--- /dev/null
+package de.juplo.accelerator;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import java.io.PrintWriter;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.HashMap;
+import java.util.Locale;
+import java.util.Map;
+import java.util.zip.GZIPOutputStream;
+import javax.servlet.Filter;
+import javax.servlet.FilterChain;
+import javax.servlet.FilterConfig;
+import javax.servlet.ServletException;
+import javax.servlet.ServletOutputStream;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
+import javax.servlet.http.Cookie;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowire;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Configurable;
+import org.springframework.beans.factory.annotation.Qualifier;
+
+
+
+/**
+ *
+ * @author kai
+ */
+@Configurable(autowire=Autowire.BY_NAME)
+public class AcceleratorFilter implements Filter {
+ private final static Logger log = LoggerFactory.getLogger(AcceleratorFilter.class);
+
+ private final static Map<String,String> EMPTY = Collections.unmodifiableMap(new HashMap<String,String>());
+
+ public final static Integer DEFAULT_BUFFER_SIZE = 1024;
+ public final static String REQUEST_URI_ATTRIBUTE = "javax.servlet.include.request_uri";
+ public final static String RESPONSE_WRAPPER = AcceleratorFilter.class.getName() + ".RESPONSE_WRAPPER";
+
+
+ @Autowired CacheControl cacheControl;
+ @Autowired(required=false) @Qualifier("defaultBufferSize") Integer defaultBufferSize = DEFAULT_BUFFER_SIZE;
+ @Autowired String eTag;
+ @Autowired Boolean weak;
+ @Autowired Long lastModified;
+ @Autowired Integer cacheSeconds;
+
+
+ @Override
+ public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
+ if (!(request instanceof HttpServletRequest)) {
+ log.error("AcceleratorFilter can only handle HTTP-requests");
+ chain.doFilter(request, response);
+ return;
+ }
+
+ HttpServletRequest httpRequest = (HttpServletRequest)request;
+ HttpServletResponse httpResponse = (HttpServletResponse)response;
+
+ AccelerationWrapper wrapper;
+
+ wrapper = (AccelerationWrapper)request.getAttribute(AcceleratorFilter.RESPONSE_WRAPPER);
+ if (wrapper != null) {
+ if (wrapper.getFilter() == this) {
+ /** Ignore multiple mappings of the same filter-instance */
+ log.warn("Ignoring multiple mappings on same URL: {}", httpRequest.getRequestURI());
+ chain.doFilter(request, response);
+ return;
+ }
+ else {
+ log.error("Only one instance of AcceleratorFilter must be mapped to any URL: {}", httpRequest.getRequestURI());
+ httpResponse.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "Only one instance of AcceleratorFilter must be mapped to any URL!");
+ return;
+ }
+ }
+
+ wrapper = new AccelerationWrapper(httpRequest, httpResponse);
+ httpRequest.setAttribute(RESPONSE_WRAPPER, wrapper);
+ cacheControl.init(wrapper);
+ try {
+ chain.doFilter(request, wrapper);
+ wrapper.finish();
+ }
+ catch (NotModifiedException nm) {
+ log.trace("Not modified: {}", httpRequest.getRequestURI());
+ }
+ }
+
+ @Override
+ public void init(FilterConfig filterConfig) throws ServletException {
+ }
+
+ @Override
+ public void destroy() {
+ }
+
+
+ class AccelerationWrapper implements HttpServletResponse, CacheMethodHandle {
+
+ private final HttpServletRequest request;
+ private final HttpServletResponse response;
+
+ private final AcceleratorServletOutputStream out;
+
+ private ServletOutputStream stream;
+ private PrintWriter writer;
+
+ private boolean guessing = true;
+ protected boolean zipped = false; // << CacheControll greift direkt auf diese Variable zu!
+
+ private long now;
+ private int status;
+ private int cacheSeconds;
+ private boolean cacheSecondsSet = false;
+ private long lastModified, expires = 0l;
+ private String eTag;
+ private boolean weak;
+ private Map<String,String> cacheParams;
+
+ /** Für den AcceleratorOutputStream */
+ private boolean committed = false;
+ private OutputStream os = null;
+ private int bufferSize;
+ private byte[] buffer;
+ private int pos = 0;
+ private int size = 0;
+
+
+
+ AccelerationWrapper(HttpServletRequest request, HttpServletResponse response) throws IOException {
+
+ this.request = request;
+ this.response = response;
+
+ now = System.currentTimeMillis();
+ status = HttpServletResponse.SC_OK;
+ cacheSeconds = AcceleratorFilter.this.cacheSeconds;
+ lastModified = AcceleratorFilter.this.lastModified;
+ eTag = AcceleratorFilter.this.eTag;
+ weak = AcceleratorFilter.this.weak;
+ cacheParams = new HashMap<String,String>();
+
+ Enumeration values = request.getHeaders(Headers.HEADER_ACCEPT_ENCODING);
+ while (values.hasMoreElements()) {
+ String value = (String) values.nextElement();
+ if (value.indexOf("gzip") != -1) {
+ zipped = true;
+ break;
+ }
+ }
+
+ out = new AcceleratorServletOutputStream();
+ }
+
+
+ private AcceleratorFilter getFilter() {
+ return AcceleratorFilter.this;
+ }
+
+ private void finish() throws IOException {
+ flushBuffer();
+ out.close();
+ }
+
+ @Override
+ public void setStatus(int sc) {
+ response.setStatus(sc);
+ status = sc;
+ }
+
+ @Override
+ public void setStatus(int sc, String sm) {
+ response.setStatus(sc,sm);
+ status = sc;
+ }
+
+ @Override
+ public void addDateHeader(String name, long value) {
+
+ if (!guessing) {
+ response.addDateHeader(name, value);
+ return;
+ }
+
+ if (Headers.HEADER_DATE.equalsIgnoreCase(name)) {
+ now = value;
+ calculateCacheSeconds();
+ return;
+ }
+
+ if (Headers.HEADER_EXPIRES.equalsIgnoreCase(name)) {
+ expires = value;
+ calculateCacheSeconds();
+ return;
+ }
+
+ if (Headers.HEADER_LAST_MODIFIED.equalsIgnoreCase(name)) {
+ lastModified = value;
+ return;
+ }
+
+ /** Unknown header: pass throug! */
+ response.addDateHeader(name, value);
+ }
+
+ @Override
+ public void addHeader(String name, String value) {
+
+ if (!guessing) {
+ response.addHeader(name, value);
+ return;
+ }
+
+ if (value == null)
+ return;
+ analyzeHeader(name, value, false);
+ }
+
+ @Override
+ public void addIntHeader(String name, int value) {
+
+ if (!guessing) {
+ response.addIntHeader(name, value);
+ return;
+ }
+
+ analyzeHeader(name, Integer.toString(value), false);
+ }
+
+ @Override
+ public void setDateHeader(String name, long value) {
+
+ if (!guessing) {
+ response.setDateHeader(name, value);
+ return;
+ }
+
+ if (Headers.HEADER_DATE.equalsIgnoreCase(name)) {
+ now = value;
+ calculateCacheSeconds();
+ return;
+ }
+
+ if (Headers.HEADER_EXPIRES.equalsIgnoreCase(name)) {
+ expires = value;
+ calculateCacheSeconds();
+ return;
+ }
+
+ if (Headers.HEADER_LAST_MODIFIED.equalsIgnoreCase(name)) {
+ lastModified = value;
+ return;
+ }
+
+ /** Unknown header: pass throug! */
+ response.setDateHeader(name, value);
+ }
+
+ @Override
+ public void setHeader(String name, String value) {
+
+ if (!guessing) {
+ response.setHeader(name, value);
+ return;
+ }
+
+ analyzeHeader(name, value, true);
+ }
+
+ @Override
+ public void setIntHeader(String name, int value) {
+
+ if (!guessing) {
+ response.setIntHeader(name, value);
+ return;
+ }
+
+ analyzeHeader(name, Integer.toString(value), true);
+ }
+
+ @Override
+ public ServletOutputStream getOutputStream() throws IOException {
+
+ if (writer != null)
+ throw new IllegalStateException("ServletOutputStream and PrintWriter cannot be requested both!");
+
+ if (stream == null) {
+ stream = out;
+ }
+
+ return out;
+ }
+
+ @Override
+ public PrintWriter getWriter() throws IOException {
+
+ if (stream != null)
+ throw new IllegalStateException("ServletOutputStream and PrintWriter cannot be requested both!");
+
+ if (writer == null) {
+ writer = new PrintWriter(new OutputStreamWriter(out, response.getCharacterEncoding()));
+ }
+
+ return writer;
+ }
+
+ @Override
+ public void setContentLength(int len) {
+ if (zipped)
+ log.info("Supressing explicit content-length {} for request {}, because content will be zipped!", len, request.getRequestURI());
+ else
+ response.setContentLength(len);
+ }
+
+ @Override
+ public int getBufferSize() {
+ return bufferSize;
+ }
+
+ @Override
+ public void setBufferSize(int size) {
+ if (this.size > 0)
+ throw new IllegalStateException("cannot change buffer size, because content was already written!");
+ bufferSize = size;
+ buffer = new byte[size];
+ }
+
+ @Override
+ public void resetBuffer() {
+ if (committed)
+ throw new IllegalStateException("cannot reset buffer, because response is already commited!");
+ pos = 0;
+ stream = null;
+ writer = null;
+ }
+
+ @Override
+ public void reset() {
+ if (committed)
+ throw new IllegalStateException("cannot reset response, because response is already commited!");
+ /**
+ * Da committed==false gilt, wurde die Dekoration noch nicht angestßen
+ * und muss entsprechend auch nicht rückgängig gemacht werden!
+ */
+ response.reset();
+ pos = 0;
+ size = 0;
+ stream = null;
+ writer = null;
+ }
+
+ @Override
+ public void flushBuffer() throws IOException {
+ if (writer != null)
+ writer.flush();
+ else if (stream != null)
+ stream.flush();
+ }
+
+ @Override
+ public void addCookie(Cookie cookie) {
+ // TODO: Je nach Vary-Einstellung ETag anpassen?
+ response.addCookie(cookie);
+ }
+
+ @Override
+ public boolean containsHeader(String name) {
+ return response.containsHeader(name);
+ }
+
+ @Override
+ public String encodeURL(String url) {
+ return response.encodeURL(url);
+ }
+
+ @Override
+ public String encodeRedirectURL(String url) {
+ return response.encodeRedirectURL(url);
+ }
+
+ @Override
+ public String encodeUrl(String url) {
+ return response.encodeUrl(url);
+ }
+
+ @Override
+ public String encodeRedirectUrl(String url) {
+ return response.encodeRedirectUrl(url);
+ }
+
+ @Override
+ public void sendError(int sc, String msg) throws IOException {
+ response.sendError(sc,msg);
+ }
+
+ @Override
+ public void sendError(int sc) throws IOException {
+ response.sendError(sc);
+ }
+
+ @Override
+ public void sendRedirect(String location) throws IOException {
+ response.sendRedirect(location);
+ }
+
+ @Override
+ public String getCharacterEncoding() {
+ return response.getCharacterEncoding();
+ }
+
+ @Override
+ public String getContentType() {
+ return response.getContentType();
+ }
+
+ @Override
+ public void setCharacterEncoding(String charset) {
+ // TODO: Je nach Vary-Einstellung ETag anpassen?
+ response.setCharacterEncoding(charset);
+ }
+
+ @Override
+ public void setContentType(String type) {
+ // TODO: Je nach Vary-Einstellung ETag anpassen?
+ response.setContentType(type);
+ }
+
+ @Override
+ public boolean isCommitted() {
+ return committed;
+ }
+
+ @Override
+ public void setLocale(Locale loc) {
+ // TODO: Je nach Vary-Einstellung ETag anpassen?
+ response.setLocale(loc);
+ }
+
+ @Override
+ public Locale getLocale() {
+ return getLocale();
+ }
+
+
+
+ @Override
+ public boolean isZipped() {
+ return zipped;
+ }
+
+ @Override
+ public long getTimestamp() {
+ return now;
+ }
+
+ @Override
+ public int accepts(HttpServletRequest request) {
+ return status;
+ }
+
+ @Override
+ public int getCacheSeconds(HttpServletRequest request) {
+ return cacheSeconds;
+ }
+
+ @Override
+ public long getLastModified(HttpServletRequest request) {
+ return lastModified;
+ }
+
+ @Override
+ public String getETag(HttpServletRequest request) {
+ return eTag;
+ }
+
+ @Override
+ public boolean isETagWeak() {
+ return weak;
+ }
+
+ @Override
+ public void cacheControl(HttpServletRequest request, Map<String, String> cacheControlMap) {
+ cacheControlMap.putAll(cacheParams);
+ }
+
+ @Override
+ public Map<String,String> getAdditionalHeaders(HttpServletRequest request) {
+ return EMPTY;
+ }
+
+ public void supressGuessing() {
+ guessing = false;
+ }
+
+
+ private void analyzeHeader(String name, String value, boolean overwrite) {
+ if (name == null)
+ return;
+ name = name.trim();
+
+ if (name.equalsIgnoreCase(Headers.HEADER_DATE)) {
+ if (value == null) {
+ if (overwrite) {
+ now = System.currentTimeMillis();
+ cacheSeconds = AcceleratorFilter.this.cacheSeconds;
+ }
+ return;
+ }
+ try {
+ SimpleDateFormat parser = new SimpleDateFormat(Headers.RFC_1123_DATE_FORMAT, Locale.US);
+ now = parser.parse(value).getTime();
+ calculateCacheSeconds();
+ }
+ catch (ParseException e) {
+ log.warn("ignoring date for header \"Date\" in invalid format: {}", value);
+ }
+ return;
+ }
+
+ if (name.equalsIgnoreCase(Headers.HEADER_EXPIRES)) {
+ if (value == null) {
+ if (overwrite) {
+ expires = 0;
+ cacheSeconds = AcceleratorFilter.this.cacheSeconds;
+ }
+ return;
+ }
+ try {
+ SimpleDateFormat parser = new SimpleDateFormat(Headers.RFC_1123_DATE_FORMAT, Locale.US);
+ expires = parser.parse(value).getTime();
+ calculateCacheSeconds();
+ }
+ catch (ParseException e) {
+ log.warn("ignoring date for header \"Expires\" in invalid format: {}", value);
+ }
+ return;
+ }
+
+ if (name.equalsIgnoreCase(Headers.HEADER_LAST_MODIFIED)) {
+ if (value == null) {
+ if (overwrite)
+ lastModified = AcceleratorFilter.this.lastModified;
+ return;
+ }
+ try {
+ SimpleDateFormat parser = new SimpleDateFormat(Headers.RFC_1123_DATE_FORMAT, Locale.US);
+ lastModified = parser.parse(value).getTime();
+ }
+ catch (ParseException e) {
+ log.warn("ignoring date for header \"Last-Modified\" in invalid format: {}", value);
+ }
+ return;
+ }
+
+ if (name.equalsIgnoreCase(Headers.HEADER_ETAG)) {
+ if (value == null) {
+ if (overwrite) {
+ eTag = AcceleratorFilter.this.eTag;
+ weak = AcceleratorFilter.this.weak;
+ }
+ return;
+ }
+ value = value.trim();
+ int start = 0;
+ int end = value.length();
+ if (value.startsWith("W/")) {
+ weak = true;
+ start = 2;
+ }
+ else {
+ weak = false;
+ }
+ if (value.charAt(start) == '"')
+ start++;
+ else
+ log.warn("Quote at the beginning ov ETag is missing: {}", value);
+ if (value.charAt(end -1) == '"')
+ end--;
+ else
+ log.warn("Quote at the end of ETag is missing: {}", value);
+ eTag = value.substring(start, end);
+ String filtered = eTag.replaceAll("[^\\x00-\\x21\\x23-\\x7F]+","");
+ if (filtered.length() < eTag.length()) {
+ log.warn("filtering out illegal characters in ETag: \"{}\" -> \"{}\"", eTag, filtered);
+ eTag = filtered;
+ }
+ }
+
+ if (name.equalsIgnoreCase(Headers.HEADER_CACHE_CONTROL)) {
+ if (overwrite)
+ cacheParams.clear();
+ if (value == null)
+ return;
+ for (String param : value.split(",")) {
+ param = param.trim();
+ int pos = param.indexOf("=");
+ if (pos < 0) {
+ cacheParams.put(param, null);
+ }
+ else {
+ String paramName = param.substring(0, pos).trim();
+ if (paramName.equalsIgnoreCase("max-age")) {
+ try {
+ cacheSeconds = Integer.parseInt(param.substring(pos + 1));
+ cacheSecondsSet = true;
+ }
+ catch (NumberFormatException e) {
+ log.warn("illegal value for Header \"Cache-Control\":", param);
+ }
+ }
+ else {
+ cacheParams.put(paramName, param.substring(pos + 1));
+ }
+ }
+ }
+ return;
+ }
+
+ if (name.equalsIgnoreCase(Headers.HEADER_PRAGMA)) {
+ if (value != null && value.trim().equalsIgnoreCase("no-cache"))
+ cacheSeconds = 0;
+ return;
+ }
+
+ /** Pass header through, if no value from intrest was found */
+ if (overwrite)
+ response.setHeader(name, value);
+ else
+ response.addHeader(name, value);
+ }
+
+ private void calculateCacheSeconds() {
+ if (!cacheSecondsSet && expires >= now) {
+ cacheSeconds = (int)(expires/1000 - now/1000);
+ log.debug("calculating cache-seconds from DATE and EXPIRES: {}", cacheSeconds);
+ }
+ }
+
+
+ private class AcceleratorServletOutputStream extends ServletOutputStream {
+
+ private final ServletOutputStream sos;
+
+
+ private AcceleratorServletOutputStream() throws IOException {
+ bufferSize = defaultBufferSize;
+ buffer = new byte[bufferSize];
+ sos = AccelerationWrapper.this.response.getOutputStream();
+ }
+
+
+ private OutputStream out() throws IOException {
+ if (os == null)
+ os = zipped ? new GZIPOutputStream(sos) : sos;
+ return os;
+ }
+
+ @Override
+ public void write(int i) throws IOException {
+ if (pos == bufferSize) {
+ out().write(buffer);
+ committed = true;
+ /** Dekoration nur beim ersten Schreib-Schub anstoßen */
+ if (pos == size) {
+ if (!cacheControl.decorate(request, response)) {
+ zipped = false;
+ os = null;
+ pos = 0;
+ throw new NotModifiedException();
+ }
+ }
+ pos = 0;
+ }
+ buffer[pos++] = (byte) i;
+ size++;
+ }
+
+ @Override
+ public void flush() throws IOException {
+ if (pos == 0)
+ return;
+
+ committed = true;
+ /** Dekoration nur beim ersten Schreib-Schub anstoßen */
+ if (pos == size) {
+ if (!cacheControl.decorate(request, response)) {
+ zipped = false;
+ os = null;
+ pos = 0;
+ throw new NotModifiedException();
+ }
+ }
+ out().write(buffer, 0, pos);
+ out().flush();
+ pos = 0;
+ }
+
+ @Override
+ public void close() throws IOException {
+ if (size == 0) {
+ committed = true;
+ zipped = false;
+ if (!cacheControl.decorate(request, response))
+ throw new NotModifiedException();
+ sos.close();
+ }
+ else {
+ flush();
+ out().close();
+ }
+ }
+ }
+ }
+}
+
+class NotModifiedException extends IOException {}
\ No newline at end of file