Struts 2 Download File Annotations Example
Examples on how to download a file from Struts2 with annotations only.
Features:
- Example 1 direct file download
- Example 2 dynamic file download with parameter
- Error page with 404 file not found
- Takes path from Servlet context
Download deployable war file with sources here
Example 1
package com.test.action;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import javax.servlet.ServletContext;
import org.apache.struts2.ServletActionContext;
import org.apache.struts2.convention.annotation.Action;
import org.apache.struts2.convention.annotation.Namespace;
import org.apache.struts2.convention.annotation.Result;
import org.apache.struts2.convention.annotation.Results;
import com.opensymphony.xwork2.ActionSupport;
@Namespace("/")
@Results({ @Result(name = "error", location = "/error", type = "redirect") })
public class ExampleDownload1 extends ActionSupport {
private static final long serialVersionUID = -7434672720094336409L;
private static ServletContext servletContext = ServletActionContext.getServletContext();
private static String webContentRoot = servletContext.getRealPath("/");
private static final String pathToFile = webContentRoot + "zip/file.zip";
private InputStream inputStream;
@Action(value = "/file.zip",
results = { @Result(name = "success", type = "stream",
params = { "contentType", "application/octet-stream",
"bufferSize", "1024"
}) })
public String execute() throws Exception {
try {
inputStream = new FileInputStream(new File(pathToFile));
} catch (Exception e) {
return ERROR;
}
return SUCCESS;
}
public InputStream getInputStream() {
return inputStream;
}
public void setInputStream(InputStream inputStream) {
this.inputStream = inputStream;
}
}
Example 2
package com.test.action;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import javax.servlet.ServletContext;
import org.apache.struts2.ServletActionContext;
import org.apache.struts2.convention.annotation.Action;
import org.apache.struts2.convention.annotation.Namespace;
import org.apache.struts2.convention.annotation.Result;
import org.apache.struts2.convention.annotation.Results;
import com.opensymphony.xwork2.ActionSupport;
@Namespace("/")
@Results({ @Result(name = "error", location = "error", type = "redirect") })
public class ExampleDownload2 extends ActionSupport {
private static final long serialVersionUID = -7434672720094336410L;
private static ServletContext servletContext = ServletActionContext.getServletContext();
private static String webContentRoot = servletContext.getRealPath("/");
private InputStream inputStream;
private String fileName;
@Action(value = "/download",
results = { @Result(name = "success", type = "stream",
params = { "contentType", "application/octet-stream",
"inputName", "inputStream",
"bufferSize", "1024",
"contentDisposition","filename=\"${fileName}\"" }) })
public String execute() throws Exception {
String pathToFile = webContentRoot + "zip/" + fileName;
try {
inputStream = new FileInputStream(new File(pathToFile));
} catch (Exception e) {
return ERROR;
}
return SUCCESS;
}
public InputStream getInputStream() {
return inputStream;
}
public void setInputStream(InputStream inputStream) {
this.inputStream = inputStream;
}
public String getFileName() {
return fileName;
}
public void setFileName(String fileName) {
this.fileName = fileName;
}
}
Not Found (Error) Action
package com.test.action;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts2.ServletActionContext;
import org.apache.struts2.convention.annotation.Action;
import org.apache.struts2.convention.annotation.Actions;
import org.apache.struts2.convention.annotation.Result;
import com.opensymphony.xwork2.ActionSupport;
public class Error extends ActionSupport{
private static final long serialVersionUID = 2086900467866735407L;
@Actions({
@Action(value = "/error", results = @Result(name = "success", location = "/error.jsp")) })
public String execute() {
ServletActionContext.getResponse().setStatus(
HttpServletResponse.SC_NOT_FOUND);
return SUCCESS;
}
}