publicclassDom4JHelloWorld {
@TestpublicvoidparseXMLData() throwsException {
// 1.创建一个Dom4j的解析器对象，代表整个dom4j框架SAXReadersaxReader=newSAXReader();
// 2.把XML文件加载到内存中称为一个Document文档对象//        Document document = saxReader.read(new File("day15_xml_app\\src\\Contacts.xml"));// 此种通过File对象寻找的方式的缺点：需要通过模块名寻找，一旦模块名被修改，会找不到// getResourceAsStream中的"/"是直接去src下寻找文件InputStreamis=Dom4JHelloWorld.class.getResourceAsStream("/Contacts.xml");
// 通过此种方式找到文件字节输入流，再传递给read方法，即使模块名修改，不影响找到该xml文件Documentdocument=saxReader.read(is);
// 获取根元素Elementroot=document.getRootElement();
System.out.println(root.getName()); // contactList    }
}

publicclassContact {
privateintid;
privatebooleanvip;
privateStringname;
privatecharsex;
privateStringemail;
publicContact() {
    }
publicContact(intid, booleanvip, Stringname, charsex, Stringemail) {
this.id=id;
this.vip=vip;
this.name=name;
this.sex=sex;
this.emai=email;
    }
publicintgetId() {
returnid;
    }
publicvoidsetId(intid) {
this.id=id;
    }
publicbooleanisVip() {
returnvip;
    }
publicvoidsetVip(booleanvip) {
this.vip=vip;
    }
publicStringgetName() {
returnname;
    }
publicvoidsetName(Stringname) {
this.name=name;
    }
publicchargetSex() {
returnsex;
    }
publicvoidsetSex(charsex) {
this.sex=sex;
    }
publicStringgetEmail() {
returnemail;
    }
publicvoidsetEmail(Stringemail) {
this.emai=email;
    }
@OverridepublicStringtoString() {
return"Contact{"+"id="+id+", vip="+vip+", name='"+name+'\''+", sex="+sex+", email='"+emai+'\''+'}';
    }
}

publicclassDom4JTest2 {
@TestpublicvoidparseToList() throwsException {
// 1.导入Dom4J框架// 2.创建SAXReader对象SAXReadersaxReader=newSAXReader();
// 3.加载XML文件称为Document对象Documentdocument=saxReader.read(Dom4JTest2.class.getResourceAsStream("/Contacts.xml"));
// 4.获取根元素Elementroot=document.getRootElement();
// 5.提取contact子元素List<Element>contactEles=root.elements("contact");
// 6.准备ArrayList集合封装联系人信息List<Contact>contactList=newArrayList<>();
// 7.遍历contact子元素for (ElementcontactEle : contactEles) {
// xml文件中的值都是文本，需要使用包装类进行类型转换// 此处不能用强转，需要使用类型转换，强转必须保证被强转的变量类型就是强转后的类型才可以intcontactId=Integer.valueOf(contactEle.attributeValue("id"));
booleancontactIsVip=Boolean.valueOf(contactEle.attributeValue("vip"));
StringcontactName=contactEle.elementTextTrim("name");
charcontactSex=contactEle.elementTextTrim("gender").charAt(0);
StringcontactEmai=contactEle.elementTextTrim("email");
// 8.每一个子元素都是一个联系人对象// 9.把联系人对象加入到contactList集合中contactList.add(newContact(contactId, contactIsVip,
contactName, contactSex, contactEmail));
        }
// 10.遍历contactList集合for (Contactcontact : contactList) {
System.out.println(contact);
        }
    }
}

publicabstractclassComputer {
privateStringname;
privatedoubleprice;
publicComputer() {
    }
abstractvoidstart();
publicStringgetName() {
returnname;
    }
publicvoidsetName(Stringname) {
this.name=name;
    }
publicdoublegetPrice() {
returnprice;
    }
publicvoidsetPrice(doubleprice) {
this.price=price;
    }
}

publicclassMacextendsComputer{
@Overridevoidstart() {
System.out.println(this.getName() +"苹果电脑启动了");
    }
}

publicclassHuaweiextendsComputer{
@Overridevoidstart() {
System.out.println(this.getName() +"华为电脑启动了");
    }
}

publicclassFactoryPattern {
/*定义一个方法，创建对象并返回*/publicstaticComputercreatComputer(Stringinfo) {
switch (info) {
case"华为":
Computerc=newHuawei();
c.setName("Huawei pro 16");
c.setPrice(5999);
returnc;
case"苹果":
Computerc2=newMac();
c2.setName("Mac pro 2");
c2.setPrice(11999);
returnc2;
default:
returnnull;
        }
    }
}

publicclassFactoryDemo {
publicstaticvoidmain(String[] args) {
Computerc1=FactoryPattern.creatComputer("华为");
c1.start(); // Huawei pro 16华为电脑启动了Computerc2=FactoryPattern.creatComputer("苹果");
c2.start(); // Mac pro 2苹果电脑启动了    }
}

publicabstractclassInputStream {
publicabstractintread();
publicabstractintread(byte[] buffer);
}

publicclassFileInputStreamextendsInputStream {
@Overridepublicintread() {
System.out.println("以低性能的方式读取了一个字节a");
return97;
    }
@Overridepublicintread(byte[] buffer) {
buffer[0] =97;
buffer[1] =98;
buffer[2] =99;
System.out.println("以低性能的方式读取了一个字节数组"+Arrays.toString(buffer));
return3;
    }
}

publicclassBufferedInputStreamextendsInputStream {
privateInputStreamis;
publicBufferedInputStream(InputStreamis) {
this.is=is;
    }
@Overridepublicintread() {
System.out.println("提供8kb的缓冲区，提高读取性能");
returnthis.is.read();
    }
@Overridepublicintread(byte[] buffer) {
System.out.println("提供8kb的缓冲区，提高读取性能");
returnthis.is.read(buffer);
    }
}

publicclassDecoratorPattern {
publicstaticvoidmain(String[] args) {
InputStreamis=newBufferedInputStream(newFileInputStream());
System.out.println(is.read());
System.out.println(is.read(newbyte[3]));
    }
}