Ich habe es in einem Projekt verwendet, aber Sie können darin einige nützliche Codes finden, die ich in Zukunft langsam hinzufügen und aktualisieren werde:
FileUtil.xml
package com.novel.util;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
/**
* @author cy
*
* @date 2015年7月24日 上午8:38:38
*
* @Description 关于文件的一些工具
*/
public class FileUtils {
/**
* 将文件中所有内容读取到字符串中
*
* @param filePath
* 文件路径
* @return 文件内容
*/
public static String getStringFromFile(String filePath) {
File file = new File(filePath) ;
if(!file.exists()){
return "" ;
}
/**
* 处理文件读取乱码问题 :
* 只要判定两种常见的编码就可以了：GBK和UTF-8。由于中文Windows默认的编码是GBK，所以一般只要判定UTF-8编码格式。
*对于UTF-8编码格式的文本文件，其前3个字节的值就是-17、-69、-65
*/
try{
byte[] firstThreeByte = new byte[3] ;
InputStream in = new FileInputStream(file) ;
in.read(firstThreeByte) ;
in.close() ;
String encoding = "" ;
if(firstThreeByte[0] == -17 && firstThreeByte[1] == -16 && firstThreeByte[2] == -65){
encoding = "utf-8" ;
}else{
encoding = "gbk" ;
}
InputStreamReader read = new InputStreamReader(new FileInputStream(file),encoding);
Long filelength = file.length() / 2 ; // 该方法获取的是文件字节长度，
//而我要创建的是char数组，char占两个字节，
//byte一个字节，所以除以2表示的是该文件的字符长度
char[] filecontent = new char[filelength.intValue()] ;
read.read(filecontent) ;
return new String(filecontent) ;
}catch(Exception e ){
e.printStackTrace();
return "" ;
}
}
/**
* 将字符串写入文件
*
* @param content
* 字符串内容
* @param filePath
* 文件路径
* @throws IOException
*/
public static void writeStringToFile(String content, String filePath)
throws IOException {
File file = new File(filePath);
if (!file.exists()) {
file.createNewFile();
}
FileOutputStream out = new FileOutputStream(file);
out.write(content.getBytes());
out.close();
}
/**
* 删除指定的文件
* @param filePath文件路径
*/
public static void deleteFile(String filePath ) {
File file = new File(filePath) ;
if(file.exists()){
file.delete() ;
}
}
}Nach dem Login kopieren
XmlUtil.java
package com.novel.util;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.TransformerFactoryConfigurationError;
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.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;
import org.xml.sax.SAXException;
import com.novel.entity.Novel;
import com.novel.entity.User;
/**
* @author cy
*
* @date 2015年7月23日 下午3:19:06
*
* @Description 关于xml的操作
*/
public class XmlUtil {
/**
* 目标xml为 config/users.xml
*
* @param user
* 将要被写入xml的User对象
* @return 是否成功
*/
public static boolean writeUserToXml(User user) {
try {
Document doc = getDocumentFromXml("config/users.xml");
Element newUserElement = doc.createElement("user");
Element newUsernameElement = doc.createElement("name");
Text nameTextNode = doc.createTextNode("nameValue");
nameTextNode.setNodeValue(user.getName());
newUsernameElement.appendChild(nameTextNode);
Element newUserPwdElement = doc.createElement("pwd");
Text pwdTextNode = doc.createTextNode("pwdValue");
pwdTextNode.setNodeValue(user.getName());
newUserPwdElement.appendChild(pwdTextNode);
newUserElement.appendChild(newUsernameElement);
newUserElement.appendChild(newUserPwdElement);
Element usersElement = (Element) doc.getElementsByTagName("users")
.item(0);
usersElement.appendChild(newUserElement);
writeDocumentToFile(doc, "config/users.xml");
return true;
} catch (Exception e) {
e.printStackTrace();
return false;
}
}
/**
*
* @param doc
* XML中的Document对象
* @param filePath
* 输出的文件路径
* @throws TransformerFactoryConfigurationError
* @throws TransformerConfigurationException
* @throws TransformerException
*/
private static void writeDocumentToFile(Document doc, String filePath)
throws TransformerFactoryConfigurationError,
TransformerConfigurationException, TransformerException {
// 写入到硬盘
TransformerFactory tFactory = TransformerFactory.newInstance();
Transformer transformer = tFactory.newTransformer();
/** 编码 */
transformer.setOutputProperty(OutputKeys.ENCODING, "utf-8");
DOMSource source = new DOMSource(doc);
StreamResult result = new StreamResult(new File(filePath));
transformer.transform(source, result);
}
/**
* 加载config/users.xml中用户信息到对象中
*
* @return 加载后的对象
*/
public static Map<String, User> initUser() {
InitUser.users = new HashMap<String, User>();
try {
Document doc = getDocumentFromXml("config/users.xml");
NodeList usersNodeList = doc.getElementsByTagName("user");
for (int i = 0; i < usersNodeList.getLength(); i++) {
Element userElement = (Element) usersNodeList.item(i);
String userName = ((Element) (userElement
.getElementsByTagName("name").item(0))).getFirstChild()
.getNodeValue();
String passwd = ((Element) (userElement
.getElementsByTagName("pwd").item(0))).getFirstChild()
.getNodeValue();
InitUser.users.put(userName, new User(userName, passwd));
}
} catch (Exception e) {
e.printStackTrace();
} finally {
return InitUser.users;
}
}
/**
* 从xml中获取服务器运行的端口
*
* @return server.xml文件中的端口号
*/
public static int getServerPort() {
try {
Document doc = getDocumentFromXml("config/server.xml");
int serverPort = Integer.parseInt(doc
.getElementsByTagName("server-port").item(0)
.getFirstChild().getNodeValue());
return serverPort;
} catch (Exception e) {
e.printStackTrace();
return 0;
}
}
/**
*
* @param xmlPath
* xml文件的位置
* @return 这个xml文件相应的Document对象
* @throws SAXException
* @throws IOException
* @throws ParserConfigurationException
*/
public static Document getDocumentFromXml(String xmlPath)
throws SAXException, IOException, ParserConfigurationException {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();
Document doc = builder.parse(xmlPath);
return doc;
}
/**
* 读取xml中小说的信息到List中
*
* @param novelId
* 小说id
* @return 小说列表
* @throws ParserConfigurationException
* @throws IOException
* @throws SAXException
*/
public static List<Novel> getNovelListFromXml(String filePath) throws SAXException, IOException, ParserConfigurationException {
List<Novel> novelList = new ArrayList<Novel>();
Document doc = getDocumentFromXml(filePath);
NodeList novels = doc.getElementsByTagName("novel");
for (int i = 0; i < novels.getLength(); i++) {
Element novel = ((Element) novels.item(i));
int id = Integer.parseInt(novel.getElementsByTagName("id").item(0)
.getFirstChild().getNodeValue());
String name = novel.getElementsByTagName("name").item(0)
.getFirstChild().getNodeValue();
String author = novel.getElementsByTagName("author").item(0)
.getFirstChild().getNodeValue();
String category = novel.getElementsByTagName("category").item(0)
.getFirstChild().getNodeValue();
String description = novel.getElementsByTagName("description")
.item(0).getFirstChild().getNodeValue();
Novel oneNovel = new Novel(id, category, name, author, description);
novelList.add(oneNovel);
}
return novelList ;
}
/**
* 将Novel信息写入到config/novelsInfo.xml中并且将小说内容写入到novel文件夹下
* @param novel 小说对象
* @return 是否写入成功
* TODO：确定原子操作
*/
public static boolean writeNovelToFile(Novel novel ) {
/**
* 先将小说内容写入到novel文件夹下，再将小说信息写入到config/novelsInfo.xml中
*/
try{
FileUtils.writeStringToFile(novel.getContent(), "novel/" + novel.getName() + ".txt");
XmlUtil.writeNovelInfoToXml(novel) ;
return true ;
}catch(Exception e ){
/**
* 如果写入小说到文件中出现问题，要将已经写入的信息删除
* 这段代码应该很少执行到 ~~~~
*
*/
System.out.println("小说写入文件失败，正在回滚~~");
FileUtils.deleteFile("novel/" + novel.getName() + ".txt") ;
XmlUtil.deleteNovelInfoFromXml(novel) ;
e.printStackTrace();
return false ;
}
}
/**
* 从config/novelsInfo.xml中删除与novel对象相对应的的novel标签，根据ID号判断是否相同
*
* @param novel
* 小说对象
*/
public static void deleteNovelInfoFromXml(Novel novel) {
try {
Document doc = getDocumentFromXml("config/novelsInfo.xml");
Element novelsElement = (Element) doc
.getElementsByTagName("novels").item(0);
NodeList novelElements = novelsElement
.getElementsByTagName("novel");
Node deleteElement = null;
for (int i = 0; i < novelElements.getLength(); i++) {
String id = ((Element) novelElements.item(i))
.getElementsByTagName("id").item(0).getFirstChild()
.getNodeValue();
if (id.equals(String.valueOf(novel.getId()))) {
deleteElement = novelElements.item(i);
break;
}
}
novelsElement.removeChild(deleteElement);
writeDocumentToFile(doc, "config/novlesInfo.xml");
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 将小说信息写入到config/novelsInfo.xml文件中
* @param novel小说对象
*/
public static void writeNovelInfoToXml(Novel novel){
Document doc = null ;
try {
doc = getDocumentFromXml("config/novelsInfo.xml");
} catch (Exception e) {
e.printStackTrace();
return ;
}
Element novelDocument = (Element)doc.createElement("novel") ;
// id
Element novelIdDocument = (Element)doc.createElement("id") ;
Text novelIdTextNode = doc.createTextNode("idValue") ;
novelIdTextNode.setNodeValue(String.valueOf(novel.getId()));
novelIdDocument.appendChild(novelIdTextNode);
// name
Element novelNameDocument = (Element)doc.createElement("name") ;
Text novelNameTextNode = doc.createTextNode("nameValue") ;
novelNameTextNode.setNodeValue(String.valueOf(novel.getName()));
novelNameDocument.appendChild(novelNameTextNode);
// author
Element novelAuthorDocument = (Element)doc.createElement("author") ;
Text novelAuthorTextNode = doc.createTextNode("authorValue") ;
novelAuthorTextNode.setNodeValue(String.valueOf(novel.getAuthor()));
novelAuthorDocument.appendChild(novelAuthorTextNode);
// category
Element novelCategoryDocument = (Element)doc.createElement("category") ;
Text novelCategoryTextNode = doc.createTextNode("categoryValue") ;
novelCategoryTextNode.setNodeValue(String.valueOf(novel.getCategory()));
novelCategoryDocument.appendChild(novelCategoryTextNode);
// description
Element novelDescriptionDocument = (Element)doc.createElement("description") ;
Text novelDescriptionTextNode = doc.createTextNode("descriptionValue") ;
novelDescriptionTextNode.setNodeValue(String.valueOf(novel.getDescription()));
novelDescriptionDocument.appendChild(novelDescriptionTextNode);
novelDocument.appendChild(novelIdDocument) ;
novelDocument.appendChild(novelNameDocument) ;
novelDocument.appendChild(novelAuthorDocument) ;
novelDocument.appendChild(novelCategoryDocument) ;
novelDocument.appendChild(novelDescriptionDocument) ;
doc.getElementsByTagName("novels").item(0).appendChild(novelDocument) ;
// 写到文件中
try {
writeDocumentToFile(doc, "config/novelsInfo.xml");
} catch (Exception e) {
e.printStackTrace();
}
}
}Nach dem Login kopieren
Das obige ist der detaillierte Inhalt vonxml, ausführliche Erläuterung des Beispielcodes der Dateioperationsfunktionsklasse. Für weitere Informationen folgen Sie bitte anderen verwandten Artikeln auf der PHP chinesischen Website!
