opencsv.utils.CsvMapper Maven / Gradle / Ivy

Go to download
package opencsv.utils;

import au.com.bytecode.opencsv.CSVReader;
import au.com.bytecode.opencsv.CSVWriter;
import au.com.bytecode.opencsv.bean.CsvToBean;
import au.com.bytecode.opencsv.bean.HeaderColumnNameTranslateMappingStrategy;

import java.io.Reader;
import java.io.Writer;
import java.lang.reflect.Field;
import java.util.*;

import static au.com.bytecode.opencsv.CSVWriter.DEFAULT_SEPARATOR;
import static au.com.bytecode.opencsv.CSVWriter.NO_QUOTE_CHARACTER;

public class CsvMapper implements ICsvMapper {

    private final Map columnMapping = new HashMap();
    private final HashMap fieldMap = new HashMap();
    private final Class type;

    public CsvMapper(Class type) {
        this.type = type;
    }

    @Override
    public ICsvMapper withMapping(Map mapping) {
        this.columnMapping.putAll(mapping);
        return this;
    }

    @Override
    public ICsvMapper withMapping(ICsvColumnMapping mapping) {
        return withMapping(mapping.getColumnMapping());
    }

    @Override
    public ICsvMapper withMapping(String header, String property) {
        this.columnMapping.put(header, property);
        return this;
    }

    @Override
    public List fromCsv(Reader reader) {

        HeaderColumnNameTranslateMappingStrategy strategy = new HeaderColumnNameTranslateMappingStrategy();
        strategy.setType(type);
        strategy.setColumnMapping(columnMapping);

        List list = new ArrayList();
        try {
            list = new CsvToBean().parse(strategy, new CSVReader(reader));
        } catch (Exception ex) {
            throw new CsvMapperRuntimeException(ex);
        } finally {
            if (reader != null) {
                try {
                    reader.close();
                    reader = null;
                } catch (Exception ex) {
                    throw new CsvMapperRuntimeException("Close the reader failed.", ex);
                }
            }
        }
        return list;
    }

    @Override
    public void toCsv(Writer writer, List list) throws Exception {
        CSVWriter csvWriter = new CSVWriter(writer, DEFAULT_SEPARATOR, NO_QUOTE_CHARACTER);
        final List lines = new ArrayList();
        for (T item : list) {
            lines.add(getLine(item));
        }
        csvWriter.writeNext(columnMapping.keySet().toArray(new String[0]));
        csvWriter.writeAll(lines);
        csvWriter.flush();
    }

    private String[] getLine(T item) throws Exception {
        final List list = new ArrayList();
        for (String key : columnMapping.keySet()) {
            if (!fieldMap.containsKey(key)) {
                final String fieldName = columnMapping.get(key);
                fieldMap.put(key, item.getClass().getDeclaredField(fieldName));
            }
            Field field = fieldMap.get(key);
            field.setAccessible(true);
            final Object value = field.get(item);
            list.add(value == null ? "" : value.toString());
        }
        return list.toArray(new String[0]);
    }

}