我之前已经看过一些关于此的问题，但我仍然不清楚我应该做些什么。我有一个servlet，它将文件上传到我的web目录中的文件夹，并将图像目录（img / image.jpg）存储在数据库中。当我提交表单并上传文件时，我会重定向到另一个servlet以显示表单中的新信息，但是在我单击ctrl + f5之前图像不会显示。有没有解决的办法？以下是我的文件上传代码：
String upDir = "C://Users//Ben//Documents//NetBeansProjects//GigForMe//web//img";
userDAO uDAO = new userDAO();
String userid = null;
String Email = null;
String BIO = null;
String admin = null;
String ban = null;
String password = null;
String password1 = null;
int i = 0;
//process only if its multipart content
if(ServletFileUpload.isMultipartContent(request)){
try {
List<FileItem> multiparts = new ServletFileUpload(
new DiskFileItemFactory()).parseRequest(request);
for(FileItem item : multiparts){
if(item.isFormField()){
if (i ==0) {
userid = item.getString();
System.out.println(userid);
}else if( i== 1){
Email = item.getString();
System.out.println(Email);
}else if(i == 2){
BIO = item.getString();
System.out.println(BIO);
}else if(i == 3){
admin = item.getString();
System.out.println(admin);
}else if(i == 4){
ban = item.getString();
System.out.println(ban);
}else if(i == 5){
password = item.getString();
System.out.println(password);
if(password.isEmpty()){
int UserID = Integer.parseInt(userid);
String userPassword = uDAO.getUserPassword(UserID);
uDAO.updateUser(UserID, Email, BIO, admin, ban, userPassword);
}else if( password.equals("checkboxPassword")){
}
}else if(i==6){
int UserID = Integer.parseInt(userid);
password1 = item.getString();
System.out.println(password1);
if (password.equals("checkboxPassword")) {
uDAO.updateUser(UserID, Email, BIO, admin, ban, password1);
}
}
//uDAO.updateUser(UserID, Email, BIO, admin, ban, userPassword);
i++;
}else if(!item.isFormField()){
String name = new File(item.getName()).getName();
Random rn = new Random();
int answer = rn.nextInt(1000000000);
if (name.length() == 0) {
}else{
String rename = answer + name;
String rename1 = rename.replace(" ","");
int UserID = Integer.parseInt(userid);
item.write( new File(upDir+ File.separator + rename1));
uDAO.updateDirectory(UserID, rename1);
//File uploaded successfully
request.setAttribute("message", "File Uploaded Successfully");
}
}
}
System.out.println("File Uploaded Successfully");
} catch (Exception ex) {
request.setAttribute("message", "File Upload Failed due to " + ex);
}
}else{
request.setAttribute("message",
"Sorry this Servlet only handles file upload request");
}
Random rn = new Random();
int uid = rn.nextInt(1000000000);
response.sendRedirect("UserManagement?id="+uid);