关于Java中方法引用的示例

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());
    }
}