File 转换成String--- 按原格式转换

StringBuffer sb=new StringBuffer();
        try {
            FileReader fileReader = new FileReader(new File(filePath));
            BufferedReader bufReader=new BufferedReader(fileReader);
           
            LineNumberReader reader = new LineNumberReader(bufReader); 
           
            String line; 

            try {
                while ((line = reader.readLine()) != null) { 

                        sb.append(line).append(System.getProperty("line.separator")); 

                }
                reader.close();
            }
            catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } 
           
           
            String content=sb.toString();
          
            System.out.println(content);
        }
        catch (FileNotFoundException e1) {
            e1.printStackTrace();
        }