[OLINGO-659] better debug output in error case

Change-Id: I3f0a270807c4a929027894ed42c51523e56bbc14

Signed-off-by: Michael Bolz <michael.bolz@sap.com>

lib/server-api/src/main/java/org/apache/olingo/server/api/debug/DebugSupport.java

@@ -32,26 +32,25 @@ public interface DebugSupport {
   public static final String ODATA_DEBUG_DOWNLOAD = "download";
 
   /**
-   * Initializes the debug support implementation. Is called before {@link #isUserAuthorized()} and
+   * Initializes the debug support implementation.
-   * {@link #createDebugResponse(String, DebugInformation)}
+   * Is called before {@link #isUserAuthorized()} and
+   * {@link #createDebugResponse(String, DebugInformation)}.
    * @param odata
    */
   void init(OData odata);
 
   /**
-   * This method is called to make sure that the user that requested the debug output is authorized to see this output.
+   * Ensures that the user that requested the debug output is authorized to see this output.
    * @return true if the current user is authorized
    */
   boolean isUserAuthorized();
 
   /**
-   * This method should create a debug response and deliver it back to the Olingo library. This method MUST NEVER throw
+   * Creates a debug response and delivers it back to the Olingo library.
-   * an exception.
+   * This method MUST NEVER throw an exception.
-   * @param debugFormat which is requested via the odata-debug query parameter
+   * @param debugFormat the value of the odata-debug query parameter
-   * @param request object which was send to the server
+   * @param debugInfo   all necessary information to construct debug output
-   * @param response object which was filled by the application
+   * @return a new debug response which will be sent to the client
-   * @param exception which has been thrown. Might be null in case there was no exception
-   * @return a new debug response which will be send to the client
    */
   ODataResponse createDebugResponse(String debugFormat, DebugInformation debugInfo);
 

lib/server-core/src/main/java/org/apache/olingo/server/core/ODataHandler.java

@@ -74,7 +74,7 @@ public class ODataHandler {
 
   public ODataResponse process(final ODataRequest request) {
     ODataResponse response = new ODataResponse();
-    int measurementHandel = debugger.startRuntimeMeasurement("ODataHandler", "processInternal");
+    final int responseHandle = debugger.startRuntimeMeasurement("ODataHandler", "process");
     try {
       processInternal(request, response);
     } catch (final UriValidationException e) {
@@ -111,29 +111,51 @@ public class ODataHandler {
       ODataServerError serverError = ODataExceptionHelper.createServerErrorObject(e);
       handleException(request, response, serverError, e);
     }
-    debugger.stopRuntimeMeasurement(measurementHandel);
+    debugger.stopRuntimeMeasurement(responseHandle);
     return response;
   }
 
   private void processInternal(final ODataRequest request, final ODataResponse response)
       throws ODataApplicationException, ODataLibraryException {
+    final int measurementHandle = debugger.startRuntimeMeasurement("ODataHandler", "processInternal");
+
     response.setHeader(HttpHeader.ODATA_VERSION, ODataServiceVersion.V40.toString());
-
+    try {
       validateODataVersion(request);
+    } catch (final ODataHandlerException e) {
+      debugger.stopRuntimeMeasurement(measurementHandle);
+      throw e;
+    }
 
-    int measurementUriParser = debugger.startRuntimeMeasurement("UriParser", "parseUri");
+    final int measurementUriParser = debugger.startRuntimeMeasurement("UriParser", "parseUri");
+    try {
       uriInfo = new Parser().parseUri(request.getRawODataPath(), request.getRawQueryPath(), null,
           serviceMetadata.getEdm());
+    } catch (final ODataLibraryException e) {
+      debugger.stopRuntimeMeasurement(measurementUriParser);
+      debugger.stopRuntimeMeasurement(measurementHandle);
+      throw e;
+    }
     debugger.stopRuntimeMeasurement(measurementUriParser);
 
-    int measurementUriValidator = debugger.startRuntimeMeasurement("UriValidator", "validate");
+    final int measurementUriValidator = debugger.startRuntimeMeasurement("UriValidator", "validate");
     final HttpMethod method = request.getMethod();
+    try {
       new UriValidator().validate(uriInfo, method);
+    } catch (final UriValidationException e) {
+      debugger.stopRuntimeMeasurement(measurementUriValidator);
+      debugger.stopRuntimeMeasurement(measurementHandle);
+      throw e;
+    }
     debugger.stopRuntimeMeasurement(measurementUriValidator);
 
-    int measurementDispatcher = debugger.startRuntimeMeasurement("Dispatcher", "dispatch");
+    final int measurementDispatcher = debugger.startRuntimeMeasurement("ODataDispatcher", "dispatch");
+    try {
       new ODataDispatcher(uriInfo, this).dispatch(request, response);
+    } finally {
       debugger.stopRuntimeMeasurement(measurementDispatcher);
+      debugger.stopRuntimeMeasurement(measurementHandle);
+    }
   }
 
   public void handleException(final ODataRequest request, final ODataResponse response,
@@ -154,13 +176,12 @@ public class ODataHandler {
     } catch (final ContentNegotiatorException e) {
       requestedContentType = ContentType.JSON;
     }
-    int measurementHandle = debugger.startRuntimeMeasurement("ErrorProcessor", "processError");
+    final int measurementHandle = debugger.startRuntimeMeasurement("ErrorProcessor", "processError");
     exceptionProcessor.processError(request, response, serverError, requestedContentType);
     debugger.stopRuntimeMeasurement(measurementHandle);
   }
 
-  private void validateODataVersion(final ODataRequest request)
+  private void validateODataVersion(final ODataRequest request) throws ODataHandlerException {
-      throws ODataHandlerException {
     final String maxVersion = request.getHeader(HttpHeader.ODATA_MAX_VERSION);
     if (maxVersion != null && ODataServiceVersion.isBiggerThan(ODataServiceVersion.V40.toString(), maxVersion)) {
         throw new ODataHandlerException("ODataVersion not supported: " + maxVersion,

lib/server-core/src/main/java/org/apache/olingo/server/core/ODataHttpHandlerImpl.java

@@ -45,10 +45,10 @@ import org.apache.olingo.server.api.ODataResponse;
 import org.apache.olingo.server.api.ODataServerError;
 import org.apache.olingo.server.api.ServiceMetadata;
 import org.apache.olingo.server.api.debug.DebugSupport;
+import org.apache.olingo.server.api.deserializer.DeserializerException;
 import org.apache.olingo.server.api.etag.CustomETagSupport;
 import org.apache.olingo.server.api.processor.Processor;
 import org.apache.olingo.server.api.serializer.CustomContentTypeSupport;
-import org.apache.olingo.server.api.serializer.SerializerException;
 import org.apache.olingo.server.core.debug.ServerCoreDebugger;
 
 public class ODataHttpHandlerImpl implements ODataHttpHandler {
@@ -72,21 +72,17 @@ public class ODataHttpHandlerImpl implements ODataHttpHandler {
     ODataResponse odResponse;
     debugger.resolveDebugMode(request);
 
-    int processMethodHandel = debugger.startRuntimeMeasurement("ODataHttpHandlerImpl", "process");
+    final int processMethodHandle = debugger.startRuntimeMeasurement("ODataHttpHandlerImpl", "process");
     try {
-      int requestHandel = debugger.startRuntimeMeasurement("ODataHttpHandlerImpl", "fillODataRequest");
       fillODataRequest(odRequest, request, split);
-      debugger.stopRuntimeMeasurement(requestHandel);
 
-      int responseHandel = debugger.startRuntimeMeasurement("ODataHandler", "process");
       odResponse = handler.process(odRequest);
-      debugger.stopRuntimeMeasurement(responseHandel);
       // ALL future methods after process must not throw exceptions!
     } catch (Exception e) {
       exception = e;
       odResponse = handleException(odRequest, e);
     }
-    debugger.stopRuntimeMeasurement(processMethodHandel);
+    debugger.stopRuntimeMeasurement(processMethodHandle);
 
     if (debugger.isDebugMode()) {
       Map<String, String> serverEnvironmentVariables = createEnvironmentVariablesMap(request);
@@ -95,7 +91,7 @@ public class ODataHttpHandlerImpl implements ODataHttpHandler {
         exception = handler.getLastThrownException();
       }
       odResponse =
-          debugger.createDebugResponse(request, exception, odRequest, odResponse, handler.getUriInfo(),
+          debugger.createDebugResponse(odRequest, odResponse, exception, handler.getUriInfo(),
               serverEnvironmentVariables);
     }
 
@@ -103,7 +99,7 @@ public class ODataHttpHandlerImpl implements ODataHttpHandler {
   }
 
   private Map<String, String> createEnvironmentVariablesMap(HttpServletRequest request) {
-    LinkedHashMap<String, String> environment = new LinkedHashMap<String, String>();
+    Map<String, String> environment = new LinkedHashMap<String, String>();
     environment.put("authType", request.getAuthType());
     environment.put("localAddr", request.getLocalAddr());
     environment.put("localName", request.getLocalName());
@@ -186,9 +182,9 @@ public class ODataHttpHandlerImpl implements ODataHttpHandler {
     }
   }
 
-  private ODataRequest fillODataRequest(final ODataRequest odRequest, final HttpServletRequest httpRequest,
+  private ODataRequest fillODataRequest(ODataRequest odRequest, final HttpServletRequest httpRequest,
-      final int split)
+      final int split) throws ODataLibraryException {
-      throws ODataLibraryException {
+    final int requestHandle = debugger.startRuntimeMeasurement("ODataHttpHandlerImpl", "fillODataRequest");
     try {
       odRequest.setBody(httpRequest.getInputStream());
       odRequest.setProtocol(httpRequest.getProtocol());
@@ -198,13 +194,14 @@ public class ODataHttpHandlerImpl implements ODataHttpHandler {
 
       return odRequest;
     } catch (final IOException e) {
-      throw new SerializerException("An I/O exception occurred.", e,
+      throw new DeserializerException("An I/O exception occurred.", e,
-          SerializerException.MessageKeys.IO_EXCEPTION);
+          DeserializerException.MessageKeys.IO_EXCEPTION);
+    } finally {
+      debugger.stopRuntimeMeasurement(requestHandle);
     }
   }
 
-  static HttpMethod extractMethod(final HttpServletRequest httpRequest)
+  static HttpMethod extractMethod(final HttpServletRequest httpRequest) throws ODataLibraryException {
-      throws ODataLibraryException {
     try {
       HttpMethod httpRequestMethod = HttpMethod.valueOf(httpRequest.getMethod());
 

lib/server-core/src/main/java/org/apache/olingo/server/core/debug/DebugResponseHelperImpl.java

@@ -65,7 +65,7 @@ public class DebugResponseHelperImpl implements DebugResponseHelper {
   }
 
   @Override
-  public ODataResponse createDebugResponse(DebugInformation debugInfo) {
+  public ODataResponse createDebugResponse(final DebugInformation debugInfo) {
     try {
       final List<DebugTab> parts = createParts(debugInfo);
 
@@ -100,7 +100,7 @@ public class DebugResponseHelperImpl implements DebugResponseHelper {
     }
   }
 
-  private List<DebugTab> createParts(DebugInformation debugInfo) {
+  private List<DebugTab> createParts(final DebugInformation debugInfo) {
     List<DebugTab> parts = new ArrayList<DebugTab>();
 
     // request
@@ -182,20 +182,18 @@ public class DebugResponseHelperImpl implements DebugResponseHelper {
   }
 
   /**
-   * Get version field information for response.
+   * Gets version field information for response.  Result is never null.
-   * Result is never null.
-   *
    * @return version field information
    */
-  private String getVersion() {
+  protected static String getVersion() {
-    final String version = DebugResponseHelperImpl.class.getPackage().getImplementationVersion();
+    final Package pack = DebugResponseHelperImpl.class.getPackage();
-    if (version == null) {
+    final String name = pack.getImplementationTitle();
-      return "Olingo";
+    final String version = pack.getImplementationVersion();
-    }
+    return (name == null ? "Olingo" : name)
-    return "Olingo " + version;
+        + (version == null ? "" : " Version " + version);
   }
 
-  private InputStream wrapInHtml(final List<DebugTab> parts, String title) throws IOException {
+  private InputStream wrapInHtml(final List<DebugTab> parts, final String title) throws IOException {
     StringWriter writer = new StringWriter();
 
     writer.append("<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.1//EN\"\n")
@@ -265,24 +263,29 @@ public class DebugResponseHelperImpl implements DebugResponseHelper {
     return value == null ? null : value.replace("&", "&amp;").replace("<", "&lt;").replace(">", "&gt;");
   }
 
-  protected static void appendJsonTable(final JsonGenerator gen, final Map<String, String> entries)
+  protected static void appendJsonTable(JsonGenerator gen, final Map<String, String> entries)
       throws IOException {
-    gen.writeStartObject();
+    if (entries == null || entries.isEmpty()) {
-
+      gen.writeNull();
-    for (Map.Entry<String, String> entry : entries.entrySet()) {
-      if (entry.getValue() != null) {
-        gen.writeStringField(entry.getKey(), entry.getValue());
     } else {
-        gen.writeNullField(entry.getKey());
+      gen.writeStartObject();
+      for (Map.Entry<String, String> entry : entries.entrySet()) {
+        gen.writeFieldName(entry.getKey());
+        if (entry.getValue() == null) {
+          gen.writeNull();
+        } else {
+          gen.writeString(entry.getValue());
         }
       }
       gen.writeEndObject();
     }
+  }
 
-  protected static void appendHtmlTable(final Writer writer, final Map<String, String> entries) throws IOException {
+  protected static void appendHtmlTable(Writer writer, final Map<String, String> entries) throws IOException {
     writer.append("<table>\n<thead>\n")
         .append("<tr><th class=\"name\">Name</th><th class=\"value\">Value</th></tr>\n")
         .append("</thead>\n<tbody>\n");
+    if (entries != null && !entries.isEmpty()) {
       for (final Entry<String, String> entry : entries.entrySet()) {
         writer.append("<tr><td class=\"name\">").append(entry.getKey()).append("</td>")
             .append("<td class=\"value\">");
@@ -293,6 +296,7 @@ public class DebugResponseHelperImpl implements DebugResponseHelper {
         }
         writer.append("</td></tr>\n");
       }
+    }
     writer.append("</tbody>\n</table>\n");
   }
 }

lib/server-core/src/main/java/org/apache/olingo/server/core/debug/DebugTabBody.java

@@ -106,12 +106,12 @@ public class DebugTabBody implements DebugTab {
     case XML:
       writer.append("<pre class=\"code").append(" xml").append("\">\n");
       writer.append(DebugResponseHelperImpl.escapeHtml(body));
-      writer.append("</pre>\n");
+      writer.append("\n</pre>\n");
       break;
     case JSON:
       writer.append("<pre class=\"code").append(" json").append("\">\n");
       writer.append(DebugResponseHelperImpl.escapeHtml(body));
-      writer.append("</pre>\n");
+      writer.append("\n</pre>\n");
       break;
     case IMAGE:
       writer.append("<img src=\"data:").append(response.getHeader(HttpHeader.CONTENT_TYPE)).append(";base64,")
@@ -122,7 +122,7 @@ public class DebugTabBody implements DebugTab {
     default:
       writer.append("<pre class=\"code").append("\">\n");
       writer.append(DebugResponseHelperImpl.escapeHtml(body));
-      writer.append("</pre>\n");
+      writer.append("\n</pre>\n");
       break;
     }
   }

lib/server-core/src/main/java/org/apache/olingo/server/core/debug/DebugTabResponse.java

@@ -85,7 +85,7 @@ public class DebugTabResponse implements DebugTab {
   private Map<String, String> map(Map<String, List<String>> headers) {
     Map<String, String> result = new HashMap<String, String>();
     for (Map.Entry<String, List<String>> entry : headers.entrySet()) {
-      if(entry.getValue().size() == 1) {
+      if (entry.getValue().size() == 1) {
         result.put(entry.getKey(), entry.getValue().get(0));
       } else {
         result.put(entry.getKey(), entry.getValue().toString());
@@ -105,7 +105,7 @@ public class DebugTabResponse implements DebugTab {
     if (response != null && response.getContent() != null) {
       new DebugTabBody(response).appendHtml(writer);
     } else {
-      writer.append("<p>ODataLibrary: no response body</p>");
+      writer.append("<p>ODataLibrary: no response body</p>\n");
     }
   }
 }

lib/server-core/src/main/java/org/apache/olingo/server/core/debug/DebugTabRuntime.java

@@ -89,7 +89,7 @@ public class DebugTabRuntime implements DebugTab {
   private void appendRuntimeNode(final RuntimeNode node, final String draw, final boolean isLast, final Writer writer)
       throws IOException {
     if (node.className != null) {
-      writer.append("<li>")
+      writer.append("<li>\n")
           .append("<span class=\"code\">")
           .append("<span class=\"draw\">").append(draw)
           .append(isLast ? "&#x2514;" : "&#x251C;").append("&#x2500;&nbsp;</span>")

lib/server-core/src/main/java/org/apache/olingo/server/core/debug/DebugTabServer.java

@@ -42,22 +42,14 @@ public class DebugTabServer implements DebugTab {
 
   @Override
   public void appendJson(JsonGenerator gen) throws IOException {
-    if (serverEnvironmentVariables != null && !serverEnvironmentVariables.isEmpty()) {
     DebugResponseHelperImpl.appendJsonTable(gen, serverEnvironmentVariables);
-    } else {
-      gen.writeNull();
-    }
   }
 
   @Override
   public void appendHtml(Writer writer) throws IOException {
-    final Package pack = DebugResponseHelperImpl.class.getPackage();
     writer.append("<h2>Library Version</h2>\n")
-        .append("<p>").append(pack.getImplementationTitle())
+        .append("<p>").append(DebugResponseHelperImpl.getVersion()).append("</p>\n")
-        .append(" Version ").append(pack.getImplementationVersion()).append("</p>\n")
         .append("<h2>Server Environment</h2>\n");
-    if (serverEnvironmentVariables != null && !serverEnvironmentVariables.isEmpty()) {
     DebugResponseHelperImpl.appendHtmlTable(writer, serverEnvironmentVariables);
   }
-  }
 }

lib/server-core/src/main/java/org/apache/olingo/server/core/debug/DebugTabUri.java

@@ -19,12 +19,9 @@
 package org.apache.olingo.server.core.debug;
 
 import java.io.IOException;
-import java.io.InputStream;
-import java.io.OutputStream;
 import java.io.Writer;
 import java.util.List;
 
-import org.apache.commons.io.IOUtils;
 import org.apache.olingo.server.api.uri.UriInfo;
 import org.apache.olingo.server.api.uri.UriResource;
 import org.apache.olingo.server.api.uri.queryoption.CountOption;
@@ -38,9 +35,7 @@ import org.apache.olingo.server.api.uri.queryoption.SelectOption;
 import org.apache.olingo.server.api.uri.queryoption.SkipOption;
 import org.apache.olingo.server.api.uri.queryoption.TopOption;
 import org.apache.olingo.server.api.uri.queryoption.expression.Expression;
-import org.apache.olingo.server.core.serializer.utils.CircleStreamBuffer;
 
-import com.fasterxml.jackson.core.JsonEncoding;
 import com.fasterxml.jackson.core.JsonFactory;
 import com.fasterxml.jackson.core.JsonGenerator;
 import com.fasterxml.jackson.core.util.DefaultPrettyPrinter;
@@ -63,11 +58,6 @@ public class DebugTabUri implements DebugTab {
 
   @Override
   public void appendJson(JsonGenerator gen) throws IOException {
-    if (uriInfo == null) {
-      gen.writeNull();
-      return;
-    }
-
     gen.writeStartObject();
 
     if (uriInfo.getFormatOption() != null) {
@@ -233,7 +223,7 @@ public class DebugTabUri implements DebugTab {
       boolean first = true;
       for (UriResource resourcePart : selectItem.getResourcePath().getUriResourceParts()) {
         if (!first) {
-          selectedProperty = selectedProperty + "/";
+          selectedProperty += "/";
         }
         selectedProperty = resourcePart.toString();
         first = false;
@@ -245,62 +235,12 @@ public class DebugTabUri implements DebugTab {
 
   @Override
   public void appendHtml(final Writer writer) throws IOException {
-    if (uriInfo == null) {
-      return;
-    }
-
     writer.append("<h2>Uri Information</h2>\n")
-        .append("<ul class=\"json\"><li>");
+        .append("<ul class=\"json\">\n<li>\n");
-    writer.append(getJsonString());
+    JsonGenerator json = new JsonFactory().createGenerator(writer)
-    writer.append("</li></ul>\n");
-  }
-
-  private String getJsonString() throws IOException {
-    CircleStreamBuffer csb = new CircleStreamBuffer();
-    IOException cachedException = null;
-    OutputStream outputStream = csb.getOutputStream();
-    try {
-      JsonGenerator json =
-          new JsonFactory().createGenerator(outputStream, JsonEncoding.UTF8)
         .setPrettyPrinter(new DefaultPrettyPrinter());
     appendJson(json);
     json.close();
-      outputStream.close();
+    writer.append("\n</li>\n</ul>\n");
-    } catch (IOException e) {
-      throw e;
-    } finally {
-      if (outputStream != null) {
-        try {
-          outputStream.close();
-        } catch (IOException e) {
-          if (cachedException != null) {
-            throw cachedException;
-          } else {
-            throw e;
-          }
-        }
-      }
-    }
-
-    InputStream inputStream = csb.getInputStream();
-    try {
-      String jsonString = IOUtils.toString(inputStream);
-      inputStream.close();
-      return jsonString;
-    } catch (IOException e) {
-      throw e;
-    } finally {
-      if (inputStream != null) {
-        try {
-          inputStream.close();
-        } catch (IOException e) {
-          if (cachedException != null) {
-            throw cachedException;
-          } else {
-            throw e;
-          }
-        }
-      }
-    }
   }
 }

lib/server-core/src/main/java/org/apache/olingo/server/core/debug/ServerCoreDebugger.java

@@ -61,17 +61,16 @@ public class ServerCoreDebugger {
     }
   }
 
-  public ODataResponse createDebugResponse(final HttpServletRequest request, final Exception exception,
+  public ODataResponse createDebugResponse(final ODataRequest request, final ODataResponse response,
-      final ODataRequest odRequest, final ODataResponse odResponse, UriInfo uriInfo,
+      final Exception exception, final UriInfo uriInfo, final Map<String, String> serverEnvironmentVariables) {
-      Map<String, String> serverEnvironmentVariables) {
     //Failsafe so we do not generate unauthorized debug messages
-    if(!isDebugMode){
+    if (!isDebugMode) {
-      return odResponse;
+      return response;
     }
 
     try {
       DebugInformation debugInfo =
-          createDebugInformation(request, exception, odRequest, odResponse, uriInfo, serverEnvironmentVariables);
+          createDebugInformation(request, response, exception, uriInfo, serverEnvironmentVariables);
 
       return debugSupport.createDebugResponse(debugFormat, debugInfo);
     } catch (Exception e) {
@@ -88,16 +87,15 @@ public class ServerCoreDebugger {
     return odResponse;
   }
 
-  private DebugInformation createDebugInformation(final HttpServletRequest request, final Exception exception,
+  private DebugInformation createDebugInformation(final ODataRequest request, final ODataResponse response,
-      final ODataRequest odRequest, final ODataResponse odResponse, UriInfo uriInfo,
+      final Exception exception, final UriInfo uriInfo, final Map<String, String> serverEnvironmentVariables) {
-      Map<String, String> serverEnvironmentVaribles) {
     DebugInformation debugInfo = new DebugInformation();
-    debugInfo.setRequest(odRequest);
+    debugInfo.setRequest(request);
-    debugInfo.setApplicationResponse(odResponse);
+    debugInfo.setApplicationResponse(response);
 
     debugInfo.setException(exception);
 
-    debugInfo.setServerEnvironmentVariables(serverEnvironmentVaribles);
+    debugInfo.setServerEnvironmentVariables(serverEnvironmentVariables);
 
     debugInfo.setUriInfo(uriInfo);
 

lib/server-core/src/test/java/org/apache/olingo/server/core/debug/AbstractDebugTabTest.java

@@ -18,41 +18,28 @@
  */
 package org.apache.olingo.server.core.debug;
 
-import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.StringWriter;
 
-import org.apache.commons.io.IOUtils;
-import org.apache.olingo.server.core.serializer.utils.CircleStreamBuffer;
-
-import com.fasterxml.jackson.core.JsonEncoding;
 import com.fasterxml.jackson.core.JsonFactory;
 import com.fasterxml.jackson.core.JsonGenerator;
 
 public abstract class AbstractDebugTabTest {
 
-  protected String createHtml(DebugTab tab) throws Exception {
+  protected String createHtml(DebugTab tab) throws IOException {
     StringWriter writer = new StringWriter();
     tab.appendHtml(writer);
     writer.flush();
-    byte[] bytes = writer.toString().getBytes("UTF-8");
+    return writer.toString();
-    return IOUtils.toString(new ByteArrayInputStream(bytes));
   }
 
-  protected String createJson(DebugTab requestTab) throws IOException {
+  protected String createJson(DebugTab tab) throws IOException {
-    CircleStreamBuffer csb = new CircleStreamBuffer();
+    StringWriter writer = new StringWriter();
-    JsonGenerator gen = new JsonFactory().createGenerator(csb.getOutputStream(), JsonEncoding.UTF8);
+    JsonGenerator gen = new JsonFactory().createGenerator(writer);
-    requestTab.appendJson(gen);
+    tab.appendJson(gen);
     gen.flush();
     gen.close();
-    csb.closeWrite();
+    writer.flush();
-    return IOUtils.toString(csb.getInputStream());
+    return writer.toString();
   }
-  
-  protected void print(DebugTab tab) throws Exception{
-    System.out.println(createJson(tab));
-    System.out.println("---------------------------------------------------------");
-    System.out.println(createHtml(tab));
-  }
-
 }

lib/server-core/src/test/java/org/apache/olingo/server/core/debug/DebugTabBodyTest.java

@@ -28,10 +28,7 @@ public class DebugTabBodyTest extends AbstractDebugTabTest {
   public void nullResponseMustNotLeadToException() throws Exception {
     DebugTabBody tab = new DebugTabBody(null);
 
-    String expectedHtml = "<pre class=\"code\">\n"
-        + "ODataLibrary: No body.</pre>\n";
-
     assertEquals("null", createJson(tab));
-    assertEquals(expectedHtml, createHtml(tab));
+    assertEquals("<pre class=\"code\">\nODataLibrary: No body.\n</pre>\n", createHtml(tab));
   }
 }

lib/server-core/src/test/java/org/apache/olingo/server/core/debug/DebugTabResponseTest.java

@@ -42,7 +42,7 @@ public class DebugTabResponseTest extends AbstractDebugTabTest {
         + "</tbody>\n"
         + "</table>\n"
         + "<h2>Response Body</h2>\n"
-        + "<p>ODataLibrary: no response body</p>";
+        + "<p>ODataLibrary: no response body</p>\n";
 
     assertEquals(expectedJson, createJson(tab));
     assertEquals(expectedHtml, createHtml(tab));
@@ -71,7 +71,7 @@ public class DebugTabResponseTest extends AbstractDebugTabTest {
         + "</tbody>\n"
         + "</table>\n"
         + "<h2>Response Body</h2>\n"
-        + "<p>ODataLibrary: no response body</p>";
+        + "<p>ODataLibrary: no response body</p>\n";
     assertEquals(expectedJson, createJson(tab));
     assertEquals(expectedHtml, createHtml(tab));
   }

lib/server-core/src/test/java/org/apache/olingo/server/core/debug/DebugTabServerTest.java

@@ -18,7 +18,8 @@
  */
 package org.apache.olingo.server.core.debug;
 
-import static org.junit.Assert.*;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 
 import java.util.Collections;
 import java.util.LinkedHashMap;
@@ -35,18 +36,17 @@ public class DebugTabServerTest extends AbstractDebugTabTest {
     assertEquals("null", createJson(serverTab));
     String html = createHtml(serverTab);
     assertTrue(html.startsWith("<h2>Library Version</h2>"));
-    assertTrue(html.endsWith("<h2>Server Environment</h2>\n"));
+    assertTrue(html.contains("<h2>Server Environment</h2>\n"));
   }
 
   @Test
   public void initialServerInformationMustNotleadToException() throws Exception {
-    Map<String, String> env = Collections.emptyMap();
+    DebugTabServer serverTab = new DebugTabServer(Collections.<String, String> emptyMap());
-    DebugTabServer serverTab = new DebugTabServer(env);
 
     assertEquals("null", createJson(serverTab));
     String html = createHtml(serverTab);
     assertTrue(html.startsWith("<h2>Library Version</h2>"));
-    assertTrue(html.endsWith("<h2>Server Environment</h2>\n"));
+    assertTrue(html.contains("<h2>Server Environment</h2>\n"));
   }
 
   @Test

lib/server-core/src/test/java/org/apache/olingo/server/core/debug/ServerCoreDebuggerTest.java

@@ -18,9 +18,10 @@
  */
 package org.apache.olingo.server.core.debug;
 
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.anyString;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
@@ -30,6 +31,7 @@ import javax.servlet.http.HttpServletRequest;
 
 import org.apache.commons.io.IOUtils;
 import org.apache.olingo.commons.api.ex.ODataRuntimeException;
+import org.apache.olingo.commons.api.http.HttpStatusCode;
 import org.apache.olingo.server.api.OData;
 import org.apache.olingo.server.api.ODataResponse;
 import org.apache.olingo.server.api.debug.DebugInformation;
@@ -44,11 +46,15 @@ public class ServerCoreDebuggerTest {
   @Before
   public void setupDebugger() {
     debugger = new ServerCoreDebugger(OData.newInstance());
-    debugger.setDebugSupportProcessor(new LocalDebugProcessor());
+    DebugSupport processor = mock(DebugSupport.class);
+    when(processor.isUserAuthorized()).thenReturn(true);
+    when(processor.createDebugResponse(anyString(), any(DebugInformation.class)))
+        .thenThrow(new ODataRuntimeException("Test"));
+    debugger.setDebugSupportProcessor(processor);
   }
 
   @Test
-  public void standardIsDebugModeIsFlase() {
+  public void standardIsDebugModeIsFalse() {
     assertFalse(debugger.isDebugMode());
   }
 
@@ -86,36 +92,20 @@ public class ServerCoreDebuggerTest {
   }
 
   @Test
-  public void testFailResponse() throws IOException {
+  public void failResponse() throws IOException {
     HttpServletRequest request = mock(HttpServletRequest.class);
     when(request.getParameter(DebugSupport.ODATA_DEBUG_QUERY_PARAMETER)).thenReturn(DebugSupport.ODATA_DEBUG_JSON);
     debugger.resolveDebugMode(request);
-    ODataResponse debugResponse = debugger.createDebugResponse(null, null, null, null, null, null);
+    ODataResponse debugResponse = debugger.createDebugResponse(null, null, null, null, null);
-    assertEquals(500, debugResponse.getStatusCode());
+    assertEquals(HttpStatusCode.INTERNAL_SERVER_ERROR.getStatusCode(), debugResponse.getStatusCode());
     assertEquals("ODataLibrary: Could not assemble debug response.", IOUtils.toString(debugResponse.getContent()));
   }
 
   @Test
   public void noDebugModeCreateDebugResponseCallMustDoNothing() {
     ODataResponse odResponse = new ODataResponse();
-    ODataResponse debugResponse = debugger.createDebugResponse(null, null, null, odResponse, null, null);
+    ODataResponse debugResponse = debugger.createDebugResponse(null, odResponse, null, null, null);
 
-    assertTrue(odResponse == debugResponse);
+    assertEquals(odResponse, debugResponse);
-  }
-
-  public class LocalDebugProcessor implements DebugSupport {
-
-    @Override
-    public void init(OData odata) {}
-
-    @Override
-    public boolean isUserAuthorized() {
-      return true;
-    }
-
-    @Override
-    public ODataResponse createDebugResponse(String debugFormat, DebugInformation debugInfo) {
-      throw new ODataRuntimeException("Test");
-    }
   }
 }