（Java学习笔记-01）考虑用静态工厂方法代替构造器 - JAVA

s
Services.registerDefaultProvider(DEFAULT_PROVIDER);
Services.registerProvider("comp", COMP_PROVIDER);
Services.registerProvider("armed", ARMED_PROVIDER);

// Clients would execute these lines
Service s1 = Services.newInstance();
Service s2 = Services.newInstance("comp");
Service s3 = Services.newInstance("armed");
System.out.printf("%s, %s, %s%n", s1, s2, s3);
}

private static Provider DEFAULT_PROVIDER = new Provider() {
public Service newService() {
return new Service() {
@Override public String toString() {
return "Default service";
}
};
}
};

private static Provider COMP_PROVIDER = new Provider() {
public Service newService() {
return new Service() {
@Override public String toString() {
return "Complementary service";
}
};
}
};

private static Provider ARMED_PROVIDER = new Provider() {
public Service newService() {
return new Service() {
@Override public String toString() {
return "Armed service";
}
};
}
};
}

摘自 horsttnann的专栏

（Java学习笔记-01）考虑用静态工厂方法代替构造器 (二)