D-Net

package eu.dnetlib.enabling.is.jdbc;

import java.io.IOException;

import java.io.StringWriter;

import java.sql.Array;

import java.sql.ResultSet;

import java.sql.ResultSetMetaData;

import java.sql.SQLException;

import org.springframework.jdbc.core.RowMapper;

import com.google.gson.stream.JsonWriter;

public class JsonRowMapper implements RowMapper<String> {

	@Override

	public String mapRow(final ResultSet rs, final int pos) throws SQLException {

		final ResultSetMetaData rsMetadata = rs.getMetaData();

		final StringWriter sw = new StringWriter();

		try {

			final JsonWriter writer = new JsonWriter(sw);

			writer.beginObject();

			for (int i = 1; i <= rsMetadata.getColumnCount(); i++) {

				writer.name(rsMetadata.getColumnLabel(i));

				writeValue(writer, rs.getObject(i));

			}

			writer.endObject();

			writer.close();

		} catch (IOException e) {

			throw new SQLException("Error during Json conversion", e);

		}

		return sw.toString();

	}

	private void writeValue(final JsonWriter writer, final Object object) throws IOException, SQLException {

		if (object == null) {

			return;

		} else if (object instanceof Boolean) {

			writer.value((Boolean) object);

		} else if (object instanceof Number) {

			writer.value((Number) object);

		} else if (object instanceof Array) {

			writer.beginArray();

			for (Object o : (Object[]) ((Array) object).getArray()) {

				writeValue(writer, o);

			}

			writer.endArray();

		} else {

			writer.value(object.toString());

		}

	}

}