Converter.java

package org.openprovenance.prov.json;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Writer;

import org.openprovenance.prov.model.Document;
import org.openprovenance.prov.model.ProvFactory;

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

public class Converter {
    final private ProvFactory pFactory;

    final private Gson gson;
    final Class class1;

    public Converter(ProvFactory pFactory) {
	this.pFactory = pFactory;

	class1 = pFactory.newDocument().getClass();

	gson = new GsonBuilder().registerTypeAdapter(class1,
						     new ProvDocumentDeserializer(pFactory))
				.registerTypeAdapter(class1,
						     new ProvDocumentSerializer(pFactory))
				.setPrettyPrinting().create();

    }

    @SuppressWarnings("unchecked")
    public Document readDocument(String file) throws JsonSyntaxException,
					     JsonIOException,
					     FileNotFoundException {
	Document doc = (Document) gson.fromJson(new BufferedReader(new FileReader(file)),
						class1);
	return doc;
    }

    @SuppressWarnings("unchecked")
    public Document readDocument(InputStream is) throws JsonSyntaxException,
						JsonIOException,
						FileNotFoundException {
	Document doc = (Document) gson.fromJson(new BufferedReader(new InputStreamReader(is)),
						class1);
	return doc;
    }

    public void writeDocument(Document doc, String file) throws IOException {
	BufferedWriter writer = new BufferedWriter(new FileWriter(file));
	gson.toJson(doc, writer);
	writer.close();
    }

    public void writeDocument(Document doc, Writer out) throws IOException {
	BufferedWriter writer = new BufferedWriter(out);
	gson.toJson(doc, writer);
	writer.close();
    }

    public String getString(Document doc) {
	return gson.toJson(doc);
    }

    @SuppressWarnings("unchecked")
    public Document fromString(String jsonStr) {
	return (Document) gson.fromJson(jsonStr, class1);
    }

}