BufferedWriter、BufferedReader读写文件

写文件：

bw = new BufferedWriter(new FileWriter(localPath, false));

false:重新写入文件

true:在原文件之后增加内容。

bw.newLine(); 换行
bw.flush();BufferedWriter是缓冲输入流，意思是调用BufferedWriter的write方法时候。数据是先写入到缓冲区里，并没有直接写入到目的文件里。必须调用BufferedWriter的flush()方法。这个方法会刷新一下该缓冲流，也就是会把数据写入到目的文件里。或者你可以调用BufferedWriter的close()方法，该方法会在关闭该输入流之前先刷新一下该缓冲流。也会把数据写入到目的文件里。

     /**
     * 生成输入数据文件
     *
     * @param list 数据
     * @param fileName 文件名
     */
    public void writeList(List<String[]> list, String fileName) throws IOException {
        BufferedWriter bw = null;
        String strLineData = "";
        String localPath = Constant.getServiceFilesPath() + "/test/" + fileName + ".txt";
        bw = new BufferedWriter(new FileWriter(localPath, false));
        if (list != null && list.size() > 0) {
            for (int i = 0; i < list.size(); i++) {
                String[] str = list.get(i);
                for (int j = 0; j < str.length; j++) {
                    strLineData = strLineData + str[j] + " ";
                }
                bw.write(strLineData);
                bw.newLine();
                bw.flush();
                strLineData = "";
            }
        }
    }

读文件：

/**
     * 解析文件，数据入库
     *
     * @param 日期
     * @return true:成功，false:失败
     */
    public boolean saveUnitCpower(String date) {
        FileInputStream fr = null;
        BufferedReader br = null;
        String[] str = null;
        List<String[]> list = new ArrayList();
        try {
            String fileName = "TEST.txt";
            String localPath = Constant.getServiceFilesPath() + "/test/";
            fr = new FileInputStream(localPath + fileName);
            InputStreamReader is = new InputStreamReader(fr, "UTF8");
            br = new BufferedReader(is);
            String line = br.readLine();
            while (line != null) {
                line = br.readLine();
                str = line.split(" ");
                list.add(new String[]{str[0], str[1], str[2], str[3]});
            }
        } catch (IOException e) {
            return false;
        } finally {
            try {
                if (br != null) {
                    br.close();
                }
                if (br != null) {
                    fr.close();
                }
            } catch (IOException ex) {
                Exceptions.printStackTrace(ex);
            }
            return mapper.save(date, list);
        }
    }