JpaReport.java

package org.cryptocoinpartners.report;

import java.util.ArrayList;
import java.util.List;

import javax.inject.Inject;

import org.apache.commons.lang.ArrayUtils;
import org.cryptocoinpartners.schema.dao.ReportDao;
import org.cryptocoinpartners.util.Visitor;
import org.slf4j.Logger;

/**
 * @author Tim Olson
 */
public abstract class JpaReport implements Report {
    @Inject
    protected ReportDao reportDao;

    public int getLimit() {
        return limit;
    }

    public void setLimit(int limit) {
        this.limit = limit;
    }

    @Override
    public TableOutput runReport() {
        final Query query = getQuery();
        final List<String[]> rowStrings = new ArrayList<>();

        if (log.isTraceEnabled())
            log.trace("Querying: " + query.queryStr + " / " + ArrayUtils.toString(query.params));
        if (limit != 0) {
            Visitor<Object[]> visitor = new Visitor<Object[]>() {
                private int count = 0;

                @Override
                public boolean handleItem(Object[] row) {
                    handleResult(row, rowStrings);
                    return ++count < limit;
                }
            };
            reportDao.queryEach(visitor, limit, query.queryStr, query.params);
        } else {
            Visitor<Object[]> visitor = new Visitor<Object[]>() {
                @Override
                public boolean handleItem(Object[] row) {
                    handleResult(row, rowStrings);
                    return true;
                }
            };
            reportDao.queryEach(visitor, query.queryStr, query.params);
        }
        String[][] rowStringTable = new String[rowStrings.size()][];
        rowStrings.toArray(rowStringTable);
        final String[] headers = query.headers;
        return new TableOutput(headers, rowStringTable);
    }

    protected void handleResult(Object[] row, List<String[]> rowStrings) {
        final String[] rowFormat = formatRow(row);
        rowStrings.add(rowFormat);
    }

    @SuppressWarnings("UnusedDeclaration")
    public static class Query {
        public Query(String[] headers, String queryStr, Object[] params) {
            this.headers = headers;
            this.queryStr = queryStr;
            this.params = params;
        }

        public Query(String[] headers, String queryStr) {
            this.headers = headers;
            this.queryStr = queryStr;
            this.params = new Object[] {};
        }

        String[] headers;
        String queryStr;
        Object[] params;
    }

    protected abstract Query getQuery();

    protected String[] formatRow(Object[] row) {
        final String[] result = new String[row.length];
        for (int i = 0; i < row.length; i++) {
            Object item = row[i];
            result[i] = formatColumn(i, item);
        }
        return result;
    }

    protected String formatColumn(@SuppressWarnings("UnusedParameters") int columnIndex, Object item) {
        return String.valueOf(item);
    }

    @Inject
    private Logger log;

    private int limit;
}