ECMAscript 基础

创建一个新的FlowFile

var flowFile = session.create();

从父FlowFile创建新的FlowFile

var newFlowFile = session.create(flowFile);

向流文件添加属性

flowFile = session.putAttribute(flowFile, 'myAttr', 'myValue')

向流文件添加多个属性

var attrMap = {'myAttr1':'1', 'myAttr2': number2.toString()}
flowFile = session.putAllAttributes(flowFile, attrMap)

从流文件中获取属性

var myAttr = flowFile.getAttribute('filename')

var attrs = flowFile.getAttributes();
for each (var attrKey in attrs.keySet()) {
    //attrs[attrKey]
}

将流文件传输到关系

session.transfer(flowFile, REL_FAILURE)
session.transfer(flowFile, REL_SUCCESS)

使用回调读取传入流文件的内容

session.read(flowFile,new InputStreamCallback(function(inputStream) {
    var text = IOUtils.toString(inputStream, StandardCharsets.UTF_8);
    // Do something with text here
}));

使用回调将内容写入传出流文件

flowFile = session.write(flowFile,new OutputStreamCallback(function(outputStream) {
    outputStream.write("Hello World!".getBytes(StandardCharsets.UTF_8))
}));

使用回调覆盖带有更新内容的传入流文件

flowFile = session.write(flowFile,new StreamCallback(function(inputStream, outputStream) {
    var text = IOUtils.toString(inputStream, StandardCharsets.UTF_8)
    outputStream.write(text.split("").reverse().join("").getBytes(StandardCharsets.UTF_8))
}));

处理脚本处理过程中的错误

var flowFile = session.get();
if(flowFile != null) {
      try {
          session.transfer(flowFile, REL_SUCCESS)
    } catch(e) {
      log.error('Something went wrong', e)
      session.transfer(flowFile, REL_FAILURE)
    }
}

以指定的日志记录级别向日志发送消息

var ObjectArrayType = Java.type("java.lang.Object[]");
var objArray = new ObjectArrayType(3);
objArray[0] = 'Hello';
objArray[1] = 1;
objArray[2] = true;
log.info('Found these things: {} {} {}', objArray)