Java 文件和byte數組轉換

/** 
     * 獲得指定文件的byte數組 
     */  
    private byte[] getBytes(String filePath){  
        byte[] buffer = null;  
        try {  
            File file = new File(filePath);  
            FileInputStream fis = new FileInputStream(file);  
            ByteArrayOutputStream bos = new ByteArrayOutputStream(1000);  
            byte[] b = new byte[1000];  
            int n;  
            while ((n = fis.read(b)) != -1) {  
                bos.write(b, 0, n);  
            }  
            fis.close();  
            bos.close();  
            buffer = bos.toByteArray();  
        } catch (FileNotFoundException e) {  
            e.printStackTrace();  
        } catch (IOException e) {  
            e.printStackTrace();  
        }  
        return buffer;  
    }
    
    /** 
     * 根據byte數組，生成文件 
     */  
    public static void getFile(byte[] bfile, String filePath,String fileName) {  
        BufferedOutputStream bos = null;  
        FileOutputStream fos = null;  
        File file = null;  
        try {  
            File dir = new File(filePath);  
            if(!dir.exists()&&dir.isDirectory()){//判斷文件目錄是否存在  
                dir.mkdirs();  
            }  
            file = new File(filePath+"\\"+fileName);  
            fos = new FileOutputStream(file);  
            bos = new BufferedOutputStream(fos);  
            bos.write(bfile);  
        } catch (Exception e) {  
            e.printStackTrace();  
        } finally {  
            if (bos != null) {  
                try {  
                    bos.close();  
                } catch (IOException e1) {  
                    e1.printStackTrace();  
                }  
            }  
            if (fos != null) {  
                try {  
                    fos.close();  
                } catch (IOException e1) {  
                    e1.printStackTrace();  
                }  
            }  
        }  
    } 
後臺封裝圖片數據：map.put("imgUrl","data:image/png;base64,"+new Base64().encodeToString(getBytes(pnameString)))