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1.垃圾数据冗余,我们要求输错了就要给提示,而不是默认!
class Person{ private String name; private String sex; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getSex() { return sex; } public void setSex(String sex) { if ("man".equalsIgnoreCase(sex) || "woman".equalsIgnoreCase(sex)) { this.sex = sex; }else{ this.sex = "man"; } } } public class EnumTest { public static void main(String[] args) { Person p = new Person(); p.setName("张三"); p.setSex("人妖"); System.out.println(p.getName()+"的性别是:"+p.getSex());//张三的性别是:man } }
2.优化 抛出异常,但是是运行时异常,我们想要的是在编译的时候就给我们提示,所以还是要继续优化...
public void setSex(String sex) {
if ("man".equalsIgnoreCase(sex) || "woman".equalsIgnoreCase(sex)) {
this.sex = sex;
}else{
throw new RuntimeException("性别不能乱输呀");
}
}
3.继续优化: Enum的雏形到来了
class Person{
private String name;
private Gender sex;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Gender getSex() {
return sex;
}
public void setSex(Gender sex) {//接收Gender类型
this.sex = sex ;
}
}
class Gender{//Enum的爷爷
String gender ;
private Gender(String gender){this.gender = gender;}//构造器私有化,防止别人new 对象,随意改变数据!
public static final Gender MAN = new Gender("man");
public static final Gender WOMAN = new Gender("wowan");
}
public class EnumTest {
public static void main(String[] args) {
Person p = new Person();
p.setName("张三");
p.setSex(Gender.WOMAN);
System.out.println(p.getName()+"的性别是:"+p.getSex().gender);//张三的性别是:wowan
}
}
4.Enum到来了!春天来了...
enum Gender{
MAN("man"),WOWAN("woman"); //枚举值必须放置第一行
String gender;
private Gender(String gender){this.gender = gender;}
}
public class EnumTest {
public static void main(String[] args) {
Person p = new Person();
p.setName("张三");
p.setSex(Gender.MAN);
System.out.println(p.getName()+"的性别是:"+p.getSex().gender);//张三的性别是:man
}
}
5.enum注意事项:
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原文地址：http://www.cnblogs.com/bravolove/p/5851467.html
