J2EE Servlet上传文件到服务器并相应显示功能的实现代码
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2024-02-16 23:35:28
编辑上传文件的页面upload.html
注意事项:上传方式使用post不能使用get(get不能上传文件)
表单 enctype 属性应该设置为 multipart/...
编辑上传文件的页面upload.html
注意事项:上传方式使用post不能使用get(get不能上传文件)
表单 enctype 属性应该设置为 multipart/form-data.(表示提交的数据是二进制文件)
upload.html
<!doctype html> <html> <head> <meta charset="utf-8"> <title>文件上传</title> </head> <body> <form action="uploadphotoservlet" method="post" enctype="multipart/form-data"> 人物名称:<input type="text" name="heroname"/><br> 上传头像:<input type="file" name="filepath"/><br> <input type="submit" value="上传"> </form> </body> </html>
uploadptotoservlet文件上传类--上传功能的开发
将commons-io-1.4.jar和commons-fileupload-1.2.2.jar 两个jar包放到web-inf/lib 目录下。
import java.io.file; import java.io.fileoutputstream; import java.io.ioexception; import java.io.inputstream; import java.io.printwriter; import java.util.iterator; import java.util.list; import javax.servlet.servletexception; import javax.servlet.annotation.webservlet; 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.fileuploadexception; import org.apache.commons.fileupload.disk.diskfileitemfactory; import org.apache.commons.fileupload.servlet.servletfileupload; /** * servlet implementation class uploadphotoservlet */ @webservlet("/uploadphotoservlet") public class uploadphotoservlet extends httpservlet { private static final long serialversionuid = 1l; /** * @see httpservlet#httpservlet() */ public uploadphotoservlet() { super(); // todo auto-generated constructor stub } /** * @see httpservlet#doget(httpservletrequest request, httpservletresponse response) */ protected void doget(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception { // todo auto-generated method stub // response.getwriter().append("served at: ").append(request.getcontextpath()); string filename=null; diskfileitemfactory factory=new diskfileitemfactory(); //磁盘文件条目工厂 servletfileupload upload=new servletfileupload(factory); //负责处理上传的文件数据,并将表单中每个输入项封装成一个fileitem对象中 //设置上传文件的大小为10m factory.setsizethreshold(2*1024*1024); list items=null; try { //parse 解析 items=upload.parserequest(request); //得到一个保存了所有上传内容的list对象 } catch (fileuploadexception e) { // todo auto-generated catch block e.printstacktrace(); } iterator iter=items.iterator(); //迭代上传的文件数据 while(iter.hasnext()){ fileitem item=(fileitem) iter.next(); if(!item.isformfield()){ //如果不是上传的 //根据时间戳创建头像文件 filename=system.currenttimemillis()+".jpg"; //通过getrealpath获取上传文件夹,如果项目存在将存在当前项目下 不存在的话创建项目文件夹 //图片文件夹 string photofolder=request.getservletcontext().getrealpath("uploaded"); file f=new file(photofolder,filename); f.getparentfile().mkdirs(); //如果父文件夹不存在则自动创建 //通过item.getinputstream() 获取浏览器上传的文件 inputstream is = item.getinputstream(); //将文件读进来 //复制文件 fileoutputstream fos=new fileoutputstream(f); //往界面上显示 byte[] b=new byte[2*1024*1024]; int len=0; while((len=is.read(b))!=-1){ fos.write(b, 0, len); } fos.close(); }else{ system.out.println(item.getfieldname());//heroname string value=item.getstring(); value=new string(value.getbytes("iso-8859-1"), "utf-8"); system.out.println(value); //桑葚 } } string html="<img width='200' height='150' src='uploaded/%s'/>"; response.setcontenttype("text/html"); printwriter pw=response.getwriter(); pw.format(html, filename); } /** * @see httpservlet#dopost(httpservletrequest request, httpservletresponse response) */ protected void dopost(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception { // todo auto-generated method stub doget(request, response); } }
运行结果:
总结
以上所述是小编给大家介绍的j2ee servlet上传文件到服务器并相应显示功能的实现代码,希望对大家有所帮助
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