java文件上传源码下载
// 这是我写的一个方法，里面只需要传两个参数就OK了，在任何地方调用此方法都可以文件上传
/**
* 上传文件
* @param file待上传的文件
* @param storePath待存储的路径(该路径还包括文件名)
*/
public void uploadFormFile(FormFile file,String storePath)throws Exception{
// 开始上传
InputStream is =null;
OutputStream os =null;
try {
is = file.getInputStream();
os = new FileOutputStream(storePath);
int bytes = 0;
byte[] buffer = new byte[8192];
while ((bytes = is.read(buffer, 0, 8192)) != -1) {
os.write(buffer, 0, bytes);
}
os.close();
is.close();
} catch (Exception e) {
throw e;
}
finally{
if(os!=null){
try{
os.close();
os=null;
}catch(Exception e1){
;
}
}
if(is!=null){
try{
is.close();
is=null;
}catch(Exception e1){
;
}
}
}
}
⑵ jsp+servlet实现文件上传与下载源码
上传：
需要导入两个包：commons-fileupload-1.2.1.jar,commons-io-1.4.jar
import java.io.File;
import java.io.IOException;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
/**
* 上传附件
* @author new
*
*/
public class UploadAnnexServlet extends HttpServlet {
private static String path = "";
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}
/*
* post处理
* (non-Javadoc)
* @see javax.servlet.http.HttpServlet#doPost(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
path = this.getServletContext().getRealPath("/upload");
try {
DiskFileItemFactory factory = new DiskFileItemFactory();
ServletFileUpload up = new ServletFileUpload(factory);
List<FileItem> ls = up.parseRequest(request);
for (FileItem fileItem : ls) {
if (fileItem.isFormField()) {
String FieldName = fileItem.getFieldName();
//getName()返回的是文件名字 普通域没有文件 返回NULL
// String Name = fileItem.getName();
String Content = fileItem.getString("gbk");
request.setAttribute(FieldName, Content);
} else {
String nm = fileItem.getName().substring(
fileItem.getName().lastIndexOf("\\") + 1);
File mkr = new File(path, nm);
if (mkr.createNewFile()) {
fileItem.write(mkr);//非常方便的方法
}
request.setAttribute("result", "上传文件成功！");
}
}
} catch (Exception e) {
e.printStackTrace();
request.setAttribute("result", "上传失败，请查找原因，重新再试！");
}
request.getRequestDispatcher("/pages/admin/annex-manager.jsp").forward(
request, response);
}
}
下载（i/o流）无需导包：
import java.io.IOException;
import java.net.URLEncoder;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* 下载文件
* @author
*
*/
public class DownloadFilesServlet extends HttpServlet {
/**
*
*/
private static final long serialVersionUID = 8594448765428224944L;
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}
/*
* 处理请求
* (non-Javadoc)
* @see javax.servlet.http.HttpServlet#doPost(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String name = request.getParameter("fileName");
System.out.print("dddddddddd:" + name);
// web绝对路径
String path = request.getSession().getServletContext().getRealPath("/");
String savePath = path + "upload";
// 设置为下载application/x-download
response.setContentType("application/x-download");
// 即将下载的文件在服务器上的绝对路径
String filenamedownload = savePath + "/" + name;
// 下载文件时显示的文件保存名称
String filenamedisplay = name;
// 中文编码转换
filenamedisplay = URLEncoder.encode(filenamedisplay, "UTF-8");
response.addHeader("Content-Disposition", "attachment;filename="
+ filenamedisplay);
try {
java.io.OutputStream os = response.getOutputStream();
java.io.FileInputStream fis = new java.io.FileInputStream(
filenamedownload);
byte[] b = new byte[1024];
int i = 0;
while ((i = fis.read(b)) > 0) {
os.write(b, 0, i);
}
fis.close();
os.flush();
os.close();
} catch (Exception e) {
}
}
}
⑶ java如何实现文件上传和下载的功能
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.jspsmart.upload.*;
import net.sf.json.JSONObject;
import action.StudentAction;
public class UploadServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
boolean result=true;
SmartUpload mySmartUpload=new SmartUpload();
mySmartUpload.initialize(this.getServletConfig(), request,response);
mySmartUpload.setTotalMaxFileSize(50*1024*1024);//大小限制
mySmartUpload.setAllowedFilesList("doc,docx");//后缀名限制
try {
mySmartUpload.upload();
com.jspsmart.upload.File myFile = mySmartUpload.getFiles().getFile(0);
myFile.saveAs("/file/"+1+".doc");//保存目录
} catch (SmartUploadException e) {
e.printStackTrace();result=false;
}
//*****************************//
response.setContentType("text/html;charset=UTF-8");
response.setHeader("Cache-Control","no-cache");
PrintWriter out = response.getWriter();
out.print(result);
out.flush();
out.close();
}
}
//我这是ajax方式的，不想这样,把//**********************//以下部分修改就行了
//需要SmartUpload组件，去网上下个就行了，也有介绍的
⑷ 用Java的三大框架实现文件的上传下载，求代码啊，最好是分为action,service,serv
package cn.itcast.struts2.demo1;
import java.io.File;
import org.apache.commons.io.FileUtils;
import org.apache.struts2.ServletActionContext;
import com.opensymphony.xwork2.ActionSupport;
/**
* 完成文件上传 （不是解析上传内容，因为上传内容 由fileUpload拦截器负责解析）
*
* @author seawind
*
*/
public class UploadAction extends ActionSupport {
// 接收上传内容
// <input type="file" name="upload" />
private File upload; // 这里变量名 和 页面表单元素 name 属性一致
private String uploadContentType;
private String uploadFileName;
public void setUpload(File upload) {
this.upload = upload;
}
public void setUploadContentType(String uploadContentType) {
this.uploadContentType = uploadContentType;
}
public void setUploadFileName(String uploadFileName) {
this.uploadFileName = uploadFileName;
}
@Override
public String execute() throws Exception {
if (upload == null) { // 通过xml配置 required校验器 完成校验
// 没有上传文件
return NONE;
}
// 将上传文件 保存到服务器端
// 源文件 upload
// 目标文件
File destFile = new File(ServletActionContext.getServletContext()
.getRealPath("/upload") + "/" + uploadFileName);
// 文件复制 使用commons-io包 提供 工具类
FileUtils.File(upload, destFile);
return NONE;
}
}
多文件上传
package cn.itcast.struts2.demo1;
import java.io.File;
import org.apache.commons.io.FileUtils;
import org.apache.struts2.ServletActionContext;
import com.opensymphony.xwork2.ActionSupport;
/**
* 支持多文件上传
*
* @author seawind
*
*/
public class MultiUploadAction extends ActionSupport {
// 接收多文件上传参数，提供数组接收就可以了
private File[] upload;
private String[] uploadContentType;
private String[] uploadFileName;
public void setUpload(File[] upload) {
this.upload = upload;
}
public void setUploadContentType(String[] uploadContentType) {
this.uploadContentType = uploadContentType;
}
public void setUploadFileName(String[] uploadFileName) {
this.uploadFileName = uploadFileName;
}
@Override
public String execute() throws Exception {
for (int i = 0; i < upload.length; i++) {
// 循环完成上传
File srcFile = upload[i];
String filename = uploadFileName[i];
// 定义目标文件
File destFile = new File(ServletActionContext.getServletContext()
.getRealPath("/upload" + "/" + filename));
FileUtils.File(srcFile, destFile);
}
return NONE;
}
}
⑸ 如何利用字节流实现java的文件上传下载
实现上传下载实际上就是io的转换。举例：
import hkrt.b2b.view.util.Log;
import hkrt.b2b.view.util.ViewUtil;
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPFile;
public class CCFCCBFTP {
/**
* 上传文件
*
* @param fileName
* @param plainFilePath 明文文件路径路径
* @param filepath
* @return
* @throws Exception
*/
public static String fileUploadByFtp(String plainFilePath, String fileName, String filepath) throws Exception {
FileInputStream fis = null;
ByteArrayOutputStream bos = null;
FTPClient ftpClient = new FTPClient();
String bl = "false";
try {
fis = new FileInputStream(plainFilePath);
bos = new ByteArrayOutputStream(fis.available());
byte[] buffer = new byte[1024];
int count = 0;
while ((count = fis.read(buffer)) != -1) {
bos.write(buffer, 0, count);
}
bos.flush();
Log.info("加密上传文件开始");
Log.info("连接远程上传服务器"+CCFCCBUtil.CCFCCBHOSTNAME+":"+22);
ftpClient.connect(CCFCCBUtil.CCFCCBHOSTNAME, 22);
ftpClient.login(CCFCCBUtil.CCFCCBLOGINNAME, CCFCCBUtil.CCFCCBLOGINPASSWORD);
FTPFile[] fs;
fs = ftpClient.listFiles();
for (FTPFile ff : fs) {
if (ff.getName().equals(filepath)) {
bl="true";
ftpClient.changeWorkingDirectory("/"+filepath+"");
}
}
Log.info("检查文件路径是否存在：/"+filepath);
if("false".equals(bl)){
ViewUtil.dataSEErrorPerformedCommon( "查询文件路径不存在："+"/"+filepath);
return bl;
}
ftpClient.setBufferSize(1024);
ftpClient.setControlEncoding("GBK");
// 设置文件类型（二进制）
ftpClient.setFileType(FTPClient.BINARY_FILE_TYPE);
ftpClient.storeFile(fileName, fis);
Log.info("上传文件成功："+fileName+"。文件保存路径："+"/"+filepath+"/");
return bl;
} catch (Exception e) {
throw e;
} finally {
if (fis != null) {
try {
fis.close();
} catch (Exception e) {
Log.info(e.getLocalizedMessage(), e);
}
}
if (bos != null) {
try {
bos.close();
} catch (Exception e) {
Log.info(e.getLocalizedMessage(), e);
}
}
}
}
/**
*下载文件
*
* @param localFilePath
* @param fileName
* @param routeFilepath
* @return
* @throws Exception
*/
public static String fileDownloadByFtp(String localFilePath, String fileName,String routeFilepath) throws Exception {
FileInputStream fis = null;
ByteArrayOutputStream bos = null;
FileOutputStream fos = null;
FTPClient ftpClient = new FTPClient();
String SFP = System.getProperty("file.separator");
String bl = "false";
try {
Log.info("下载并解密文件开始");
Log.info("连接远程下载服务器"+CCFCCBUtil.CCFCCBHOSTNAME+":"+22);
ftpClient.connect(CCFCCBUtil.CCFCCBHOSTNAME, 22);
ftpClient.login(CCFCCBUtil.CCFCCBLOGINNAME, CCFCCBUtil.CCFCCBLOGINPASSWORD);
// ftpClient.connect(CMBCUtil.CMBCHOSTNAME, 2021);
// ftpClient.login(CMBCUtil.CMBCLOGINNAME, CMBCUtil.CMBCLOGINPASSWORD);
FTPFile[] fs;
ftpClient.makeDirectory(routeFilepath);
ftpClient.changeWorkingDirectory(routeFilepath);
bl = "false";
fs = ftpClient.listFiles();
for (FTPFile ff : fs) {
if (ff.getName().equals(fileName)) {
bl = "true";
Log.info("下载文件开始。");
ftpClient.setBufferSize(1024);
// 设置文件类型（二进制）
ftpClient.setFileType(FTPClient.BINARY_FILE_TYPE);
InputStream is = ftpClient.retrieveFileStream(fileName);
bos = new ByteArrayOutputStream(is.available());
byte[] buffer = new byte[1024];
int count = 0;
while ((count = is.read(buffer)) != -1) {
bos.write(buffer, 0, count);
}
bos.flush();
fos = new FileOutputStream(localFilePath+SFP+fileName);
fos.write(bos.toByteArray());
Log.info("下载文件结束："+localFilePath);
}
}
Log.info("检查文件是否存："+fileName+" "+bl);
if("false".equals(bl)){
ViewUtil.dataSEErrorPerformedCommon("查询无结果，请稍后再查询。");
return bl;
}
return bl;
} catch (Exception e) {
throw e;
} finally {
if (fis != null) {
try {
fis.close();
} catch (Exception e) {
Log.info(e.getLocalizedMessage(), e);
}
}
if (bos != null) {
try {
bos.close();
} catch (Exception e) {
Log.info(e.getLocalizedMessage(), e);
}
}
if (fos != null) {
try {
fos.close();
} catch (Exception e) {
Log.info(e.getLocalizedMessage(), e);
}
}
}
}}
备注：以上方法就实现了流的二进制上传下载转换，只需要将服务器连接部分调整为本地的实际ftp服务用户名和密码即可。
⑹ JAVA中如何将文件上传到服务器以供下载
<a href="app的路径">点击下载xxx.app</a>