package cn.zyw.utils; import java.io.File; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.UnsupportedEncodingException; import org.dom4j.Document; import org.dom4j.DocumentException; import org.dom4j.io.OutputFormat; import org.dom4j.io.SAXReader; import org.dom4j.io.XMLWriter; //3 public class XmlUtils { private static String filepath; static{ filepath=XmlUtils.class.getClassLoader().getResource("users.xml").getPath(); filepath=filepath.replace("%20", " "); } public static Document getDocument() throws Exception{ SAXReader reader = new SAXReader(); Document document = reader.read(new File(filepath)); return document; } public static void write2Xml(Document document) throws Exception{ OutputFormat format = OutputFormat.createPrettyPrint(); format.setEncoding("UTF-8"); XMLWriter writer = new XMLWriter(new FileOutputStream(filepath), format ); writer.write( document ); writer.close(); } }
有时我们想做做一个小的项目需要保存一定的数据,如果用数据库当然是可以的。但是总觉得有点浪费资源。所以今天就学习了一点Xml总结如下:
1:Xml文件如下:
<?xml version="1.0" encoding="UTF-8"?> <users> <user id="234343434" username="aaa" password="123" email="[email protected]" birthday="1900-09-18" nickname="强子" /> </users>
2:操作Xml文件的工具类
XmlUtils.java
package cn.zyw.utils;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.UnsupportedEncodingException;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;
//3
public class XmlUtils {
private static String filepath;
static{
filepath=XmlUtils.class.getClassLoader().getResource("users.xml").getPath();
filepath=filepath.replace("%20", " ");
}
public static Document getDocument() throws Exception{
SAXReader reader = new SAXReader();
Document document = reader.read(new File(filepath));
return document;
}
public static void write2Xml(Document document) throws Exception{
OutputFormat format = OutputFormat.createPrettyPrint();
format.setEncoding("UTF-8");
XMLWriter writer = new XMLWriter(new FileOutputStream(filepath), format );
writer.write( document );
writer.close();
}
}
package cn.zyw.utils; import java.io.File; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.UnsupportedEncodingException; import org.dom4j.Document; import org.dom4j.DocumentException; import org.dom4j.io.OutputFormat; import org.dom4j.io.SAXReader; import org.dom4j.io.XMLWriter; //3 public class XmlUtils { private static String filepath; static{ filepath=XmlUtils.class.getClassLoader().getResource("users.xml").getPath(); filepath=filepath.replace("%20", " "); } public static Document getDocument() throws Exception{ SAXReader reader = new SAXReader(); Document document = reader.read(new File(filepath)); return document; } public static void write2Xml(Document document) throws Exception{ OutputFormat format = OutputFormat.createPrettyPrint(); format.setEncoding("UTF-8"); XMLWriter writer = new XMLWriter(new FileOutputStream(filepath), format ); writer.write( document ); writer.close(); } }
3:用户登录的Dao
UserDao .java
package cn.zyw.dao;
import cn.zyw.domain.User;
//5
public interface UserDao {
void add(User user);
User find(String username, String password);
//查找注册的用户是否在数据库中存在
boolean find(String username);
}
package cn.zyw.dao; import cn.zyw.domain.User; //5 public interface UserDao { void add(User user); User find(String username, String password); //查找注册的用户是否在数据库中存在 boolean find(String username); }
4:用户登录的实现类
UserDaoImpl .java
package cn.zyw.dao.impl;
import java.text.SimpleDateFormat;
import org.dom4j.Document;
import org.dom4j.Element;
import cn.zyw.dao.UserDao;
import cn.zyw.domain.User;
import cn.zyw.utils.XmlUtils;
//2
public class UserDaoImpl implements UserDao {
public void add(User user){
try {
Document document=XmlUtils.getDocument();
Element root=document.getRootElement();//得到根节点
Element user_tag=root.addElement("user");
user_tag.setAttributeValue("id", user.getId());
user_tag.setAttributeValue("username", user.getUsername());
user_tag.setAttributeValue("password", user.getPassword());
user_tag.setAttributeValue("email", user.getEmail());
user_tag.setAttributeValue("nickname", user.getNickname());
user_tag.setAttributeValue("birthday", user.getBirthday()==null ? "" : user.getBirthday().toLocaleString());
XmlUtils.write2Xml(document);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
public User find(String username,String password){
try {
Document document=XmlUtils.getDocument();
Element e=(Element) document.selectSingleNode("//user[@username=‘"+username+"‘ and @password=‘"+password+"‘]");
if(e==null)
return null;
User user=new User();
user.setUsername(e.attributeValue("username"));//获取xml里面的值
user.setNickname(e.attributeValue("nickname"));
user.setPassword(e.attributeValue("password"));
user.setEmail(e.attributeValue("email"));
user.setId(e.attributeValue("id"));
String date=e.attributeValue("birthday");
if(date==null || date.equals("")){
user.setBirthday(null);
}else{
SimpleDateFormat df=new SimpleDateFormat("yyyy-MM-dd");
user.setBirthday(df.parse(date));
}
return user;
} catch (Exception e) {
throw new RuntimeException(e);
}
}
//查找注册的用户是否在数据库中存在
public boolean find(String username){
try {
Document document=XmlUtils.getDocument();
Element e=(Element) document.selectSingleNode("//user[@username=‘"+username+"‘]");
if(e==null){
return false;
}
return true;
} catch (Exception e) {
throw new RuntimeException(e);
}
}
}
package cn.zyw.dao.impl; import java.text.SimpleDateFormat; import org.dom4j.Document; import org.dom4j.Element; import cn.zyw.dao.UserDao; import cn.zyw.domain.User; import cn.zyw.utils.XmlUtils; //2 public class UserDaoImpl implements UserDao { public void add(User user){ try { Document document=XmlUtils.getDocument(); Element root=document.getRootElement();//得到根节点 Element user_tag=root.addElement("user"); user_tag.setAttributeValue("id", user.getId()); user_tag.setAttributeValue("username", user.getUsername()); user_tag.setAttributeValue("password", user.getPassword()); user_tag.setAttributeValue("email", user.getEmail()); user_tag.setAttributeValue("nickname", user.getNickname()); user_tag.setAttributeValue("birthday", user.getBirthday()==null ? "" : user.getBirthday().toLocaleString()); XmlUtils.write2Xml(document); } catch (Exception e) { throw new RuntimeException(e); } } public User find(String username,String password){ try { Document document=XmlUtils.getDocument(); Element e=(Element) document.selectSingleNode("//user[@username=‘"+username+"‘ and @password=‘"+password+"‘]"); if(e==null) return null; User user=new User(); user.setUsername(e.attributeValue("username"));//获取xml里面的值 user.setNickname(e.attributeValue("nickname")); user.setPassword(e.attributeValue("password")); user.setEmail(e.attributeValue("email")); user.setId(e.attributeValue("id")); String date=e.attributeValue("birthday"); if(date==null || date.equals("")){ user.setBirthday(null); }else{ SimpleDateFormat df=new SimpleDateFormat("yyyy-MM-dd"); user.setBirthday(df.parse(date)); } return user; } catch (Exception e) { throw new RuntimeException(e); } } //查找注册的用户是否在数据库中存在 public boolean find(String username){ try { Document document=XmlUtils.getDocument(); Element e=(Element) document.selectSingleNode("//user[@username=‘"+username+"‘]"); if(e==null){ return false; } return true; } catch (Exception e) { throw new RuntimeException(e); } } }
5:用户登录的测试
UserDaoTest.java
package junit.test;
import java.util.Date;
import org.junit.Test;
import cn.zyw.dao.UserDao;
import cn.zyw.dao.impl.UserDaoImpl;
import cn.zyw.domain.User;
//4
public class UserDaoTest {
@Test
public void testAdd(){
User user=new User();
user.setBirthday(new Date());
user.setEmail("[email protected]");
user.setId("34343434");
user.setNickname("李子");
user.setPassword("123");
user.setUsername("aaa");
UserDao dao=new UserDaoImpl();
dao.add(user);
}
@Test
public void testFind(){
UserDao dao=new UserDaoImpl();
User user=dao.find("aaa","123");
String aa=user.getEmail();
if(aa.endsWith("kk"))
{
System.out.println("kkdf");
}
}
@Test
public void testFindByUsername(){
UserDao dao=new UserDaoImpl();
boolean b=dao.find("aaa");
}
}
package junit.test; import java.util.Date; import org.junit.Test; import cn.zyw.dao.UserDao; import cn.zyw.dao.impl.UserDaoImpl; import cn.zyw.domain.User; //4 public class UserDaoTest { @Test public void testAdd(){ User user=new User(); user.setBirthday(new Date()); user.setEmail("[email protected]"); user.setId("34343434"); user.setNickname("李子"); user.setPassword("123"); user.setUsername("aaa"); UserDao dao=new UserDaoImpl(); dao.add(user); } @Test public void testFind(){ UserDao dao=new UserDaoImpl(); User user=dao.find("aaa","123"); String aa=user.getEmail(); if(aa.endsWith("kk")) { System.out.println("kkdf"); } } @Test public void testFindByUsername(){ UserDao dao=new UserDaoImpl(); boolean b=dao.find("aaa"); } }