1 files changed, 123 insertions, 0 deletions
diff --git a/src/main/java/at/gv/egiz/pdfas/web/filter/EncodingFilter.java b/src/main/java/at/gv/egiz/pdfas/web/filter/EncodingFilter.java
new file mode 100644
index 0000000..5267918
--- /dev/null
+++ b/src/main/java/at/gv/egiz/pdfas/web/filter/EncodingFilter.java
@@ -0,0 +1,123 @@
+package at.gv.egiz.pdfas.web.filter;
+
+import java.io.IOException;
+import java.nio.charset.Charset;
+
+import javax.servlet.FilterChain;
+import javax.servlet.FilterConfig;
+import javax.servlet.ServletException;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
+
+import org.apache.commons.lang.StringUtils;
+import org.apache.commons.lang.builder.ToStringBuilder;
+import org.apache.log4j.Logger;
+
+/**
+ * @author <a href="mailto:thomas.knall@iaik.tugraz.at">Thomas Knall</a>
+ */
+public class EncodingFilter implements javax.servlet.Filter {
+
+   private static final String SERVLET_INIT_PARAM_ENCODING = "encoding";
+   
+   private static final String SERVLET_INIT_PARAM_SET_REQUEST_ENCODING    = "setRequestEncoding";
+   private static final String SERVLET_INIT_PARAM_FORCE_REQUEST_ENCODING  = "forceRequestEncoding";
+
+   private static final String SERVLET_INIT_PARAM_SET_RESPONSE_ENCODING   = "setResponseEncoding";
+   private static final String SERVLET_INIT_PARAM_FORCE_RESPONSE_ENCODING = "forceResponseEncoding";
+   
+   private static final boolean DEFAULT_SET_REQUEST_ENCODING_VALUE    = true;
+   private static final boolean DEFAULT_FORCE_REQUEST_ENCODING_VALUE  = true;
+   private static final boolean DEFAULT_SET_RESPONSE_ENCODING_VALUE   = false;
+   private static final boolean DEFAULT_FORCE_RESPONSE_ENCODING_VALUE = false;
+   
+   private Logger log = Logger.getLogger(getClass().getName());
+
+   private String encoding = null;
+   
+   private boolean setRequestEncoding;
+   private boolean forceRequestEncoding;
+
+   private boolean setResponseEncoding;
+   private boolean forceResponseEncoding;
+   
+   private boolean enabled = false;
+   
+   private boolean parseBooleanInitParameter(final FilterConfig filterConfig, String parameterName, boolean defaultValue) {
+      String paramValue = filterConfig.getInitParameter(parameterName);
+      if (paramValue == null) {
+         return defaultValue;
+      }
+      paramValue = paramValue.trim();
+      if (paramValue.equalsIgnoreCase("true")) {
+         return true;
+      } else if (paramValue.equalsIgnoreCase("false")){
+         return false;
+      } else {
+         log.warn("Unknown value \"" + paramValue + "\" for init parameter \"" + parameterName + "\" detected. Should be \"true\" or \"false\". Using default value \"" + defaultValue + "\".");
+         return defaultValue;
+      }
+   }
+
+   public void init(final FilterConfig filterConfig) throws ServletException {
+      log.debug("Initializing encoding filter (" + getClass().getName() + ").");
+
+      // mandatory parameter encoding
+      String desiredEncoding = filterConfig.getInitParameter(SERVLET_INIT_PARAM_ENCODING);
+      if (StringUtils.isEmpty(desiredEncoding)) {
+         log.warn("Unable to initialize encoding filter (" + getClass().getName() + "). Init parameter \"" + SERVLET_INIT_PARAM_ENCODING + "\" empty or not supplied.");
+      } else if (!Charset.isSupported(desiredEncoding)) {
+         log.warn("Unable to initialize encoding filter (" + getClass().getName() + "). Encoding \"" + desiredEncoding + "\" is not supported.");
+      } else {
+         this.encoding = desiredEncoding;
+         this.enabled = true;
+         this.setRequestEncoding    = this.parseBooleanInitParameter(filterConfig, SERVLET_INIT_PARAM_SET_REQUEST_ENCODING,    DEFAULT_SET_REQUEST_ENCODING_VALUE);
+         this.forceRequestEncoding  = this.parseBooleanInitParameter(filterConfig, SERVLET_INIT_PARAM_FORCE_REQUEST_ENCODING,  DEFAULT_FORCE_REQUEST_ENCODING_VALUE);
+         this.setResponseEncoding   = this.parseBooleanInitParameter(filterConfig, SERVLET_INIT_PARAM_SET_RESPONSE_ENCODING,   DEFAULT_SET_RESPONSE_ENCODING_VALUE);
+         this.forceResponseEncoding = this.parseBooleanInitParameter(filterConfig, SERVLET_INIT_PARAM_FORCE_RESPONSE_ENCODING, DEFAULT_FORCE_RESPONSE_ENCODING_VALUE);
+         log.debug("Encoding filter \"" + getClass().getName() + "\" configured: " + this.toString(true));
+         
+      }
+   }
+   
+   public String toString(boolean verbose) {
+      if (verbose) {
+         return new ToStringBuilder(this)
+            .append(SERVLET_INIT_PARAM_ENCODING, this.encoding)
+            .append(SERVLET_INIT_PARAM_SET_REQUEST_ENCODING, this.setRequestEncoding)
+            .append(SERVLET_INIT_PARAM_FORCE_REQUEST_ENCODING, this.forceRequestEncoding)
+            .append(SERVLET_INIT_PARAM_SET_RESPONSE_ENCODING, this.setResponseEncoding)
+            .append(SERVLET_INIT_PARAM_FORCE_RESPONSE_ENCODING, this.forceResponseEncoding)
+         .toString();
+      } else {
+         return super.toString();
+      }
+   }
+
+   public void doFilter(ServletRequest request, ServletResponse response, final FilterChain filterChain) throws IOException, ServletException {
+      if (this.enabled) {
+         if (this.setRequestEncoding) {
+            if (this.forceRequestEncoding) {
+               log.trace("Forcing request encoding \"" + this.encoding + "\".");
+               request.setCharacterEncoding(this.encoding);
+            } else if (request.getCharacterEncoding() == null) {
+               log.trace("Request character encoding not set. Setting to \"" + this.encoding + "\".");
+               request.setCharacterEncoding("UTF8");
+            }
+         }
+         if (this.setResponseEncoding) {
+            if (this.forceResponseEncoding) {
+               log.trace("Forcing response encoding \"" + this.encoding + "\".");
+               response.setCharacterEncoding(this.encoding);
+            } else if (response.getCharacterEncoding() == null) {
+               log.trace("Response character encoding not set. Setting to \"" + this.encoding + "\".");
+               response.setCharacterEncoding("UTF8");
+            }
+         }
+      }
+      filterChain.doFilter(request, response);
+   }
+
+   public void destroy() {
+   }
+}