JAVA SE实现存储字符到文件，为什么每次不保存上次的结果？只是存储当前字符串。

[孔德]

我编了一段程序，在IO处理这里出了如标题的问题，另外删除功能也不能实现。我拿别人的代码，模仿着编的。主要代码：

public class Contact
{
	private static String IDNumber,ConName,Gender,Call,QQ,WeChat,Remark;
	private static String Delimeter = "||";
	private static String[] ContactProfile = new String[8];
	private static String[] myIDNumber = new String[1];
	private static String FileName = "";
	private static String FoundRecord = "";
	private static String SearchRecord = "";
	private static String thisline = "";
	public static boolean isSave = false;

	Contact(String InputName){FileName = InputName;}
	
	public static void setConName(String InputValue){ConName = InputValue;}
	public static String getConName(){return ConName;}

	public static void setGender(String InputValue){Gender = InputValue;}
	public static String getGender(){return Gender;}
	
	public static void setCall(String InputValue){Call = InputValue;}
	public static String getCall(){return Call;}

	public static void setQQ(String InputValue){QQ = InputValue;}
	public static String getQQ(){return QQ;}

	public static void setWeChat(String InputValue){WeChat = InputValue;}
	public static String getWeChat(){return WeChat;}

	public static void setRemark(String InputValue){Remark = InputValue;}
	public static String getRemark(){return Remark;}

	public static void setIDNumber(String InputValue){IDNumber = InputValue;}
	public static String getIDNumber(){return IDNumber;}
	
	private static String ContactFormat()
	{	
		return IDNumber+Delimeter+ConName+Delimeter+Gender+
		Delimeter+Call+Delimeter+QQ+Delimeter+WeChat+Delimeter+Remark;
	}
//--------------------------Generate IDNember---------------------------//
	/*-----------------Not use this function at all---------------------
	public static String IDGnerate()
	{
		String IDNumLine = "0";
		try
		{
			BufferedReader myfile = new BufferedReader(new FileReader(FileName));
			while((thisline = myfile.readLine()) != null)
			{
				myIDNumber = thisline.split("\\"+ Delimeter);
				if(Integer.parseInt(myIDNumber[0]) > Integer.parseInt(IDNumLine))
					IDNumLine = myIDNumber[0];
			}
			myfile.close();
		}
		catch (IOException ioe)
		{
			System.err.println("Capture Input  IOException!");
		}
		int IDNumFinal = Integer.parseInt(IDNumLine);
		return String.valueOf(IDNumFinal) + 1;
	}
	*/
//---------------------------Save File----------------------------------//
	public static void SaveFile()
	{
		if(Integer.parseInt(getIDNumber()) >= 1)
		{
			Delete(getIDNumber());
			StoreToLocal(FileName, ContactFormat());
		}
	}
//-------------------------------------------------------------
	private static void StoreToLocal(String inputFile, String storeData)
	{
		try
		{
			FileWriter  fileout = new FileWriter(inputFile,true);
			PrintWriter printdata = new PrintWriter(fileout);
			printdata.printf("%s" + "%n", storeData);
			printdata.close();
		}
		catch (IOException e)
		{
			System.err.println("Output IOException!");
		}
	}
//---------------------------------------Search Record Using ID-------------------------//
	public static void SearchIDNum(String keyword)
	{
		isSave = false;
		try
		{
			BufferedReader myinput = new BufferedReader(new FileReader(FileName));
			while((thisline = myinput.readLine()) != null)
			{
				myIDNumber = thisline.split("\\" + Delimeter);
				if(Integer.parseInt(myIDNumber[0]) == Integer.parseInt(keyword))
				{
					FoundRecord = thisline;
					isSave = true;
				}
				if(FoundRecord != "")
					LoardRecord(FoundRecord);
			}
			myinput.close();
		}
		catch (IOException e)
		{
			System.err.printf("Search Error");
		}
	}
	//--------------------------------------------------------------------------------
	private static void LoardRecord(String foundData)
	{
		ContactProfile = foundData.split("\\" + Delimeter);
		setIDNumber(ContactProfile[0]);
		setConName(ContactProfile[1]);
		setGender(ContactProfile[2]);
		setCall(ContactProfile[3]);
		setQQ(ContactProfile[4]);
		setWeChat(ContactProfile[5]);
		setRemark(ContactProfile[6]);
	}
//-------------------------------Delete Record Use ID-------------------------------//
	public static void Delete(String inputkey)
	{
		try
		{
			FileInputStream filein = new FileInputStream(FileName);
			BufferedReader mydelete = new BufferedReader(new InputStreamReader(filein));
			while((thisline = mydelete.readLine()) != null)
			{
				myIDNumber = thisline.split("\\" + Delimeter);
				SearchRecord = thisline;
				if(Integer.parseInt(myIDNumber[0]) != Integer.parseInt(inputkey))
				{StoreToLocal("Template.txt", SearchRecord);}
			}
			mydelete.close();
			File oldfile = new File(FileName);
			oldfile.delete();
			File templateTxt = new File("Template.txt");
			templateTxt.renameTo(new File(FileName));
		}
		catch (IOException e)
		{
			System.err.printf("It's a Delete Exception!");
		}
	}
}

窗口的代码如下（保存按钮）：

		jbtnAdd.addActionListener(new ActionListener()
		{
			public void actionPerformed(ActionEvent e)
			{
				myContact.setIDNumber(jtextID.getText());
				myContact.setConName(jtextName.getText());
				myContact.setGender((String)jcboxGender.getSelectedItem());
				myContact.setCall(jtextCall.getText());
				myContact.setQQ(jtextQQ.getText());
				myContact.setWeChat(jtextWeChat.getText());
				myContact.setRemark(jtextRemark.getText());
				myContact.SaveFile();
				JOptionPane.showMessageDialog(null,"Contact is already saved!","Add",JOptionPane.INFORMATION_MESSAGE);
				ClearControl();
			}
		});

删除：

		jbtnRemove.addActionListener(new ActionListener()
		{
			public void actionPerformed(ActionEvent e)
			{
				myContact.Delete(jtextID.getText());
				ClearControl();
				jtextID.requestFocusInWindow();
				JOptionPane.showMessageDialog(null,"Contact is already Removed!","Remove",JOptionPane.INFORMATION_MESSAGE);
			}
		});