建造者模式 就是建造不同的东西,但是基本流程不变,将复杂的对象的构建与它的表示分离,使得同样的构建过程可以创建不同的表示。 //构建产品 public class Person { private String head; private String body; private String foot; public String getHead() { return head; } public void setHead(String head) { this.head = head; } public String getBody() { return body; } public void setBody(String body) { this.body = body; } public String getFoot() { return foot; } public void setFoot(String foot) { this.foot = foot; }
}
//产品接口 public interface PersonBuilder { void buildhead(); void buildbody(); void buildfoot(); Person buildperson(); }
//实例一个产品 public class ManBuilder implements PersonBuilder{
Person person;
public ManBuilder(){
person = new Person();
}
public void buildhead() {
person.setHead("建造男人的头");
}
public void buildbody() {
person.setBody("建造男人的身体");
}
public void buildfoot() {
person.setFoot("建造男人的脚");
}
public Person buildperson() {
return person;
}
}
//调用具体建造者来创建对象的各个部分,不涉及具体信息, //之负责保证对象各部分完整创建。 public class PersonDirector { public Person constructPerson(PersonBuilder pb){ pb.buildbody(); pb.buildfoot(); pb.buildhead(); return pb.buildperson(); } }
public class Test {
public static void main(String[] args) {
// TODO Auto-generated method stub
PersonDirector pd=new PersonDirector();
Person person=pd.constructPerson(new ManBuilder());
System.out.println(person.getHead());
System.out.println(person.getBody());
System.out.println(person.getFoot());
}
}
1.浅复制 被复制对象的所有变量都含有与原来的对象相同的值,而所有的对其他对象的引用仍然指向原来的对象,浅复制仅仅复制所考虑的对象,而不复制它所引用的对象。
//浅拷贝 public class Person implements Cloneable{ private int age; private String name; public Person(int age,String name){ this.age=age; this.name=name; } public Person(){} public int getAge(){ return age; } public String getName(){ return name; } public static void main(String[] args){ Person p=new Person(23,”ha “); Person p1=null; try { p1 = (Person)p.clone(); //克隆 } catch (CloneNotSupportedException e) { // TODO Auto-generated catch block e.printStackTrace(); } //测试p和p1是否指向同一对象 String result=p.getName()== p1.getName()?”clone是浅拷贝”:”clone是深拷贝”; System.out.println(result); }
}
2、深复制 被复制对象的所有变量都含有与原来的对象相同的值,但不指向原来的对象。 class Professor implements Cloneable { String name; int age; Professor(String name,int age) { this.name=name; this.age=age; } public Object clone() { Object o=null; try { o=super.clone(); //对o也进行克隆 } catch(CloneNotSupportedException e) { System.out.println(e.toString()); } return o; } }
class Student implements Cloneable { String name; int age; Professor p; Student(String name,int age,Professor p) { this.name=name; this.age=age; this.p=p; } public Object clone() { Student o=null; try { o=(Student)super.clone();
}
catch(CloneNotSupportedException e)
{
System.out.println(e.toString());
}
o.p= (Professor)p.clone();//关键句
return o;
} } public class DeepCopy{ public static void main(String[] args) { Professor p=new Professor(“wangwu”,50); Student s1=new Student(“zhangsan”,18,p); Student s2=(Student)s1.clone(); s2.p.name=”lisi”; s2.p.age=30; System.out.println(“name=”+s1.p.name+”,”+”age=”+s1.p.age); System.out.println(“name=”+s2.p.name+”,”+”age=”+s2.p.age); } }