Cleanup and improve HttpExceptions.

app/src/main/java/at/bitfire/davdroid/journalmanager/BaseManager.java

@@ -4,6 +4,7 @@ import org.apache.commons.codec.Charsets;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.net.HttpURLConnection;
 import java.util.logging.Level;
 
 import at.bitfire.davdroid.App;
@@ -36,10 +37,10 @@ abstract class BaseManager {
 
         if (!response.isSuccessful()) {
             switch (response.code()) {
-                case 401:
+                case HttpURLConnection.HTTP_UNAUTHORIZED:
                     throw new Exceptions.UnauthorizedException("Failed to connect");
                 default:
-                    throw new Exceptions.HttpException("Error getting");
+                    throw new Exceptions.HttpException(response);
             }
         }
 

app/src/main/java/at/bitfire/davdroid/journalmanager/Exceptions.java

@@ -1,5 +1,16 @@
 package at.bitfire.davdroid.journalmanager;
 
+import java.io.IOException;
+import java.io.Serializable;
+import java.net.HttpURLConnection;
+
+import at.bitfire.cert4android.Constants;
+import okhttp3.Headers;
+import okhttp3.Request;
+import okhttp3.Response;
+import okhttp3.ResponseBody;
+import okio.Buffer;
+
 public class Exceptions {
     public static class UnauthorizedException extends HttpException {
         public UnauthorizedException(String message) {
@@ -13,19 +24,103 @@ public class Exceptions {
         }
     }
 
-    public static class HttpException extends Exception {
-        public HttpException(String message) {
-            super(message);
-        }
-
-        public HttpException(int status, String message) {
-            super(status + " " + message);
-        }
-    }
-
     public static class IntegrityException extends Exception {
         public IntegrityException(String message) {
             super(message);
         }
     }
+
+    public static class HttpException extends Exception implements Serializable {
+
+        public final int status;
+        public final String message;
+
+        public final String request, response;
+
+        public HttpException(String message) {
+            super(message);
+            this.message = message;
+
+            this.status = -1;
+            this.request = this.response = null;
+        }
+
+        public HttpException(int status, String message) {
+            super(status + " " + message);
+            this.status = status;
+            this.message = message;
+
+            request = response = null;
+        }
+
+        public HttpException(Response response) {
+            super(response.code() + " " + response.message());
+
+            status = response.code();
+            message = response.message();
+
+        /* As we don't know the media type and character set of request and response body,
+           only printable ASCII characters will be shown in clear text. Other octets will
+           be shown as "[xx]" where xx is the hex value of the octet.
+         */
+
+            // format request
+            Request request = response.request();
+            StringBuilder formatted = new StringBuilder();
+            formatted.append(request.method()).append(" ").append(request.url().encodedPath()).append("\n");
+            Headers headers = request.headers();
+            for (String name : headers.names()) {
+                for (String value : headers.values(name)) {
+                    /* Redact authorization token. */
+                    if (name.equals("Authorization")) {
+                        formatted.append(name).append(": ").append("XXXXXX").append("\n");
+                    } else {
+                        formatted.append(name).append(": ").append(value).append("\n");
+                    }
+                }
+            }
+            if (request.body() != null)
+                try {
+                    formatted.append("\n");
+                    Buffer buffer = new Buffer();
+                    request.body().writeTo(buffer);
+                    while (!buffer.exhausted())
+                        appendByte(formatted, buffer.readByte());
+                } catch (IOException e) {
+                    Constants.log.warning("Couldn't read request body");
+                }
+            this.request = formatted.toString();
+
+            // format response
+            formatted = new StringBuilder();
+            formatted.append(response.protocol()).append(" ").append(response.code()).append(" ").append(response.message()).append("\n");
+            headers = response.headers();
+            for (String name : headers.names())
+                for (String value : headers.values(name))
+                    formatted.append(name).append(": ").append(value).append("\n");
+            if (response.body() != null) {
+                ResponseBody body = response.body();
+                try {
+                    formatted.append("\n");
+                    for (byte b : body.bytes())
+                        appendByte(formatted, b);
+                } catch (IOException e) {
+                    Constants.log.warning("Couldn't read response body");
+                }
+                body.close();
+            }
+            this.response = formatted.toString();
+        }
+
+        private static void appendByte(StringBuilder formatted, byte b) {
+            if (b == '\r')
+                formatted.append("[CR]");
+            else if (b == '\n')
+                formatted.append("[LF]\n");
+            else if (b >= 0x20 && b <= 0x7E)     // printable ASCII
+                formatted.append((char) b);
+            else
+                formatted.append("[" + Integer.toHexString((int) b & 0xff) + "]");
+        }
+    }
 }

app/src/main/java/at/bitfire/davdroid/journalmanager/JournalAuthenticator.java

@@ -1,6 +1,7 @@
 package at.bitfire.davdroid.journalmanager;
 
 import java.io.IOException;
+import java.net.HttpURLConnection;
 import java.util.logging.Level;
 
 import at.bitfire.davdroid.App;
@@ -44,10 +45,10 @@ public class JournalAuthenticator {
             Response response = client.newCall(request).execute();
             if (response.isSuccessful()) {
                 return GsonHelper.gson.fromJson(response.body().charStream(), AuthResponse.class).token;
-            } else if (response.code() == 400) {
+            } else if (response.code() == HttpURLConnection.HTTP_BAD_REQUEST) {
                 throw new Exceptions.UnauthorizedException("Username or password incorrect");
             } else {
-                throw new Exceptions.HttpException("Error authenticating");
+                throw new Exceptions.HttpException(response);
             }
         } catch (IOException e) {
             App.log.log(Level.SEVERE, "Couldn't download external resource", e);

app/src/main/java/at/bitfire/davdroid/ui/DebugInfoActivity.java

@@ -181,13 +181,11 @@ public class DebugInfoActivity extends AppCompatActivity implements LoaderManage
                 report.append("Authority: ").append(authority).append("\n");
 
             if (throwable instanceof HttpException) {
-                /* FIXME
                 HttpException http = (HttpException)throwable;
                 if (http.request != null)
                     report.append("\nHTTP REQUEST:\n").append(http.request).append("\n\n");
                 if (http.response != null)
                     report.append("HTTP RESPONSE:\n").append(http.response).append("\n");
-                    */
             }
 
             if (throwable != null)