java中对于文件属性的一些操作

发表于:2007-06-22来源:作者:点击数: 标签:
1. 当 Java .io中,如果文件的操作的时候,判断是否隐藏用File.ishiden() 判断是否只读,可用File.canWrite(). 2. 当要设置是否是可读或者是隐藏时,在 java 中除了提供File.setReadOnly()外,就无其他方法了。 所以我们必须到Dos环境下去设置,在java中用Ru

   


      1. 当Java.io中,如果文件的操作的时候,判断是否隐藏用File.ishiden()

判断是否只读,可用File.canWrite().
      2. 当要设置是否是可读或者是隐藏时,在java中除了提供File.setReadOnly()外,就无其他方法了。
          所以我们必须到Dos环境下去设置,在java中用Runtime.getRuntime().exec("attrib " + """ + file.getAbsolutePath() + """+ " +R")该方法可以实现。因为路径file.getAbsolutePath()中可能会还有空格,所以必须用引号把它括起来,当作一个参数。这样就可以实现了
(1)   设置只读Runtime.getRuntime().exec("attrib " + """ + file.getAbsolutePath() + """+ " +R");
(2)   设置可写Runtime.getRuntime().exec("attrib " + """ + file.getAbsolutePath() + """+ " -R");
(3)   设置隐藏Runtime.getRuntime().exec("attrib " + """ + file.getAbsolutePath() + """+ " +H");
(4)   设置非隐藏Runtime.getRuntime().exec("attrib " + """ + file.getAbsolutePath() + """+ " -H");
 
   3.对于读写文件的一些操作源代码
      package fileControl;
 
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.RandomAclearcase/" target="_blank" >ccessFile;
 
public class FileControl {
            private static String fileName;
            private static File file;
            public static void main(String[] args) {
                        try {
                                    fileName = "exercise.java";
                                    file = new File("E:" + "", fileName);
                                    if (file.exists()) {
//                                              file.delete();
                                    } else {
                                                file.createNewFile();
                                    }
                                   
                                    if (file.isDirectory()) {
                                                System.out.println("this file is directory");
                                    }
                                   
                                    if (file.isFile()) {
                                                System.out.println("this file is a file");
                                    }
                                   
                                   
                                    FileWriter fw = new FileWriter("E:" + "" + fileName);
                                    // 缓冲写入文件,并且可以通过转义符或是bw.newLine();来换行
 
                                    BufferedWriter bw = new BufferedWriter(fw);
//                                  将字符串写入文件
                                    bw.write(" 大家好!");
                                    bw.newLine();
                                    bw.write("本?是《JSP?程技巧》");
                                    bw.newLine();
                                    bw.write("?多多指教!");
                                    bw.newLine();
                                    bw.write("email:stride@sina.comqianyf");
                                    bw.flush();
                                    bw.close();
 
                                    //在文件制定位置追加内容
                                    RandomAccessFile rf = new RandomAccessFile("E:" + "" + fileName, "rw");
                                    rf.seek(rf.length());
                                    rf.writeBytes(" zui jia  de");
                                    rf.close();
                                   
                                    // 通过缓冲来读文件
                                    FileReader fr = new FileReader("E:" + "" + fileName);
                                    BufferedReader br = new BufferedReader(fr);
                                    String lineData = br.readLine();
                                    while (null != lineData) {
                                                System.out.println(lineData);
                                                lineData = br.readLine();
                                    }
                                   
                                               
                      } catch (IOException ee) {
                                    System.out.println("System Exception");
                      }
                       
            }
 
}

原文转自:http://www.ltesting.net