Java Predicate接口定义详解

@FunctionalInterface
public interface Predicate<T> {
    boolean test(T t);
}  

// Remove persons older than 18   
list.removeIf(person -> person.age > 18);  
// Check if "Hello" starts with "H"
if (startsWith("H")) { ... } 
Predicate<String> startsWithH = s -> s.startsWith("H");
// Check if person has empty name
Predicate<Person> nameNotEmpty = person -> !person.name.isEmpty(); 
// Use Predicate to filter candidates 
selectCandidates(candidates, candidate -> candidate.age > 30 && 
                                       candidate.skills.contains("Java"));

/**
     * 接收执行 predicate 表达式
     * @param predicateLamda
     * @param str
     * @return
     */
    public  static boolean checkString(Predicate<String> predicateLamda,String str){
        return predicateLamda.test(str);
    }

public static void main(String[] args) {
        // predicate 表达式
       boolean result1= checkString(str->str.equals("liyanbo"), "woshi liyanbo");
        System.out.println("result1 = " + result1);
}

/**
     * BiFunction  两个传入参数，一个返回参数
     * @param biFunction
     * @param firstName
     * @param secondName
     * @return
     */
    public  static  Integer getBiFunction(BiFunction<String,String,Integer> biFunction,String firstName,String secondName){
        //String handleName= biFunction.apply(firstName,secondName);// 处理完这个后还可以 有其它逻辑处理
        Integer handleName= biFunction.apply(firstName,secondName);// 处理完这个后还可以 有其它逻辑处理
        return  handleName+1;
    }

public static void main(String[] args) {    //BiFunction  两个传入参数，一个返回参数
//        BiFunction<String, String, String> biFunction = (firstName, lastName) -> firstName + " " + lastName;
//        String fullName = biFunction.apply("Bill","John");
        Integer fullName=getBiFunction((firstName, lastName) -> (firstName + " " + lastName).length(),"li","yanbo");
        System.out.println(fullName);     
    }

package com.multiplethread.multiplethread;
@FunctionalInterface
public interface FunctionInterfaceRealize {
    public  String  getHandleResult(Integer l,Integer p);
}

/**
     * 调用 functionInterface 函数式接口
     * @param functionInterfaceRealize
     * @param arg1
     * @param arg2
     * @return
     */
    public static  String getFunctionInterFace(FunctionInterfaceRealize functionInterfaceRealize,Integer arg1,Integer arg2){
         String handleResult= functionInterfaceRealize.getHandleResult(arg1,arg2);
         handleResult=handleResult+"123";
         return  handleResult;
    }

public static void main(String[] args) {     
        // 定义 functionInterFace ,并做相应的逻辑处理
        String handleResult=getFunctionInterFace((x,y)->(x.toString()+y.toString()),1,2);
    }