AcceleratorFilter implementiert
authorKai Moritz <kai@coolibri.de>
Sat, 26 Nov 2011 23:03:33 +0000 (00:03 +0100)
committerKai Moritz <kai@coolibri.de>
Sat, 28 Jan 2012 12:07:02 +0000 (13:07 +0100)
Der Filter belauscht das Setzen der Header und konfiguriert CacheControl
entsprechend. Auf diesem Weg lassen sich Java-Webanwendungen mit
verbessertem Caching-Verhalten ausstatten, ohne dass dafür an der Anwendung
selbst etwas geändert werden müsste.

cachecontrol/src/main/java/de/halbekunst/juplo/cachecontrol/AcceleratorFilter.java [new file with mode: 0644]
cachecontrol/src/main/java/de/halbekunst/juplo/cachecontrol/CacheControl.java
cachecontrol/src/main/java/de/halbekunst/juplo/cachecontrol/CacheControlFilter.java [deleted file]
cachecontrol/src/main/java/de/halbekunst/juplo/cachecontrol/HeaderNames.java [new file with mode: 0644]

diff --git a/cachecontrol/src/main/java/de/halbekunst/juplo/cachecontrol/AcceleratorFilter.java b/cachecontrol/src/main/java/de/halbekunst/juplo/cachecontrol/AcceleratorFilter.java
new file mode 100644 (file)
index 0000000..82c4082
--- /dev/null
@@ -0,0 +1,267 @@
+package de.halbekunst.juplo.cachecontrol;
+
+import de.halbekunst.juplo.cachecontrol.CacheControl.CacheMethodHandle;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.PrintWriter;
+import java.util.Enumeration;
+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.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.servlet.http.HttpServletResponseWrapper;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Configurable;
+
+
+
+/**
+ *
+ * @author kai
+ */
+@Configurable
+public class AcceleratorFilter implements Filter {
+  private final static Logger log = LoggerFactory.getLogger(AcceleratorFilter.class);
+
+  public final static String REQUEST_URI_ATTRIBUTE = "javax.servlet.include.request_uri";
+
+
+  @Autowired CacheControl cacheControl;
+  @Autowired(required=true) Integer buffer;
+  @Autowired(required=true) String eTag;
+  @Autowired(required=true) Boolean weak;
+  @Autowired(required=true) Long lastModified;
+  @Autowired(required=true) 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;
+    }
+
+    /** Prüfen, ob es sich um eine Anfrage für einen JSP-Include handelt */
+    if (request.getAttribute(REQUEST_URI_ATTRIBUTE) != null) {
+      log.debug("Includes cannot be accelerated");
+      chain.doFilter(request, response);
+      return;
+    }
+
+    AccelerationWrapper wrapper = new AccelerationWrapper((HttpServletRequest)request, (HttpServletResponse)response);
+    cacheControl.init(wrapper);
+    chain.doFilter(request, wrapper);
+    wrapper.finish();
+  }
+
+  @Override
+  public void init(FilterConfig filterConfig) throws ServletException {
+  }
+
+  @Override
+  public void destroy() {
+  }
+
+
+  class AccelerationWrapper extends HttpServletResponseWrapper implements CacheMethodHandle {
+
+    private final HttpServletRequest request;
+    private final HttpServletResponse response;
+
+    private boolean zipped;
+    private GZIPServletOutputStream out;
+
+    private long now;
+    private int buffer;
+    private int status;
+    private String type;
+
+
+    AccelerationWrapper(HttpServletRequest request, HttpServletResponse response) throws IOException {
+      super(response);
+
+      this.request = request;
+      this.response = response;
+
+      now = System.currentTimeMillis();
+      buffer = AcceleratorFilter.this.buffer;
+      status = HttpServletResponse.SC_OK;
+
+      zipped = false;
+      Enumeration values = request.getHeaders(HeaderNames.HEADER_ACCEPT_ENCODING);
+      while (values.hasMoreElements()) {
+        String value = (String) values.nextElement();
+        if (value.indexOf("gzip") != -1) {
+          zipped = true;
+          response.addHeader(HeaderNames.HEADER_CONTENT_ENCODING, "gzip");
+          break;
+        }
+      }
+    }
+
+
+    public void finish() throws IOException {
+      if (zipped && out != null)
+        out.zout.finish();
+    }
+
+
+    @Override
+    public void setStatus(int sc) {
+      response.setStatus(sc);
+      status = sc;
+      try {
+        cacheControl.decorate(request, response, this);
+      }
+      catch (Exception e) {
+        log.error("Error while decorating response", e);
+      }
+    }
+
+    @Override
+    public void setStatus(int sc, String sm) {
+      response.setStatus(sc,sm);
+      status = sc;
+      try {
+        cacheControl.decorate(request, response, this);
+      }
+      catch (Exception e) {
+        log.error("Error while decorating response", e);
+      }
+    }
+
+    @Override
+    public ServletOutputStream getOutputStream() throws IOException {
+      if (out == null)
+        out = new GZIPServletOutputStream(response.getOutputStream(), zipped);
+      return out;
+    }
+
+    @Override
+    public PrintWriter getWriter() throws IOException {
+      return new PrintWriter(getOutputStream());
+    }
+
+    @Override
+    public void setContentType(String type) {
+      this.type = type;
+      response.setContentType(type);
+    }
+
+    @Override
+    public void setBufferSize(int size) {
+      this.buffer = size;
+      response.setBufferSize(size);
+    }
+
+    @Override
+    public int getBufferSize() {
+      return buffer;
+    }
+
+    @Override
+    public void flushBuffer() throws IOException {
+      cacheControl.decorate(request, response, this);
+      if (zipped && out != null) {
+        out.zout.finish();
+      }
+      response.flushBuffer();
+    }
+
+    @Override
+    public void resetBuffer() {
+      response.resetBuffer();
+    }
+
+    @Override
+    public boolean isCommitted() {
+      return response.isCommitted();
+    }
+
+    @Override
+    public void reset() {
+      response.reset();
+    }
+
+
+
+    @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) {
+    }
+
+
+    class GZIPServletOutputStream extends ServletOutputStream {
+
+      private final OutputStream out;
+      private final GZIPOutputStream zout;
+      private boolean untouched = true;
+
+      public GZIPServletOutputStream(ServletOutputStream out, boolean zipped) throws IOException {
+        if (zipped) {
+          this.zout = new GZIPOutputStream(out, buffer);
+          this.out = this.zout;
+        }
+        else {
+          this.out = out;
+          this.zout = null;
+        }
+      }
+
+
+      @Override
+      public void write(int i) throws IOException {
+        if (untouched) {
+          untouched = false;
+          try {
+            AcceleratorFilter.this.cacheControl.decorate(AccelerationWrapper.this.request, response, buffer);
+          }
+          catch (Exception e) {
+            log.error("Error while guessing Cache-Header's", e);
+            response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
+          }
+        }
+        out.write(i);
+      }
+    }
+  }
+}
index 77e2004..19a60b5 100644 (file)
@@ -5,7 +5,6 @@ import de.halbekunst.juplo.cachecontrol.annotations.Accepts;
 import de.halbekunst.juplo.cachecontrol.annotations.LastModified;
 import de.halbekunst.juplo.cachecontrol.annotations.ETag;
 import java.lang.annotation.Annotation;
-import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.util.Date;
 import java.util.Map;
@@ -23,32 +22,25 @@ import org.slf4j.LoggerFactory;
 public class CacheControl {
   private final static Logger log = LoggerFactory.getLogger(CacheControl.class);
 
-  public static final String HEADER_DATE = "Date";
-  public static final String HEADER_CACHE_CONTROL = "Cache-Control";
-  public static final String HEADER_LAST_MODIFIED = "Last-Modified";
-  public static final String HEADER_ETAG = "ETag";
-  public static final String HEADER_EXPIRES = "Expires";
-  public static final String HEADER_PRAGMA = "Pragma";
-  public static final String HEADER_IF_MODIFIED_SINCE = "If-Modified-Since";
-  public static final String HEADER_IF_NONE_MATCH = "If-None-Match";
-  public static final String HEADER_RANGE = "Range";
-
   private static final ThreadLocal<CacheMethodHandle> tl = new ThreadLocal<CacheMethodHandle>();
 
   private Integer defaultCacheSeconds;
   private Long defaultLastModified;
 
 
-  public void init(Object handler) throws Exception {
-    if (CacheControl.tl.get() == null)
-      CacheControl.tl.set(new ReflectionCacheMethodHandle(handler));
+  public void init(CacheMethodHandle handle) {
+    CacheControl.tl.set(handle);
+  }
+
+  public void init(Object handler) throws NoSuchMethodException {
+    CacheControl.tl.set(new ReflectionCacheMethodHandle(handler));
   }
 
   public boolean decorate(
       HttpServletRequest request,
       HttpServletResponse response,
       Object handler
-      ) throws Exception
+      )
   {
     try {
     CacheMethodHandle controller = CacheControl.tl.get();
@@ -64,7 +56,7 @@ public class CacheControl {
      * http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.18 RFC 2616,
      * Abschnitt 14.18} einen Date-Header enthalten
      */
-    response.setDateHeader(HEADER_DATE, controller.getTimestamp());
+    response.setDateHeader(HeaderNames.HEADER_DATE, controller.getTimestamp());
 
     /** Besondere Maßnahmen für besondere HTTP-Status-Codes ?!? */
     int status = controller.accepts(request);
@@ -95,11 +87,6 @@ public class CacheControl {
       case HttpServletResponse.SC_NOT_IMPLEMENTED: // 501
       case HttpServletResponse.SC_SERVICE_UNAVAILABLE: // 503
       case HttpServletResponse.SC_HTTP_VERSION_NOT_SUPPORTED: // 505
-        /**
-         * Ein Fehlercode kann stellvertretend für den Handler gesendet werden,
-         * da im Fehlerfall eh keine weiteren Daten ausgegeben werden!
-         */
-        response.sendError(status);
         return true;
       default:
         /**
@@ -126,20 +113,20 @@ public class CacheControl {
     int cacheSeconds = controller.getCacheSeconds(request);
     if (cacheSeconds < 1) {
       log.debug("{}: caching disabled!", url);
-      response.setDateHeader(HEADER_DATE, controller.getTimestamp());
-      response.setDateHeader(HEADER_EXPIRES, 0);
-      response.addHeader(HEADER_PRAGMA, "no-cache");
-      response.addHeader(HEADER_CACHE_CONTROL, "private");
-      response.addHeader(HEADER_CACHE_CONTROL, "no-cache");
-      response.addHeader(HEADER_CACHE_CONTROL, "no-store");
-      response.addHeader(HEADER_CACHE_CONTROL, "max-age=0");
-      response.addHeader(HEADER_CACHE_CONTROL, "s-max-age=0");
+      response.setDateHeader(HeaderNames.HEADER_DATE, controller.getTimestamp());
+      response.setDateHeader(HeaderNames.HEADER_EXPIRES, 0);
+      response.addHeader(HeaderNames.HEADER_PRAGMA, "no-cache");
+      response.addHeader(HeaderNames.HEADER_CACHE_CONTROL, "private");
+      response.addHeader(HeaderNames.HEADER_CACHE_CONTROL, "no-cache");
+      response.addHeader(HeaderNames.HEADER_CACHE_CONTROL, "no-store");
+      response.addHeader(HeaderNames.HEADER_CACHE_CONTROL, "max-age=0");
+      response.addHeader(HeaderNames.HEADER_CACHE_CONTROL, "s-max-age=0");
       return true;
     }
 
     long ifModifiedSince = -1;
     try {
-      ifModifiedSince = request.getDateHeader(HEADER_IF_MODIFIED_SINCE);
+      ifModifiedSince = request.getDateHeader(HeaderNames.HEADER_IF_MODIFIED_SINCE);
     }
     catch (Exception e) {
       log.error("Exception while fetching If-Modified-Since: {}", e);
@@ -154,7 +141,7 @@ public class CacheControl {
      */
     lastModified = lastModified - (lastModified % 1000);
 
-    String ifNoneMatch = request.getHeader(HEADER_IF_NONE_MATCH);
+    String ifNoneMatch = request.getHeader(HeaderNames.HEADER_IF_NONE_MATCH);
     String eTag = controller.getETag(request);
 
     /**
@@ -170,7 +157,7 @@ public class CacheControl {
       builder.append('"');
       builder.append(eTag);
       builder.append('"');
-      response.setHeader(HEADER_ETAG, builder.toString());
+      response.setHeader(HeaderNames.HEADER_ETAG, builder.toString());
     }
 
 
@@ -204,7 +191,7 @@ public class CacheControl {
         ifNoneMatch = ifNoneMatch.substring(1, ifNoneMatch.length() - 1);
       }
 
-      if (!weak || (request.getMethod().equals("GET") && request.getHeader(HEADER_RANGE) == null)) {
+      if (!weak || (request.getMethod().equals("GET") && request.getHeader(HeaderNames.HEADER_RANGE) == null)) {
         /**
          * Die Gleichheit gilt nur, wenn die ETag's der Anfrage _und_ der
          * Antwort stark sind (starke Gleichheit!), oder wenn die Antwort nur
@@ -225,7 +212,7 @@ public class CacheControl {
     log.debug("{}: first up!", url);
 
     /** HTTP/1.1-Caching-Header richtig setzen!! */
-    response.setDateHeader(HEADER_LAST_MODIFIED, lastModified);
+    response.setDateHeader(HeaderNames.HEADER_LAST_MODIFIED, lastModified);
 
     /** Cache-Control für HTTP/1.1-Clients generieren */
     Map<String, String> cacheControl = new TreeMap<String, String>();
@@ -248,7 +235,7 @@ public class CacheControl {
        * <code>Expires</code>-Header für HTTP/1.0-Clients setzen.
        */
       cacheControl.put("max-age", Integer.toString(cacheSeconds));
-      response.setDateHeader(HEADER_EXPIRES, (controller.getTimestamp() + (long) cacheSeconds * 1000));
+      response.setDateHeader(HeaderNames.HEADER_EXPIRES, (controller.getTimestamp() + (long) cacheSeconds * 1000));
     }
 
     /** Dem Handler die Gelegenheit geben, den Cache-Controll-Header anzupassen */
@@ -264,8 +251,8 @@ public class CacheControl {
        * http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.32
        * Abschnitt 14.32})
        */
-      response.setDateHeader(HEADER_EXPIRES, 0l);
-      response.addHeader(HEADER_PRAGMA, "no-cache");
+      response.setDateHeader(HeaderNames.HEADER_EXPIRES, 0l);
+      response.addHeader(HeaderNames.HEADER_PRAGMA, "no-cache");
     }
 
     StringBuilder builder = new StringBuilder();
@@ -276,7 +263,7 @@ public class CacheControl {
         builder.append('=');
         builder.append(entry.getValue());
       }
-      response.addHeader(HEADER_CACHE_CONTROL, builder.toString());
+      response.addHeader(HeaderNames.HEADER_CACHE_CONTROL, builder.toString());
     }
 
     return true;
@@ -296,14 +283,14 @@ public class CacheControl {
   }
 
 
-  interface CacheMethodHandle {
+  public interface CacheMethodHandle {
     long getTimestamp();
-    int accepts(HttpServletRequest request) throws Exception;
-    int getCacheSeconds(HttpServletRequest request) throws Exception;
-    long getLastModified(HttpServletRequest request) throws Exception;
-    String getETag(HttpServletRequest request) throws Exception;
+    int accepts(HttpServletRequest request);
+    int getCacheSeconds(HttpServletRequest request);
+    long getLastModified(HttpServletRequest request);
+    String getETag(HttpServletRequest request);
     boolean isETagWeak();
-    void cacheControl(HttpServletRequest request, Map<String, String> cacheControlMap) throws Exception;
+    void cacheControl(HttpServletRequest request, Map<String, String> cacheControlMap);
   }
 
 
@@ -414,51 +401,63 @@ public class CacheControl {
     }
 
     @Override
-    public int accepts(HttpServletRequest request)
-        throws IllegalAccessException,
-               IllegalArgumentException,
-               InvocationTargetException
-    {
-      if (acceptsMethod == null)
+    public int accepts(HttpServletRequest request) throws IllegalArgumentException {
+      if (acceptsMethod == null) {
         return HttpServletResponse.SC_OK;
-      else
-        return (Integer)acceptsMethod.invoke(handler, request);
+      }
+      else {
+        try {
+          return (Integer)acceptsMethod.invoke(handler, request);
+        }
+        catch (Exception e) {
+          throw new IllegalArgumentException(e);
+        }
+      }
     }
 
     @Override
-    public int getCacheSeconds(HttpServletRequest request)
-        throws IllegalAccessException,
-               IllegalArgumentException,
-               InvocationTargetException
-    {
-      if (cacheSecondsMethod == null)
+    public int getCacheSeconds(HttpServletRequest request) throws IllegalArgumentException {
+      if (cacheSecondsMethod == null) {
         return cacheSeconds;
-      else
-        return (Integer)cacheSecondsMethod.invoke(handler, request);
+      }
+      else {
+        try {
+          return (Integer)cacheSecondsMethod.invoke(handler, request);
+        }
+        catch (Exception e) {
+          throw new IllegalArgumentException(e);
+        }
+      }
     }
 
     @Override
-    public long getLastModified(HttpServletRequest request)
-        throws IllegalAccessException,
-               IllegalArgumentException,
-               InvocationTargetException
-    {
-      if (lastModifiedMethod == null)
+    public long getLastModified(HttpServletRequest request) throws IllegalArgumentException {
+      if (lastModifiedMethod == null) {
         return lastModified;
-      else
-        return (Long)lastModifiedMethod.invoke(handler, request);
+      }
+      else {
+        try {
+          return (Long)lastModifiedMethod.invoke(handler, request);
+        }
+        catch (Exception e) {
+          throw new IllegalArgumentException(e);
+        }
+      }
     }
 
     @Override
-    public String getETag(HttpServletRequest request)
-        throws IllegalAccessException,
-               IllegalArgumentException,
-               InvocationTargetException
-    {
-      if (eTagMethod == null)
+    public String getETag(HttpServletRequest request) throws IllegalArgumentException {
+      if (eTagMethod == null) {
         return eTag;
-      else
-        return (String)eTagMethod.invoke(handler, request);
+      }
+      else {
+        try {
+          return (String)eTagMethod.invoke(handler, request);
+        }
+        catch (Exception e) {
+          throw new IllegalArgumentException(e);
+        }
+      }
     }
 
     @Override
@@ -471,12 +470,16 @@ public class CacheControl {
         HttpServletRequest request,
         Map<String, String> cacheControlMap
         )
-        throws IllegalAccessException,
-               IllegalArgumentException,
-               InvocationTargetException
+        throws IllegalArgumentException
     {
-      if (cacheControlMethod != null)
-        cacheControlMethod.invoke(handler, request, cacheControlMap);
+      if (cacheControlMethod != null) {
+        try {
+          cacheControlMethod.invoke(handler, request, cacheControlMap);
+        }
+        catch (Exception e) {
+          throw new IllegalArgumentException(e);
+        }
+      }
     }
   }
 
diff --git a/cachecontrol/src/main/java/de/halbekunst/juplo/cachecontrol/CacheControlFilter.java b/cachecontrol/src/main/java/de/halbekunst/juplo/cachecontrol/CacheControlFilter.java
deleted file mode 100644 (file)
index 549f35c..0000000
+++ /dev/null
@@ -1,209 +0,0 @@
-package de.halbekunst.juplo.cachecontrol;
-
-import java.io.IOException;
-import java.io.PrintWriter;
-import java.util.Locale;
-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.HttpServletResponse;
-
-/**
- *
- * @author kai
- */
-public class CacheControlFilter implements Filter {
-
-
-  @Override
-  public void init(FilterConfig filterConfig) throws ServletException {
-    throw new UnsupportedOperationException("Not supported yet.");
-  }
-
-  @Override
-  public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
-    throw new UnsupportedOperationException("Not supported yet.");
-  }
-
-  @Override
-  public void destroy() {
-    throw new UnsupportedOperationException("Not supported yet.");
-  }
-
-
-  class HttpServletResponseWrapper implements HttpServletResponse {
-
-    private final HttpServletResponse response;
-
-
-    HttpServletResponseWrapper(HttpServletResponse response) {
-      this.response = response;
-    }
-
-
-    @Override
-    public void addCookie(Cookie cookie) {
-      throw new UnsupportedOperationException("Not supported yet.");
-    }
-
-    @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 {
-      throw new UnsupportedOperationException("Not supported yet.");
-    }
-
-    @Override
-    public void sendError(int sc) throws IOException {
-      throw new UnsupportedOperationException("Not supported yet.");
-    }
-
-    @Override
-    public void sendRedirect(String location) throws IOException {
-      throw new UnsupportedOperationException("Not supported yet.");
-    }
-
-    @Override
-    public void setDateHeader(String name, long date) {
-      throw new UnsupportedOperationException("Not supported yet.");
-    }
-
-    @Override
-    public void addDateHeader(String name, long date) {
-      throw new UnsupportedOperationException("Not supported yet.");
-    }
-
-    @Override
-    public void setHeader(String name, String value) {
-      throw new UnsupportedOperationException("Not supported yet.");
-    }
-
-    @Override
-    public void addHeader(String name, String value) {
-      throw new UnsupportedOperationException("Not supported yet.");
-    }
-
-    @Override
-    public void setIntHeader(String name, int value) {
-      throw new UnsupportedOperationException("Not supported yet.");
-    }
-
-    @Override
-    public void addIntHeader(String name, int value) {
-      throw new UnsupportedOperationException("Not supported yet.");
-    }
-
-    @Override
-    public void setStatus(int sc) {
-      throw new UnsupportedOperationException("Not supported yet.");
-    }
-
-    @Override
-    public void setStatus(int sc, String sm) {
-      throw new UnsupportedOperationException("Not supported yet.");
-    }
-
-    @Override
-    public String getCharacterEncoding() {
-      return response.getCharacterEncoding();
-    }
-
-    @Override
-    public String getContentType() {
-      return response.getContentType();
-    }
-
-    @Override
-    public ServletOutputStream getOutputStream() throws IOException {
-      throw new UnsupportedOperationException("Not supported yet.");
-    }
-
-    @Override
-    public PrintWriter getWriter() throws IOException {
-      throw new UnsupportedOperationException("Not supported yet.");
-    }
-
-    @Override
-    public void setCharacterEncoding(String charset) {
-      response.setCharacterEncoding(charset);
-    }
-
-    @Override
-    public void setContentLength(int len) {
-      throw new UnsupportedOperationException("Not supported yet.");
-    }
-
-    @Override
-    public void setContentType(String type) {
-      response.setContentType(type);
-    }
-
-    @Override
-    public void setBufferSize(int size) {
-      throw new UnsupportedOperationException("Not supported yet.");
-    }
-
-    @Override
-    public int getBufferSize() {
-      throw new UnsupportedOperationException("Not supported yet.");
-    }
-
-    @Override
-    public void flushBuffer() throws IOException {
-      throw new UnsupportedOperationException("Not supported yet.");
-    }
-
-    @Override
-    public void resetBuffer() {
-      throw new UnsupportedOperationException("Not supported yet.");
-    }
-
-    @Override
-    public boolean isCommitted() {
-      throw new UnsupportedOperationException("Not supported yet.");
-    }
-
-    @Override
-    public void reset() {
-      throw new UnsupportedOperationException("Not supported yet.");
-    }
-
-    @Override
-    public void setLocale(Locale loc) {
-      response.setLocale(loc);
-    }
-
-    @Override
-    public Locale getLocale() {
-      return response.getLocale();
-    }
-  }
-}
diff --git a/cachecontrol/src/main/java/de/halbekunst/juplo/cachecontrol/HeaderNames.java b/cachecontrol/src/main/java/de/halbekunst/juplo/cachecontrol/HeaderNames.java
new file mode 100644 (file)
index 0000000..76736d2
--- /dev/null
@@ -0,0 +1,21 @@
+package de.halbekunst.juplo.cachecontrol;
+
+/**
+ *
+ * @author kai
+ */
+public abstract class HeaderNames {
+
+  public static final String HEADER_ACCEPT_ENCODING = "Accept-Encoding";
+  public static final String HEADER_CACHE_CONTROL = "Cache-Control";
+  public static final String HEADER_CONTENT_ENCODING = "Content-Encoding";
+  public static final String HEADER_DATE = "Date";
+  public static final String HEADER_ETAG = "ETag";
+  public static final String HEADER_EXPIRES = "Expires";
+  public static final String HEADER_IF_MODIFIED_SINCE = "If-Modified-Since";
+  public static final String HEADER_IF_NONE_MATCH = "If-None-Match";
+  public static final String HEADER_LAST_MODIFIED = "Last-Modified";
+  public static final String HEADER_PRAGMA = "Pragma";
+  public static final String HEADER_RANGE = "Range";
+
+}