編輯上傳文件的頁面upload.html
注意事項：上傳方式使用post不能使用get（get不能上傳文件）
表單 enctype 屬性應該設置為 multipart/form-data.（表示提交的數據是二進制文件）
upload.html
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<!doctype html><html><head><meta charset="utf-8"><title>文件上傳</title></head><body> <form action="uploadphotoservlet" method="post" enctype="multipart/form-data"> 人物名稱:<input type="text" name="heroname"/><br> 上傳頭像:<input type="file" name="filepath"/><br> <input type="submit" value="上傳"> </form></body></html> |
uploadptotoservlet文件上傳類--上傳功能的開發
將commons-io-1.4.jar和commons-fileupload-1.2.2.jar 兩個jar包放到web-inf/lib 目錄下。
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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(); //磁盤文件條目工廠 servletfileupload upload=new servletfileupload(factory); //負責處理上傳的文件數據，并將表單中每個輸入項封裝成一個fileitem對象中 //設置上傳文件的大小為10m factory.setsizethreshold(2*1024*1024); list items=null; try { //parse 解析 items=upload.parserequest(request); //得到一個保存了所有上傳內容的list對象 } catch (fileuploadexception e) { // todo auto-generated catch block e.printstacktrace(); } iterator iter=items.iterator(); //迭代上傳的文件數據 while(iter.hasnext()){ fileitem item=(fileitem) iter.next(); if(!item.isformfield()){ //如果不是上傳的 //根據時間戳創建頭像文件 filename=system.currenttimemillis()+".jpg"; //通過getrealpath獲取上傳文件夾，如果項目存在將存在當前項目下 不存在的話創建項目文件夾 //圖片文件夾 string photofolder=request.getservletcontext().getrealpath("uploaded"); file f=new file(photofolder,filename); f.getparentfile().mkdirs(); //如果父文件夾不存在則自動創建 //通過item.getinputstream() 獲取瀏覽器上傳的文件 inputstream is = item.getinputstream(); //將文件讀進來 //復制文件 fileoutputstream fos=new fileoutputstream(f); //往界面上顯示 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); }} |
運行結果：
總結
以上所述是小編給大家介紹的j2ee servlet上傳文件到服務器并相應顯示功能的實現代碼，希望對大家有所幫助，如果大家有任何疑問請給我留言，小編會及時回復大家的。在此也非常感謝大家對服務器之家網站的支持！
原文鏈接：https://www.cnblogs.com/gaohuanhuan/archive/2018/07/06/9271718.html
