I hava a servleta that serves files?
I'm building a page with a "Download" button usung a GWT.
How to make a GWT client download a file in an onClick event?
P.S. Anchor works, but Button looks better.
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2Anchor may not look as good but is much more user friendly as it gives more control to user where to save the file. The anchor allows the user to right click , pick [save as] and specify the location and file name of the download. – Mozart Brocchini Jul 18 '12 at 15:16
4 Answers
13
if you have the file address. You can open a window like below:
downloadButton.addClickHandler(new ClickHandler() {
@Override
public void onClick(ClickEvent event) {
Window.open("http://127.0.0.1:8888/file.rar", "_self", "enabled");
}
});
and that javadoc can help you http://google-web-toolkit.googlecode.com/svn/javadoc/2.1/com/google/gwt/user/client/Window.html#open%28java.lang.String,%20java.lang.String,%20java.lang.String%29
Perdi Estaquel
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Kerem
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ok - the new window closes immediately after opening (Chrome browser) – Łukasz Bownik Sep 13 '10 at 07:32
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1If the file can be read from the browser like a PDF or TXT, the above solution does not work. The file will be open in the same page . – Java Main Jul 14 '17 at 15:52
1
None of the solutions above worked for me, then I realized I already have an implementation working. Here's how I do it:
Window.open(fileUrl, "_parent", "");
But the key is in your servlet:
response.setHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");
This solution will NOT open new window and instead directly opens the "Save As" dialog. Best of both worlds imo.
user1733035
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COMPLETE EXAMPLE TO DOWNLOAD a .xls FILE USIGN GWT,apache-poi
Environment : GWT SDK 2.4
Spring 3.0.2M
JAVA : 1.7
Needed Jar file to create .xls file :: poi-3.0.1-FINAL.jar
exportButton.addClickHandler(new ClickHandler() {
@Override
public void onClick(ClickEvent event) {
String link = GWT.getModuleBaseURL() + "myfiledownload";
Window.open(link , "", "");
}//onClick
});//addClickHandler
Now at the browser when the user hits button exportButton then the control navigates to web.xml and searches for url-pattern that ends with /myfiledownload
web.xml
<servlet>
<servlet-name>fileDownload</servlet-name>
<servlet-class>com.sbabamca.server.FileDownloadServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>fileDownload</servlet-name>
<url-pattern>/app/myfiledownload</url-pattern>
</servlet-mapping>
After execuiting the code in web.xml the controls tries to execute the servlet with name FileDownloadServlet
SERVER SIDE
FileDownloadServlet.java
------------------------
package com.sbabamca.server;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.ServletException;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.metadata.ClassMetadata;
import com.fpix.hibernate.util.HibernateUtil;
import com.fpix.util.date.MyDate;
import java.io.IOException;
import java.util.ArrayList;
public class MyFileServlet extends HttpServlet {
SessionFactory sessionFactory;
Session session;
Transaction tx = null;
@SuppressWarnings({ "unchecked", "deprecation" })
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
resp.setContentType("application/vnd.ms-excel");
resp.setHeader("Content-Disposition", "attachment; filename=users.xls");
try {
sessionFactory = HibernateUtil.getSessionFactory();
if(!sessionFactory.getCurrentSession().isOpen())
{
session = sessionFactory.openSession();
}
else
{
session = sessionFactory.getCurrentSession();
}
tx = session.beginTransaction();
tx.begin();
Query qry = session.createQuery("from com.fpix.dto.User u ");
ArrayList<com.fpix.dto.User> u = (ArrayList<com.fpix.dto.User>)qry.list();
Query qry1 = session.createQuery("from com.fpix.dto.Profile p ");
ArrayList<com.fpix.dto.Profile> p = (ArrayList<com.fpix.dto.Profile>)qry1.list();
/*
* code to get the column name of User and Profile Entity
*/
ClassMetadata cm = sessionFactory.getClassMetadata(com.fpix.dto.User.class);
String userAttributes[] = cm.getPropertyNames();
ClassMetadata cm1 = sessionFactory.getClassMetadata(com.fpix.dto.Profile.class);
String profileAttributes[] = cm1.getPropertyNames();
HSSFWorkbook wb = new HSSFWorkbook();
HSSFSheet sheet = wb.createSheet("Excel Sheet");
HSSFRow rowhead = sheet.createRow((short) 0);
rowhead.createCell((short) 0).setCellValue("id");
/*
* code to create the columns names in .xls file
*/
int j = 0;
for(int i=0;i<userAttributes.length;i++){
j = i;
if(!userAttributes[i].equalsIgnoreCase("profileData") )
rowhead.createCell((short) ++j).setCellValue(userAttributes[i]);
}//for
for(int i=0;i<profileAttributes.length;i++){
if(!profileAttributes[i].equalsIgnoreCase("userData"))
rowhead.createCell((short) ++j).setCellValue(profileAttributes[i]);
}//for
int index = 1;
for(int i=0;i<u.size();i++){
HSSFRow row = sheet.createRow((short) index);
row.createCell((short) 0).setCellValue(u.get(i).getId());
row.createCell((short) 1).setCellValue(u.get(i).getUser());
row.createCell((short) 2).setCellValue(u.get(i).getPassWord());
row.createCell((short) 3).setCellValue(u.get(i).getType());
row.createCell((short) 4).setCellValue(u.get(i).getRole());
row.createCell((short) 5).setCellValue(u.get(i).getProfile());
row.createCell((short) 6).setCellValue(u.get(i).getEmail());
row.createCell((short) 7).setCellValue(MyDate.timeStampToString(u.get(i).getDor()));
// set the Profile data to the excel sheet cells
row.createCell((short) 8).setCellValue(p.get(i).getRollNo());
row.createCell((short) 9).setCellValue(p.get(i).getFname());
row.createCell((short) 10).setCellValue(p.get(i).getLname());
row.createCell((short) 11).setCellValue(MyDate.timeStampToString(Long.parseLong(p.get(i).getDoj())));
row.createCell((short) 12).setCellValue(MyDate.timeStampToString(Long.parseLong(p.get(i).getDob())));
row.createCell((short) 13).setCellValue(p.get(i).getBloodGroup());
row.createCell((short) 14).setCellValue(p.get(i).getPhoto());
row.createCell((short) 15).setCellValue(p.get(i).getPhone1());
row.createCell((short) 16).setCellValue(p.get(i).getPhone2());
row.createCell((short) 17).setCellValue(p.get(i).getAddress());
row.createCell((short) 18).setCellValue(p.get(i).getCity());
row.createCell((short) 19).setCellValue(p.get(i).getPin());
row.createCell((short) 20).setCellValue(p.get(i).getState());
row.createCell((short) 21).setCellValue(p.get(i).getCountry());
row.createCell((short) 22).setCellValue(p.get(i).getGrade());
row.createCell((short) 23).setCellValue(p.get(i).getGroups());
row.createCell((short) 24).setCellValue(p.get(i).getAssignCourse());
index++;
}//for
java.io.OutputStream out = resp.getOutputStream();
wb.write(out);
out.close();
System.out.println("Data is Exported to Excel file.");
}//try
catch (Exception e) {
System.out.println(" Data cannot be imported :: getImport() :: ImportExportData "+e);
}//catch
}//doGet
}//class
opalenzuela
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sbabamca
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