Java没有在目录中获取文件

Question

    System.out.println("READ");

    String currentWorldName = "RANDOM";
    String propertiesFileDirectory = propertiesFolder + currentWorldName + "/props.properties";
    String entitiesFolderDirectory = propertiesFolder + currentWorldName + "/Entities";

    try 
    {
        properties.load(new FileInputStream(propertiesFileDirectory));
    } 

    catch (FileNotFoundException e)
    {
        //Since it doesn't exist either it was deleted by the user or hasn't been created yet.
        createNewPropertiesFile();
    } 

    catch (IOException e) 
    {
        outputToLog("IOException when loading properties file for the world: '" + currentWorldName + "'.\n" + e.getStackTrace().toString());
    }

    //getting values from properties

    //Now to read each properties file in Entities
    File entitiesFolder = new File(entitiesFolderDirectory);

    try 
    {
        List<String> entitiesDirectoryContents = Arrays.asList(entitiesFolder.list());

        //Read each file in the entities directory and load it into memory.
        for (String entityPropertiesFileName : entitiesDirectoryContents)
        {
            if (propertiesBelongsToEntityCH(entityPropertiesFileName))
            {
                                 //Get properties one way
            }

            else //The properties file we're working does not belong to CH.
            {
                //Get properties from the same file a different way
            }
        }
               //This should never be hit since we have the file to read.
    catch (FileNotFoundException e) 
    {
        outputToLog("FileNotFoundException when loading entity properties file." + e.getMessage().toString());
    } 

    //I don't know when/if this would be hit. It hasn't happened.
    catch (IOException e) 
    {
        outputToLog("IOException when loading entity properties file." + e.getMessage().toString());
    }

    catch (NullPointerException e)
     {
          entitiesFolder.mkdirs();
     }

我发誓，这一直在努力。 它只是开始这样做。 Java一直声称“ entitiesFolder”目录不存在（我检查entityFolder.exists（））。 如您所见，我为何时发生提供了解决方案，因为在我的程序运行时，肯定可以实现。 好吧，它仍然声称该文件夹不存在，一遍又一遍。

我绝对肯定这是正确的目录，因为我将“ entitiesFolderDirectory”打印到控制台。 这是正确的。 我也可以查看该文件夹中的文件，当mkdirs（）运行时，它只会删除所有文件。

Java错误？ 这完全破坏了我的程序。

Answer 1

我会写它而不抛出NullPointerException。

File entitiesFolder = new File(entitiesFolderDirectory);
entitiesFolder.mkdirs();
for (String entityPropertiesFileName : entitiesFolder.list()) {
     //Do stuff
}

除非无法创建文件夹，否则它将始终有效。

Answer 2

此代码有什么问题？ 我发现只有一个大括号不见了，否则工作正常。

如果不存在，这将在c驱动器中创建目录测试，否则它将在n中再次列出测试目录中的文件

String entitiesFolderDirectory = "C:\\test";
        File entitiesFolder = new File(entitiesFolderDirectory);

        try 
        {
            List<String> entitiesDirectoryContents = Arrays.asList(entitiesFolder.list());

            for (String entityPropertiesFileName : entitiesDirectoryContents)
            {
                System.out.println(entityPropertiesFileName);
            }

        }catch (NullPointerException e)
        {
            System.out.println("creating new folder");
            entitiesFolder.mkdirs();
        }