//将str1替换为str1    //FilePath为文件路径    public void changeTxtContent(String FilePath,String str1,String str2) throws Exception{        File file = new File(FilePath);        String code = getFileCharacterEnding(file);//获取文件编码        InputStreamReader read = new InputStreamReader(new FileInputStream(            file), code);        BufferedReader bufferedReader = new BufferedReader(read);        String TxtBuff=null;        String out="";        while((TxtBuff = bufferedReader.readLine()) !=null){            TxtBuff = TxtBuff.replace(str1, str2);            out+= TxtBuff;        }        read.close();        FileOutputStream outputstream=null;         outputstream = new FileOutputStream(file);        outputstream.write(out.getBytes(code));          outputstream.close();     }

获取文件编码

public static String getFileCharacterEnding(File file) throws Exception {        InputStream inputStream = new FileInputStream(file);         byte[] head = new byte[3];          inputStream.read(head);           String code = "gbk";        if (head[0] == -1 && head[1] == -2){            code = "UTF-16";        }        if (head[0] == -2 && head[1] == -1){            code = "Unicode";        }        if (head[0] == -17 && head[1] == -69 && head[2] == -65){            code = "UTF-8";        }        try{ inputStream.close();}catch (Exception e) {}        System.out.println(code);                 return code;    }

 

这种方法应该不适合跨行内容的替换，如果要换行内容要替换的话 ，可以试下 out=out.replace(str1, str2);