ECMAscript 获取所有属性

把所有属性信息打印到流内容，过滤排除一些默认的服务信息属性

var StreamCallback =  Java.type("org.apache.nifi.processor.io.StreamCallback")
var IOUtils = Java.type("org.apache.commons.io.IOUtils");
var StandardCharsets = Java.type("java.nio.charset.StandardCharsets");
var flowFile = session.get();
var text = '';
if(flowFile != null) {
    try {
        var attrs = flowFile.getAttributes();
        flowFile = session.write(flowFile,new StreamCallback(function(inputStream, outputStream) {
            var obj = {};
            for each (var attrKey in attrs.keySet()) {
                  if(attrKey.indexOf('http.')==-1 && attrKey.indexOf('RouteOnAttribute.')==-1 && attrKey != 'path'){
                  obj[attrKey] = attrs[attrKey];
                }
            }
            text = JSON.stringify(obj);
            outputStream.write(text.getBytes(StandardCharsets.UTF_8))
        }));
        session.transfer(flowFile, REL_SUCCESS)
    } catch(e) {
        session.transfer(flowFile, REL_FAILURE)
    }
}