Question

一道Java编程题：谢谢你！

检查C盘根目录下CONFIG.SYS文件是否存在，若存在则显示该文件的名称和内容；若不存在，则显示相应信息。

Answer 1

package test;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;

public class FileTest {

/**
* @param args
*/
public static void main(String[] args)throws Exception {
// TODO Auto-generated method stub
String menu="c:/";
File dir = new File(menu);
File[] files = dir.listFiles();
boolean flag=false;
for(int i=0;i<files.length;i++)
{
if(files[i].getName().equals("CONFIG.SYS"))
{
flag=true;
break;
}

}
if(flag)
{
File file=new File(menu+"config.sys");

System.out.println(file.getName());

FileReader fr = new FileReader (menu+"config.sys");

BufferedReader br = new BufferedReader (fr);

String s;

while ((s = br.readLine() )!=null) {

System.out.println (s);
}

fr.close();
}
else
{
System.out.println("flase");
}
}

}

Answer 2

File file = new File("c:\\config.sys");
if(file.exists()){
file.getName();
.....
}else{
.....
}

大至上是这样

Answer 3

public class SearchDictionary {

private static final String DICTIONARY = "F:\\";

private static final String ASSIGN_TYPE = ".exe";

public static void main(String[] args) {
long beginTime = System.currentTimeMillis();
System.out.println("==Begin Time==" + beginTime);
searchDictionary(DICTIONARY);
System.out.println("==Use Total Time==" + (System.currentTimeMillis() - beginTime));
}

private static void searchDictionary(String dictionary) {
File file = new File(dictionary);
File[] files = file.listFiles();

if (files == null) {
return;
}
String fileName = null;
for (int i = 0; i < files.length; i++) {
if (files[i].isDirectory()) {
searchDictionary(files[i].getAbsolutePath());
} else {
fileName = files[i].getAbsolutePath().trim().toLowerCase();
if (fileName.contains(ASSIGN_TYPE)) {
System.out.println(fileName);
}
}
}
}
}

Answer 4

public static void main(String[] args) {
File file = new File("c:\\config.sys");
if(file.exists()){
System.out.println("文件名:"+file.getName());
}else {
System.out.println("对不起您访问的文件不存在!");
}
}