我要评论本文实例为大家分享了jsp servlet实现文件上传与下载的具体代码，供大家参考，具体内容如下
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) {
}
}
}
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持代码网。
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