuntimeException(e);
      			}
      			this.serializeFields.setAccessible(true);
      		}
      
      		@Override
      		public void serialize(Object value, JsonGenerator jgen,
      				SerializerProvider provider) throws IOException,
      				JsonProcessingException {
      
      			jgen.writeStartObject();
      
      			// Special support for toString...
      
      			provider.getKeySerializer().serialize("toString", jgen, provider);
      			provider.findTypedValueSerializer(String.class, true).serialize(
      					value.toString(), jgen, provider);
      
      			// ...then delegate
      
      			try {
      				this.serializeFields.invoke(this.delegate, value, jgen,
      						provider);
      			} catch (Exception e) {
      				throw new IOException(e);
      			}
      			jgen.writeEndObject();
      		}
      	}
      
      	private class JpaDeserializer extends BeanDeserializer {
      
      		public JpaDeserializer(JavaType type) {
      			super(type);
      		}
      
      		public Object deserializeFromString(JsonParser jp,
      				DeserializationContext ctxt) throws IOException,
      				JsonProcessingException {
      
      			// Special support for JPA entities...
      
      			if (this.getBeanClass().isAnnotationPresent(Entity.class)) {
      				return ObjectMapperProvider.this.entityManager.find(
      						this.getBeanClass(), Long.valueOf(jp.getText()));
      			}
      
      			// ...or delegate
      
      			return super.deserializeFromString(jp, ctxt);
      		}
      	}
      }
      

      ...then it ends up creating a Java file called JpaDeserializer.java, not ObjectMapperProvider.java. If I do...

               // Generate ObjectMapperProviderTemplate.jv
               JavaClass objectMapperProvider = JavaParser.parse(JavaClass.class,
                        this.objectMapperProviderTemplate.render(context));
               objectMapperProvider.setPackage(serviceBean.getPackage());
               result.add(ScaffoldUtil.createOrOverwrite(this.prompt, java.getJavaResource(serviceBean.getPackage() + ".ObjectMapperProvider.java"),
                        objectMapperProvider.toString(),
                        true));
      

      ...then it's fine.

            sso_jira Sandro Sonntag (Inactive)
            kennardconsulting Richard Kennard (Inactive)
            Votes:
            1 Vote for this issue
            Watchers:
            1 Start watching this issue

              Created:
              Updated:
              Resolved: