com.sangupta.jerry.util.ResponseUtils Maven / Gradle / Ivy
/**
*
* jerry - Common Java Functionality
* Copyright (c) 2012-2015, Sandeep Gupta
*
* http://sangupta.com/projects/jerry
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package com.sangupta.jerry.util;
import java.io.IOException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.sangupta.jerry.constants.HttpStatusCode;
/**
* Utility methods to work with {@link HttpServletResponse} object.
*
* @author sangupta
*
*/
public class ResponseUtils {
/**
* Write the given response in UTF-8 encoding to the given
* {@link HttpServletResponse} object.
*
* @param response
* the {@link HttpServletResponse} to write data to
*
* @param data
* the data that needs to be written to the stream
*
* @param mimeType
* the MIME type of the data being written
*
* @throws IOException
* if something fails while writing to
* {@link HttpServletResponse}.
*
* @throws NullPointerException
* if {@link HttpServletResponse} object is null
*
*/
public static void sendResponse(HttpServletResponse response, String data, String mimeType) throws IOException {
byte[] bytes = data.getBytes("UTF-8");
response.setContentType(mimeType + "; charset=UTF-8");
response.setStatus(HttpStatusCode.OK);
response.setContentLength(bytes.length);
response.setCharacterEncoding("UTF-8");
response.getOutputStream().write(bytes);
}
/**
* Write the given byte array as response to the given
* {@link HttpServletResponse} object
*
* @param response
* the {@link HttpServletResponse} to write data to
*
* @param bytes
* the bytes that need to be sent
*
* @param mimeType
* the MIME type of the data being written
*
* @throws IOException
* if something fails while writing to
* {@link HttpServletResponse}.
*
* @throws NullPointerException
* if {@link HttpServletResponse} object is null
*/
public static void sendResponse(HttpServletResponse response, byte[] bytes, String mimeType) throws IOException {
response.setContentType(mimeType + "; charset=UTF-8");
response.setStatus(HttpStatusCode.OK);
response.setContentLength(bytes.length);
response.setCharacterEncoding("UTF-8");
response.getOutputStream().write(bytes);
}
/**
* Push the given data as a file to the client browser for downloading. The
* response is written in such a way so that the client browser displays a
* dailog for downloading the file.
*
* @param response
* the {@link HttpServletResponse} object to write to
*
* @param data
* the data that needs to be sent to client
*
* @param fileName
* the filename to be used by browsers when displaying 'Save As'
* dialog
*
* @param mimeType
* the MIME type of the data being written
*
* @throws IOException
* if something fails when writing to
* {@link HttpServletResponse} object
*
* @throws NullPointerException
* if {@link HttpServletResponse} object is null,
* or if data is null
*
*/
public static void pushForUserDownload(HttpServletResponse response, String data, String fileName, String mimeType) throws IOException {
setOnlyDownload(response, fileName);
response.setContentType(mimeType + "; charset=UTF-8");
response.setCharacterEncoding("UTF-8");
response.setStatus(HttpStatusCode.OK);
ServletOutputStream stream = response.getOutputStream();
byte[] bytes = data.getBytes("UTF-8");
response.setContentLength(bytes.length);
stream.write(bytes);
stream.flush();
stream.close();
}
/**
* Write the given byte array to the {@link HttpServletResponse} object
* asking the client browser to present a dialog to save the file. The MIME
* type used is application/octet-stream to allow for binary
* file downloads.
*
* @param response
* the {@link HttpServletResponse} object to write to
*
* @param bytes
* the bytes to write
*
* @param fileName
* the file name to be presented to client browser
*
* @throws IOException
* if something fails when writing to
* {@link HttpServletResponse} object
*
* @throws NullPointerException
* if {@link HttpServletResponse} object is null
*
*/
public static void pushForUserDownload(HttpServletResponse response, byte[] bytes, String fileName) throws IOException {
setOnlyDownload(response, fileName);
response.setContentType("application/octet-stream");
response.setCharacterEncoding("UTF-8");
response.setStatus(HttpStatusCode.OK);
ServletOutputStream stream = response.getOutputStream();
response.setContentLength(bytes.length);
stream.write(bytes);
stream.flush();
stream.close();
}
/**
* Make sure that IE8+ do not sniff for MIME when already specified in
* response.
*
* Refer to
* http://blogs.msdn.com/b/ie/archive/2008/07/02/ie8-security-part-vcomprehensive-protection.aspx for more details.
*
* @param repsonse
* the {@link HttpServletResponse} object to use
*
* @throws NullPointerException
* if {@link HttpServletResponse} object is null
*
*/
public static void sendNoSniff(HttpServletResponse repsonse) {
repsonse.addHeader("X-Content-Type-Options", "nosniff");
}
/**
* Instruct the response to only allow file download, and not let it open
* directly in the client browser.
*
* Refer to
* http://blogs.msdn.com/b/ie/archive/2008/07/02/ie8-security-part-vcomprehensive-protection.aspx for more details.
*
* @param response
* the {@link HttpServletResponse} object to use
*
* @param fileName
* the fileName to present to client browser for allowing
* download of file
*
* @throws NullPointerException
* if {@link HttpServletResponse} object is null
*
*/
public static void setOnlyDownload(HttpServletResponse response, String fileName) {
response.addHeader("X-Download-Options", "noopen");
response.addHeader("Content-Disposition", "attachment; filename=" + fileName);
}
/**
* Set cache headers to one month from today.
*
* @param response
* the {@link HttpServletResponse} object
*/
public static void setCacheHeaders(HttpServletResponse response) {
setCacheHeaders(response, DateUtils.ONE_MONTH);
}
/**
* Set cache headers to given time from today.
*
* @param response
* the {@link HttpServletResponse} object
*
* @param ageInMillis
* the age in milliseconds
*/
public static void setCacheHeaders(HttpServletResponse response, long ageInMillis) {
response.addDateHeader("Expires", System.currentTimeMillis() + ageInMillis);
response.addHeader("Cache-Control", "public, max-age=" + (ageInMillis / DateUtils.ONE_SECOND));
}
/**
* Construct the URL prefixed with the context path in which the app is
* deployed
*
* @param request
* the {@link HttpServletRequest} object
*
* @param url
* the URL to be prefixed
*
* @return the constructed URL
*/
public static String getUrlWithContext(HttpServletRequest request, String url) {
return UriUtils.addWebPaths(request.getContextPath(), url);
}
}
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