File 对象的常用方法（三）重命名示例 5：1.import java.io.File;2.import java.io.IOException;3.4.public class FileMethodDemo5. public static void main(String args) throws IOException 6. renameToDemo();7. 8.9. public static void renameToDemo() throws IOException 10. File f1 = new File(“d:codeday210.mp3“ );11. File f2 = new File(“d:codeday211.mp3“ );12.13. boolean b = f1.renameTo(f2);14.15. System.out.println( “b = “ + b);16. 17.18.复制代码运行结果：5、系统根目录和容量获取示例 6：1.import java.io.File;2.import java.io.IOException;3.4.public class FileMethodDemo5. public static void main(String args) throws IOException 6. listRootsDemo();7. 8.9. public static void listRootsDemo() throws IOException 10. File files = File.listRoots();11.12. for(File file : files)13. System.out.println(file);14. 15.16. File file = new File(“d:“ );17.18. System.out.println( “getFreeSpace:“ + file.getFreeSpace();19. System.out.println( “getTotalSpace:“ + file.getTotalSpace();20. System.out.println( “getUsableSpace:“ + file.getUsableSpace();21. 22.23.复制代码运行结果：