Java文件类操作【工具类】

tech2022-11-27  106

上一篇博客【SMB协议的共享文件读写】刚刚出,有位朋友私信,有没有普通的文件类的操作。下面贴出一下自己以前整理过的一些文件类的操作。

import java.io.*; import java.util.ArrayList; import java.util.Calendar; import java.util.Date; import java.util.HashMap; import java.util.HashSet; import java.util.List; /** * @ Author :Janson * @ Date :Created in 2019/6/7 */ @SuppressWarnings({"resource","unused"}) public class FileUtils { /** * 获取windows/linux的项目根目录 * @return */ public static String getConTextPath(){ String fileUrl = Thread.currentThread().getContextClassLoader().getResource("").getPath(); if("usr".equals(fileUrl.substring(1,4))){ fileUrl = (fileUrl.substring(0,fileUrl.length()-16));//linux }else{ fileUrl = (fileUrl.substring(1,fileUrl.length()-16));//windows } return fileUrl; } /** * 字符串转数组 * @param str 字符串 * @param splitStr 分隔符 * @return */ public static String[] StringToArray(String str,String splitStr){ String[] arrayStr = null; if(!"".equals(str) && str != null){ if(str.indexOf(splitStr)!=-1){ arrayStr = str.split(splitStr); }else{ arrayStr = new String[1]; arrayStr[0] = str; } } return arrayStr; } /** * 读取文件 * * @param Path * @return */ public static String ReadFile(String Path) { BufferedReader reader = null; String laststr = ""; try { FileInputStream fileInputStream = new FileInputStream(Path); InputStreamReader inputStreamReader = new InputStreamReader(fileInputStream, "UTF-8"); reader = new BufferedReader(inputStreamReader); String tempString = null; while ((tempString = reader.readLine()) != null) { laststr += tempString; } reader.close(); } catch (IOException e) { e.printStackTrace(); } finally { if (reader != null) { try { reader.close(); } catch (IOException e) { e.printStackTrace(); } } } return laststr; } /** * 获取文件夹下所有文件的名称 + 模糊查询(当不需要模糊查询时,queryStr传空或null即可) * 1.当路径不存在时,map返回retType值为1 * 2.当路径为文件路径时,map返回retType值为2,文件名fileName值为文件名 * 3.当路径下有文件夹时,map返回retType值为3,文件名列表fileNameList,文件夹名列表folderNameList * @param folderPath 路径 * @param queryStr 模糊查询字符串 * @return */ public static HashMap<String, Object> getFilesName(String folderPath , String queryStr) { HashMap<String, Object> map = new HashMap<>(); List<String> fileNameList = new ArrayList<>();//文件名列表 List<String> folderNameList = new ArrayList<>();//文件夹名列表 File f = new File(folderPath); if (!f.exists()) { //路径不存在 map.put("retType", "1"); }else{ boolean flag = f.isDirectory(); if(flag==false){ //路径为文件 map.put("retType", "2"); map.put("fileName", f.getName()); }else{ //路径为文件夹 map.put("retType", "3"); File fa[] = f.listFiles(); queryStr = queryStr==null ? "" : queryStr;//若queryStr传入为null,则替换为空(indexOf匹配值不能为null) for (int i = 0; i < fa.length; i++) { File fs = fa[i]; if(fs.getName().indexOf(queryStr)!=-1){ if (fs.isDirectory()) { folderNameList.add(fs.getName()); } else { fileNameList.add(fs.getName()); } } } map.put("fileNameList", fileNameList); map.put("folderNameList", folderNameList); } } return map; } /** * 以行为单位读取文件,读取到最后一行 * @param filePath * @return */ public static List<String> readFileContent(String filePath) { BufferedReader reader = null; List<String> listContent = new ArrayList<>(); try { reader = new BufferedReader(new FileReader(filePath)); String tempString = null; int line = 1; // 一次读入一行,直到读入null为文件结束 while ((tempString = reader.readLine()) != null) { listContent.add(tempString); line++; } reader.close(); } catch (IOException e) { e.printStackTrace(); } finally { if (reader != null) { try { reader.close(); } catch (IOException e1) { } } } return listContent; } /** * 读取指定行数据 ,注意:0为开始行 * @param filePath * @param lineNumber * @return */ public static String readLineContent(String filePath,int lineNumber){ BufferedReader reader = null; String lineContent=""; try { reader = new BufferedReader(new FileReader(filePath)); int line=0; while(line<=lineNumber){ lineContent=reader.readLine(); line++; } reader.close(); } catch (IOException e) { e.printStackTrace(); } finally { if (reader != null) { try { reader.close(); } catch (IOException e1) { } } } return lineContent; } /** * 读取从beginLine到endLine数据(包含beginLine和endLine),注意:0为开始行 * @param filePath * @param beginLineNumber 开始行 * @param endLineNumber 结束行 * @return */ public static List<String> readLinesContent(String filePath,int beginLineNumber,int endLineNumber){ List<String> listContent = new ArrayList<>(); try{ int count = 0; BufferedReader reader = new BufferedReader(new FileReader(filePath)); String content = reader.readLine(); while(content !=null){ if(count >= beginLineNumber && count <=endLineNumber){ listContent.add(content); } content = reader.readLine(); count++; } } catch(Exception e){ } return listContent; } /** * 读取若干文件中所有数据 * @param listFilePath * @return */ public static List<String> readFileContent_list(List<String> listFilePath) { List<String> listContent = new ArrayList<>(); for(String filePath : listFilePath){ File file = new File(filePath); BufferedReader reader = null; try { reader = new BufferedReader(new FileReader(file)); String tempString = null; int line = 1; // 一次读入一行,直到读入null为文件结束 while ((tempString = reader.readLine()) != null) { listContent.add(tempString); line++; } reader.close(); } catch (IOException e) { e.printStackTrace(); } finally { if (reader != null) { try { reader.close(); } catch (IOException e1) { } } } } return listContent; } /** * 文件数据写入(如果文件夹和文件不存在,则先创建,再写入) * @param filePath * @param content * @param flag true:如果文件存在且存在内容,则内容换行追加;false:如果文件存在且存在内容,则内容替换 */ public static String fileLinesWrite(String filePath,String content,boolean flag){ String filedo = "write"; FileWriter fw = null; try { File file=new File(filePath); //如果文件夹不存在,则创建文件夹 if (!file.getParentFile().exists()){ file.getParentFile().mkdirs(); } if(!file.exists()){//如果文件不存在,则创建文件,写入第一行内容 file.createNewFile(); fw = new FileWriter(file); filedo = "create"; }else{//如果文件存在,则追加或替换内容 fw = new FileWriter(file, flag); } } catch (IOException e) { e.printStackTrace(); } PrintWriter pw = new PrintWriter(fw); pw.println(content); pw.flush(); try { fw.flush(); pw.close(); fw.close(); } catch (IOException e) { e.printStackTrace(); } return filedo; } /** * 写文件 * @param ins * @param out */ public static void writeIntoOut(InputStream ins, OutputStream out) { byte[] bb = new byte[10 * 1024]; try { int cnt = ins.read(bb); while (cnt > 0) { out.write(bb, 0, cnt); cnt = ins.read(bb); } } catch (IOException e) { e.printStackTrace(); } finally { try { out.flush(); ins.close(); out.close(); } catch (IOException e) { e.printStackTrace(); } } } /** * 判断list中元素是否完全相同(完全相同返回true,否则返回false) * @param list * @return */ private static boolean hasSame(List<? extends Object> list){ if(null == list) return false; return 1 == new HashSet<Object>(list).size(); } /** * 判断list中是否有重复元素(无重复返回true,否则返回false) * @param list * @return */ private static boolean hasSame2(List<? extends Object> list){ if(null == list) return false; return list.size() == new HashSet<Object>(list).size(); } /** * 增加/减少天数 * @param date * @param num * @return */ public static Date DateAddOrSub(Date date, int num) { Calendar startDT = Calendar.getInstance(); startDT.setTime(date); startDT.add(Calendar.DAY_OF_MONTH, num); return startDT.getTime(); } /** * 递归删除文件或者目录 * @param file_path */ public static void deleteEveryThing(String file_path) { try{ File file=new File(file_path); if(!file.exists()){ return ; } if(file.isFile()){ file.delete(); }else{ File[] files = file.listFiles(); for(int i=0;i<files.length;i++){ String root=files[i].getAbsolutePath();//得到子文件或文件夹的绝对路径 deleteEveryThing(root); } file.delete(); } } catch(Exception e) { System.out.println("删除文件失败"); } } /** * 创建目录 * @param dir_path */ public static void mkDir(String dir_path) { File myFolderPath = new File(dir_path); try { if (!myFolderPath.exists()) { myFolderPath.mkdir(); } } catch (Exception e) { System.out.println("新建目录操作出错"); e.printStackTrace(); } } /** * 判断指定的文件是否存在。 * * @param fileName * @return */ public static boolean isFileExist(String fileName) { return new File(fileName).isFile(); } /* 得到文件后缀名 * * @param fileName * @return */ public static String getFileExt(String fileName) { int point = fileName.lastIndexOf('.'); int length = fileName.length(); if (point == -1 || point == length - 1) { return ""; } else { return fileName.substring(point + 1, length); } } /** * 删除文件夹及其下面的子文件夹 * * @param dir * @throws IOException */ public static void deleteDir(File dir) throws IOException { if (dir.isFile()) throw new IOException("IOException -> BadInputException: not a directory."); File[] files = dir.listFiles(); if (files != null) { for (int i = 0; i < files.length; i++) { File file = files[i]; if (file.isFile()) { file.delete(); } else { deleteDir(file); } } } dir.delete(); } /** * 复制文件 * * @param src * @param dst * @throws Exception */ public static void copy(File src, File dst) throws Exception { int BUFFER_SIZE = 4096; InputStream in = null; OutputStream out = null; try { in = new BufferedInputStream(new FileInputStream(src), BUFFER_SIZE); out = new BufferedOutputStream(new FileOutputStream(dst), BUFFER_SIZE); byte[] buffer = new byte[BUFFER_SIZE]; int len = 0; while ((len = in.read(buffer)) > 0) { out.write(buffer, 0, len); } } catch (Exception e) { throw e; } finally { if (null != in) { try { in.close(); } catch (IOException e) { e.printStackTrace(); } in = null; } if (null != out) { try { out.close(); } catch (IOException e) { e.printStackTrace(); } out = null; } } } }

 

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