java读取写入文件

先来看一下java写入文件

public static void readTxt(String value) throws IOException {
        FileWriter fw = null;
        try {
            // 如果文件存在，则追加内容；如果文件不存在，则创建文件
            File f = new File("E:\dd.txt");
            fw = new FileWriter(f, true);
        } catch (IOException e) {
            e.printStackTrace();
        }
        PrintWriter pw = new PrintWriter(fw);
        pw.println(new String(value.getBytes(), "utf-8"));
        pw.flush();
        try {
            fw.flush();
            pw.close();
            fw.close();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

下面是java来读取文件

    public static String readText() throws IOException {
        String pathname = "E:\dd.txt"; // 绝对路径或相对路径都可以，这里是绝对路径，写入文件时演示相对路径
        String fileContent = "";
        File f = new File(pathname);
        if (f.isFile() && f.exists()) {
            InputStreamReader read = new InputStreamReader(new FileInputStream(f), "UTF-8");
            BufferedReader reader = new BufferedReader(read);
            String line;
            while ((line = reader.readLine()) != null) {
                fileContent += line;
            }
            read.close();
        }
        return fileContent;
    }

文件流基础，以方便查阅！！！