直接上示例：
private String name;
private int age;
private List<String> friends;
public Foo setName(String name) {
this.name = name;
return this;
}
public Foo setAge(int age) {
this.age = age;
return this;
}
public Foo setFriends(List<String> friends) {
this.friends = friends;
return this;
}
好处：
Foo foo = new Foo();
foo.setName("Tom")
.setAge(25)
.setFriends(Lists.newArrayList("Jack", "Lily"));