我的目标

我试图将简单对象(SimpleType)写入文件,以便以后可以加载文件并重新创建对象.

我的设定

我目前正在Windows 7计算机上的NetBeans IDE(JDK8)中工作.不过,我认为这不会有所作为.

这是我要写入文件的类型：

public class SimpleType implements Serializable {
    boolean[] a;
    boolean[] b;
}

这是我要运行的代码：

public class Test {
    public static void main(String[] args)
        throws IOException, ClassNotFoundException {
        String fileName = "test.txt";
        SimpleType foo = new SimpleType;
        try (ObjectOutputStream out = new ObjectOutputStream(new
             BufferedOutputStream(new FileOutputStream(fileName)))) {
            out.writeObject(foo);
            out.close();
        }
    }
}

我的问题

该代码可以编译并运行,但是总是抛出FileNotFoundException：

Exception in thread "main" java.io.FileNotFoundException: test.txt (Access is denied)
    at java.io.FileOutputStream.open(Native Method)
    at java.io.FileOutputStream.<init>(FileOutputStream.java:213)
    at java.io.FileOutputStream.<init>(FileOutputStream.java:101)
    at Test.main(Test.java:33)

我试图修复它

>根据文档,如果文件尚不存在,我希望可以创建该文件.我已经彻底阅读了我尝试使用的方法的Javadoc,在此引用其摘录(重点是我的)：

public FileOutputStream(String name) throws FileNotFoundException

[…]

Parameters:
name – the system-dependent filename
Throws:
FileNotFoundException – if the file exists but is a directory rather
than a regular file, does not exist but cannot be created, or cannot
be opened for any other reason
SecurityException – if a security manager exists and its checkWrite
method denies write access to the file.

>我确定我对该目录具有读/写权限；没有名为test.txt的现有文件,因此它不能被另一个程序锁定.
>将fileName更改为绝对路径,我确定我可以写入没有任何区别.

解决方法:

如果文件处于只读模式,则可以重现.你可以这样尝试吗

public static void main(String[] args) {
      String fileName = "sampleObjectFile.txt";
      SampleObject sampleObject = new SampleObject();
      File file = new File(fileName);
      file.setWritable(true); //make it writable.
      try(ObjectOutputStream outputStream = new ObjectOutputStream(new BufferedOutputStream(new FileOutputStream(file)))){
           outputStream.writeObject(sampleObject);
           outputStream.close();
      } catch (IOException e) {
           e.printStackTrace();
      }
 }

如果要在OS磁盘上写入文件,则需要管理员权限.因此,请避免在OS磁盘上写入.