Catch all exceptions when processing AJAX requests.

[Sone.git] / src / main / java / net / pterodactylus / sone / web / ajax / JsonPage.java

diff --git a/src/main/java/net/pterodactylus/sone/web/ajax/JsonPage.java b/src/main/java/net/pterodactylus/sone/web/ajax/JsonPage.java
index 7c3abdb..910abd5 100644 (file)
--- a/src/main/java/net/pterodactylus/sone/web/ajax/JsonPage.java
+++ b/src/main/java/net/pterodactylus/sone/web/ajax/JsonPage.java
@@ -1,5 +1,5 @@
 /*
- * Sone - JsonPage.java - Copyright © 2010 David Roden
+ * Sone - JsonPage.java - Copyright © 2010–2012 David Roden
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -17,13 +17,17 @@
 
 package net.pterodactylus.sone.web.ajax;
 
+import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.io.OutputStreamWriter;
+import java.io.PrintWriter;
 import java.net.URI;
 
 import net.pterodactylus.sone.data.Sone;
 import net.pterodactylus.sone.web.WebInterface;
 import net.pterodactylus.sone.web.page.FreenetPage;
 import net.pterodactylus.sone.web.page.FreenetRequest;
+import net.pterodactylus.util.io.Closer;
 import net.pterodactylus.util.json.JsonObject;
 import net.pterodactylus.util.json.JsonUtils;
 import net.pterodactylus.util.web.Page;
@@ -139,6 +143,7 @@ public abstract class JsonPage implements FreenetPage {
         * @return {@code true} if the form password (given as “formPassword”) is
         *         required, {@code false} otherwise
         */
+       @SuppressWarnings("static-method")
        protected boolean needsFormPassword() {
                return true;
        }
@@ -149,6 +154,7 @@ public abstract class JsonPage implements FreenetPage {
         * @return {@code true} if the user needs to be logged in to use this page,
         *         {@code false} otherwise
         */
+       @SuppressWarnings("static-method")
        protected boolean requiresLogin() {
                return true;
        }
@@ -162,7 +168,7 @@ public abstract class JsonPage implements FreenetPage {
         *
         * @return A reply signaling success
         */
-       protected JsonObject createSuccessJsonObject() {
+       protected static JsonObject createSuccessJsonObject() {
                return new JsonObject().put("success", true);
        }
 
@@ -173,7 +179,7 @@ public abstract class JsonPage implements FreenetPage {
         *            The error that has occured
         * @return The JSON object, signalling failure and the error code
         */
-       protected JsonObject createErrorJsonObject(String error) {
+       protected static JsonObject createErrorJsonObject(String error) {
                return new JsonObject().put("success", false).put("error", error);
        }
 
@@ -216,8 +222,12 @@ public abstract class JsonPage implements FreenetPage {
                                return response.setStatusCode(403).setStatusText("Forbidden").setContentType("application/json").write(JsonUtils.format(new JsonObject().put("success", false).put("error", "auth-required")));
                        }
                }
-               JsonObject jsonObject = createJsonObject(request);
-               return response.setStatusCode(200).setStatusText("OK").setContentType("application/json").write(JsonUtils.format(jsonObject));
+               try {
+                       JsonObject jsonObject = createJsonObject(request);
+                       return response.setStatusCode(200).setStatusText("OK").setContentType("application/json").write(JsonUtils.format(jsonObject));
+               } catch (Exception e1) {
+                       return response.setStatusCode(500).setStatusText(e1.getMessage()).setContentType("text/plain").write(dumpStackTrace(e1));
+               }
        }
 
        /**
@@ -228,4 +238,36 @@ public abstract class JsonPage implements FreenetPage {
                return false;
        }
 
+       //
+       // PRIVATE METHODS
+       //
+
+       /**
+        * Returns a byte array containing the stack trace of the given throwable.
+        *
+        * @param t
+        *            The throwable whose stack trace to dump into an array
+        * @return The array with the stack trace, or an empty array if the stack
+        *         trace could not be dumped
+        */
+       private static byte[] dumpStackTrace(Throwable t) {
+               ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
+               OutputStreamWriter writer = null;
+               PrintWriter printWriter = null;
+               try {
+                       writer = new OutputStreamWriter(byteArrayOutputStream, "uTF-8");
+                       printWriter = new PrintWriter(writer);
+                       t.printStackTrace(printWriter);
+                       byteArrayOutputStream.flush();
+                       return byteArrayOutputStream.toByteArray();
+               } catch (IOException ioe1) {
+                       /* quite not possible. */
+                       return new byte[0];
+               } finally {
+                       Closer.close(printWriter);
+                       Closer.close(writer);
+                       Closer.close(byteArrayOutputStream);
+               }
+       }
+
 }