(1)定义FunctionUtil工具类,结合Java8的Function函数式接口实现; (2)代码实现: publicclassFunctionUtil {//定义Map结构,key: 算法规则,value: 存放指定的计算方式privatestaticMap<String, Function<List<Integer>, Integer>> calculateMap =newHashMap<>();//静态代码块,初始化Map结构,定义指定算法规则的计算方式...
importorg.apache.flink.api.common.functions.RichMapFunction;importorg.apache.flink.api.java.ExecutionEnvironment;publicclassToUpperCaseFunctionextendsRichMapFunction<String,String>{@OverridepublicStringmap(Stringvalue){returnvalue.toUpperCase();}@Overridepublicvoidopen(Configurationparameters){// 可以用来初始化资源...
default voidreplaceAll(BiFunction<? superK,? superV,? extendsV> function) Replaces each entry's value with the result of invoking the given function on that entry until all entries have been processed or the function throws an exception. ...
但有种更优雅的做法是通过ImmutableMap<Integer, Function<Object, String>> 的方式去实现。 1publicstaticfinalImmutableMap<OrderStatus , Function<Order, String>> STATUS_HANDLERS =2ImmutableMap.<OrderStatus, Function<Order, String>>builder()3.put(OrderStatus.NEW, Order::handleNewOrder)4.put(OrderStatus....
constm=newMap();constfunctionKey=function(){};constsymbolKey=Symbol();constobjectKey=newObject();m.set(functionKey,"functionValue");m.set(symbolKey,"symbolValue");m.set(objectKey,"objectValue");alert(m.get(functionKey));// functionValuealert(m.get(symbolKey));// symbolValuealert(m.get...
Stream flatMap(Function<? super T, ? extends Stream<? extends R>> mapper) 转换流,将原Stream中的每个元素都转换成另一个Stream,然后把所有Stream连接成一个新的Stream。接收一个Function函数作为参数。 List<User> list = new ArrayList<>();
Vmerge(Kkey,Vvalue,BiFunction<? superV,? superV,? extendsV> remappingFunction) If the specified key is not already associated with a value or is associated with null, associates it with the given non-null value. Vput(Kkey,Vvalue) ...
It's mapper function produces multiple value for each input value.hence it is also called One-To-Many mapping. flattering flatMap()其实是两个方法的合并,map()好理解,主要是flattering。 Before Flattening: [[t,u], [v,w,x], [y,x]] ...
extends V> remappingFunction)1.4.3 Map 高级 API 的使用 getOrDefault() 当这个通过 key获取值，对应的 key 或者值不存在时返回默认值，避免在使用过程中 null 出现，避免程序异常。ForEach() 传入 BiConsumer 函数式接口，表达的含义其实和 Consumer 一样，都 accept 拥有方法，只是 BiConsumer 多了一个 and...
但是如果使用mapPartitions算子，但数据量非常大时，function一次处理一个分区的数据，如果一旦内存不足，...