java对象序列号到磁盘File文件

Posted 2023-02-05 老李笔记

java对象序列号到磁盘File文件

序列表java对象到磁盘

// 序列化
	public static void writeObject(String ai, Object obj) 
		File file = new File(MqConstant.MAP_SYS_PARAMS.get(MqConstant.ERROR_DATA_DIR) + "/" + ai);
		// 判断文件是否存在
		boolean isExist = false;
		if (file.exists()) 
			isExist = true;
		
		FileOutputStream os = null;
		ObjectOutputStream oos = null;
		try 
			os = new FileOutputStream(file, true);
			oos = new ObjectOutputStream(os);
			// 如果文件存在则截断streamheader；若文件不存在则保留streamheader
			if (isExist) 
				long pos = os.getChannel().position() - 4;
				os.getChannel().truncate(pos);
			
			oos.writeObject(obj);
		 catch (Exception e) 
			e.printStackTrace();
		 finally 
			if (null != oos) 
				try 
					oos.close();
				 catch (Exception e2) 
					e2.printStackTrace();
				
			
			if (null != os) 
				try 
					os.close();
				 catch (Exception e2) 
					e2.printStackTrace();
				
			
		
	

反序列化

// 反序列化
	public static List<ErrorMessage> readObjects(String ai) 
		File file = new File(MqConstant.MAP_SYS_PARAMS.get(MqConstant.ERROR_DATA_DIR) + "/" + ai);
		if (!file.exists()) 
			return null;
		
		List<ErrorMessage> list = new ArrayList<ErrorMessage>();
		FileInputStream is = null;
		ObjectInputStream ois = null;
		try 
			is = new FileInputStream(file);
			ois = new ObjectInputStream(is);
			while (is.available() > 0) 
				list.add((ErrorMessage) ois.readObject());
			
		 catch (Exception e) 
			e.printStackTrace();
		 finally 
			if (null != ois) 
				try 
					ois.close();
				 catch (Exception e2) 
					e2.printStackTrace();
				
			
			if (null != is) 
				try 
					is.close();
				 catch (Exception e2) 
					e2.printStackTrace();
				
			
		
		return list;