com.vaadin.server.VaadinResponse Maven / Gradle / Ivy
/*
* Copyright (C) 2000-2024 Vaadin Ltd
*
* This program is available under Vaadin Commercial License and Service Terms.
*
* See for the full
* license.
*/
package com.vaadin.server;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.Serializable;
import javax.servlet.ServletResponse;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletResponse;
import com.vaadin.util.CurrentInstance;
/**
* A generic response from the server, wrapping a more specific response type,
* e.g. HttpServletResponse or PortletResponse.
*
* @since 7.0
*/
public interface VaadinResponse extends Serializable {
/**
* Sets the (http) status code for the response. If you want to include an
* error message along the status code, use {@link #sendError(int, String)}
* instead.
*
* @param statusCode
* the status code to set
* @see HttpServletResponse#setStatus(int)
*/
public void setStatus(int statusCode);
/**
* Sets the content type of this response. If the content type including a
* charset is set before {@link #getWriter()} is invoked, the returned
* PrintWriter will automatically use the defined charset.
*
* @param contentType
* a string specifying the MIME type of the content
*
* @see ServletResponse#setContentType(String)
*/
public void setContentType(String contentType);
/**
* Sets the value of a generic response header. If the header had already
* been set, the new value overwrites the previous one.
*
* @param name
* the name of the header
* @param value
* the header value.
*
* @see HttpServletResponse#setHeader(String, String)
*/
public void setHeader(String name, String value);
/**
* Properly formats a timestamp as a date header. If the header had already
* been set, the new value overwrites the previous one.
*
* @param name
* the name of the header
* @param timestamp
* the number of milliseconds since epoch
*
* @see HttpServletResponse#setDateHeader(String, long)
*/
public void setDateHeader(String name, long timestamp);
/**
* Returns a OutputStream for writing binary data in the
* response.
*
* Either this method or getWriter() may be called to write the response,
* not both.
*
* @return a OutputStream for writing binary data
* @throws IOException
* if an input or output exception occurred
*
* @see #getWriter()
* @see ServletResponse#getOutputStream()
*/
public OutputStream getOutputStream() throws IOException;
/**
* Returns a PrintWriter object that can send character text to
* the client. The PrintWriter uses the character encoding defined using
* setContentType.
*
* Either this method or getOutputStream() may be called to write the
* response, not both.
*
* @return a PrintWriter for writing character text
* @throws IOException
* if an input or output exception occurred
*
* @see #getOutputStream()
* @see ServletResponse#getWriter()
*/
public PrintWriter getWriter() throws IOException;
/**
* Sets cache time in milliseconds, -1 means no cache at all. All required
* headers related to caching in the response are set based on the time.
*
* @param milliseconds
* Cache time in milliseconds
*/
public void setCacheTime(long milliseconds);
/**
* Sends an error response to the client using the specified status code and
* clears the buffer. In some configurations, this can cause a predefined
* error page to be displayed.
*
* @param errorCode
* the HTTP status code
* @param message
* a message to accompany the error
* @throws IOException
* if an input or output exception occurs
*
* @see HttpServletResponse#sendError(int, String)
*/
public void sendError(int errorCode, String message) throws IOException;
/**
* Gets the vaadin service for the context of this response.
*
* @return the vaadin service
*
* @see VaadinService
*/
public VaadinService getService();
/**
* Adds the specified cookie to the response. This method can be called
* multiple times to set more than one cookie.
*
* @param cookie
* the Cookie to return to the client
*
* @see HttpServletResponse#addCookie(Cookie)
*/
public void addCookie(Cookie cookie);
/**
* Sets the length of the content body in the response In HTTP servlets,
* this method sets the HTTP Content-Length header. For some portlet
* responses, this method sets the content-length header, for others this
* method does nothing.
*
* @param len
* an integer specifying the length of the content being returned
* to the client
* @since 7.3.8
*/
public void setContentLength(int len);
/**
* Sets all conceivable headers that might prevent a response from being
* stored in any caches.
*
* @since 8.3.2
*/
public default void setNoCacheHeaders() {
// no-store to disallow storing even if cache would be revalidated
// must-revalidate to not use stored value even if someone asks for it
setHeader("Cache-Control", "no-cache, no-store, must-revalidate");
// Also set legacy values in case of old proxies in between
setHeader("Pragma", "no-cache");
setHeader("Expires", "0");
}
/**
* Gets the currently processed Vaadin response. The current response is
* automatically defined when the request is started. The current response
* can not be used in e.g. background threads because of the way server
* implementations reuse response instances.
*
* @return the current Vaadin response instance if available, otherwise
* null
* @since 8.1
*/
public static VaadinResponse getCurrent() {
return CurrentInstance.get(VaadinResponse.class);
}
}