java 文件流的帮助类

小灰灰 2022-10-02 00:37 140阅读 0赞

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package Demo8;
    
    import java.io.*;
    import java.util.ArrayList;
    import java.util.LinkedList;
    import java.util.List;
    
    
    public class FileUtil {
        String newline = "\r\n";//windows
    
        /**
         * 写入文件,末尾自动添加\r\n
         * utf-8  追加
         *
         * @param path
         * @param str
         */
        public static void writeLog(String path, String str) {
            try {
    //            File file = new File(path);
    //            if (!file.exists())
    //                file.createNewFile();
    //            FileOutputStream out = new FileOutputStream(file); //true表示追加
    //            StringBuffer sb = new StringBuffer();
    //
    //
    //            sb.append(str + "\r\n");
    //            out.write(sb.toString().getBytes("utf-8"));//
    //            out.close();
    
                File file = new File(path);
                RandomAccessFile raf = new RandomAccessFile(file, "rw");
                //将写文件指针移到文件尾。
                raf.seek(raf.length());
                raf.writeBytes(str+"\r\n");
                raf.close();
            } catch (IOException ex) {
                System.out.println(ex.getStackTrace());
            }
        }
    
        /**
         * 写入文件,末尾自动添加\r\n
         *
         * @param path
         * @param str
         */
        public static void writeLog(String path, String str, boolean is_append, String encode) {
            try {
                File file = new File(path);
                if (!file.exists())
                    file.createNewFile();
                FileOutputStream out = new FileOutputStream(file, is_append); //true表示追加
                StringBuffer sb = new StringBuffer();
                sb.append(str + "\r\n");
                out.write(sb.toString().getBytes(encode));//
                out.close();
            } catch (IOException ex) {
                System.out.println(ex.getStackTrace());
            }
        }
    
        /**
         * 整个文件以string放回，添加\r\n换行
         *
         * @param path
         * @return
         */
        public static String readLogByString(String path) {
            StringBuffer sb = new StringBuffer();
            String tempstr = null;
            try {
                File file = new File(path);
                if (!file.exists())
                    throw new FileNotFoundException();
                FileInputStream fis = new FileInputStream(file);
                BufferedReader br = new BufferedReader(new InputStreamReader(fis, "utf-8"));
                while ((tempstr = br.readLine()) != null) {
                    sb.append(tempstr + "\r\n");
                }
            } catch (IOException ex) {
                System.out.println(ex.getStackTrace());
            }
            return sb.toString();
        }
    
        /**
         * 加入编码
         * 整个文件以string放回，添加\r\n换行
         *
         * @param path
         * @return
         */
        public static String readLogByStringAndEncode(String path, String encode) {
            StringBuffer sb = new StringBuffer();
            String tempstr = null;
            try {
                File file = new File(path);
                if (!file.exists())
                    throw new FileNotFoundException();
                FileInputStream fis = new FileInputStream(file);
                BufferedReader br = new BufferedReader(new InputStreamReader(fis, encode));
                while ((tempstr = br.readLine()) != null) {
                    sb.append(tempstr + "\r\n");
                }
            } catch (IOException ex) {
                System.out.println(ex.getStackTrace());
            }
            return sb.toString();
        }
    
        /**
         * 按行读取文件，以list<String>的形式返回
         *
         * @param path
         * @return
         */
        public static List<String> readLogByList(String path) {
            List<String> lines = new ArrayList<String>();
            String tempstr = null;
            try {
                File file = new File(path);
                if (!file.exists()) {
                    throw new FileNotFoundException();
                }
                FileInputStream fis = new FileInputStream(file);
                BufferedReader br = new BufferedReader(new InputStreamReader(fis, "utf-8"));
                while ((tempstr = br.readLine()) != null) {
                    lines.add(tempstr.toString());
                }
            } catch (IOException ex) {
                System.out.println(ex.getStackTrace());
            }
            return lines;
        }
    
    
        /**
         * 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) {
    
                e.printStackTrace();
            }
        }
    
        /**
         * 创建文件
         *
         * @param file_path
         */
        public static void createNewFile(String file_path) {
            File myFilePath = new File(file_path);
            try {
                if (!myFilePath.exists()) {
                    myFilePath.createNewFile();
                }
            } catch (Exception e) {
    
                e.printStackTrace();
            }
        }
    
    
        /**
         * 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) {
            }
        }
    
    
        /*
         * 得到一个文件夹下所有文件
         */
        public static List<String> getAllFileNameInFold(String fold_path) {
            List<String> file_paths = new ArrayList<String>();
    
            LinkedList<String> folderList = new LinkedList<String>();
            folderList.add(fold_path);
            while (folderList.size() > 0) {
                File file = new File(folderList.peekLast());
                folderList.removeLast();
                File[] files = file.listFiles();
                ArrayList<File> fileList = new ArrayList<File>();
                for (int i = 0; i < files.length; i++) {
                    if (files[i].isDirectory()) {
                        folderList.add(files[i].getPath());
                    } else {
                        fileList.add(files[i]);
                    }
                }
                for (File f : fileList) {
                    file_paths.add(f.getAbsoluteFile().getPath());
                }
            }
            return file_paths;
        }
    }

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