Java文件操作工具类

绝地灬酷狼 2022-05-24 10:49 282阅读 0赞

import java.io.BufferedReader;
    import java.io.BufferedWriter;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileOutputStream;
    import java.io.FileWriter;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.InputStreamReader;
    import java.io.OutputStream;
    import java.io.OutputStreamWriter;
    import java.io.Writer;
    import java.net.HttpURLConnection;
    import java.net.URL;
    
    public class FileUtils {
    
        /**
         * 从输入流中读取string
         * @param inputStream
         * @return
         */
        public static String getString(InputStream inputStream){
            String returnStr = "";
            try{
                BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream, "utf-8"));
                StringBuffer sb = new StringBuffer();
                String str = "";
                while ((str = reader.readLine()) != null)
                {
                    sb.append(str).append("\n");
                }
                returnStr = sb.toString();
            }catch(Exception e){
    
            }
            return returnStr;
        }
    
    
        /**
         * 新建一个文件并写入内容
         *
         * @param String path     文件全路径
         * @param String fileName 文件名
         * @param String content  内容
         * @param int bufLen      设置缓冲区大小
         * @param boolean isWrite 是否追加写入文件
         * @return boolean
         * @throws IOException
         */
        public  static boolean newStaticFile(String path, String fileName, String content,
                                             int bufLen, boolean isWrite)  {
    
            if (path == null || path.equals("") || content == null
                    || content.equals(""))
                return false;
            boolean flag = false;
            File file = new File(path);
            if (!file.exists()) {
                file.mkdirs();
            }
            FileOutputStream fos = null;
            Writer out = null;
            try {
                fos = new FileOutputStream(path + File.separator + fileName,
                        isWrite);
                out = new BufferedWriter(new OutputStreamWriter(fos, "UTF-8"),
                        bufLen);
                out.write(content);
                out.flush();
                flag = true;
                //log.info(content);
            } catch (IOException e) {
                System.out.println("写入文件出错");
                flag = false;
            } finally {
                if (out != null) {
                    try {
                        out.close();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
                if (fos != null) {
                    try {
                        fos.close();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
            }
            return flag;
        }
    
    
        /**
         * 复制一个目录及其子目录、文件到另外一个目录
         * @param src
         * @param dest
         * @throws IOException
         */
        public static void copyFolder(File src, File dest){
            try{
                if (src.isDirectory()) {
                    if (!dest.exists()) {
                        dest.mkdirs();
                    }
                    String files[] = src.list();
                    for (String file : files) {
                        File srcFile = new File(src, file);
                        File destFile = new File(dest, file);
                        // 递归复制
                        copyFolder(srcFile, destFile);
                    }
                } else {
                    InputStream in = new FileInputStream(src);
                    OutputStream out = new FileOutputStream(dest);
    
                    byte[] buffer = new byte[1024];
    
                    int length;
    
                    while ((length = in.read(buffer)) > 0) {
                        out.write(buffer, 0, length);
                    }
                    in.close();
                    out.close();
                }
            }catch(Exception e){
                e.printStackTrace();
            }
    
        }
    
        /**
         * 递归删除目录下的所有文件及子目录下所有文件
         * @param dir 将要删除的文件目录
         * @return boolean Returns "true" if all deletions were successful.
         *                 If a deletion fails, the method stops attempting to
         *                 delete and returns "false".
         */
        public static boolean deleteDir(File dir) {
            if (dir.isDirectory()) {
                String[] children = dir.list();
                for (int i=0; i<children.length; i++) {
                    boolean success = deleteDir(new File(dir, children[i]));
                    if (!success) {
                        return false;
                    }
                }
            }
            // 目录此时为空，可以删除
            return dir.delete();
        }
    
        /**
         * 复制单个文件
         *
         * @param oldPath
         *            String 原文件路径 如：c:/fqf.txt
         * @param newPath
         *            String 复制后路径 如：f:/
         * @return boolean
         */
        public static boolean copyFile(String oldPath, String newPath,
                                       String newFileName) throws IOException {
    
            boolean flag = false;
            if (oldPath == null || newPath == null || newPath.equals("")
                    || oldPath.equals("")) {
                return flag;
            }
            InputStream inStream = null;
            FileOutputStream fs = null;
            try {
                int bytesum = 0;
                int byteread = 0;
                File file = null;
                file = new File(newPath);
                if (!file.exists()) {
                    file.mkdirs();
                }
                file = new File(oldPath);
                if (file.exists()) { // 文件存在时
                    inStream = new FileInputStream(oldPath); // 读入原文件
                    if (newFileName == null || newFileName.equals("")) {
                        newFileName = file.getName();
                    }
                    fs = new FileOutputStream(newPath + File.separator
                            + newFileName);
                    byte[] buffer = new byte[1024 * 8];
                    while ((byteread = inStream.read(buffer)) != -1) {
                        bytesum += byteread; // 字节数 文件大小
    //					System.out.println(bytesum);
                        fs.write(buffer, 0, byteread);
                    }
                    flag = true;
                }
            } catch (IOException e) {
                throw e;
    
            } finally {
                try {
                    if (fs != null) {
                        fs.close();
                    }
                    if (inStream != null) {
                        inStream.close();
                    }
                } catch (IOException e) {
                    throw e;
                }
            }
            return flag;
        }
    
        /**
         * 读取文本文件内容，以行的形式读取
         *
         * @param String
         *            filePathAndName 带有完整绝对路径的文件名
         * @return String 返回文本文件的内容
         */
        public static String readFileContent(String filePathAndName)
                throws IOException {
            return readFileContent(filePathAndName, null, null, 1024);
        }
    
        /**
         * 读取文本文件内容，以行的形式读取
         *
         * @param String
         *            filePathAndName 带有完整绝对路径的文件名
         * @param String
         *            encoding 文本文件打开的编码方式 例如 GBK,UTF-8
         * @param String
         *            sep 分隔符 例如：#，默认为/n;
         * @param int
         *            bufLen 设置缓冲区大小
         * @return String 返回文本文件的内容
         */
        public static String readFileContent(String filePathAndName,
                                             String encoding, String sep, int bufLen) throws IOException {
            if (filePathAndName == null || filePathAndName.equals("")) {
                return "";
            }
            if (sep == null || sep.equals("")) {
                sep = System.getProperty("line.separator");
            }
            if (!new File(filePathAndName).exists()) {
                return "";
            }
            StringBuffer str = new StringBuffer("");
            FileInputStream fs = null;
            InputStreamReader isr = null;
            BufferedReader br = null;
            try {
                fs = new FileInputStream(filePathAndName);
                if (encoding == null || encoding.trim().equals("")) {
                    isr = new InputStreamReader(fs);
                } else {
                    isr = new InputStreamReader(fs, encoding.trim());
                }
                br = new BufferedReader(isr, bufLen);
    
                String data = "";
                while ((data = br.readLine()) != null) {
                    if(!str.toString().isEmpty()){
                        str.append(sep);
                    }
                    str.append(data);
                }
    
            } catch (IOException e) {
                throw e;
            } finally {
                try {
                    if (br != null)
                        br.close();
                    if (isr != null)
                        isr.close();
                    if (fs != null)
                        fs.close();
                } catch (IOException e) {
                    throw e;
                }
    
            }
            return str.toString();
        }
        /**
         * 新建一个文件并写入内容
         *
         * @param String
         *            path 文件全路径
         * @param String
         *            fileName 文件名
         * @param String
         *            content 内容
         * @return boolean
         * @throws IOException
         */
        public static boolean newFile(String path, String fileName, String content)
                throws IOException {
    
            return newFile(path, fileName, content, 1024, false);
        }
        /**
         * 新建一个文件并写入内容
         *
         * @param String
         *            path 文件全路径
         * @param String
         *            fileName 文件名
         * @param String
         *            content 内容
         * @param int
         *            bufLen 设置缓冲区大小
         * @param boolean
         *            isWrite 是否追加写入文件
         * @return boolean
         * @throws IOException
         */
        public static boolean newFile(String path, String fileName, String content,
                                      int bufLen, boolean isWrite) throws IOException {
    
            if (path == null || path.equals("") || content == null
                    || content.equals(""))
                return false;
            boolean flag = false;
            FileWriter fw = null;
            BufferedWriter bw = null;
    
            File file = new File(path);
            if (!file.exists()) {
                file.mkdirs();
    
            }
            try {
                fw = new FileWriter(path + File.separator + fileName, isWrite);
                bw = new BufferedWriter(fw, bufLen);
                bw.write(content);
                flag = true;
            } catch (IOException e) {
                System.out.println("写入文件出错");
                flag = false;
                throw e;
            } finally {
                if (bw != null) {
                    bw.flush();
                    bw.close();
                }
                if (fw != null)
                    fw.close();
            }
    
            return flag;
        }
    
        /**
         * 通过url下载文件
         * @param urlStr
         * @return
         * @throws Exception
         */
        public static InputStream downLoadFromUrl(String urlStr/*,String fileName,String savePath*/) throws Exception{
            URL url = new URL(urlStr);
            HttpURLConnection conn = (HttpURLConnection)url.openConnection();
            //设置超时间为3秒
            conn.setConnectTimeout(3*1000);
            //防止屏蔽程序抓取而返回403错误
            conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");
    
            //得到输入流
            InputStream inputStream = conn.getInputStream();
    		/*//获取自己数组
    		byte[] getData = readInputStream(inputStream);
    
    		//文件保存位置
    		File saveDir = new File(savePath);
    		if(!saveDir.exists()){
    			saveDir.mkdir();
    		}
    		File file = new File(saveDir+File.separator+fileName);
    		FileOutputStream fos = new FileOutputStream(file);
    		fos.write(getData);
    		if(fos!=null){
    			fos.close();
    		}
    		if(inputStream!=null){
    			inputStream.close();
    		}
    		System.out.println("info:"+url+" download success");*/
            return inputStream;
        }
    }