JYaml - Yaml library for
the Java language

Notice: I am no longer maintaining JYaml. See this this Q&A for a list of alternatives.


YAML4DbUnit integrates JYaml with DbUnit so that you can write your data set files in YAML rather than XML. Here is an example:

  - id: 1
    name: "John McEnroe"
    login: jMAC
  - id: 2
    name: "Larry Bird"
    login: larryB
  - id: 1
    customer_id: 1
    item_id: 1
    purchase_date: "2007-05-15 15:40:16.638"
  - id: 2
    customer_id: 2
    item_id: 2
    purchase_date: "2007-03-12 15:40:16.638"
  - id: 1
    name: "Wilson Tennis Racquet"
    price: 230.00
  - id: 2
    name: "Autographed Basketball Jersey"
    price: 100.00

This is equivalent to the following dbUnit data set file in XML:

<?xml version='1.0' encoding='UTF-8'?>
  <customer id="1" name="John McEnroe" login="jMAC"/>
  <customer id="2" name="Larry Bird" login="larryB"/>
  <transactions id="1" customer_id="1" item_id="1" purchase_date="2007-05-15 15:40:16.0"/>
  <transactions id="2" customer_id="2" item_id="2" purchase_date="2007-03-12 15:40:16.0"/>
  <item id="1" name="Wilson Tennis Racquet" price="230.0"/>
  <item id="2" name="Autographed Basketball Jersey" price="100.0"/>


Which is better? You decide.


To use this, all you need to do is to replace

IDataSet dataSet = new FlatXmlDataSet(new FileInputStream("dataset.xml"));


IDataSet dataSet = new YamlDataSet(new File("dataset.yml"));

Code for YAML4DbUnit

Below is the complete source code for YAML4DbUnit.

package org.dbunit.dataset.yaml;

import java.io.File;
import java.io.FileNotFoundException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.dbunit.dataset.Column;
import org.dbunit.dataset.DataSetException;
import org.dbunit.dataset.DefaultTableIterator;
import org.dbunit.dataset.DefaultTableMetaData;
import org.dbunit.dataset.IDataSet;
import org.dbunit.dataset.ITable;
import org.dbunit.dataset.ITableIterator;
import org.dbunit.dataset.ITableMetaData;
import org.dbunit.dataset.RowOutOfBoundsException;
import org.dbunit.dataset.datatype.DataType;
import org.ho.yaml.Yaml;

public class YamlDataSet implements IDataSet {

    Map<String, MyTable> tables = new HashMap<String, MyTable>();
    public YamlDataSet(File file) throws FileNotFoundException{
        Map<String, List<Map>> data = (Map<String, List<Map>>)Yaml.load(file);
        for (Map.Entry<String, List<Map>> ent: data.entrySet()){
            String tableName = ent.getKey();
            List<Map> rows = ent.getValue();
            createTable(tableName, rows);
    class MyTable implements ITable{
        String name;
        List<Map> data;
        ITableMetaData meta;
        MyTable(String name, List<String> columnNames){
            this.name = name;
            this.data = new ArrayList<Map>();
            meta = createMeta(name, columnNames);
        ITableMetaData createMeta(String name, List<String> columnNames){
            Column[] columns = null;
            if (columnNames != null){
                columns = new Column[columnNames.size()];
                for (int i = 0; i < columnNames.size(); i++)
                    columns[i] = new Column(columnNames.get(i), DataType.UNKNOWN);
            return new DefaultTableMetaData(name, columns);
        public int getRowCount() {
            return data.size();

        public ITableMetaData getTableMetaData() {
            return meta;

        public Object getValue(int row, String column) throws DataSetException {
            if (data.size() <= row)
                throw new RowOutOfBoundsException("" +row);
            return data.get(row).get(column.toUpperCase());
        public void addRow(Map values){
        Map convertMap(Map<String, Object> values){
            Map ret = new HashMap();
            for (Map.Entry<String, Object> ent: values.entrySet()){
                ret.put(ent.getKey().toUpperCase(), ent.getValue());
            return ret;
    MyTable createTable(String name, List<Map> rows){
        MyTable table = new MyTable(name, rows.size() > 0? 
        	new ArrayList(rows.get(0).keySet()) : null);
        for (Map values: rows)
        tables.put(name, table);
        return table;
    public ITable getTable(String tableName) throws DataSetException {
        return tables.get(tableName);

    public ITableMetaData getTableMetaData(String tableName)
            throws DataSetException {
        return tables.get(tableName).getTableMetaData();

    public String[] getTableNames() throws DataSetException {
        return (String[])tables.keySet().toArray(new String[tables.size()]);

    public ITable[] getTables() throws DataSetException {
        return (ITable[])tables.values().toArray(new ITable[tables.size()]);

    public ITableIterator iterator() throws DataSetException {
        return new DefaultTableIterator(getTables());

    public ITableIterator reverseIterator() throws DataSetException {
        return new DefaultTableIterator(getTables(), true);


117 lines of code in total, not too bad, ehh?