Jersey client in applet doesn't parse JSON

Question

I have a simple application which can be used either as applet and standalone app. It sends a request to REST service and tries to display the result which is a List<City> .

City class code is as follows:

@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
public class City implements Serializable {

    private Integer cityId;
    private String name;

    public Integer getCityId() {
        return cityId;
    }

    public void setCityId(Integer cityId) {
        this.cityId = cityId;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

It uses jersey-bundle-1.17 to send request and get a response.

Code to send request and get response:

ClientConfig clientConfig = new DefaultClientConfig();
clientConfig.getFeatures().put(JSONConfiguration.FEATURE_POJO_MAPPING, Boolean.TRUE);
Client c = Client.create(clientConfig);
List<City> result = c.resource(resource url here).get(new GenericType<java.util.List<City>>(){});

After building the app i have two jar files - MyJar.jar with my app and jersey-bundle-1.17.jar. Class-Path to jersey is specifiend in the Manifest of MyJar.jar.

When i run my jar file as a standalone app (java -jar MyJar.jar) everything is ok, request is sent and response is received and deserialised to the List<City> . When i run my jar file as applet (in html page or appletviewer) request is sent, response is received but it can't deserialise response to the List<City> saying

A message body reader for Java class java.util.List, and Java type java.util.List<City>, and MIME media type application/json was not found

I tried to add JacksonJsonProvider.class to the list of Jersey providers, tried to deserialise just to String, to City[] - it always says that appropriate message body reader is no found when running from applet. And everything works fine when runnig as a desktop application.

Applet definitely loads jersy-bundle jar as i see it in server access logs and request is sent, but it looks so that it is loaded not correctly (maybe it ignores manifest of the jersey-bundle jar while loading, i don't know). Problem occures only when code is being executed from applet.

Could anyone help me?

Answer 1

The problem was that Jersey read properties and used reflection and all these actions were prohibited for untrusted applet. It wasn't obvious as there were no errors in Java Console. I had to put the parsing code to the try/catch block, catch any Throwable and print it to the Console and only then i could see errors about security restrictions.

To solve the problem i had to self-sign my applet jar file, jersey jar file and ALL other libs which were used by Jersey