GroupByJsonDelegate.java

package eu.leads.processor.execute.operators;

import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.util.StdConverter;
import eu.leads.processor.plan.NodeStatus;
import eu.leads.processor.utils.SQLUtils;
import net.sf.jsqlparser.expression.Function;
import net.sf.jsqlparser.schema.Column;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

/**
 * Created with IntelliJ IDEA.
 * User: vagvaz
 * Date: 11/3/13
 * Time: 9:49 PM
 * To change this template use File | Settings | File Templates.
 */
//Class converting json tree node to groupby
public class GroupByJsonDelegate extends StdConverter<JsonNode, GroupByOperator> {
    @Override
    public GroupByOperator convert(JsonNode jsonNode) {
        String name = jsonNode.path("name").asText();
        String output = jsonNode.path("output").asText();
        ArrayList<Column> columns = new ArrayList<Column>();
        ObjectMapper mapper = new ObjectMapper();
        Iterator<JsonNode> iterator = jsonNode.path("columns").elements();
        while (iterator.hasNext()) {
            JsonNode col = iterator.next();
            try {
                Column c = mapper.readValue(col.toString(), Column.class);
                columns.add(c);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        ArrayList<Function> functions = new ArrayList<Function>();
        iterator = jsonNode.path("functions").elements();
        while (iterator.hasNext()) {
            JsonNode func = iterator.next();
            Function f = SQLUtils.extractFunction(func);
            functions.add(f);
        }
        List<String> sources = null;
        NodeStatus status = NodeStatus.PENDING;

        GroupByOperator result = new GroupByOperator(name, output, columns, functions);
        try {
//            status = mapper.readValue(jsonNode.path("status").toString(), NodeStatus.class);
            sources = mapper.readValue(jsonNode.path("sources").toString(), new TypeReference<List<String>>() {
            });
        } catch (IOException e) {
            e.printStackTrace();
        }
        result.setSources(sources);
        return result;
    }
}