Dom4J读写xml

解析读取XML

public static void main(String[] args) {
        //1获取SaxReader对象
        SAXReader reader=new SAXReader();
        try {
            //2使用Saxrreader对象加载xml文件，返回Document对象
            Document document=reader.read(new File("student.xml"));
            
            //3使用document对象或根元素
            Element rootele=document.getRootElement();
            
            //4获取子元素的集合(获取的是student子元素的集合)
            List<Element> lsstu_ele=rootele.elements("student");
            
            System.out.println("student元素的个数:"+lsstu_ele.size());
            //遍历student元素
            for (Element stuele : lsstu_ele) {
                /***********************************
                //获取student元素下的子元素
                Element sid_ele=stuele.element("sid");
                Element sname_ele=stuele.element("sname");
                Element sex_ele=stuele.element("sex");
                Element address_ele=stuele.element("address");
                Element age_ele=stuele.element("age");
                
                //获取每个子元素的文本内容
                System.out.println("编号:"+sid_ele.getText());
                System.out.println("姓名:"+sname_ele.getText());
                System.out.println("性别:"+sex_ele.getText());
                System.out.println("地址:"+address_ele.getText());
                System.out.println("年龄:"+age_ele.getText());
                System.out.println("========================");
                **************************************/
                //获取每个子元素的文本内容
                System.out.println("编号:"+stuele.elementText("sid"));
                System.out.println("姓名:"+stuele.elementText("sname"));
                System.out.println("性别:"+stuele.elementText("sex"));
                System.out.println("地址:"+stuele.elementText("address"));
                System.out.println("年龄:"+stuele.elementText("age"));
                System.out.println("========================");
            }
        } catch (DocumentException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

向xml文件中添加节点并写入文件保存；

public static void main(String[] args) {
        //1创建SaxReader对象
        SAXReader reader=new SAXReader();
        
        try {
            //2读取xml文档，并返回document对象
            Document document=reader.read(new File("student.xml"));
            
            //3获取根元素
            Element rootele=document.getRootElement();
            
            //4在根元素下添加student子元素
            Element st_ele=rootele.addElement("student");
            
            //在新增的student元素下添加其他子元素
            Element sid_ele=st_ele.addElement("sid");
            Element sname_ele=st_ele.addElement("sname");
            Element sex_ele=st_ele.addElement("sex");
            Element address_ele=st_ele.addElement("address");
            Element age_ele=st_ele.addElement("age");
            
            //在每个子元素下添加内容
            Scanner sc=new Scanner(System.in);
            
            System.out.println("输入编号:");
            sid_ele.setText(sc.next());
            
            System.out.println("输入姓名:");
            sname_ele.setText(sc.next());
            
            System.out.println("输入性别:");
            sex_ele.setText(sc.next());
            
            System.out.println("输入地址:");
            address_ele.setText(sc.next());
            
            System.out.println("输入年龄:");
            age_ele.setText(sc.next());
            
            //创建字节输出流对象
            FileOutputStream fout=new FileOutputStream("student.xml");
            
            //创建缓冲区字符输出流对象
            BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(fout, "utf-8"));
            
            //写文档到xml文件
            document.write(bw);
            bw.flush();
            bw.close();
            System.out.println("增加成功！");
        } catch (DocumentException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

修改xml 文件中的节点并写入文件保存；

public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        //1创建SaxReader对象
        SAXReader reader=new SAXReader();
        
        try {
            //2读取xml文档，并返回document对象
            Document document=reader.read(new File("student.xml"));
            
            //3获取根元素
            Element rootele=document.getRootElement();
            
            //4获取student子元素的集合
            List<Element> lsst_ele=rootele.elements("student");
            
            System.out.println("请输入要修改的学生编号:");
            String sid=sc.next();
            
            for (Element stu_ele : lsst_ele) {
                if(stu_ele.elementText("sid").equals(sid)){
                    System.out.println("输入姓名:");
                    stu_ele.element("sname").setText(sc.next());
                    
                    System.out.println("输入性别:");
                    stu_ele.element("sex").setText(sc.next());
                    
                    System.out.println("输入地址:");
                    stu_ele.element("address").setText(sc.next());
                    
                    System.out.println("输入年龄:");
                    stu_ele.element("age").setText(sc.next());
                    break;
                }
            }
            
            //创建字节输出流对象
            FileOutputStream fout=new FileOutputStream("student.xml");
            
            //创建缓冲区字符输出流对象
            BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(fout, "utf-8"));
            
            //写文档到xml文件
            document.write(bw);
            bw.flush();
            bw.close();
            System.out.println("修改成功！");
        } catch (DocumentException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

删除xml文件中的节点

public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        //1创建SaxReader对象
        SAXReader reader=new SAXReader();
        
        try {
            //2读取xml文档，并返回document对象
            Document document=reader.read(new File("student.xml"));
            
            //3获取根元素
            Element rootele=document.getRootElement();
            
            //获取要移除的学生编号
            System.out.println("请输入要删除的学生编号:");
            String sid=sc.next();
            
            //获取student元素的集合
            List<Element> lsstu_ele=rootele.elements("student");
            for (Element stu_ele : lsstu_ele) {
                //在元素中查找学生编号内容是否与输入的一致
                if(stu_ele.elementText("sid").equals(sid)){
                    rootele.remove(stu_ele);//删除整个student元素
                    System.out.println("元素删除成功！");
                    break;
                }
            }
            //创建字节输出流对象
            FileOutputStream fout=new FileOutputStream("student.xml");
            
            //创建缓冲区字符输出流对象
            BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(fout, "utf-8"));
            
            //写文档到xml文件
            document.write(bw);
            bw.flush();
            bw.close();
            System.out.println("移除成功！");
        } catch (DocumentException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

 xml读写的工具类方法示例

    /**
     * 将Document对象写入到xml文件
     * @throws IOException 
     * */
    public static void XmlToFile(Document doc) throws IOException{
        
            //创建字节输出流对象
            FileOutputStream fout=new FileOutputStream(new File("student.xml"));
            //创建字节流缓冲区，加快写出速度
            BufferedOutputStream bout=new BufferedOutputStream(fout);
            
            //创建字符输出流对象
            BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(bout, "utf-8"));
            
            doc.write(bw);
            
            bw.flush();
            bw.close();
            System.out.println("写xml文件成功");
    }
    /**
     * 从xml文件中获取学生的对象集合
     * */
    public static List<Student> fileToList(){
        SAXReader reader=new SAXReader();
        List<Student> lsst=new ArrayList<Student>();
        
        try {
            Document doc=reader.read(new File("student.xml"));
            
            //获取根元素
            Element root_ele=doc.getRootElement();
            
            
            //从xml文件获取student子元素集合
            List<Element> lsst_ele=root_ele.elements("student");
            if(lsst_ele!=null&&!lsst_ele.isEmpty()){//有student子元素存在
                for (Element stu_ele : lsst_ele) {
                    Student st=new Student();
                    st.setSid(stu_ele.elementText("sid"));
                    st.setSname(stu_ele.elementText("sname"));
                    st.setSex(stu_ele.elementText("sex"));
                    st.setAddress(stu_ele.elementText("address"));
                    st.setAge(Integer.parseInt(stu_ele.elementText("age")));
                    
                    lsst.add(st);//将学生对象加入到集合中
                }
            }
        } catch (NumberFormatException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (DocumentException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return lsst;
    }