android - Custom converter of Simple XML is not serializing from xml to java object -

i have simple xml annotated class want use serialization/deserialization. have byte[] array using custom converter fails @ read method..

here simple xml annotated object

@root public class device implements serializable {     @element     @convert(bytearrayconverter.class)     protected byte[] imageref; ... } 

here converter

import org.simpleframework.xml.convert.converter; import org.simpleframework.xml.stream.inputnode; import org.simpleframework.xml.stream.outputnode;  public class bytearrayconverter implements converter<byte[]> {      @override     public byte[] read(inputnode node) throws exception      {         string value = node.getvalue();         //return value.getbytes();                 return new byte[]{1,2,3,4,5};     }      @override     public void write(outputnode node, byte[] bytearray) throws exception      {                node.setvalue("something");          }          } 

here xml called device.xml

<device>     <imageref>aqidbau=</imageref> </device> 

here serialization code failing

strategy strategy = new annotationstrategy(); serializer serializer = new persister(strategy); file file = new file("device.xml");      device device = serializer.read(device.class, file); 

i have put break point in bytearrayconverter.read() method , executes correctly , returns byte array. after somewhere in simple xml

exception in thread "main" org.simpleframework.xml.core.instantiationexception: incompatible class [b field 'imageref' protected byte[] com.test.device.imageref @ line 4 @ org.simpleframework.xml.core.factory.getoverride(factory.java:147) @ org.simpleframework.xml.core.primitivefactory.getinstance(primitivefactory.java:82) @ org.simpleframework.xml.core.primitive.readelement(primitive.java:186) @ org.simpleframework.xml.core.primitive.read(primitive.java:124) @ org.simpleframework.xml.core.composite.readvariable(composite.java:623) @ org.simpleframework.xml.core.composite.readinstance(composite.java:573) @ org.simpleframework.xml.core.composite.readunion(composite.java:549) @ org.simpleframework.xml.core.composite.readelement(composite.java:532) @ org.simpleframework.xml.core.composite.readelements(composite.java:445) @ org.simpleframework.xml.core.composite.access$400(composite.java:59) @ org.simpleframework.xml.core.composite$builder.read(composite.java:1383) @ org.simpleframework.xml.core.composite.read(composite.java:201) @ org.simpleframework.xml.core.composite.read(composite.java:148) @ org.simpleframework.xml.core.traverser.read(traverser.java:92) @ org.simpleframework.xml.core.persister.read(persister.java:625) @ org.simpleframework.xml.core.persister.read(persister.java:606) @ org.simpleframework.xml.core.persister.read(persister.java:584) @ org.simpleframework.xml.core.persister.read(persister.java:543) @ org.simpleframework.xml.core.persister.read(persister.java:521) @ org.simpleframework.xml.core.persister.read(persister.java:426)

any pointers helpful..

you using primitive type array, may cause exception. byte array encoded (e.g. base64)? if use encoding, have care in read() / write() too.

a converter not best choice here, better take transform. can implemented object <-> string transformation own.

here's simple example:

public class bytearraytransformer implements transform<byte[]> {     @override     public byte[] read(string value) throws exception     {         /*          * todo: implement proper encoding          */         return value.getbytes();     }       @override     public string write(byte[] value) throws exception     {         /*          * todo: implement proper encoding          */         return new string(value);     }  } 

this allows remove converter (@convert annotation of field , annotationstrategy).

and here's how bind transformer:

registrymatcher m = new registrymatcher(); m.bind(byte[].class, new bytearraytransformer());  serializer ser = new persister(m);  device d = ser.read(device.class, f);