Java之Stream流及方法引用的详细解析二

public class Actor {
    private String name;
​
    public Actor(String name) {
        this.name = name;
    }
​
    public String getName() {
        return name;
    }
​
    public void setName(String name) {
        this.name = name;
    }
}

public class StreamTest {
    public static void main(String[] args) {
        //创建集合
        ArrayList<String> manList = new ArrayList<String>();
        manList.add("周润发");
        manList.add("成龙");
        manList.add("刘德华");
        manList.add("吴京");
        manList.add("周星驰");
        manList.add("李连杰");
        ArrayList<String> womanList = new ArrayList<String>();
        womanList.add("林心如");
        womanList.add("张曼玉");
        womanList.add("林青霞");
        womanList.add("柳岩");
        womanList.add("林志玲");
        womanList.add("王祖贤");
        //男演员只要名字为3个字的前三人
        Stream<String> manStream = manList.stream().filter(s -> s.length() == 3).limit(3);
        //女演员只要姓林的，并且不要第一个
        Stream<String> womanStream = womanList.stream().filter(s -> s.startsWith("林")).skip(1);
        //把过滤后的男演员姓名和女演员姓名合并到一起
        Stream<String> stream = Stream.concat(manStream, womanStream);
        // 将流中的数据封装成Actor对象之后打印
        stream.forEach(name -> {
            Actor actor = new Actor(name);
            System.out.println(actor);
        }); 
    }
}

public interface Printable {
    void printString(String s);
}
​
public class PrintableDemo {
    public static void main(String[] args) {
        //在主方法中调用usePrintable方法
//        usePrintable((String s) -> {
//            System.out.println(s);
//        });
        //Lambda简化写法
        usePrintable(s -> System.out.println(s));
​
        //方法引用
        usePrintable(System.out::println);
​
    }
​
    private static void usePrintable(Printable p) {
        p.printString("爱生活爱Java");
    }
}

public interface Converter {
    int convert(String s);
}
​
public class ConverterDemo {
    public static void main(String[] args) {
​
        //Lambda写法
        useConverter(s -> Integer.parseInt(s));
​
        //引用类方法
        useConverter(Integer::parseInt);
​
    }
​
    private static void useConverter(Converter c) {
        int number = c.convert("666");
        System.out.println(number);
    }
}

public class PrintString {
    //把字符串参数变成大写的数据，然后在控制台输出
    public void printUpper(String s) {
        String result = s.toUpperCase();
        System.out.println(result);
    }
}
​
public interface Printer {
    void printUpperCase(String s);
}
​
public class PrinterDemo {
    public static void main(String[] args) {
​
        //Lambda简化写法
        usePrinter(s -> System.out.println(s.toUpperCase()));
​
        //引用对象的实例方法
        PrintString ps = new PrintString();
        usePrinter(ps::printUpper);
​
    }
​
    private static void usePrinter(Printer p) {
        p.printUpperCase("HelloWorld");
    }
}

public interface MyString {
    String mySubString(String s,int x,int y);
}
​
public class MyStringDemo {
    public static void main(String[] args) {
        //Lambda简化写法
        useMyString((s,x,y) -> s.substring(x,y));
​
        //引用类的实例方法
        useMyString(String::substring);
​
    }
​
    private static void useMyString(MyString my) {
        String s = my.mySubString("HelloWorld", 2, 5);
        System.out.println(s);
    }
}

public class Student {
    private String name;
    private int age;
​
    public Student() {
    }
​
    public Student(String name, int age) {
        this.name = name;
        this.age = age;
    }
​
    public String getName() {
        return name;
    }
​
    public void setName(String name) {
        this.name = name;
    }
​
    public int getAge() {
        return age;
    }
​
    public void setAge(int age) {
        this.age = age;
    }
}
​
public interface StudentBuilder {
    Student build(String name,int age);
}
​
public class StudentDemo {
    public static void main(String[] args) {
​
        //Lambda简化写法
        useStudentBuilder((name,age) -> new Student(name,age));
​
        //引用构造器
        useStudentBuilder(Student::new);
​
    }
​
    private static void useStudentBuilder(StudentBuilder sb) {
        Student s = sb.build("林青霞", 30);
        System.out.println(s.getName() + "," + s.getAge());
    }
}