常用工具類（一）：FileUtile 檔案相關操作

public class FileUtil {
    private static final Logger logger = LoggerFactory.getLogger(FileUtils.class);

    //讀取檔案
    public static String readFile(String fileName){
        InputStreamReader streamReader = null;
        InputStream inputStream = FileUtil.class.getResourceAsStream("/"
 
 + fileName);
        StringBuilder sb = new StringBuilder();
        try {
            if (inputStream == null) {
                logger.error("InputStream為null，fileName為"+fileName);
                throw new IOException();
            }
            streamReader = new InputStreamReader(inputStream,"utf-8"
 
);
            int len = 0;
            char[] chars = new char[1024 * 10];
            while((len = streamReader.read(chars))!= -1) {
                sb.append(chars,0,len);
            }
        } catch (IOException e) {
           logger.info("讀取檔案錯誤",e);
           throw new RuntimeException();
        } finally
 
 {
            try {
               if (inputStream != null){
                   inputStream.close();
               }
               if (streamReader != null){
                   streamReader.close();
               }
            } catch (IOException e) {
                logger.error("資源關閉時出錯",e);
            }
        }
        return sb.toString();
    }

    //建立目錄
    public static void mkdir(String path){
        File file = new File(path);
        if (!file.exists()) {
            //mkdir只能建立一級的資料夾，mkdirs可以建立多級資料夾
            if (file.mkdirs()){
                logger.info("目錄 "+path+" 建立成功");
            } else {
                logger.error("目錄 "+path+" 建立失敗");
            }
        }
    }

    //刪除目錄
    public static void delDir(String path) {
        File file = new File(path);
        if (file.exists()) {
            if (file.isDirectory()) {
                File[] files = file.listFiles();
                for (File f : files) {
                    f.delete();
                }
            } else {
                file.delete();
            }
            logger.info(path+" 刪除成功");
        } else {
            logger.error(path+" 路徑不存在");
        }
    }

    //拷貝檔案
    public static void copyFile(String fromPath, String toPath){
        File fromFile = new File(fromPath);
        File[] files = fromFile.listFiles();
        File toFile = new File(toPath);
        if (!toFile.exists()){
            toFile.mkdirs();
        }
        for (File f : files) {
            if (f.isFile()){
                copy(f.getPath(), toPath+"/"+f.getName());
            } else {
                copyFile(f.getPath(),toPath+"/"+f.getName());
            }
        }
    }

    public static void copy(String fromPath,  String toPath){
        BufferedReader br = null;
        BufferedWriter bw = null;
        try {
            br = new BufferedReader(new InputStreamReader(new FileInputStream(fromPath),"GBK"));
            bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(toPath),"GBK"));
            String s = null;
            while ((s = br.readLine()) != null) {
                bw.write(s);
                bw.newLine();
                bw.flush();
            }
        } catch (FileNotFoundException e) {
            logger.error("檔案沒有找到",e);
        } catch (IOException e) {
            logger.error("讀取檔案異常",e);
        } finally {
            try {
                if (br != null) {
                    br.close();
                }
                if (bw != null) {
                    bw.close();
                }
            } catch (IOException e) {
                logger.info("資源關閉時出錯",e);
            }
        }
    }

    public static void main(String args[]){
        //update目錄位置，如下如所示
        String fromPath = FileUtil.class.getClassLoader().getResource("update").getFile();
        FileUtil.copyFile(fromPath,"C:/test/");
    }
}