Java字符串與文件的互轉

Java字符串與文件的互轉

 

Java中有時候須要讀取一個文本類的文件,將其轉換爲字符串，而後作進一步處理。Java中沒有現成的API方法，本身手動實現一個，你們來分享。

 

1、字符串轉換爲文件

         /**
         * 將字符串寫入指定文件(當指定的父路徑中文件夾不存在時，會最大限度去建立，以保證保存成功！)
         *
         * @param res            原字符串
         * @param filePath 文件路徑
         * @return 成功標記
         */
         public static boolean string2File(String res, String filePath) {
                 boolean flag = true;
                BufferedReader bufferedReader = null;
                BufferedWriter bufferedWriter = null;
                 try {
                        File distFile = new File(filePath);
                         if (!distFile.getParentFile().exists()) distFile.getParentFile().mkdirs();
                        bufferedReader = new BufferedReader( new StringReader(res));
                        bufferedWriter = new BufferedWriter( new FileWriter(distFile));
                         char buf[] = new char[1024];         //字符緩衝區
                         int len;
                         while ((len = bufferedReader.read(buf)) != -1) {
                                bufferedWriter.write(buf, 0, len);
                        }
                        bufferedWriter.flush();
                        bufferedReader.close();
                        bufferedWriter.close();
                } catch (IOException e) {
                        e.printStackTrace();
                        flag = false;
                         return flag;
                } finally {
                         if (bufferedReader != null) {
                                 try {
                                        bufferedReader.close();
                                } catch (IOException e) {
                                        e.printStackTrace();
                                }
                        }
                }
                 return flag;
        }

 

2、文件轉換爲字符串

 

         /**
         * 文本文件轉換爲指定編碼的字符串
         *
         * @param file         文本文件
         * @param encoding 編碼類型
         * @return 轉換後的字符串
         * @throws IOException
         */
         public static String file2String(File file, String encoding) {
                InputStreamReader reader = null;
                StringWriter writer = new StringWriter();
                 try {
                         if (encoding == null || "".equals(encoding.trim())) {
                                reader = new InputStreamReader( new FileInputStream(file), encoding);
                        } else {
                                reader = new InputStreamReader( new FileInputStream(file));
                        }
                         //將輸入流寫入輸出流
                         char[] buffer = new char[DEFAULT_BUFFER_SIZE];
                         int n = 0;
                         while (-1 != (n = reader.read(buffer))) {
                                writer.write(buffer, 0, n);
                        }
                } catch (Exception e) {
                        e.printStackTrace();
                         return null;
                } finally {
                         if (reader != null)
                                 try {
                                        reader.close();
                                } catch (IOException e) {
                                        e.printStackTrace();
                                }
                }
                 //返回轉換結果
                 if (writer != null)
                         return writer.toString();
                 else return null;
        }

 

不想拋出太多的檢查異常，若是你須要捕捉，就拋出吧。

 

注意：對於文件轉換爲字符串，存在一個編碼問題。上面的file2String方法中，若是你不知道編碼，調用時候方法設爲null便可，此時使用系統默認的編碼類型。