java读写文件代码

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//写入文件File file = new File(sessionNumFileName);        FileWriter writer = null;        try {            //创建输出流            writer = new FileWriter(file);            //将SessionNum写入文件            writer.write(String.valueOf(sessionNum));        } catch (IOException e) {            //若写入失败，则记录日志，并返回            logger.dead("DSCTRL1009W", e, sessionNumFileName);            throw new SystemException(e);        } finally {            try {                if (writer != null) {                    //关闭输出流                    writer.flush();                    writer.close();                }            } catch (IOException e) {                logger.dead("DSCTRL1009W", e, sessionNumFileName);                throw new SystemException(e);            }        }        return true;

读取文件

File file = new File(fileName);        //若指定文件不存在，则创建新文件，并记录日志        if (!file.exists()) {            try {                file.createNewFile();                logger.note("DSCTRL0092N", fileName);            } catch (IOException e) {                logger.dead("DSCTRL0093E", fileName);                throw new SystemException("can not create SessionNumFile:["                        + fileName + "]", e);            }        }        BufferedReader reader = null;        try {            reader = new BufferedReader(new FileReader(file));            String tempString = reader.readLine();            ret = Integer.parseInt(tempString == null ? "" : tempString.trim());        } catch (Exception e) {            logger.note("DSCTRL0094N", fileName);            logger.note("DSCTRL0002N", "SessionNum", "0");            ret = 0;        } finally {            try {                if (reader != null) {                    reader.close();                }            } catch (IOException e1) {                logger.note("DSCTRL0095N", e1, fileName);            }        }        return ret;