有参构造函数效率高。Autowired public CDPlayer(CompactDisc cd, Power power) { this.cd cd; this.power power; System.out.println(CDPlayer多参构造函数); }成员变量利用反射效率低。Autowired private Power power;setter 方法private CompactDisc cd; Autowired public void setCd(CompactDisc cd) { this.cd cd; System.out.println(调用 setCd); }用在任意一个方法上private CompactDisc cd; private Power power; Autowired public void prepare(CompactDisc cd, Power power){ this.cd cd; this.power power; System.out.println(调用prepare); }