All Downloads are FREE. Search and download functionalities are using the official Maven repository.
  • Log In
  • Register

    • io.github.fallwizard.rabbitmq.httpclient.GsonMessageBodyHandler Maven / Gradle / Ivy

    The newest version!
    package io.github.fallwizard.rabbitmq.httpclient;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import io.github.fallwizard.rabbitmq.httpclient.deserializers.ParameterDeserializer;
import io.github.fallwizard.rabbitmq.mgmt.model.Parameter;

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 java.io.*;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;

/**
 * Encapsulates GSON support for custom serializing/deserializing objects.
 */
@Provider
@Produces(MediaType.APPLICATION_JSON)
public final class GsonMessageBodyHandler implements MessageBodyWriter, MessageBodyReader {

    private static final Logger logger = LoggerFactory.getLogger(GsonMessageBodyHandler.class);

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

    private Gson gson;

    private Gson getGson() {

        if (gson == null) {

            GsonBuilder builder = new GsonBuilder();

            builder.registerTypeAdapter(Parameter.class, new ParameterDeserializer());

            gson = builder.create();

        }

        return gson;
    }

    @Override
	public boolean isReadable(
			Class clazz, Type type, Annotation[] annotations,
			MediaType mediaType) {
		
		return true;
	}
    
    @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 httpHeaders,
        OutputStream entityStream) throws IOException, WebApplicationException {
    	
        OutputStreamWriter outputStreamWriter = null;
        
        try {
        	
        	outputStreamWriter = new OutputStreamWriter(entityStream, CHARSET);
        	
            Type jsonType = getAppropriateType(type, genericType);

            String json = getGson().toJson(object, jsonType);

            logger.trace("Outgoing JSON Entity: {}", json);

            getGson().toJson(object, jsonType, outputStreamWriter);
            
        } finally {
        	
        		if (outputStreamWriter != null)
        			outputStreamWriter.close();
        }
    }

	@Override
	public Object readFrom(Class type, Type genericType, Annotation[] annotations,
			MediaType mediaType, MultivaluedMap httpHeaders,
			InputStream inputStream) throws IOException, WebApplicationException {
		
		Object result = null;
		InputStreamReader inputStreamReader = null;
		
		try {
		
			inputStreamReader = new InputStreamReader(inputStream, CHARSET);
			
			Type jsonType = getAppropriateType(type, genericType);

            String json = getStringFromInputStream(inputStream);

            logger.trace("Incoming JSON Entity: {}", json);

			result = getGson().fromJson(json, jsonType);
		
		} finally {
		
			if (inputStreamReader != null)
				inputStreamReader.close();
		}
		
		return result;
	}
	
	Type getAppropriateType(Class type, Type genericType){
		
		return (type.equals(genericType))? type : genericType;
	}

    private static String getStringFromInputStream(InputStream is) {

        BufferedReader br = null;
        StringBuilder sb = new StringBuilder();

        String line;
        try {

            br = new BufferedReader(new InputStreamReader(is));
            while ((line = br.readLine()) != null) {
                sb.append(line);
            }

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (br != null) {
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

        return sb.toString();
    }

}    
    
    
    

    




    
    
    © 2015 - 2025 Weber Informatics LLC | Privacy Policy