86 lines
2.1 KiB
Markdown
86 lines
2.1 KiB
Markdown
# XML
|
||
|
||
语法：
|
||
|
||
## XML约束-schema约束
|
||
|
||
本质还是一个xml文件
|
||
|
||
|
||
|
||
### 代码演示：
|
||
|
||
**此为xsd文件**
|
||
|
||
complexType:复杂属性
|
||
|
||
sequence：序列 后可加maxOccurs来表示元素是否可为多个
|
||
|
||
attribute：属性 后可加属性标签来约束xml标签属性有什么为什么类型是否是必需
|
||
|
||
element：元素 后写名称来标识你在xml中应有的元素
|
||
|
||
```xml
|
||
<?xml version="1.0" encoding="UTF-8" ?>
|
||
<schema xmlns="http://www.w3.org/2001/XMLSchema"
|
||
targetNamespace="ice.cat.home"
|
||
elementFormDefault="qualified">
|
||
<element name="students">
|
||
<complexType>
|
||
<sequence maxOccurs="unbounded">
|
||
<element name="Student">
|
||
<complexType>
|
||
<sequence maxOccurs="unbounded">
|
||
<element name="name"></element>
|
||
<element name="age"></element>
|
||
</sequence>
|
||
<attribute name="id" type="string" use="required"/>
|
||
</complexType>
|
||
</element>
|
||
</sequence>
|
||
</complexType>
|
||
</element>
|
||
</schema>
|
||
```
|
||
|
||
**下方为约束效果**
|
||
|
||
```xml
|
||
<?xml version="1.0" encoding="UTF-8" ?>
|
||
<students xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"
|
||
xmlns = "ice.cat.home"
|
||
xsi:schemaLocation="ice.cat.home schema.xsd">
|
||
<Student id="1">
|
||
<name>张三</name>
|
||
<age>12</age>
|
||
<name>杏菜</name>
|
||
<age>14</age>
|
||
</Student>
|
||
</students>
|
||
```
|
||
|
||
## 解析：
|
||
|
||
将xml文件读取到Java
|
||
|
||
### SAX解析：
|
||
|
||
|
||
|
||
### DOM解析：
|
||
|
||
|
||
|
||
**一般用DOM**
|
||
|
||
**首先导入DOM4j的jar包**
|
||
|
||
方法：
|
||
|
||
<img src="imgh/image-20260106172208442.png" alt="image-20260106172208442" style="zoom: 67%;" />
|
||
|
||
### DOM解析代码：
|
||
|
||
<img src="https://gitee.com/icecat2233/picture/raw/master/20260106172046827.png" alt="image-20260106172045711" style="zoom:150%;" />
|
||
|