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Jodd Servlet is set of web tools, including the nice tag library, wrappers and some filters.
// Copyright (c) 2003-present, Jodd Team (http://jodd.org)
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
package jodd.servlet.wrapper;
import jodd.util.CharUtil;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.Writer;
import java.nio.charset.Charset;
/**
* Buffered servlet response wrapper.
*/
public class BufferResponseWrapper extends HttpServletResponseWrapper {
protected static final String CONTENT_TYPE = "content-type";
protected static final String CONTENT_LENGTH = "content-length";
protected static final String LAST_MODIFIED = "last-modified";
protected final LastModifiedData lastModifiedData;
protected Buffer buffer;
public BufferResponseWrapper(final HttpServletResponse originalResponse) {
this(originalResponse, new LastModifiedData());
}
public BufferResponseWrapper(final HttpServletResponse originalResponse, final LastModifiedData lastModifiedData) {
super(originalResponse);
this.lastModifiedData = lastModifiedData;
lastModifiedData.startNewResponse();
enableBuffering();
}
// ---------------------------------------------------------------- commit
/**
* Called just before stream or writer is accessed.
* After that point response is considered as committed
* and should not be modified.
*/
protected void preResponseCommit() {
}
/**
* Commits a response if not already committed. Invokes
* {@link #preResponseCommit()} if response is going to
* be committed.
*/
public void commitResponse() {
if (!getResponse().isCommitted()) {
preResponseCommit();
}
}
// ---------------------------------------------------------------- enable/disable
/**
* Enables buffering by transferring the output to the buffer.
*/
protected void enableBuffering() {
if (buffer != null) {
return;
}
buffer = new Buffer();
}
/**
* Disables buffering by transferring the output to original destinations.
*/
protected void disableBuffering() {
if (buffer == null) {
return;
}
buffer = null;
}
// ---------------------------------------------------------------- get
/**
* Returns true if buffering is enabled.
*/
public boolean isBufferingEnabled() {
return buffer != null;
}
/**
* Returns true if underlying buffer was written to
* using {@link #getOutputStream()} (as opposed to {@link #getWriter()}.
* If buffering was not enabled at all, false will be returned,
* therefore an additional {@link #isBufferingEnabled() check} is required.
*/
public boolean isBufferStreamBased() {
return buffer != null && buffer.isUsingStream();
}
/**
* Returns buffered writer if buffering is enabled,
* otherwise returns the original writer.
*/
@Override
public PrintWriter getWriter() throws IOException {
preResponseCommit();
if (buffer == null) {
return getResponse().getWriter();
}
return buffer.getWriter();
}
/**
* Returns buffered output stream if buffering is enabled,
* otherwise returns the original stream.
*/
@Override
public ServletOutputStream getOutputStream() throws IOException {
preResponseCommit();
if (buffer == null) {
return getResponse().getOutputStream();
}
return buffer.getOutputStream();
}
/**
* Returns last modified data.
*/
public LastModifiedData getLastModifiedData() {
return lastModifiedData;
}
// ---------------------------------------------------------------- content
/**
* Returns buffered content or null if buffering was not enabled.
*/
public char[] getBufferedChars() {
if (buffer == null) {
return null;
}
return buffer.toCharArray();
}
/**
* Returns buffered bytes or null if buffering was not enabled.
*/
public byte[] getBufferedBytes() {
if (buffer == null) {
return null;
}
return buffer.toByteArray();
}
/**
* Returns buffered content as chars, no matter if stream or writer is used.
* Returns null if buffering was not enabled.
*/
public char[] getBufferContentAsChars() {
if (buffer == null) {
return null;
}
if (!buffer.isUsingStream()) {
return buffer.toCharArray();
}
final byte[] content = buffer.toByteArray();
final String encoding = getContentTypeEncoding();
if (encoding == null) {
// assume default encoding
return CharUtil.toCharArray(content);
} else {
return CharUtil.toCharArray(content, Charset.forName(encoding));
}
}
/**
* Returns buffered content as bytes, no matter if stream or writer is used.
* Returns null if buffering was not enabled.
*/
public byte[] getBufferContentAsBytes() {
if (buffer == null) {
return null;
}
if (buffer.isUsingStream()) {
return buffer.toByteArray();
}
final char[] content = buffer.toCharArray();
final String encoding = getContentTypeEncoding();
if (encoding == null) {
// assume default encoding
return CharUtil.toByteArray(content);
} else {
return CharUtil.toByteArray(content, Charset.forName(encoding));
}
}
/**
* Writes content to original output stream, using either output stream or writer, depending
* on how the content was buffered. It is assumed that provided content is a modified
* wrapped content.
*/
public void writeContentToResponse(final char[] content) throws IOException {
if (buffer == null) {
return;
}
if (buffer.isUsingStream()) {
final ServletOutputStream outputStream = getResponse().getOutputStream();
final String encoding = getContentTypeEncoding();
if (encoding == null) {
outputStream.write(CharUtil.toByteArray(content));
} else {
outputStream.write(CharUtil.toByteArray(content, Charset.forName(encoding)));
}
outputStream.flush();
} else {
final Writer out = getResponse().getWriter();
out.write(content);
out.flush();
}
}
/**
* Writes (unmodified) buffered content, using either output stream or writer.
* May be used for writing the unmodified response. Of course, you may
* {@link #print(String) modify} buffered data by altering the buffer content.
*/
public void writeContentToResponse() throws IOException {
if (buffer == null) {
return;
}
if (buffer.isUsingStream()) {
final ServletOutputStream outputStream = getResponse().getOutputStream();
outputStream.write(buffer.toByteArray());
outputStream.flush();
} else {
final Writer out = getResponse().getWriter();
out.write(buffer.toCharArray());
out.flush();
}
}
// ---------------------------------------------------------------- content type
protected ContentTypeHeaderResolver contentTypeResolver;
/**
* Returns content encoding or null.
*/
public String getContentTypeEncoding() {
if (contentTypeResolver == null) {
return null;
}
return contentTypeResolver.getEncoding();
}
/**
* Returns content mime type or null.
*/
public String getContentMimeType() {
if (contentTypeResolver == null) {
return null;
}
return contentTypeResolver.getMimeType();
}
/**
* Determines if some content type has to be buffered. By default returns true.
* @param contentType full content-type, e.g. "text/html; charset=utf-8"
* @param mimeType extracted mime-type, e.g. "text/html"
* @param encoding extracted encoding, e.g. "utf-8" (may be null)
*/
protected boolean bufferContentType(final String contentType, final String mimeType, final String encoding) {
return true;
}
/**
* Sets the content type and enables or disables buffering.
*/
@Override
public void setContentType(final String type) {
super.setContentType(type);
contentTypeResolver = new ContentTypeHeaderResolver(type);
if (bufferContentType(type, contentTypeResolver.getMimeType(), contentTypeResolver.getEncoding())) {
enableBuffering();
} else {
disableBuffering();
}
}
/**
* Prevents flushing buffer if buffering enabled.
*/
@Override
public void flushBuffer() throws IOException {
if (buffer == null) {
super.flushBuffer();
}
}
// ---------------------------------------------------------------- content headers
/**
* Prevents content-length being set if buffering enabled.
*/
@Override
public void setContentLength(final int contentLength) {
if (buffer == null) {
super.setContentLength(contentLength);
}
}
/**
* Prevents setting content-length if buffering enabled.
*/
@Override
public void setHeader(final String name, final String value) {
final String lowerName = name.toLowerCase();
if (lowerName.equals(CONTENT_TYPE)) {
setContentType(value);
} else if (buffer == null || !lowerName.equals(CONTENT_LENGTH)) {
super.setHeader(name, value);
}
}
/**
* Prevents setting content-length if buffering enabled.
*/
@Override
public void addHeader(final String name, final String value) {
final String lowerName = name.toLowerCase();
if (lowerName.equals(CONTENT_TYPE)) {
setContentType(value);
} else if (buffer == null || !lowerName.equals(CONTENT_LENGTH)) {
super.addHeader(name, value);
}
}
/**
* Prevents setting content-length if buffering enabled.
*/
@Override
public void setIntHeader(final String name, final int value) {
if (buffer == null || !name.equalsIgnoreCase(CONTENT_LENGTH)) {
super.setIntHeader(name, value);
}
}
/**
* Prevents setting content-length if buffering enabled.
*/
@Override
public void addIntHeader(final String name, final int value) {
if (buffer == null || !name.equalsIgnoreCase(CONTENT_LENGTH)) {
super.addIntHeader(name, value);
}
}
// ---------------------------------------------------------------- date headers
@Override
public void setDateHeader(final String name, final long value) {
if (name.equalsIgnoreCase(LAST_MODIFIED)) {
lastModifiedData.updateLastModified(value);
} else {
super.setDateHeader(name, value);
}
}
@Override
public void addDateHeader(final String name, final long value) {
if (name.equalsIgnoreCase(LAST_MODIFIED)) {
lastModifiedData.updateLastModified(value);
} else {
super.addDateHeader(name, value);
}
}
// ---------------------------------------------------------------- status
@Override
public void setStatus(final int statusCode) {
stopBufferingForStatusCode(statusCode);
super.setStatus(statusCode);
}
@Override
public void setStatus(final int statusCode, final String reason) {
stopBufferingForStatusCode(statusCode);
super.setStatus(statusCode);
}
@Override
public void sendError(final int statusCode) throws IOException {
stopBufferingForStatusCode(statusCode);
super.sendError(statusCode);
}
@Override
public void sendError(final int statusCode, final String reason) throws IOException {
stopBufferingForStatusCode(statusCode);
super.sendError(statusCode, reason);
}
@Override
public void sendRedirect(final String location) throws IOException {
stopBufferingForStatusCode(HttpServletResponse.SC_TEMPORARY_REDIRECT);
super.sendRedirect(location);
}
protected void stopBufferingForStatusCode(final int statusCode) {
if (!bufferStatusCode(statusCode)) {
disableBuffering();
}
}
/**
* Determines if buffering should be used for some HTTP status code.
* By default returns true only for status code 200.
*/
protected boolean bufferStatusCode(final int statusCode) {
return statusCode == 200;
}
// ---------------------------------------------------------------- alter buffer
/**
* Appends string to the buffer.
*/
public void print(final String string) throws IOException {
if (isBufferStreamBased()) {
final String encoding = getContentTypeEncoding();
final byte[] bytes;
if (encoding == null) {
bytes = string.getBytes();
} else {
bytes = string.getBytes(encoding);
}
buffer.getOutputStream().write(bytes);
return;
}
// make sure at least writer is initialized
buffer.getWriter().write(string);
}
}