com.wadpam.open.io.CsvConverter Maven / Gradle / Ivy

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package com.wadpam.open.io;

import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

/**
 *
 * @author os
 */
public class CsvConverter implements Converter {

    private DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");

    protected final ThreadLocal pw = new ThreadLocal();

    public String convertToString(Object o) {
        if (null == o) {
            return null;
        }

        if (o instanceof Boolean) {
            return ((Boolean) o) ? "True" : "False";
        }
        else if (o instanceof Date) {
            return dateFormat.format((Date) o);
        }
        else {
            return o.toString();
        }
    }

    public static String escapeCsv(String s) {
        if (null == s) {
            return null;
        }
        // first, escape all double quotes:
        final String escaped = s.replaceAll("\\\"", "\"\"");
        // then, qoute the string:
        final String quoted = String.format("\"%s\"", escaped);
        
        return quoted;
    }
    
    @Override
    public Object preExport(OutputStream out, Object arg, Object preExport, D[] daos) {
        return null;
    }

    @Override
    public Object postExport(OutputStream out, Object arg, Object preExport, Object postExport, D[] daos) {
        return null;
    }

    @Override
    public Object initPreDao(OutputStream out, Object arg) {
        try {
            pw.set(new PrintWriter(new OutputStreamWriter(out, "UTF-8")));
        }
        catch (UnsupportedEncodingException willNeverHappen) {}
        return null;
    }

    @Override
    public Object preDao(OutputStream out, Object arg, Object preExport, Object preDao, 
            String tableName, Iterable columns, Map headers, int daoIndex, D dao) {
        final HashMap headerValues = new HashMap();
        String headerName;
        for (String col : columns) {
            headerName = headers.get(col);
            headerValues.put(col, headerName != null ? headerName : col);
        }
        return writeValues(out, arg, preExport, preDao, columns, -1, dao, -1, null, headerValues);
    }

    @Override
    public Object postDao(OutputStream out, Object arg, Object preExport, Object preDao, Object postDao, D dao) {
        pw.get().flush();
        pw.remove();
        return null;
    }

    @Override
    public Object writeValues(OutputStream out, Object arg, Object preExport, Object preDao, 
            Iterable columns, int daoIndex, D dao, int entityIndex, Object entity, 
            Map values) {
        String s = null;
        // skip this entity / row ?
        if (null != values) {
            StringBuffer sb = new StringBuffer();
            boolean isFirst = true;
            for (String col : columns) {
                if (isFirst) {
                    isFirst = false;
                }
                else {
                    sb.append(',');
                }
                sb.append(escapeCsv(convertToString(values.get(col))));
            }

            s = sb.toString();
            pw.get().println(s);
        }
        return s;
    }

    public void setDatePattern(String pattern) {
        dateFormat = new SimpleDateFormat(pattern);
    }
}