Java操作文件输出为字符串以及字符串输出为文件的方法

/**
  * 读取文件为字符串
  * 
  * @return
  */
public static String readString() {
  String str = "";
  File file = new File("C:/Users/wan7/Desktop/表单/粗集料试验/粗集料冲击值试验（T0322-2000).html");
  try {
   FileInputStream in = new FileInputStream(file);
   // size 为字串的长度 ，这里一次性读完
   int size = in.available();
   byte[] buffer = new byte[size];
   in.read(buffer);
   in.close();
   str = new String(buffer, "utf-8");
  } catch (IOException e) {
   return null;
  }
  return str;
 }

 /**
  * 输出到文件
  */
 public static void outFile(String s) {
  File file = new File("C:/Users/wan7/Desktop/11111111111.html");
  try (FileOutputStream fop = new FileOutputStream(file)) {
   // if file doesn't exists, then create it
   if (!file.exists()) {
    file.createNewFile();
   }
   // get the content in bytes
   byte[] contentInBytes = s.getBytes();
   fop.write(contentInBytes);
   fop.flush();
   fop.close();
   System.out.println("Done");
  } catch (IOException e) {
   e.printStackTrace();
  }
 }