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！！！