xml解析

package XMLParse;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.util.Iterator;
import java.util.List;

import org.dom4j.Attribute;
import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.Node;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;

/**
 * dom4j解析xml 对内存消耗小，可进行crud操作
 * 
 * @author l
 */
public class Dom4jParseXml {

    private static final String path = "src/student.xml";
    private static final String newPath = "src/books.xml";
    private static final String book = "src/book.xml";

    public static void readXml() {

    }

    public static void writeToXml(Document document) throws Exception {

        FileOutputStream fileOutputStream = new FileOutputStream(book);
        OutputStreamWriter outputStreamWriter = new OutputStreamWriter(
                fileOutputStream, "utf-8");
        XMLWriter writer = new XMLWriter(outputStreamWriter);
        writer.write(document);
        writer.close();

    }

    public static void update(Document document) throws Exception {
        String pattern = "//book[@id='b3']/title";
        Node node = document.selectSingleNode(pattern);
        System.out.println(node.getText());
        node.setText("java疯狂讲义");
        System.out.println(node.getText());
        // FileOutputStream fileOutputStream = new FileOutputStream(book);
        // OutputStreamWriter outputStreamWriter = new OutputStreamWriter(
        // fileOutputStream, "utf-8");
        // XMLWriter writer = new XMLWriter(outputStreamWriter);
        // writer.write(document);
        // writer.close();
    }

    public static void delete(Document document) throws Exception {

        Element root = document.getRootElement();
        for (Iterator<?> it = root.elementIterator(); it.hasNext();) {
            Element book = (Element) it.next();
            String id = book.attributeValue("id");
            if ("1".equals(id)) {
                Element parent = book.getParent();
                parent.remove(book);
            }
        }

        // Node node = (Element) document.selectSingleNode("//book[@id='b3']");
        // System.out.println(node);
        // Element parent = node.getParent();
        // System.out.println(parent);
        // parent.remove(node);
        // System.out.println(parent);
    }

    public static void main(String[] args) throws Exception {
        // 获取解析器
        SAXReader saxReader = new SAXReader();
        // 指定解析那个文件
        Document document = saxReader.read(book);
        // 可以使用xpath随心所欲读取
        // List element = document.selectNodes("/class/student/name");
        // // System.out.println(((Attribute) element.get(0)).getText());
        // for (int i = 0; i < element.size(); i++) {
        // System.out.println(((Element) element.get(i)).getText());
        // }

        //

        //delete(document);
         update(document);

        // FileOutputStream fileOutputStream = new FileOutputStream(book);
        // OutputStreamWriter outputStreamWriter = new OutputStreamWriter(
        // fileOutputStream, "utf-8");
        // XMLWriter writer = new XMLWriter(outputStreamWriter);
        // writer.write(document);
        // writer.close();         
        writeToXml(document);
        
    }

}

package XMLParse;

import java.io.File;
import java.io.IOException;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

/**
 * desc:通过dom技术解析xml文件，实现crud操作
 * 
 * @author lc
 */
public class DomParseXml {

    private static final String path = "src/student.xml";

    public static void read(Document document)
            throws TransformerConfigurationException {
        NodeList nodeList = document.getElementsByTagName("student");

        Element element = (Element) nodeList.item(0);
        System.out.println("该学生的年龄是：" + element.getAttribute("age"));
        Element name = (Element) element.getElementsByTagName("age").item(0);
        System.out.println(name.getTextContent());
        TransformerFactory tf = TransformerFactory.newInstance();
        Transformer t = tf.newTransformer();
        try {
            t.transform(new DOMSource(document), new StreamResult(path));
        } catch (TransformerException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }

    public static void readXml(Document document) {

        NodeList nodeList = document.getElementsByTagName("student");
        System.out.println(nodeList.getLength());
        
        for (int i = 0; i < nodeList.getLength(); i++) {

            Element stu = (Element) nodeList.item(i);
//            String name = stu.getElementsByTagName("name").item(0).getFirstChild().getNodeValue();
//            System.out.println(name);
//            String age = stu.getElementsByTagName("age").item(0).getFirstChild().getNodeValue();
//            System.out.println(age);
//            String introduce =  stu.getElementsByTagName("introduce").item(0).getFirstChild().getNodeValue();
//            System.out.println(introduce);
            
            Element name = (Element)stu.getElementsByTagName("name").item(0);
            System.out.println(name.getTextContent());
            Element age = (Element)stu.getElementsByTagName("age").item(0);
            System.out.println(age.getTextContent());
            Element introduce = (Element)stu.getElementsByTagName("introduce").item(0);
            System.out.println(introduce.getTextContent());
        }

        
    }

    public static void addXml(Document document) throws Exception {
        Element stu = document.createElement("student");
        Element stu_name = document.createElement("name");
        stu_name.setTextContent("小六");
        Element stu_age = document.createElement("age");
        stu_age.setTextContent("22");
        Element stu_introduce = document.createElement("introduce");
        stu_introduce.setTextContent("生存或是死亡，这是一个问题");
        stu.appendChild(stu_name);
        stu.appendChild(stu_age);
        stu.appendChild(stu_introduce);
        document.getDocumentElement().appendChild(stu);
        // TransformerFactory tf = TransformerFactory.newInstance();
        // Transformer t = tf.newTransformer();
        // t.transform(new DOMSource(document), new StreamResult(path));

    }

    public static void deleteXml(Document document) throws Exception {
        Node node = document.getElementsByTagName("student").item(2);
        System.out.println(node.getParentNode().getNodeName());
        node.getParentNode().removeChild(node);
        // 更新xml
        // 获取转换工厂
        // TransformerFactory factory = TransformerFactory.newInstance();
        // 获取转换器
        // Transformer transformer = factory.newTransformer();
        // transformer.transform(new DOMSource(document), new
        // StreamResult(path));
    }

    public static void updateXml(Document document) {
        Element node = (Element) document.getElementsByTagName("student").item(
                0);
        Element node_name = (Element) node.getElementsByTagName("name").item(0);
        node_name.setTextContent("宋江");
    }

    public static void main(String[] args) throws Exception {
        File xml = new File(path);
        DocumentBuilderFactory builderFactory = DocumentBuilderFactory
                .newInstance();
        DocumentBuilder builder = builderFactory.newDocumentBuilder();
        Document document = builder.parse(xml);
        document.getDocumentElement().normalize();
        // System.out.println("根元素：" +
        // document.getDocumentElement().getNodeName());
        NodeList nodelist = document.getElementsByTagName("student");
        // 取出第一个学生
        // Element stu = (Element) nodelist.item(0);
        // Element name = (Element) stu.getElementsByTagName("name").item(0);
        // System.out.println(name.getTextContent());

        System.out.println("------------------");
        
        readXml(document);

        // addXml(document);

        // deleteXml(document);

        // updateXml(document);
        // 更新xml
        // 获取转换工厂
        TransformerFactory factory = TransformerFactory.newInstance();
        // 获取转换器
        Transformer transformer = factory.newTransformer();
        transformer.transform(new DOMSource(document), new StreamResult(path));
    }

}

package XMLParse;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

public class MyDefaultHandler extends DefaultHandler {

    private boolean isName = false;
    private boolean isAge = false;
    @Override
    public void characters(char[] ch, int start, int length)
            throws SAXException {

        String content = new String(ch,start,length);
        if(!content.equals("") && (isName || isAge)){
            System.out.println(content);
        }
        isName = false;
        isAge = false;
        super.characters(ch, start, length);
    }
    
    @Override
    public void endDocument() throws SAXException {
        // TODO Auto-generated method stub
        super.endDocument();
    }
    
    @Override
    public void endElement(String uri, String localName, String name)
            throws SAXException {
        // TODO Auto-generated method stub
        super.endElement(uri, localName, name);
    }
    
    @Override
    public void startDocument() throws SAXException {
        // TODO Auto-generated method stub
        super.startDocument();
    }
    @Override
    public void startElement(String uri, String localName, String name,
            Attributes attributes) throws SAXException {
        if(name.equals("name")){
            this.isName = true;
        }else if(name.equals("age")){
            this.isAge = true;
        }
    }
    
    
}

package XMLParse;

import java.io.File;
import java.io.IOException;
import java.lang.instrument.ClassDefinition;

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

/**
 * desc: dom解析xml文件会加载到内存,如果xml过大，会导致内存溢出 sax解析可以在不加载全部xml文件时，就可以解析xml文档
 * sax只能对xml进行读取，不可进行修改，添加，删除
 * 
 * @author lc
 */
public class SaxParseXml {

    private static final String path = "src/student.xml";
    //private static final String path = "src/status.xml";
    public static void main(String[] args) throws Exception, IOException {
        // 创建代理对象
        SAXParserFactory factory = SAXParserFactory.newInstance();
        // 创建解析器
        SAXParser saxParser = factory.newSAXParser();
        // 将xml与事件处理相关联
        saxParser.parse(path, new MyDefaultHandler());
        
    }

}

package entity;

public class Book {
    public String id;
    public String title;
    public String price;

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getPrice() {
        return price;
    }

    public void setPrice(String price) {
        this.price = price;
    }

    @Override
    public String toString() {
        return "Book [id=" + id + ", title=" + title + ", price=" + price + "]";
    }

}

<?xml version="1.0" encoding="UTF-8" ?>
<AAA>
  <BBB id = "b1">
    <CCC>
     <KKK>k2</KKK>
    </CCC>
    <CCC>
     <KKK>k1</KKK>
    </CCC>
  </BBB>
  <BBB id ="b2">
    <BBB name="bbb"></BBB>
  </BBB>
</AAA>
    

<?xml version="1.0" encoding="UTF-8"?>
<books>
    
    <book id="2">
        <title>java</title>
        <price>23</price>
    </book>
    <book id="b3">
        <title>java疯狂讲义</title>
        <price>34</price>
    </book>
</books>

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<class>
    <student id="1">
        <name>宋江</name>
        <age>22</age>
        <introduce>学习Xml-Dom</introduce>
    </student>
    <student id ="2">
        <name>李四</name>
        <age>22</age>
        <introduce>学习Xml-Sax</introduce>
    </student>
    <student id ="3">
        <name>小六</name>
        <age>22</age>
        <introduce>身存或是死亡，这是一个问题</introduce>
    </student>
</class>

DES加密解密

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.security.Key;
import java.security.SecureRandom;

import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.KeyGenerator;

public class TestDES {

      Key key;   
      public TestDES(String str) {   
        getKey(str);//生成密匙   
      }   
      /**  
      * 根据参数生成KEY  
      */   
      public void getKey(String strKey) {   
        try {   
            KeyGenerator _generator = KeyGenerator.getInstance("DES");   
            _generator.init(new SecureRandom(strKey.getBytes()));   
            this.key = _generator.generateKey();   
            _generator = null;   
        } catch (Exception e) {   
            throw new RuntimeException("Error initializing SqlMap class. Cause: " + e);   
        }   
      }   
      
      /**  
      * 文件file进行加密并保存目标文件destFile中  
      *  
      * @param file   要加密的文件 如c:/test/srcFile.txt  
      * @param destFile 加密后存放的文件名 如c:/加密后文件.txt  
      */   
      public void encrypt(String file, String destFile) throws Exception {   
        Cipher cipher = Cipher.getInstance("DES");   
        // cipher.init(Cipher.ENCRYPT_MODE, getKey());   
        cipher.init(Cipher.ENCRYPT_MODE, this.key);   
        InputStream is = new FileInputStream(file);   
        OutputStream out = new FileOutputStream(destFile);   
        CipherInputStream cis = new CipherInputStream(is, cipher);   
        byte[] buffer = new byte[1024];   
        int r;   
        while ((r = cis.read(buffer)) > 0) {   
            out.write(buffer, 0, r);   
        }   
        cis.close();   
        is.close();   
        out.close();   
      }   
      /**  
      * 文件采用DES算法解密文件  
      *  
      * @param file 已加密的文件 如c:/加密后文件.txt  
      *         * @param destFile  
      *         解密后存放的文件名 如c:/ test/解密后文件.txt  
      */   
      public void decrypt(String file, String dest) throws Exception {   
        Cipher cipher = Cipher.getInstance("DES");   
        cipher.init(Cipher.DECRYPT_MODE, this.key);   
        InputStream is = new FileInputStream(file);   
        OutputStream out = new FileOutputStream(dest);   
        CipherOutputStream cos = new CipherOutputStream(out, cipher);   
        byte[] buffer = new byte[1024];   
        int r;   
        while ((r = is.read(buffer)) >= 0) {   
            System.out.println();  
            cos.write(buffer, 0, r);   
        }   
        cos.close();   
        out.close();   
        is.close();   
      }   
      public static void main(String[] args) throws Exception {   
        TestDES td = new TestDES("aaa");   
        td.encrypt("d:/status.xml", "d:/jiastatus.xml"); //加密   
        td.decrypt("d:/jiastatus.xml", "d:/jiestatus.xml"); //解密   
        System.out.println("执行完成");
          
      }   
}