import java.io.File;
import java.io.IOException;
public class Filetest
{
public static void main (String[] args) throws IOException
{ File file= new File(".");
System.out.println(file.getName());
System.out.println(file.getParent());
System.out.println(file.getAbsoluteFile());
System.out.println(file.getAbsoluteFile().getParent());
File tmpFile = File.createTempFile("aaa",".txt",file);
tmpFile.deleteOnExit();
File newFile = new File(System.currentTimeMillis() + "");
System.out.println("newFile对象是否存在: " + newFile.exists());
newFile.createNewFile();
newFile.mkdir();
String[] fileList = file.list();
System.out.println("====当前路径下所有文件和路径如下====");
for (String fileName:fileList)
{
System.out.println("fileName");
}
File[] roots = File.listRoots();
System.out.println("====系统所有根路径如下====");
for (File root : roots)
{
System.out.println(root);
}
}
}
运行时出现错误,显示如下
d:\documents>javac -d . Filetest.java
d:\documents>java Filetest
.
null
d:\documents\.
file.getabsolutefile().getparent()
exception in thread"main"java.io.IOException:系统找不到指定的路径。
at java.io.winNIFileststem.createFileExclusively(native method)
at java.io.File.createNewFile(Unknows source)
at java.io.File.createTempFile(Unknows source)
at Filetest.main(Filetest.java:24)
d:\documents>
这是错误显示不 java 运行时命令格式是什么,参数怎么写,举个例子,谢谢