Java 8新特性方法引用详细介绍

/** *   静态方法引用 * @param <P> 引用方法的参数类型 * @param <R> 引用方法的返回类型 */@FunctionalInterfaceinterface FunStaticRef<P,R>{  public R tranTest(P p);}public static void main(String[] args) {    /*    *  静态方法引用: public static String valueOf    *   即将String的valueOf() 方法引用为 FunStaticRef#tranTest 方法    */    FunStaticRef<Integer, String> funStaticRef = String::valueOf;    String str = funStaticRef.tranTest(10000);    System.out.println(str.replaceAll("0", "9"));}

/** *  普通方法引用 * @param <R> 引用方法返回类型 */@FunctionalInterfaceinterface InstanRef<R>{  public R upperCase();}public static void main(String[] args) {     /*   * 普通方法的引用: public String toUpperCase()   *   */   String str2 = "i see you";   InstanRef<String> instanRef = str2 :: toUpperCase;   System.out.println(instanRef.upperCase());}

　/** * 特定方法的引用 * @param <P> */@FunctionalInterfaceinterface SpecificMethodRef<P>{  public int compare(P p1 , P p2);}public static void main(String[] args) {   /*    * 特定方法的引用 public int compareTo(String anotherString)    *  与之前相比，方法引用前不再需要定义对象，而是可以理解为将对象定义在了参数上！    */   SpecificMethodRef<String> specificMethodRef = String :: compareTo;   System.out.println(specificMethodRef.compare("A","B"));   ConstructorRef<Book> constructorRef = Book :: new;   Book book = constructorRef.createObject("Java",100.25);   System.out.println(book);}

class Book{  private String title;  private double price;  public Book() {  }  public Book(String title,double price){    this.price = price;    this.title = title;  }  @Override  public String toString() {    return "Book{" +"title='" + title + '/'' +", price=" + price +'}';  }}public static void main(String[] args) {  /*   * 构造方法引用   */  ConstructorRef<Book> constructorRef = Book :: new;  Book book = constructorRef.createObject("Java",100.25);  System.out.println(book);}