69期-Java SE-029_XML解析

- 日理万妓 2021-12-03 15:43 239阅读 0赞

### 综合练习
    
    使用 Socket 和多线程编写一个简单的聊天小程序，要求客户端和服务端交替发送消息，在客户端和服务端都能看到彼此的聊天记录。
    
    Server
    
    ```java
    import java.io.IOException;
    import java.net.ServerSocket;
    import java.net.Socket;
    
    public class Server {
        public static void main(String[] args) {
            ServerSocket serverSocket = null;
            Socket socket = null;
            try {
                serverSocket = new ServerSocket(8080);
                System.out.println("服务端已启动");
                while(true) {
                    socket = serverSocket.accept();
                    new Thread(new SocketThread(socket)).start();;
                }
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
    ```
    
    ServerThread
    
    ```java
    import java.io.DataInputStream;
    import java.io.DataOutputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.OutputStream;
    import java.net.Socket;
    import java.util.Scanner;
    
    public class SocketThread implements Runnable {
        private Socket socket;
        public SocketThread(Socket socket) {
            this.socket = socket;
        }
        @Override
        public void run() {
            // TODO Auto-generated method stub
            InputStream inputStream = null;
            DataInputStream dataInputStream = null;
            Scanner scanner = new Scanner(System.in);
            String message = null;
            OutputStream outputStream = null;
            DataOutputStream dataOutputStream = null;
            try {
                while(true) {
                    //读
                    inputStream = socket.getInputStream();
                    dataInputStream = new DataInputStream(inputStream);
                    message = dataInputStream.readUTF();
                    System.out.println("客户端："+message);
                    //写
                    System.out.print("服务器：");
                    message = scanner.next();
                    outputStream = socket.getOutputStream();
                    dataOutputStream = new DataOutputStream(outputStream);
                    dataOutputStream.writeUTF(message);
                }
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }finally {
                try {
                    dataOutputStream.close();
                    outputStream.close();
                    dataInputStream.close();
                    inputStream.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }
    ```
    
    Client
    
    ```java
    import java.io.DataInputStream;
    import java.io.DataOutputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.OutputStream;
    import java.net.Socket;
    import java.net.UnknownHostException;
    import java.util.Scanner;
    
    public class Client {
        public static void main(String[] args) {
            Socket socket = null;
            InputStream inputStream = null;
            DataInputStream dataInputStream = null;
            OutputStream outputStream = null;
            DataOutputStream dataOutputStream = null;
            System.out.println("客户端已启动...");
            try {
                socket = new Socket("127.0.0.1", 8080);
                Scanner scanner = new Scanner(System.in);
                String message = null;
                while(true) {
                    //写
                    System.out.print("客户端：");
                    message = scanner.next();
                    outputStream = socket.getOutputStream();
                    dataOutputStream = new DataOutputStream(outputStream);
                    dataOutputStream.writeUTF(message);
                    //读
                    inputStream = socket.getInputStream();
                    dataInputStream = new DataInputStream(inputStream);
                    message = dataInputStream.readUTF();
                    System.out.println("服务器："+message);
                }
            } catch (UnknownHostException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }finally {
                try {
                    dataInputStream.close();
                    inputStream.close();
                    dataOutputStream.close();
                    outputStream.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }
    ```
    
    
    
    ### XML 解析
    
    XML：Extensible Markup Language 可扩展标记语言
    
    特点：
    
    XML 与操作系统无关、与编程语言无关，可以实现不同系统之间的数据交换。
    
    XML 文档内容由一系列标签元素组成
    
    <标签名 属性名="属性值">元素内容</标签名>
    
    - 属性值用双引号包裹
    - 一个元素可以包含多个属性
    - 属性值中不能直接包含<、>、"、&、'
    
    ```xml
    <?xml version="1.0" encoding="UTF-8"?>
    <books>
        <book id="001">
            <author>张三</author>
            <name>Java高级编程</name>
            <description>Java是一门面向对象高级编程语言</description>
        </book>
        <book id="002" author="李四" name="C#" description="面向对象"></book>
    </books>
    ```
    
    注意事项
    
    - 所有 XML 元素都必须有结束标签
    - XML 标签对大小写敏感
    - XML 必须有正确的嵌套
    - 同级标签以缩进对齐
    - 元素名称可以包含字母、数字或其他字符
    - 元素名称不能以数字或标点符号开头
    - 元素名称不能包含空格
    
    XML 的转义字符
    
    特殊字符：<    >    "    '    &
    
    转义符：
    
    ```
    <    >    "    '    &
    ```
    
    
    
    衣服型号                            对应身高
    
    S                                                <165
    
    M                                            165-170
    
    L                                              170-175
    
    XL                                            175-180
    
    XXL                                            180-185
    
    ```xml
    <?xml version="1.0" encoding="UTF-8"?>
    <cloth>
        <size range="height>165">S</size>
        <size range="165<height<170">M</size>
        <size range="170<height<175">L</size>
        <size range="175<height<180">XL</size>
        <size range="180<height<185">XXL</size>
    </cloth>
    ```
    
    
    
    考生姓名            预计得分            实际得分
    
    张三                        75                        80
    
    李四                        75                        88
    
    ```xml
    <?xml version="1.0" encoding="UTF-8"?>
    <students>
        <student name="张三" expected_score="75" score="80"></student>
        <student name="李四" expected_score="75" score="88"></student>
    </students>
    ```
    
    
    
    ### 解析XML
    
    用 Java 程序读取、操作 XML 文件中的数据
    
    dom4j 主流的 Java XML API，性能优异，功能强大。
    
    ```xml
    <?xml version="1.0" encoding="GBK"?>
    <phoneinfo id="1">
        <brand name="华为">
            <type name="U8650"></type>
            <type name="HW123"></type>
            <type name="HW321"></type>
        </brand>
        <brand name="苹果">
            <type name="iPhone"></type>
        </brand>
        <brand name="三星">
            <type name="Note4"></type>
        </brand>
    </phoneinfo>
    ```
    
    ```java
    import java.util.Iterator;
    
    import org.dom4j.Document;
    import org.dom4j.DocumentException;
    import org.dom4j.Element;
    import org.dom4j.io.SAXReader;
    
    public class Test {
        public static void main(String[] args) {
            SAXReader saxReader = new SAXReader();
            try {
                Document document = saxReader.read("src/phone.xml");
                //获取根节点
                Element root = document.getRootElement();
                Iterator<Element> rootIter = root.elementIterator();
                while(rootIter.hasNext()) {
                    Element ele = rootIter.next();
                    String name = ele.attributeValue("name");
                    System.out.println(name);
                    Iterator<Element> eleIter = ele.elementIterator();
                    while(eleIter.hasNext()) {
                        Element type = eleIter.next();
                        String typeName = type.attributeValue("name");
                        System.out.println(typeName);
                    }
                }
            } catch (DocumentException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
    ```
    
    ```java
    import java.io.FileWriter;
    import java.io.IOException;
    import java.io.OutputStream;
    import java.io.Writer;
    
    import org.dom4j.Document;
    import org.dom4j.DocumentException;
    import org.dom4j.Element;
    import org.dom4j.io.OutputFormat;
    import org.dom4j.io.SAXReader;
    import org.dom4j.io.XMLWriter;
    
    public class Test2 {
        public static void main(String[] args) {
            SAXReader saxReader = new SAXReader();
            try {
                Document document = saxReader.read("src/phone.xml");
                Element root = document.getRootElement();
                Element newEle = root.addElement("brand");
                newEle.addAttribute("name", "Vivo");
                Element type = newEle.addElement("type");
                type.addAttribute("name", "型号1");
                OutputFormat format = OutputFormat.createPrettyPrint();
                format.setEncoding("UTF-8");
                Writer fileWriter = new FileWriter("src/phone.xml");
                XMLWriter writer = new XMLWriter(fileWriter,format);
                writer.write(document);
                writer.close();
            } catch (DocumentException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
    ```

![1603260-20190711231543102-223523771.png][]

Client.java

import java.io.DataInputStream;
    import java.io.DataOutputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.OutputStream;
    import java.net.Socket;
    import java.net.UnknownHostException;
    import java.util.Scanner;
    
    public class Client {
        public static void main(String[] args) {
            Socket socket = null;
            InputStream inputStream = null;
            DataInputStream dataInputStream = null;
            OutputStream outputStream = null;
            DataOutputStream dataOutputStream = null;
            System.out.println("客户端已启动...");
            try {
                socket = new Socket("127.0.0.1", 8080);
                Scanner scanner = new Scanner(System.in);
                String message = null;
                while(true) {
                    //写
                    System.out.print("客户端：");
                    message = scanner.next();
                    outputStream = socket.getOutputStream();
                    dataOutputStream = new DataOutputStream(outputStream);
                    dataOutputStream.writeUTF(message);
                    //读
                    inputStream = socket.getInputStream();
                    dataInputStream = new DataInputStream(inputStream);
                    message = dataInputStream.readUTF();
                    System.out.println("服务器："+message);
                }
            } catch (UnknownHostException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }finally {
                try {
                    dataInputStream.close();
                    inputStream.close();
                    dataOutputStream.close();
                    outputStream.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }

cloth.xml

<?xml version="1.0" encoding="UTF-8"?>
    <cloth>
        <size range="height>165">S</size>
        <size range="165<height<170">M</size>
        <size range="170<height<175">L</size>
        <size range="175<height<180">XL</size>
        <size range="180<height<185">XXL</size>
    </cloth>

phone.xml

<?xml version="1.0" encoding="UTF-8"?>
    
    <phoneinfo id="1"> 
      <brand name="华为"> 
        <type name="U8650"/>  
        <type name="HW123"/>  
        <type name="HW321"/> 
      </brand>  
      <brand name="苹果"> 
        <type name="iPhone"/> 
      </brand>  
      <brand name="三星"> 
        <type name="Note4"/> 
      </brand>  
      <brand name="Vivo"/>  
      <brand name="Vivo">
        <type name="型号1"/>
      </brand>
    </phoneinfo>

score.xml

<?xml version="1.0" encoding="UTF-8"?>
    <students>
        <student name="张三" expected_score="75" score="80"></student>
        <student name="李四" expected_score="75" score="88"></student>
    </students>

Server.java

import java.io.IOException;
    import java.net.ServerSocket;
    import java.net.Socket;
    
    public class Server {
        public static void main(String[] args) {
            ServerSocket serverSocket = null;
            Socket socket = null;
            try {
                serverSocket = new ServerSocket(8080);
                System.out.println("服务端已启动");
                while(true) {
                    socket = serverSocket.accept();
                    new Thread(new SocketThread(socket)).start();;
                }
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }

SocketThread.java

import java.io.DataInputStream;
    import java.io.DataOutputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.OutputStream;
    import java.net.Socket;
    import java.util.Scanner;
    
    public class SocketThread implements Runnable {
        private Socket socket;
        public SocketThread(Socket socket) {
            this.socket = socket;
        }
        @Override
        public void run() {
            // TODO Auto-generated method stub
            InputStream inputStream = null;
            DataInputStream dataInputStream = null;
            Scanner scanner = new Scanner(System.in);
            String message = null;
            OutputStream outputStream = null;
            DataOutputStream dataOutputStream = null;
            try {
                while(true) {
                    //读
                    inputStream = socket.getInputStream();
                    dataInputStream = new DataInputStream(inputStream);
                    message = dataInputStream.readUTF();
                    System.out.println("客户端："+message);
                    //写
                    System.out.print("服务器：");
                    message = scanner.next();
                    outputStream = socket.getOutputStream();
                    dataOutputStream = new DataOutputStream(outputStream);
                    dataOutputStream.writeUTF(message);
                }
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }finally {
                try {
                    dataOutputStream.close();
                    outputStream.close();
                    dataInputStream.close();
                    inputStream.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    
    }

Test.java

import java.util.Iterator;
    
    import org.dom4j.Document;
    import org.dom4j.DocumentException;
    import org.dom4j.Element;
    import org.dom4j.io.SAXReader;
    
    public class Test {
        public static void main(String[] args) {
            SAXReader saxReader = new SAXReader();
            try {
                Document document = saxReader.read("src/phone.xml");
                //获取根节点
                Element root = document.getRootElement();
                Iterator<Element> rootIter = root.elementIterator();
                while(rootIter.hasNext()) {
                    Element ele = rootIter.next();
                    String name = ele.attributeValue("name");
                    System.out.println(name);
                    Iterator<Element> eleIter = ele.elementIterator();
                    while(eleIter.hasNext()) {
                        Element type = eleIter.next();
                        String typeName = type.attributeValue("name");
                        System.out.println(typeName);
                    }
                }
            } catch (DocumentException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }

test.xml

<?xml version="1.0" encoding="UTF-8"?>
    <books>
        <book id="001">
            <author>张三</author>
            <name>Java高级编程</name>
            <description>Java是一门面向对象高级编程语言</description>
        </book>
        <book id="002" author="李四" name="C#" description="面向对象"></book>
    </books>

Test2.java

import java.io.FileWriter;
    import java.io.IOException;
    import java.io.OutputStream;
    import java.io.Writer;
    
    import org.dom4j.Document;
    import org.dom4j.DocumentException;
    import org.dom4j.Element;
    import org.dom4j.io.OutputFormat;
    import org.dom4j.io.SAXReader;
    import org.dom4j.io.XMLWriter;
    
    public class Test2 {
        public static void main(String[] args) {
            SAXReader saxReader = new SAXReader();
            try {
                Document document = saxReader.read("src/phone.xml");
                Element root = document.getRootElement();
                Element newEle = root.addElement("brand");
                newEle.addAttribute("name", "Vivo");
                Element type = newEle.addElement("type");
                type.addAttribute("name", "型号1");
                OutputFormat format = OutputFormat.createPrettyPrint();
                format.setEncoding("UTF-8");
                Writer fileWriter = new FileWriter("src/phone.xml");
                XMLWriter writer = new XMLWriter(fileWriter,format);
                writer.write(document);
                writer.close();
            } catch (DocumentException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }

转载于:https://www.cnblogs.com/HiJackykun/p/11173474.html

[1603260-20190711231543102-223523771.png]: /images/20211203/0b781b9f74c544a98b2d2db761110469.png