FileHelper-文件操作工具

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import javax.servlet.http.HttpServletResponse;

public class FileHelper {

static File file ;

/**

* @删除文件

* input 输入 output 输出

* */

public static boolean deleteFile(String url){

boolean flag = false;

try{

if(null == file){

file = new File(url);

if(file.isFile()){

if(file.canWrite()){

file.delete();

}

flag = true;

}

}else{

if(url == file.getPath()){

file.delete();

flag = true;

}

}

}catch(Exception e){

flag = false ;

e.printStackTrace();

}finally{

file = null;

System.gc();

}

return flag;

}

/**

* 新建目录

* @param folderPath String 如 c:/fqf

* @return boolean

*/

public static void newFolder(String folderPath) {

try {

String filePath = folderPath;

filePath = filePath.toString();

java.io.File myFilePath = new java.io.File(filePath);

if (!myFilePath.exists()) {

myFilePath.mkdir();

}

}

catch (Exception e) {

e.printStackTrace();

}

}

/**

* 复制单个文件

* @param oldPath String 原文件路径 如：c:/fqf.txt

* @param newPath String 复制后路径 如：f:/fqf.txt

* @return boolean

*/

public static void copyFile(String oldPath, String newPath) {

try {

int bytesum = 0;

int byteread = 0;

File oldfile = new File(oldPath);

if (oldfile.exists()) { //文件存在时

InputStream inStream = new FileInputStream(oldPath); //读入原文件

FileOutputStream fs = new FileOutputStream(newPath);

byte[] buffer = new byte[1444];

int length;

while ( (byteread = inStream.read(buffer)) != -1) {

bytesum += byteread; //字节数 文件大小

fs.write(buffer, 0, byteread);

}

inStream.close();

fs.close();

}

}

catch (Exception e) {

e.printStackTrace();

}

}

/**

* 使用文件通道的方式复制文件

* @param s  源文件

* @param t  复制到的新文件

*/

public static void fileChannelCopy(String srcPath,String outpath) {

File s = new File(srcPath);

File t = new File(outpath);

FileInputStream fi = null;

FileOutputStream fo = null;

FileChannel in = null;

FileChannel out = null;

try {

fi = new FileInputStream(s);

fo = new FileOutputStream(t);

in = fi.getChannel();//得到对应的文件通道

out = fo.getChannel();//得到对应的文件通道

in.transferTo(0, in.size(), out);//连接两个通道，并且从in通道读取，然后写入out通道

} catch (IOException e) {

e.printStackTrace();

} finally {

try {

fi.close();

in.close();

fo.close();

out.close();

} catch (IOException e) {

e.printStackTrace();

}

}

}

/**

* 上传文件

* @param upFile 上传文件

* @param targetFile 目标文件

* @param b

* @return

*/

public static boolean fileUpload(File upFile , File targetFile , byte[] b){

InputStream is = null ;

OutputStream os = null ;

try{

is =  new FileInputStream(upFile);

os= new FileOutputStream(targetFile);

int length = 0;

while((length = is.read(b))>0){

os.write(b, 0, length);

}

}catch(Exception e){

e.printStackTrace();

return false;

}finally{

try {

if(null != is){

is.close();

}if(null != os){

os.close();

}

} catch (IOException e) {

e.printStackTrace();

}

}

return true;

}

/**

* 删除文件

* @param f

* @return

*/

public static boolean deleteFile(File f){

if (f.isFile())

f.delete();

return true;

}

/**

* 删除文件夹

* @param f

* @return

*/

public static boolean deleteDir(File f){

if(f.isDirectory()){

File[] files = f.listFiles();

for(int i=0;i<files.length;i++){

if(files[i].isDirectory()) deleteDir(files[i]);

else deleteFile(files[i]);

}

}

f.delete();

return true ;

}

/**

* 文件下载

* @param filePath 文件路径

* @param fileType 文件类型

* @param downName 下载文件名称

* @param response 响应

*/

public static void downLoadFile(String filePath,String fileType ,String downName,HttpServletResponse response){

OutputStream out = null;// 创建一个输出流对象

String headerStr = downName;

try{

InputStream is=new FileInputStream(filePath);

out = response.getOutputStream();//

headerStr =new String( headerStr.getBytes("gb2312"), "ISO8859-1" );//headerString为中文时转码

response.setHeader("Content-disposition", "attachment; filename="+ headerStr+"."+fileType);// filename是下载的xls的名，建议最好用英文

response.setContentType("application/msexcel;charset=GB2312");// 设置类型

response.setHeader("Pragma", "No-cache");// 设置头

response.setHeader("Cache-Control", "no-cache");// 设置头

response.setDateHeader("Expires", 0);// 设置日期头

// 输入流 和 输出流

int len = 0;

byte[] b = new byte[1024];

while ((len = is.read(b)) != -1) {

out.write(b, 0, len);

}

is.close();

out.flush();

out.close();

} catch (Exception e) {

e.printStackTrace();

} finally {

try {

if (out != null) {

out.close();

}

} catch (IOException e) {

e.printStackTrace();

}

}

}

}