用Nifi 从web api 取数据到HDFS

1. 全景图

2. 用ExecuteScript生成动态日期参数

为了只生成一个flowfile：

Groovy 代码：

import org.apache.commons.io.IOUtils
import java.nio.charset.*
import java.text.SimpleDateFormat;
import java.lang.StringBuilder;
import java.util.Calendar;

def flowFile = session.create()

def days = 10000

flowFile = session.write(flowFile, {inputStream, outputStream ->
SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
Calendar cal = Calendar.getInstance();
StringBuilder sb = new StringBuilder();

cal.add(Calendar.DATE,1)

for(int i = 0; i < days; i++) {
cal.add(Calendar.DATE, -1);
sb.append(sdf.format(cal.getTime()) + "\n" );
}

//println(sb);

outputStream.write(sb.toString().getBytes(StandardCharsets.UTF_8))
} as StreamCallback)

//flowFile = session.putAttribute(flowFile, 'filename', 'get_date')
session.transfer(flowFile, REL_SUCCESS)