以下代码演示function, filter, projection的使用，可结合注释

省略部分代码，省略部分可参考：https://blog.csdn.net/nickta/article/details/79666918

FixedBatchSpout spout = new FixedBatchSpout(new Fields("user", "score"), 3,  new Values("nickt1", 4), new Values("nickt2", 7),  new Values("nickt3", 8), new Values("nickt4", 9),  new Values("nickt5", 7), new Values("nickt6", 11), new Values("nickt7", 5) ); spout.setCycle(false); TridentTopology topology = new TridentTopology(); topology.newStream("spout1", spout) .shuffle() .each(new Fields("user"),new BaseFilter() {@Overridepublic boolean isKeep(TridentTuple tuple) {if(tuple.getString(0).equals("nickt2")) {return false;}return true;}})//过滤点user为nickt2的tuple.each(new Fields("user", "score"),new Debug("filter print:")).each(new Fields("score"), new BaseFunction() {@Overridepublic void execute(TridentTuple tuple, TridentCollector collector) {collector.emit(new Values(tuple.getIntegerByField("score") + 100));}}, new Fields("sum"))//把score加上100后，生成新的sum字段，并追加到原字段后面，此步操作后就包括了user/score/sum三个字段.each(new Fields("user", "score", "sum"),new Debug("function print:")).project(new Fields("user")).each(new Fields("user"),new Debug("project print:"));//project投射之后，只有user字段了

输出：

<Sat Mar 24 13:41:42 CST 2018[partition0-Thread-68-b-0-executor[33 33]]> DEBUG(filter print:): [nickt1, 4]
<Sat Mar 24 13:41:42 CST 2018[partition0-Thread-68-b-0-executor[33 33]]> DEBUG(function print:): [nickt1, 4, 104]
<Sat Mar 24 13:41:42 CST 2018[partition0-Thread-68-b-0-executor[33 33]]> DEBUG(project print:): [nickt1]
<Sat Mar 24 13:41:42 CST 2018[partition0-Thread-68-b-0-executor[33 33]]> DEBUG(filter print:): [nickt3, 8]
<Sat Mar 24 13:41:42 CST 2018[partition0-Thread-68-b-0-executor[33 33]]> DEBUG(function print:): [nickt3, 8, 108]
<Sat Mar 24 13:41:42 CST 2018[partition0-Thread-68-b-0-executor[33 33]]> DEBUG(project print:): [nickt3]
<Sat Mar 24 13:41:42 CST 2018[partition0-Thread-68-b-0-executor[33 33]]> DEBUG(filter print:): [nickt4, 9]
<Sat Mar 24 13:41:42 CST 2018[partition0-Thread-68-b-0-executor[33 33]]> DEBUG(function print:): [nickt4, 9, 109]
<Sat Mar 24 13:41:42 CST 2018[partition0-Thread-68-b-0-executor[33 33]]> DEBUG(project print:): [nickt4]
<Sat Mar 24 13:41:42 CST 2018[partition0-Thread-68-b-0-executor[33 33]]> DEBUG(filter print:): [nickt5, 7]
<Sat Mar 24 13:41:42 CST 2018[partition0-Thread-68-b-0-executor[33 33]]> DEBUG(function print:): [nickt5, 7, 107]
<Sat Mar 24 13:41:42 CST 2018[partition0-Thread-68-b-0-executor[33 33]]> DEBUG(project print:): [nickt5]
<Sat Mar 24 13:41:42 CST 2018[partition0-Thread-68-b-0-executor[33 33]]> DEBUG(filter print:): [nickt6, 11]
<Sat Mar 24 13:41:42 CST 2018[partition0-Thread-68-b-0-executor[33 33]]> DEBUG(function print:): [nickt6, 11, 111]
<Sat Mar 24 13:41:42 CST 2018[partition0-Thread-68-b-0-executor[33 33]]> DEBUG(project print:): [nickt6]
<Sat Mar 24 13:41:42 CST 2018[partition0-Thread-68-b-0-executor[33 33]]> DEBUG(filter print:): [nickt7, 5]
<Sat Mar 24 13:41:42 CST 2018[partition0-Thread-68-b-0-executor[33 33]]> DEBUG(function print:): [nickt7, 5, 105]
<Sat Mar 24 13:41:42 CST 2018[partition0-Thread-68-b-0-executor[33 33]]> DEBUG(project print:): [nickt7]