我一个项目中用到的,里面的方法不是太通用,但是可以从里面找到一些有用的代码,以后慢慢添补更新:
FileUtil.
1 package com.novel.util; 2 3 import java.io.File; 4 import java.io.FileInputStream; 5 import java.io.FileOutputStream; 6 import java.io.IOException; 7 import java.io.InputStream; 8 import java.io.InputStreamReader; 9 10 /**11 * @author cy12 *13 * @date 2015年7月24日 上午8:38:3814 *15 * @Description 关于文件的一些工具16 */17 public class FileUtils {18 /**19 * 将文件中所有内容读取到字符串中20 * 21 * @param filePath22 * 文件路径23 * @return 文件内容24 */25 public static String getStringFromFile(String filePath) {26 File file = new File(filePath) ;27 if(!file.exists()){28 return "" ;29 }30 /**31 * 处理文件读取乱码问题 :32 * 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。33 *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、-6534 */35 try{36 byte[] firstThreeByte = new byte[3] ;37 InputStream in = new FileInputStream(file) ;38 in.read(firstThreeByte) ;39 in.close() ;40 String encoding = "" ;41 if(firstThreeByte[0] == -17 && firstThreeByte[1] == -16 && firstThreeByte[2] == -65){42 encoding = "utf-8" ;43 }else{44 encoding = "gbk" ;45 }46 InputStreamReader read = new InputStreamReader(new FileInputStream(file),encoding); 47 Long filelength = file.length() / 2 ; // 该方法获取的是文件字节长度,48 //而我要创建的是char数组,char占两个字节,49 //byte一个字节,所以除以2表示的是该文件的字符长度50 char[] filecontent = new char[filelength.intValue()] ; 51 read.read(filecontent) ;52 return new String(filecontent) ;53 }catch(Exception e ){54 e.printStackTrace();55 return "" ;56 }57 }58 59 /**60 * 将字符串写入文件61 * 62 * @param content63 * 字符串内容64 * @param filePath65 * 文件路径66 * @throws IOException67 */68 public static void writeStringToFile(String content, String filePath)69 throws IOException {70 71 File file = new File(filePath);72 if (!file.exists()) {73 file.createNewFile();74 }75 FileOutputStream out = new FileOutputStream(file);76 out.write(content.getBytes());77 out.close();78 }79 /**80 * 删除指定的文件 81 * @param filePath文件路径 82 */83 public static void deleteFile(String filePath ) {84 File file = new File(filePath) ;85 if(file.exists()){86 file.delete() ;87 }88 }89 }
1 package com.novel.util; 2 3 import java.io.File; 4 import java.io.IOException; 5 import java.util.ArrayList; 6 import java.util.HashMap; 7 import java.util.List; 8 import java.util.Map; 9 10 import javax. 11 import javax. 12 import javax. 13 import javax. 14 import javax. 15 import javax. 16 import javax. 17 import javax. 18 import javax. 19 import javax. 20 import javax. 21 22 import org.w3c.dom.Document; 23 import org.w3c.dom.Element; 24 import org.w3c.dom.Node; 25 import org.w3c.dom.NodeList; 26 import org.w3c.dom.Text; 27 import org. 28 29 import com.novel.entity.Novel; 30 import com.novel.entity.User; 31 32 /** 33 * @author cy 34 * 35 * @date 2015年7月23日 下午3:19:06 36 * 37 * @Description 关于 38 */ 39 public class 40 /** 41 * 目标 42 * 43 * @param user 44 * 将要被写入 45 * @return 是否成功 46 */ 47 public static boolean writeUserTo 48 try { 49 Document doc = getDocumentFrom); 50 Element newUserElement = doc.createElement("user"); 51 Element newUsernameElement = doc.createElement("name"); 52 Text nameTextNode = doc.createTextNode("nameValue"); 53 nameTextNode.setNodeValue(user.getName()); 54 newUsernameElement.appendChild(nameTextNode); 55 Element newUserPwdElement = doc.createElement("pwd"); 56 Text pwdTextNode = doc.createTextNode("pwdValue"); 57 pwdTextNode.setNodeValue(user.getName()); 58 newUserPwdElement.appendChild(pwdTextNode); 59 newUserElement.appendChild(newUsernameElement); 60 newUserElement.appendChild(newUserPwdElement); 61 Element usersElement = (Element) doc.getElementsByTagName("users") 62 .item(0); 63 usersElement.appendChild(newUserElement); 64 65 writeDocumentToFile(doc, "config/users.); 66 return true; 67 } catch (Exception e) { 68 e.printStackTrace(); 69 return false; 70 } 71 } 72 73 /** 74 * 75 * @param doc 76 * 77 * @param filePath 78 * 输出的文件路径 79 * @throws TransformerFactoryConfigurationError 80 * @throws TransformerConfigurationException 81 * @throws TransformerException 82 */ 83 private static void writeDocumentToFile(Document doc, String filePath) 84 throws TransformerFactoryConfigurationError, 85 TransformerConfigurationException, TransformerException { 86 // 写入到硬盘 87 TransformerFactory tFactory = TransformerFactory.newInstance(); 88 Transformer transformer = tFactory.newTransformer(); 89 /** 编码 */ 90 transformer.setOutputProperty(OutputKeys.ENCODING, "utf-8"); 91 DOMSource source = new DOMSource(doc); 92 StreamResult result = new StreamResult(new File(filePath)); 93 transformer.transform(source, result); 94 } 95 96 /** 97 * 加载config/users. 98 * 99 * @return 加载后的对象100 */101 public static Map<String, User> initUser() {102 InitUser.users = new HashMap<String, User>();103 try {104 Document doc = getDocumentFrom);105 NodeList usersNodeList = doc.getElementsByTagName("user");106 for (int i = 0; i < usersNodeList.getLength(); i++) {107 Element userElement = (Element) usersNodeList.item(i);108 String userName = ((Element) (userElement109 .getElementsByTagName("name").item(0))).getFirstChild()110 .getNodeValue();111 String passwd = ((Element) (userElement112 .getElementsByTagName("pwd").item(0))).getFirstChild()113 .getNodeValue();114 InitUser.users.put(userName, new User(userName, passwd));115 }116 } catch (Exception e) {117 e.printStackTrace();118 } finally {119 return InitUser.users;120 }121 }122 123 /**124 * 从125 * 126 * @return server.127 */128 public static int getServerPort() {129 try {130 Document doc = getDocumentFrom);131 int serverPort = Integer.parseInt(doc132 .getElementsByTagName("server-port").item(0)133 .getFirstChild().getNodeValue());134 return serverPort;135 } catch (Exception e) {136 e.printStackTrace();137 return 0;138 }139 }140 141 /**142 * 143 * @param 144 * 145 * @return 这个146 * @throws SAXException147 * @throws IOException148 * @throws ParserConfigurationException149 */150 public static Document getDocumentFrom151 throws SAXException, IOException, ParserConfigurationException {152 DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();153 DocumentBuilder builder = factory.newDocumentBuilder();154 Document doc = builder.parse(155 return doc;156 }157 158 /**159 * 读取160 * 161 * @param novelId162 * 小说id163 * @return 小说列表164 * @throws ParserConfigurationException 165 * @throws IOException 166 * @throws SAXException 167 */168 public static List<Novel> getNovelListFromthrows SAXException, IOException, ParserConfigurationException {169 List<Novel> novelList = new ArrayList<Novel>();170 Document doc = getDocumentFrom171 NodeList novels = doc.getElementsByTagName("novel");172 for (int i = 0; i < novels.getLength(); i++) {173 Element novel = ((Element) novels.item(i));174 int id = Integer.parseInt(novel.getElementsByTagName("id").item(0)175 .getFirstChild().getNodeValue());176 String name = novel.getElementsByTagName("name").item(0)177 .getFirstChild().getNodeValue();178 String author = novel.getElementsByTagName("author").item(0)179 .getFirstChild().getNodeValue();180 String category = novel.getElementsByTagName("category").item(0)181 .getFirstChild().getNodeValue();182 String description = novel.getElementsByTagName("description")183 .item(0).getFirstChild().getNodeValue();184 185 Novel oneNovel = new Novel(id, category, name, author, description);186 novelList.add(oneNovel);187 }188 return novelList ;189 }190 /**191 * 将Novel信息写入到config/novelsInfo.192 * @param novel 小说对象193 * @return 是否写入成功 194 * TODO:确定原子操作195 */196 public static boolean writeNovelToFile(Novel novel ) {197 /**198 * 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.199 */200 try{201 FileUtils.writeStringToFile(novel.getContent(), "novel/" + novel.getName() + ".txt");202 203 return true ;204 }catch(Exception e ){205 /**206 * 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207 * 这段代码应该很少执行到 ~~~~208 * 209 */210 System.out.println("小说写入文件失败,正在回滚~~");211 FileUtils.deleteFile("novel/" + novel.getName() + ".txt") ;212 213 e.printStackTrace();214 return false ;215 }216 }217 218 /**219 * 从config/novelsInfo.220 * 221 * @param novel222 * 小说对象223 */224 public static void deleteNovelInfoFrom225 try {226 Document doc = getDocumentFrom);227 Element novelsElement = (Element) doc228 .getElementsByTagName("novels").item(0);229 NodeList novelElements = novelsElement230 .getElementsByTagName("novel");231 232 Node deleteElement = null;233 for (int i = 0; i < novelElements.getLength(); i++) {234 String id = ((Element) novelElements.item(i))235 .getElementsByTagName("id").item(0).getFirstChild()236 .getNodeValue();237 if (id.equals(String.valueOf(novel.getId()))) {238 deleteElement = novelElements.item(i);239 break;240 }241 }242 novelsElement.removeChild(deleteElement);243 writeDocumentToFile(doc, "config/novlesInfo.);244 } catch (Exception e) {245 e.printStackTrace();246 }247 }248 /**249 * 将小说信息写入到config/novelsInfo.250 * @param novel小说对象251 */252 public static void writeNovelInfoTo253 Document doc = null ;254 try {255 doc = getDocumentFrom);256 } catch (Exception e) {257 e.printStackTrace();258 return ;259 }260 Element novelDocument = (Element)doc.createElement("novel") ;261 // id262 Element novelIdDocument = (Element)doc.createElement("id") ;263 Text novelIdTextNode = doc.createTextNode("idValue") ;264 novelIdTextNode.setNodeValue(String.valueOf(novel.getId()));265 novelIdDocument.appendChild(novelIdTextNode);266 // name267 Element novelNameDocument = (Element)doc.createElement("name") ;268 Text novelNameTextNode = doc.createTextNode("nameValue") ;269 novelNameTextNode.setNodeValue(String.valueOf(novel.getName()));270 novelNameDocument.appendChild(novelNameTextNode);271 // author272 Element novelAuthorDocument = (Element)doc.createElement("author") ;273 Text novelAuthorTextNode = doc.createTextNode("authorValue") ;274 novelAuthorTextNode.setNodeValue(String.valueOf(novel.getAuthor()));275 novelAuthorDocument.appendChild(novelAuthorTextNode);276 // category277 Element novelCategoryDocument = (Element)doc.createElement("category") ;278 Text novelCategoryTextNode = doc.createTextNode("categoryValue") ;279 novelCategoryTextNode.setNodeValue(String.valueOf(novel.getCategory()));280 novelCategoryDocument.appendChild(novelCategoryTextNode);281 // description 282 Element novelDescriptionDocument = (Element)doc.createElement("description") ;283 Text novelDescriptionTextNode = doc.createTextNode("descriptionValue") ;284 novelDescriptionTextNode.setNodeValue(String.valueOf(novel.getDescription()));285 novelDescriptionDocument.appendChild(novelDescriptionTextNode);286 287 novelDocument.appendChild(novelIdDocument) ;288 novelDocument.appendChild(novelNameDocument) ;289 novelDocument.appendChild(novelAuthorDocument) ;290 novelDocument.appendChild(novelCategoryDocument) ;291 novelDocument.appendChild(novelDescriptionDocument) ;292 doc.getElementsByTagName("novels").item(0).appendChild(novelDocument) ;293 // 写到文件中294 try {295 writeDocumentToFile(doc, "config/novelsInfo.);296 } catch (Exception e) {297 e.printStackTrace();298 }299 }300 }
原标题:xml、文件操作功能类
关键词:xml