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; public class FileUtils { public static String getStringFromFile(String filePath) { File file = new File(filePath) ; if(!file.exists()){ return "" ; } 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 "" ; } } 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(); } public static void deleteFile(String filePath ) { File file = new File(filePath) ; if(file.exists()){ file.delete() ; } }}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; public class XmlUtil { 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; } } 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(); transformer.setOutputProperty(OutputKeys.ENCODING, "utf-8"); DOMSource source = new DOMSource(doc); StreamResult result = new StreamResult(new File(filePath)); transformer.transform(source, result); } public static Map initUser() { InitUser.users = new HashMap(); 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; } } 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; } } 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; } public static List getNovelListFromXml(String filePath) throws SAXException, IOException, ParserConfigurationException { List novelList = new ArrayList(); 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 ; } public static boolean writeNovelToFile(Novel novel ) { try{ FileUtils.writeStringToFile(novel.getContent(), "novel/" + novel.getName() + ".txt"); XmlUtil.writeNovelInfoToXml(novel) ; return true ; }catch(Exception e ){ 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 ; } } 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(); } } 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(); } }} 以上就是xml，文件操作功能类的示例代码详解的详细内容，更多请关注考高分网其它相关文章！
