Flink学习笔记 --- DataSet Source and Sink_flink dataset 读取 richsourcefunction

DataSouce
InputFormat:
1.File-based:
    readTextFile(path):Read files line wise and returns them as Strings.
    readTextFileWithValue(path):Reads files line wise and returns them as StringValues(String Values are mutable strings).
    readCsvFile(path):Parses file of comma(or anthor char) delimited fiedls.Returns a DataSet of tuples, case class
        or POJOs, Supports the basic java types and their values counterparts as field types.
    readFileOfPrimitives(path, delimiter):Parses files of new-line(or anthor char sequence) delimited primitive data types
        such as String or Integer using the given delimiter.
    readHadoopFile(FileInputFormat, key, Value, path):Create a JobConf and reads file from the specified FileInputFormat,Key class and Value class and return
        them as Tuple2<key, value>.
    readSequenceFile(key, va