001    package de.deepamehta.plugins.webservice.provider;
002    
003    import de.deepamehta.core.JSONEnabled;
004    
005    import java.io.BufferedWriter;
006    import java.io.IOException;
007    import java.io.OutputStream;
008    import java.io.OutputStreamWriter;
009    import java.lang.annotation.Annotation;
010    import java.lang.reflect.Type;
011    import java.util.logging.Logger;
012    
013    import javax.ws.rs.WebApplicationException;
014    import javax.ws.rs.core.MediaType;
015    import javax.ws.rs.core.MultivaluedMap;
016    import javax.ws.rs.ext.MessageBodyWriter;
017    import javax.ws.rs.ext.Provider;
018    
019    
020    
021    @Provider
022    public class JSONEnabledProvider implements MessageBodyWriter<JSONEnabled> {
023    
024        // ---------------------------------------------------------------------------------------------- Instance Variables
025    
026        private Logger logger = Logger.getLogger(getClass().getName());
027    
028        // -------------------------------------------------------------------------------------------------- Public Methods
029    
030        // *** MessageBodyWriter Implementation ***
031    
032        @Override
033        public boolean isWriteable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
034            // Note: unlike equals() isCompatible() ignores parameters like "charset" in "application/json;charset=UTF-8"
035            return JSONEnabled.class.isAssignableFrom(type) && mediaType.isCompatible(MediaType.APPLICATION_JSON_TYPE);
036        }
037    
038        @Override
039        public long getSize(JSONEnabled jsonEnabled, Class<?> type, Type genericType, Annotation[] annotations,
040                            MediaType mediaType) {
041            return -1;
042        }
043    
044        @Override
045        public void writeTo(JSONEnabled jsonEnabled, Class<?> type, Type genericType, Annotation[] annotations,
046                            MediaType mediaType, MultivaluedMap<String, Object> httpHeaders, OutputStream entityStream)
047                            throws IOException, WebApplicationException {
048            try {
049                BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(entityStream));
050                jsonEnabled.toJSON().write(writer);
051                writer.flush();
052            } catch (Exception e) {
053                throw new RuntimeException("Writing message body failed", e);
054            }
055        }
056    }