如何将新数据附加到属性文件中的现有数据？

我使用以下代码将数据写入属性文件

public void WritePropertiesFile(String key, String data) { Properties configProperty = new Properties(); configProperty.setProperty(key, data); File file = new File("D:\\Helper.properties"); FileOutputStream fileOut = new FileOutputStream(file,true); configProperty.store(fileOut, "sample properties"); fileOut.close(); } I am calling the above method 3 times as follows: help.WritePropertiesFile("appwrite1","write1"); help.WritePropertiesFile("appwrite2","write2"); help.WritePropertiesFile("appwrite3","write3"); 

但是，Helper.properties文件中的数据显示如下：

 #sample properties #Mon Jul 01 15:01:45 IST 2013 appwrite1=write1 #sample properties #Mon Jul 01 15:01:45 IST 2013 appwrite2=write2 appwrite1=write1 #sample properties #Mon Jul 01 15:01:45 IST 2013 appwrite3=write3 appwrite2=write2 appwrite1=write1 

我希望数据附加到现有数据并且不需要重复数据，如下所示：

 appwrite3=write3 appwrite2=write2 appwrite1=write1 

请建议怎么做？

Answer 1

只是不要在追加模式下打开文件。

您从文件中读取现有属性并再次写入它们。 如果您附加到该文件，将附加Properties对象的所有内容，因为这是您要求的。

只需更换：

 FileOutputStream fileOut = new FileOutputStream(file,true); 

有：

 FileOutputStream fileOut = new FileOutputStream(file); 

旁注：您应该在finally块中.close()输出流。

Answer 2

我知道这已经得到了回答，但仅仅为了将来的参考代码应该看起来更像是这样：

 import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.util.Properties; import java.util.logging.Level; import java.util.logging.Logger; class WritePropertiesFile { public void WritePropertiesFile(String key, String data) { FileOutputStream fileOut = null; FileInputStream fileIn = null; try { Properties configProperty = new Properties(); File file = new File("D:\\Helper.properties"); fileIn = new FileInputStream(file); configProperty.load(fileIn); configProperty.setProperty(key, data); fileOut = new FileOutputStream(file); configProperty.store(fileOut, "sample properties"); } catch (Exception ex) { Logger.getLogger(WritePropertiesFile.class.getName()).log(Level.SEVERE, null, ex); } finally { try { fileOut.close(); } catch (IOException ex) { Logger.getLogger(WritePropertiesFile.class.getName()).log(Level.SEVERE, null, ex); } } } public static void main(String[] args) { WritePropertiesFile help = new WritePropertiesFile(); help.WritePropertiesFile("appwrite1", "write1"); help.WritePropertiesFile("appwrite2", "write2"); help.WritePropertiesFile("appwrite3", "write3"); } }