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本文实例讲述了JSP基于dom解析xml的方法。分享给大家供大家参考，具体如下：
初次学习用dom操作xml文件，有很多不足之处，牛人多给点建议，练习时我没对中文做乱码处理，也没做验证哦！O(∩_∩)O~
实体类：User
public class User {
private String name;
private String pwd;
private String email;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPwd() {
return pwd;
}
public void setPwd(String pwd) {
this.pwd = pwd;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
}
</div>
数据访问层接口：UserDao
public interface UserDao {
boolean login(String name, String pwd);
void insertUser(User user);
List<User> selectUser();
void updateUser(User user);
boolean deleteUser(String name);
public User findByName(String name);
}
</div>
接口实现类：UserDaoImpl
public class UserDaoImpl implements UserDao {
private static final String PATH="xml文件路径";
private void build(Document dom) {
try {
//定义转换器
Transformer f = TransformerFactory.newInstance().newTransformer();
//设置输出的编码格式
f.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
//构建dom源
DOMSource source = new DOMSource(dom);
//指定文件存放的目标路劲
StreamResult sr = new StreamResult(new File(PATH));
//执行转换操作
f.transform(source, sr);
} catch (Exception e) {
e.printStackTrace();
}
}
//登陆
public boolean login(String name, String pwd) {
boolean flag = false;
try {
//根据以有的xml文件创建Document对象
Document dom = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new File(PATH));
//获取user节点下的子节点
NodeList list = dom.getElementsByTagName("user");
//遍历list，数据匹配退出
for(int i = 0; i<list.getLength(); i++) {
Element el = (Element)list.item(i);
if(name.equals(el.getAttribute("name")) && pwd.equals(el.getAttribute("pwd"))) {
flag = true;
break;
}
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return flag;
}
//添加操作
public void insertUser(User user) {
try {
//创建全新的Document对象
Document dom = DocumentBuilderFactory.newInstance().newDocumentBuilder().newDocument();
//创建根节点users
Element el = dom.createElement("users");
//将根节点添加到dom中
dom.appendChild(el);
//创建子节点
Element e2 = dom.createElement("user");
//将子节点添加到根节点中
el.appendChild(e2);
//取得xml文件中现有的信息
List<User> users = this.selectUser();
for(int i = 0; i < users.size(); i++){
//创建节点user
Element el3 = dom.createElement("user");
User us =users.get(i);
//设置节点的属性（name,pwd,email）
el3.setAttribute("name", us.getName());
el3.setAttribute("pwd", us.getPwd());
el3.setAttribute("email", us.getEmail());
//添加到根节点中
el.appendChild(el3);
}
e2.setAttribute("name", user.getName());
e2.setAttribute("pwd", user.getPwd());
e2.setAttribute("email", user.getEmail());
build(dom);
} catch (ParserConfigurationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
//查询操作
public List<User> selectUser() {
List<User> userList = new ArrayList<User>();
try {
//根据已有的xml文件创建dom
Document dom = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new File(PATH));
//获取所有user节点下的子节点
NodeList list = dom.getElementsByTagName("user");
for(int i = 0;i <list.getLength();i++){
User user =new User();
Element element = (Element)list.item(i);
user.setName(element.getAttribute("name"));
user.setPwd(element.getAttribute("pwd"));
user.setEmail(element.getAttribute("email"));
userList.add(user);
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return userList;
}
//修改操作
public void updateUser(User user) {
try {
//根据以有的xml文件创建dom
Document dom = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new File(PATH));
//获取user节点下的子节点
NodeList list = dom.getElementsByTagName("user");
//遍历list
for(int i = 0;i < list.getLength();i++) {
Element el = (Element)list.item(i);
//根据name属性去修改
if(user.getName().equals(el.getAttribute("name"))) {
el.setAttribute("pwd", user.getPwd());
el.setAttribute("email", user.getEmail());
build(dom);
}
}
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ParserConfigurationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
//删除操作
public boolean deleteUser(String name) {
try {
//根据以有xml文件创建domcumet对象
Document dom = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new File(PATH));
//获取user节点下的子节点
NodeList list = dom.getElementsByTagName("user");
//遍历list
for(int i=0;i<list.getLength();i++) {
Element el = (Element)list.item(i);
if(name.equals(el.getAttribute("name"))) {
el.getParentNode().removeChild(el);
build(dom);
return true;
}
}
} catch (Exception e) {
// TODO: handle exception
}
return false;
}
//根据name查找
public User findByName(String name) {
User user = new User();
try {
//根据以后的xml文件创建document对象
Document dom = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new File(PATH));
//获取user节点下的子节点集合
NodeList list = dom.getElementsByTagName("user");
for(int i=0;i<list.getLength();i++) {
Element el = (Element)list.item(i);
if(name.equals(el.getAttribute("name"))) {
user.setName(el.getAttribute("name"));
user.setPwd(el.getAttribute("pwd"));
user.setEmail(el.getAttribute("email"));
break;
}
}
} catch (Exception e) {
e.printStackTrace();
}
return user;
}
}
</div>
业务逻辑层接口：UserService
boolean login(String name, String pwd); void insertUser(User user); List<User> selectUser(); void updateUser(User user); boolean deleteUser(String name); public User findByName(String name);</div>
接口实现类：UserServiceImpl
public class UserServiceImpl implements UserService {
UserDao dao = new UserDaoImpl();
public boolean login(String name, String pwd) {
return dao.login(name, pwd);
}
public void insertUser(User user) {
dao.insertUser(user);
}
public List<User> selectUser() {
return dao.selectUser();
}
public void updateUser(User user) {
dao.updateUser(user);
}
public boolean deleteUser(String name) {
return dao.deleteUser(name);
}
public User findByName(String name) {
return dao.findByName(name);
}
}
</div>
控制层：UserAction
public class UserAction extends ActionSupport{
private User user;
public User getUser() {
return user;
}
public void setUser(User user) {
this.user = user;
}
UserService userService = new UserServiceImpl();
public String selectUser(){
HttpServletRequest request = ServletActionContext.getRequest();
List<User> users = new ArrayList<User>();
users = userService.selectUser();
request.setAttribute("USER", users);
return "select";
}
/**
* 登陆
* @return
*/
public String login(){
if(user.getName() != null && user.getPwd() != null) {
bool