球衣不適用於指定提供商

Question

我正在與Jersey合作，嘗試使用Gson提供程序而不是Jackson。 我使用了Moritz Post的Blogpost。

我定義的REST服務：@Path（“ user”）

public class UserResource extends AbstractResource {
    @POST
    @Path("auth")
    @Consumes(MediaType.APPLICATION_JSON)
    public String postAuth(Login obj) {
        // Session session = HibernateHelper.getSessionFactory().openSession();
        //Login obj = new Gson().fromJson(json, Login.class);
        return "Response: " + obj;
    }
}

它返回：響應：null null

當我明確使用Gson提供程序時：

@Path("user")
public class UserResource extends AbstractResource {

    @POST
    @Path("auth")
    @Consumes(MediaType.APPLICATION_JSON)
    public String postAuth(String json) {
        Login obj = new Gson().fromJson(json, Login.class);
        return "Response: " + obj;
    }
}

它返回：響應：用戶名密碼

我在Grizzly明確注冊了提供商：

rc.register(GsonProvider.class);

提供程序的以下代碼：

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;

import javax.ws.rs.Consumes;
import javax.ws.rs.Produces;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.ext.MessageBodyReader;
import javax.ws.rs.ext.MessageBodyWriter;
import javax.ws.rs.ext.Provider;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;

@Provider
@Produces(MediaType.APPLICATION_JSON)
@Consumes(MediaType.APPLICATION_JSON)
public final class GsonProvider implements MessageBodyWriter<Object>,
        MessageBodyReader<Object> {

    private static final String UTF_8 = "UTF-8";

    private Gson gson;

    private Gson getGson() {
        System.out.println("ja");

        if (gson == null) {
            final GsonBuilder gsonBuilder = new GsonBuilder();
            gson = gsonBuilder.create();
        }
        return gson;
    }

    @Override
    public boolean isReadable(Class<?> type, Type genericType,
            java.lang.annotation.Annotation[] annotations, MediaType mediaType) {
        return true;
    }

    @Override
    public Object readFrom(Class<Object> type, Type genericType,
            Annotation[] annotations, MediaType mediaType,
            MultivaluedMap<String, String> httpHeaders, InputStream entityStream)
            throws IOException {
        InputStreamReader streamReader = new InputStreamReader(entityStream,
                UTF_8);
        try {
            Type jsonType;
            if (type.equals(genericType)) {
                jsonType = type;
            } else {
                jsonType = genericType;
            }
            return getGson().fromJson(streamReader, jsonType);
        } finally {
            streamReader.close();
        }
    }

    @Override
    public boolean isWriteable(Class<?> type, Type genericType,
            Annotation[] annotations, MediaType mediaType) {
        return true;
    }

    @Override
    public long getSize(Object object, Class<?> type, Type genericType,
            Annotation[] annotations, MediaType mediaType) {
        return -1;
    }

    @Override
    public void writeTo(Object object, Class<?> type, Type genericType,
            Annotation[] annotations, MediaType mediaType,
            MultivaluedMap<String, Object> httpHeaders,
            OutputStream entityStream) throws IOException,
            WebApplicationException {
        OutputStreamWriter writer = new OutputStreamWriter(entityStream, UTF_8);
        try {
            Type jsonType;
            if (type.equals(genericType)) {
                jsonType = type;
            } else {
                jsonType = genericType;
            }
            getGson().toJson(object, jsonType, writer);
        } finally {
            writer.close();
        }
    }
}

Answer 1

我在github上添加了此案例的示例（使用Gson代替Jackson）。

您可以在此處找到GsonUtil的實現+整個示例：

https://github.com/DominikAngerer/java-GsonJerseyProvider

希望對您有所幫助-您還將看到一個用於配置整個提供程序的示例web.xml。