andThen(Function after):作用是将两个Function组合。首先执行当前函数,再执行andThen函数,并将当前函数的结果作为参数传递给andThen函数。 compose(Function before):同理,将两个Function组合,将先执行compose函数,再执行当前函数,并将compose函数的结果作为参数传递给当前函数。 identity(): 返回一个执行恒等转换的函数...
Java8的Predicate,让代码更简洁 在我们的代码中,经常会编写是否为真的代码,比如用户名是否存在,客户是否存在等。类似如下代码: public boolean exist(Long userId){ ... return false; } 这样做已经很棒了。但你需要了解一个java8的Predicate。通过Predicate可以让你的代码更加的简洁。学习下Predicate吧。 Predicate...
3.`Predicate`有默认实现的逻辑判断方法## Function接口### 基本使用见 [Java8 Function接口(apply compose andThen)](https://www.cnblogs.com/greatLong/articles/11975684.html)### 链式调用进阶使用首先定义接口`ProcessUnit`继承`Function`接口并提供`apply`方法的默认实现:> ProcessUnit.java public interface ...
public static String validInput(String name,Function<String,String> function) { return function.apply(name); } } 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 解释: 定义validInput 方法,传入 function 接口,然后在该方法中定义 function.apply(name),也就是说,传入一个 name 参数,应用某些规...
Implementation-wise, aPredicateis used to pass the behavior (functions) as arguments to methods. In simple words,aPredicateis essentially a boolean-valued function that takes an input and returnstrueorfalse. For reference, in mathematics as well, a predicate is commonly understood as a boolean-va...
Two countries from the list fulfill the conditions: Iran and India. The Predicate.isEqual method ThePredicate.isEqualreturns a predicate that tests if two arguments are equal according toObjects.equals. Main.java import java.util.List; import java.util.function.Predicate; ...
java.util.function.Predicate boolValue = x -> x > 5; System.out.println(boolValue.test(1));//false System.out.println(boolValue.test(6));//true } 第1行代码:定义一个Predicate实现,入参为Integer,返回传入参数与5做比较。 第2,3行代码调用第一行,传入相关参数。
* @param [operation] function that takes current accumulator value and an element, * and calculates the next accumulator value. * 匿名函数,该函数获取当前累加器值和一个元素,并计算下一个累加器值。 */publicinline fun<T,R>Iterable<T>.fold(initial:R,operation:(acc:R,T)->R):R{varaccumulator...
java.util.function Interface Predicate<T> Type Parameters: T- the type of the input to the predicate Functional Interface: This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference. ...
Learn to create aPredicatewith the negating effect that will match all the elementsnot matchingthe original predicate. Thenegated predicateacts as apass functionand selects all the elements from the stream that were filtered out by the original predicate. ...