001 package de.deepamehta.plugins.webservice.provider;
002
003 import de.deepamehta.core.util.JavaUtils;
004 import de.deepamehta.core.util.DeepaMehtaUtils;
005
006 import org.codehaus.jettison.json.JSONArray;
007
008 import java.io.BufferedWriter;
009 import java.io.InputStream;
010 import java.io.IOException;
011 import java.io.OutputStream;
012 import java.io.OutputStreamWriter;
013 import java.lang.annotation.Annotation;
014 import java.lang.reflect.ParameterizedType;
015 import java.lang.reflect.Type;
016 import java.util.Collection;
017 import java.util.List;
018 import java.util.logging.Logger;
019
020 import javax.ws.rs.WebApplicationException;
021 import javax.ws.rs.core.MediaType;
022 import javax.ws.rs.core.MultivaluedMap;
023 import javax.ws.rs.ext.MessageBodyReader;
024 import javax.ws.rs.ext.MessageBodyWriter;
025 import javax.ws.rs.ext.Provider;
026
027
028
029 @Provider
030 public class StringCollectionProvider implements MessageBodyReader<List<String>>,
031 MessageBodyWriter<Collection<String>> {
032
033 // ---------------------------------------------------------------------------------------------- Instance Variables
034
035 private Logger logger = Logger.getLogger(getClass().getName());
036
037 // -------------------------------------------------------------------------------------------------- Public Methods
038
039 // *** MessageBodyReader Implementation ***
040
041 @Override
042 public boolean isReadable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
043 if (genericType instanceof ParameterizedType) {
044 Type[] typeArgs = ((ParameterizedType) genericType).getActualTypeArguments();
045 if (type == List.class && typeArgs.length == 1 && typeArgs[0] == String.class) {
046 // Note: unlike equals() isCompatible() ignores parameters
047 // like "charset" in "application/json;charset=UTF-8"
048 if (mediaType.isCompatible(MediaType.APPLICATION_JSON_TYPE)) {
049 return true;
050 }
051 }
052 }
053 return false;
054 }
055
056 @Override
057 public List<String> readFrom(Class<List<String>> type, Type genericType, Annotation[] annotations,
058 MediaType mediaType, MultivaluedMap<String, String> httpHeaders, InputStream entityStream)
059 throws IOException, WebApplicationException {
060 try {
061 String json = JavaUtils.readText(entityStream);
062 return DeepaMehtaUtils.toList(new JSONArray(json));
063 } catch (Exception e) {
064 throw new RuntimeException("Creating a List<String> from message body failed", e);
065 }
066 }
067
068 // *** MessageBodyWriter Implementation ***
069
070 @Override
071 public boolean isWriteable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
072 if (genericType instanceof ParameterizedType) {
073 Type[] typeArgs = ((ParameterizedType) genericType).getActualTypeArguments();
074 if (Collection.class.isAssignableFrom(type) && typeArgs.length == 1 && typeArgs[0] == String.class) {
075 // Note: unlike equals() isCompatible() ignores parameters
076 // like "charset" in "application/json;charset=UTF-8"
077 if (mediaType.isCompatible(MediaType.APPLICATION_JSON_TYPE)) {
078 return true;
079 }
080 }
081 }
082 return false;
083 }
084
085 @Override
086 public long getSize(Collection<String> strings, Class<?> type, Type genericType, Annotation[] annotations,
087 MediaType mediaType) {
088 return -1;
089 }
090
091 @Override
092 public void writeTo(Collection<String> strings, Class<?> type, Type genericType, Annotation[] annotations,
093 MediaType mediaType, MultivaluedMap<String, Object> httpHeaders, OutputStream entityStream)
094 throws IOException, WebApplicationException {
095 try {
096 BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(entityStream));
097 DeepaMehtaUtils.stringsToJson(strings).write(writer);
098 writer.flush();
099 } catch (Exception e) {
100 throw new RuntimeException("Writing message body failed (" + strings + ")", e);
101 }
102 }
103 }