/** * 不使用遞迴,遍曆檔案夾.速度沒有遞迴效果快 */private static List<File> getFile(String rootDir) {List<File> files = new ArrayList<File>();LinkedList<File> list = new LinkedList<File>();File dir = new File(rootDir);File file[] = dir.listFiles();for (int i = 0; i < file.length; i++) {if (file[i].isDirectory()){list.add(file[i]);} else{//System.out.println(file[i].getAbsolutePath());files.add(file[i]);}}File tmp;while (!list.isEmpty()) {tmp = list.removeFirst();//迴圈操作，刪除元素。if (tmp.isDirectory()) {file = tmp.listFiles();if (file == null)continue;for (int i = 0; i < file.length; i++) {if (file[i].isDirectory()) {list.add(file[i]);} else {//System.out.println(file[i].getAbsolutePath());files.add(file[i]);}}} else {//System.out.println(tmp.getAbsolutePath());files.add(tmp);}}return files;}
--------------------------------------------------------------------------------------------- **
* 輸出目錄中的所有檔案及目錄名字
* @param filePath
*/
public void readFolderByFile(String filePath)
{
File file = new File(filePath);
File[] tempFile = file.listFiles();
for(int i = 0;i<tempFile.length;i++)
{
if(tempFile[i].isFile())
{
System.out.println("File : "+tempFile[i].getName());
}
if(tempFile[i].isDirectory())
{
System.out.println("Directory : "+tempFile[i].getName());
}
} 2. 如何用 java 修改檔案的副檔名 File file=new File("c:/test.txt");
file.renameTo(new File("c:/test.log")); import java.io.*;
public class test1
{
public static void main(String[] args) {
File file=new File("c:/test.rtf"); // 指定檔案名稱及路徑
String filename=file.getAbsolutePath();
if(filename.indexOf(".")>=0)
{
filename = filename.substring(0, filename.lastIndexOf("."));
}
file.renameTo(new File(filename+".doc")); // 改名
}
}
3. 檔案夾遍曆
<%@ page contentType="text/html; charset=gb2312" %>
<%@ page import="java.io.*" %>
<%
String url1="C:/aaa";
File f=(new File(url1));
if(f.isDirectory()){
File [] fe = f.listFiles();
go_on:
for (int i = 0;i<fe.length;i++){
if (fe[i].isDirectory()){
File [] fe1 = fe[i].listFiles();
for (int j = 0;j<fe1.length;j++){
if (fe1[j].isDirectory())
continue go_on;
out.println(fe1[j].toString());
}
}
else out.println(fe[i].toString());
}
}
} **
* 建立與刪除檔案
* @param filePath
* @param fileName
* @return 建立成功返回 true
* @throws IOException
*/
public boolean createAndDeleteFile(String filePath,String fileName) throws IOException
{
boolean result = false;
File file = new File(filePath,fileName);
if(file.exists())
{
file.delete();
result = true;
System.out.println(" 檔案已經刪除。 ");
}
else
{
file.createNewFile();
result = true;
System.out.println(" 檔案已經建立。 ");
}
return result;
}
/**
* 建立和刪除目錄
* @param folderName
* @param filePath
* @return 刪除成功返回 true
*/
public boolean createAndDeleteFolder(String folderName,String filePath)
{
boolean result = false;
try
{
File file = new File(filePath+folderName);
if(file.exists())
{
file.delete();
System.out.println(" 目錄已經存在，已刪除 !");
result = true;
}
else
{
file.mkdir();
System.out.println(" 目錄不存在，已經建立 !");
result = true;
}
}
catch(Exception ex)
{
result = false;
System.out.println("CreateAndDeleteFolder is error:"+ex);
}
return result;
}
/**
* 輸出目錄中的所有檔案及目錄名字
* @param filePath
*/
public void readFolderByFile(String filePath)
{
File file = new File(filePath);
File[] tempFile = file.listFiles();
for(int i = 0;i<tempFile.length;i++)
{
if(tempFile[i].isFile())
{
System.out.println("File : "+tempFile[i].getName());
}
if(tempFile[i].isDirectory())
{
System.out.println("Directory : "+tempFile[i].getName());
}
}
}
/**
* 檢查檔案中是否為一個空
* @param filePath
* @param fileName
* @return 為空白返回 true
* @throws IOException
*/
public boolean fileIsNull(String filePath,String fileName) throws IOException
{
boolean result = false;
FileReader fr = new FileReader(filePath+fileName);
if(fr.read() == -1)
{
result = true;
System.out.println(fileName+" 檔案中沒有資料 !");
}
else
{
System.out.println(fileName+" 檔案中有資料 !");
}
fr.close();
return result;
}
/**
* 讀取檔案中的所有內容
* @param filePath
* @param fileName
* @throws IOException
*/
public void readAllFile(String filePath,String fileName) throws IOException
{
FileReader fr = new FileReader(filePath+fileName);
int count = fr.read();
while(count != -1)
{
System.out.print((char)count);
count = fr.read();
if(count == 13)
{
fr.skip(1);
}
}
fr.close();
}
/**
* 一行一行的讀取檔案中的資料
* @param filePath
* @param fileName
* @throws IOException
*/
public void readLineFile(String filePath,String fileName) throws IOException
{
FileReader fr = new FileReader(filePath+fileName);
BufferedReader br = new BufferedReader(fr);
String line = br.readLine();
while(line != null)
{
System.out.println(line);
line = br.readLine();
}
br.close();
fr.close();
}
}
