Java 为什么 FileWriter 不创建新文件？文件未找到异常
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Why is FileWriter not creating a new file ? FileNotFoundException
提问by seeker
So I have a code snippet as follows. Im trying to find out why it throws a FileNotFoundException.
所以我有一个代码片段如下。我试图找出它抛出 FileNotFoundException 的原因。
File file= new File (WORKSPACE_PATH+fname);
FileWriter fw;
if (file.exists())
{
fw = new FileWriter(file,true);//if file exists append to file. Works fine.
}
else
{
fw = new FileWriter(file);// If file does not exist. Create it. This throws a FileNotFoundException. Why?
}
回答by nbz
Using concatenation when creating the File won't add the necessary path separator.
创建文件时使用连接不会添加必要的路径分隔符。
File file = new File(WORKSPACE_PATH, fname);
回答by roelofs
This might work:
这可能有效：
File file= new File (WORKSPACE_PATH+fname);
FileWriter fw;
if (file.exists())
{
fw = new FileWriter(file,true);//if file exists append to file. Works fine.
}
else
{
file.createNewFile();
fw = new FileWriter(file);
}
回答by roelofs
You need to add a separator (Windows : \and Unix : /, you can use File.separatorto get the system's separator) if WORKSPACE_PATHdoes not have one at its end, and manually creating the file with its parent directories might help.
如果末尾没有分隔符，则需要添加分隔符（Windows :\和 Unix : /，您可以使用它File.separator来获取系统的分隔符）WORKSPACE_PATH，并且使用其父目录手动创建文件可能会有所帮助。
Try this if WORKSPACE_PATHdoes not have a separator at its end :
如果WORKSPACE_PATH末尾没有分隔符，请尝试此操作：
File file = new File(WORKSPACE_PATH + File.separator + fname);
And add this before fw = new FileWriter(file);
并在此之前添加 fw = new FileWriter(file);
file.mkdirs(); // If the directory containing the file and/or its parent(s) does not exist
file.createNewFile();
