Data Pipeline-轻识

Data Pipeline 是一个Java的数据转换工具包，主要的功能包括：

* 读: CSV, fixed-width, Excel, database, weblogs, custom
* 写: CSV, fixed-width, Excel, database, PDF, Word, XML, custom
* 操作: validate, filter, sort, lookup, 去除重复数据, convert, throttle, calculate, custom, and more
* 运行时表达式过滤器、数据验证以及公式计算

典型的应用场景包括:
1. 读取 CSV 文件
2. 删除重复的记录
3. 添加计算列
4. 删除无用的列
5. 数据保存到数据库

代码示例：

DataReader reader = new CSVReader(new File("credit-balance.csv"))
.setFieldNamesInFirstRow(true);

// Use only the "Rating" and "CreditLimit" fields in duplicate test
reader = new RemoveDuplicatesReader(reader, new FieldList("Rating", "CreditLimit"));

// Add AvailableCredit field, remove "CreditLimit", "Balance" fields
reader = new TransformingReader(reader)
.add(new SetCalculatedField("AvailableCredit", "parseDouble(CreditLimit) - parseDouble(Balance)"))
.add(new ExcludeFields("CreditLimit", "Balance"));

DataWriter writer = new JdbcWriter(getJdbcConnection(), "dp_credit_balance")
.setAutoCloseConnection(true);

JobTemplate.DEFAULT.transfer(reader, writer);