Java中写文件操作

        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        bos.write(‘q‘);
        bos.write(‘a‘);   //将字节写入该字符数组   
        bos.reset();      //重置该字节数组，即将如上写入的‘q‘ ‘a‘字节清空
        byte[] b = {‘a‘,‘b‘,‘c‘,‘d‘,‘e‘,‘f‘,‘g‘,‘h‘,‘i‘,‘j‘,‘k‘,‘l‘,‘m‘,‘n‘};
        bos.write(b, 1, 7);   //从b数组的第一个下标连续写入长度为7个字符
        try {
            FileOutputStream fs = new FileOutputStream("SourceFile/employee");
            bos.writeTo(fs);   //将字符数组写入文档
            fs.close();
            bos.flush();
            bos.close();
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        try {
            FileOutputStream fs1 = new FileOutputStream(FileDescriptor.out);
            FileOutputStream fs2 = new FileOutputStream(new File("SourceFile/employee"), true); //在该文件的末尾添加内容
            fs1.write("https://www.cnblogs.com/zhanglei93/".getBytes());   //write()方法可以写入byte数组、int
            fs1.close();
            fs2.write("https://www.cnblogs.com/zhanglei93/".getBytes());
            fs2.flush();   //清空缓存里的数据，并通知底层去进行实际的写操作
            fs2.close();
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        try {
            FileOutputStream fs = new FileOutputStream("SourceFile/employee");
            BufferedOutputStream bos = new BufferedOutputStream(fs);
            bos.write("https://www.cnblogs.com/zhanglei93/".getBytes());  //write()方法可以写入byte数组、int
            fs.close();
            bos.flush();
            bos.close();
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        try {
            BufferedWriter bw = new BufferedWriter(new FileWriter("SourceFile/employee"));
            bw.write("http://www.cnblogs.com/zhanglei93/".toCharArray());   //写入char数组
            bw.write("http://www.cnblogs.com/zhanglei93/");   //写入String,还可以写入int
            CharSequence csq = "http://www.cnblogs.com/zhanglei93/p/5846592.html";
            bw.append(csq, 0, 34);
            bw.close();
        } catch (IOException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }

      CharArrayWriter cw = new CharArrayWriter(5);
      for(Employee e : employees){
          try {
              cw.write(e.getName());
              cw.append(e.getSalary() + "");
              cw.write(e.getDate().toString() + "\r\n");
              FileWriter fw = new FileWriter("SourceFile/employee");
              cw.writeTo(fw);
              fw.close();
              cw.close();
          } catch (IOException e1) {
              // TODO Auto-generated catch block
              e1.printStackTrace();
          }
      }

PrintWriter pw = null;
    
    /**
     * PrintWriter(String fileName, String csn)  
     * 创建具有指定文件名称和字符集且不带自动行刷新的新 PrintWriter。如不执行pw.close()则不刷新文件内容
     * @param name
     * @param code
     * @param employees
     */
    public void writeData(String name, String code, Employee[] employees){
        try {
            pw = new PrintWriter(name, code);
            writeToFile(pw, employees);
            pw.close();
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    
    /**
     * PrintWriter(Writer out, boolean autoFlush)  
     * 创建新 PrintWriter, flag = true表示能自动刷新,即不执行pw.close()也会自动刷新内容到文件
     * @param write
     * @param flag
     * @param employees
     */
    public void writeData(Writer write, boolean flag, Employee[] employees){
        pw = new PrintWriter(write, flag);
        writeToFile(pw, employees);
        pw.close();
    }
    
    private void writeToFile(PrintWriter pw, Employee[] employees){
        pw.println(employees.length);
        for(Employee e : employees)
            e.writeEmployee(pw);
    }