diff --git a/gson/src/main/java/com/google/gson/DelegatingJsonElementVisitor.java b/gson/src/main/java/com/google/gson/DelegatingJsonElementVisitor.java
index 74be57b6..9bdffc0e 100644
--- a/gson/src/main/java/com/google/gson/DelegatingJsonElementVisitor.java
+++ b/gson/src/main/java/com/google/gson/DelegatingJsonElementVisitor.java
@@ -16,6 +16,8 @@
 
 package com.google.gson;
 
+import java.io.IOException;
+
 /**
  * A simple implementation of the {@link JsonElementVisitor} that simply delegates the method
  * invocation onto a {@code delegate} instance of the {@link JsonElementVisitor}.  This object
@@ -50,62 +52,66 @@ class DelegatingJsonElementVisitor implements JsonElementVisitor {
     this.delegate = delegate;
   }
 
-  public void endArray(JsonArray array) {
+  public void endArray(JsonArray array) throws IOException {
     delegate.endArray(array);
   }
 
-  public void endObject(JsonObject object) {
+  public void endObject(JsonObject object) throws IOException {
     delegate.endObject(object);
   }
 
-  public void startArray(JsonArray array) {
+  public void startArray(JsonArray array) throws IOException {
     delegate.startArray(array);
   }
 
-  public void startObject(JsonObject object) {
+  public void startObject(JsonObject object) throws IOException {
     delegate.startObject(object);
   }
 
-  public void visitArrayMember(JsonArray parent, JsonPrimitive member, boolean isFirst) {
+  public void visitArrayMember(JsonArray parent, JsonPrimitive member, 
+      boolean isFirst) throws IOException {
     delegate.visitArrayMember(parent, member, isFirst);
   }
 
-  public void visitArrayMember(JsonArray parent, JsonArray member, boolean isFirst) {
+  public void visitArrayMember(JsonArray parent, JsonArray member, 
+      boolean isFirst) throws IOException {
     delegate.visitArrayMember(parent, member, isFirst);
   }
 
-  public void visitArrayMember(JsonArray parent, JsonObject member, boolean isFirst) {
+  public void visitArrayMember(JsonArray parent, JsonObject member, 
+      boolean isFirst) throws IOException {
     delegate.visitArrayMember(parent, member, isFirst);
   }
 
-  public void visitObjectMember(
-      JsonObject parent, String memberName, JsonPrimitive member, boolean isFirst) {
+  public void visitObjectMember(JsonObject parent, String memberName, JsonPrimitive member, 
+      boolean isFirst) throws IOException {
     delegate.visitObjectMember(parent, memberName, member, isFirst);
   }
 
-  public void visitObjectMember(
-      JsonObject parent, String memberName, JsonArray member, boolean isFirst) {
+  public void visitObjectMember(JsonObject parent, String memberName, JsonArray member, 
+      boolean isFirst) throws IOException {
     delegate.visitObjectMember(parent, memberName, member, isFirst);
   }
 
-  public void visitObjectMember(
-      JsonObject parent, String memberName, JsonObject member, boolean isFirst) {
+  public void visitObjectMember(JsonObject parent, String memberName, JsonObject member, 
+      boolean isFirst) throws IOException {
     delegate.visitObjectMember(parent, memberName, member, isFirst);
   }
 
-  public void visitNullObjectMember(JsonObject parent, String memberName, boolean isFirst) {
+  public void visitNullObjectMember(JsonObject parent, String memberName, 
+      boolean isFirst) throws IOException {
     delegate.visitNullObjectMember(parent, memberName, isFirst);
   }
 
-  public void visitPrimitive(JsonPrimitive primitive) {
+  public void visitPrimitive(JsonPrimitive primitive) throws IOException {
     delegate.visitPrimitive(primitive);
   }
 
-  public void visitNull() {
+  public void visitNull() throws IOException {
     delegate.visitNull();
   }
 
-  public void visitNullArrayMember(JsonArray parent, boolean isFirst) {
+  public void visitNullArrayMember(JsonArray parent, boolean isFirst) throws IOException {
     delegate.visitNullArrayMember(parent, isFirst);
   }
 }
diff --git a/gson/src/main/java/com/google/gson/Gson.java b/gson/src/main/java/com/google/gson/Gson.java
index 11e5dfaf..78b3456c 100644
--- a/gson/src/main/java/com/google/gson/Gson.java
+++ b/gson/src/main/java/com/google/gson/Gson.java
@@ -17,7 +17,6 @@
 package com.google.gson;
 
 import java.io.IOException;
-import java.io.PrintWriter;
 import java.io.Reader;
 import java.io.StringReader;
 import java.io.StringWriter;
@@ -191,7 +190,7 @@ public final class Gson {
    * of Java. Note that this method works fine if the any of the object fields are of generic type,
    * just the object itself should not be of a generic type. If the object is of generic type, use
    * {@link #toJson(Object, Type)} instead. If you want to write out the object to a
-   * {@link Writer}, use {@link #toJson(Object, Writer)} instead.
+   * {@link Writer}, use {@link #toJson(Object, Appendable)} instead.
    *
    * @param src the object for which Json representation is to be created setting for Gson
    * @return Json representation of {@code src}.
@@ -207,7 +206,7 @@ public final class Gson {
    * This method serializes the specified object, including those of generic types, into its
    * equivalent Json representation. This method must be used if the specified object is a generic
    * type. For non-generic objects, use {@link #toJson(Object)} instead. If you want to write out
-   * the object to a {@link Writer}, use {@link #toJson(Object, Type, Writer)} instead.
+   * the object to a {@link Appendable}, use {@link #toJson(Object, Type, Appendable)} instead.
    *
    * @param src the object for which JSON representation is to be created
    * @param typeOfSrc The specific genericized type of src. You can obtain
@@ -231,24 +230,28 @@ public final class Gson {
    * {@code getClass()} loses the generic type information because of the Type Erasure feature
    * of Java. Note that this method works fine if the any of the object fields are of generic type,
    * just the object itself should not be of a generic type. If the object is of generic type, use
-   * {@link #toJson(Object, Type, Writer)} instead.
+   * {@link #toJson(Object, Type, Appendable)} instead.
    *
    * @param src the object for which Json representation is to be created setting for Gson
    * @param writer Writer to which the Json representation needs to be written
    * @since 1.2
    */
-  public void toJson(Object src, Writer writer) {
-    if (src != null) {
-      toJson(src, src.getClass(), writer);
-    } else if (serializeNulls) {
-      writeOutNullString(writer);
+  public void toJson(Object src, Appendable writer) {
+    try {
+      if (src != null) {
+        toJson(src, src.getClass(), writer);
+      } else if (serializeNulls) {
+        writeOutNullString(writer);
+      }
+    } catch (IOException ioe) {
+      throw new RuntimeException(ioe);
     }
   }
 
   /**
    * This method serializes the specified object, including those of generic types, into its
    * equivalent Json representation. This method must be used if the specified object is a generic
-   * type. For non-generic objects, use {@link #toJson(Object, Writer)} instead.
+   * type. For non-generic objects, use {@link #toJson(Object, Appendable)} instead.
    *
    * @param src the object for which JSON representation is to be created
    * @param typeOfSrc The specific genericized type of src. You can obtain
@@ -260,18 +263,22 @@ public final class Gson {
    * @param writer Writer to which the Json representation of src needs to be written.
    * @since 1.2
    */
-  public void toJson(Object src, Type typeOfSrc, Writer writer) {
-    if (src != null) {
-      JsonSerializationContext context = new JsonSerializationContextDefault(
-          createDefaultObjectNavigatorFactory(), serializeNulls, serializers);
-      JsonElement jsonElement = context.serialize(src, typeOfSrc);
+  public void toJson(Object src, Type typeOfSrc, Appendable writer) {
+    try {
+      if (src != null) {
+        JsonSerializationContext context = new JsonSerializationContextDefault(
+            createDefaultObjectNavigatorFactory(), serializeNulls, serializers);
+        JsonElement jsonElement = context.serialize(src, typeOfSrc);
 
-      //TODO(Joel): instead of navigating the "JsonElement" inside the formatter, do it here.
-      formatter.format(jsonElement, new PrintWriter(writer), serializeNulls);
-    } else {
-      if (serializeNulls) {
-        writeOutNullString(writer);
+        //TODO(Joel): instead of navigating the "JsonElement" inside the formatter, do it here.
+        formatter.format(jsonElement, writer, serializeNulls);
+      } else {
+        if (serializeNulls) {
+          writeOutNullString(writer);
+        }
       }
+    } catch (IOException ioe) {
+      throw new RuntimeException(ioe);
     }
   }
 
@@ -388,13 +395,8 @@ public final class Gson {
    *
    * @param writer the object to append the null value to
    */
-  private void writeOutNullString(Writer writer) {
-    try {
-      writer.append(NULL_STRING);
-    } catch (IOException e) {
-      // Should this be a different exception???
-      throw new JsonParseException(e);
-    }
+  private void writeOutNullString(Appendable writer) throws IOException {
+    writer.append(NULL_STRING);
   }
   
   @Override 
diff --git a/gson/src/main/java/com/google/gson/JsonCompactFormatter.java b/gson/src/main/java/com/google/gson/JsonCompactFormatter.java
index 5f2651a6..561a2bb0 100644
--- a/gson/src/main/java/com/google/gson/JsonCompactFormatter.java
+++ b/gson/src/main/java/com/google/gson/JsonCompactFormatter.java
@@ -16,7 +16,7 @@
 
 package com.google.gson;
 
-import java.io.PrintWriter;
+import java.io.IOException;
 
 /**
  * Formats Json in a compact way eliminating all unnecessary whitespace.
@@ -26,61 +26,64 @@ import java.io.PrintWriter;
 final class JsonCompactFormatter implements JsonFormatter {
 
   private static class FormattingVisitor implements JsonElementVisitor {
-    private final PrintWriter writer;
+    private final Appendable writer;
     private final boolean serializeNulls;
 
-    FormattingVisitor(PrintWriter writer, boolean serializeNulls) {
+    FormattingVisitor(Appendable writer, boolean serializeNulls) {
       this.writer = writer;
       this.serializeNulls = serializeNulls;
     }
 
-    public void visitPrimitive(JsonPrimitive primitive) {
+    public void visitPrimitive(JsonPrimitive primitive) throws IOException {
       writer.append(primitive.toString());
     }
 
-    public void visitNull() {
+    public void visitNull() throws IOException {
       writer.append("null");
     }
     
-    public void startArray(JsonArray array) {
+    public void startArray(JsonArray array) throws IOException {
       writer.append('[');
     }
 
-    public void visitArrayMember(JsonArray parent, JsonPrimitive member, boolean isFirst) {
+    public void visitArrayMember(JsonArray parent, JsonPrimitive member, 
+        boolean isFirst) throws IOException {
       if (!isFirst) {
         writer.append(',');
       }
       writer.append(member.toString());
     }
 
-    public void visitArrayMember(JsonArray parent, JsonArray member, boolean isFirst) {
+    public void visitArrayMember(JsonArray parent, JsonArray member, 
+        boolean isFirst) throws IOException {
       if (!isFirst) {
         writer.append(',');
       }
     }
 
-    public void visitArrayMember(JsonArray parent, JsonObject member, boolean isFirst) {
+    public void visitArrayMember(JsonArray parent, JsonObject member, 
+        boolean isFirst) throws IOException {
       if (!isFirst) {
         writer.append(',');
       }
     }
 
-    public void visitNullArrayMember(JsonArray parent, boolean isFirst) {
+    public void visitNullArrayMember(JsonArray parent, boolean isFirst) throws IOException {
       if (!isFirst) {
         writer.append(',');
       }
     }
 
-    public void endArray(JsonArray array) {
+    public void endArray(JsonArray array) throws IOException {
       writer.append(']');
     }
 
-    public void startObject(JsonObject object) {
+    public void startObject(JsonObject object) throws IOException {
       writer.append('{');
     }
 
     public void visitObjectMember(JsonObject parent, String memberName, JsonPrimitive member,
-        boolean isFirst) {
+        boolean isFirst) throws IOException {
       if (!isFirst) {
         writer.append(',');
       }
@@ -91,7 +94,7 @@ final class JsonCompactFormatter implements JsonFormatter {
     }
 
     public void visitObjectMember(JsonObject parent, String memberName, JsonArray member,
-        boolean isFirst) {
+        boolean isFirst) throws IOException {
       if (!isFirst) {
         writer.append(',');
       }
@@ -101,7 +104,7 @@ final class JsonCompactFormatter implements JsonFormatter {
     }
 
     public void visitObjectMember(JsonObject parent, String memberName, JsonObject member,
-        boolean isFirst) {
+        boolean isFirst) throws IOException {
       if (!isFirst) {
         writer.append(',');
       }
@@ -110,18 +113,20 @@ final class JsonCompactFormatter implements JsonFormatter {
       writer.append("\":");
     }
 
-    public void visitNullObjectMember(JsonObject parent, String memberName, boolean isFirst) {
+    public void visitNullObjectMember(JsonObject parent, String memberName, 
+        boolean isFirst) throws IOException {
       if (serializeNulls) {
         visitObjectMember(parent, memberName, (JsonObject) null, isFirst);
       }      
     }
     
-    public void endObject(JsonObject object) {
+    public void endObject(JsonObject object) throws IOException {
       writer.append('}');
     }
   }
 
-  public void format(JsonElement root, PrintWriter writer, boolean serializeNulls) {
+  public void format(JsonElement root, Appendable writer, 
+      boolean serializeNulls) throws IOException {
     if (root == null) {
       return;
     }
diff --git a/gson/src/main/java/com/google/gson/JsonElementVisitor.java b/gson/src/main/java/com/google/gson/JsonElementVisitor.java
index 29d908a3..4d5fda19 100644
--- a/gson/src/main/java/com/google/gson/JsonElementVisitor.java
+++ b/gson/src/main/java/com/google/gson/JsonElementVisitor.java
@@ -16,27 +16,32 @@
 
 package com.google.gson;
 
+import java.io.IOException;
+
 /**
  * Definition of a visitor for a JsonElement tree.
  * 
  * @author Inderjeet Singh
  */
 interface JsonElementVisitor {
-  void visitPrimitive(JsonPrimitive primitive);
-  void visitNull();
+  void visitPrimitive(JsonPrimitive primitive) throws IOException;
+  void visitNull() throws IOException;
 
-  void startArray(JsonArray array);
-  void visitArrayMember(JsonArray parent, JsonPrimitive member, boolean isFirst);
-  void visitArrayMember(JsonArray parent, JsonArray member, boolean isFirst);
-  void visitArrayMember(JsonArray parent, JsonObject member, boolean isFirst);
-  void visitNullArrayMember(JsonArray parent, boolean isFirst);
-  void endArray(JsonArray array);
+  void startArray(JsonArray array) throws IOException;
+  void visitArrayMember(JsonArray parent, JsonPrimitive member, boolean isFirst) throws IOException;
+  void visitArrayMember(JsonArray parent, JsonArray member, boolean isFirst) throws IOException;
+  void visitArrayMember(JsonArray parent, JsonObject member, boolean isFirst) throws IOException;
+  void visitNullArrayMember(JsonArray parent, boolean isFirst) throws IOException;
+  void endArray(JsonArray array) throws IOException;
   
-  void startObject(JsonObject object);
+  void startObject(JsonObject object) throws IOException;
   void visitObjectMember(JsonObject parent, String memberName, JsonPrimitive member, 
-      boolean isFirst);
-  void visitObjectMember(JsonObject parent, String memberName, JsonArray member, boolean isFirst);
-  void visitObjectMember(JsonObject parent, String memberName, JsonObject member, boolean isFirst);
-  void visitNullObjectMember(JsonObject parent, String memberName, boolean isFirst);
-  void endObject(JsonObject object);
+      boolean isFirst) throws IOException;
+  void visitObjectMember(JsonObject parent, String memberName, JsonArray member, 
+      boolean isFirst) throws IOException;
+  void visitObjectMember(JsonObject parent, String memberName, JsonObject member, 
+      boolean isFirst) throws IOException;
+  void visitNullObjectMember(JsonObject parent, String memberName, 
+      boolean isFirst) throws IOException;
+  void endObject(JsonObject object) throws IOException;
 }
\ No newline at end of file
diff --git a/gson/src/main/java/com/google/gson/JsonEscapingVisitor.java b/gson/src/main/java/com/google/gson/JsonEscapingVisitor.java
index 6630f913..5f282a18 100644
--- a/gson/src/main/java/com/google/gson/JsonEscapingVisitor.java
+++ b/gson/src/main/java/com/google/gson/JsonEscapingVisitor.java
@@ -16,6 +16,8 @@
 
 package com.google.gson;
 
+import java.io.IOException;
+
 /**
  * Performs JSON escaping and passes on the new escaped value to the delegate
  * {@link JsonElementVisitor}.
@@ -34,18 +36,19 @@ class JsonEscapingVisitor extends DelegatingJsonElementVisitor {
   }
 
   @Override
-  public void visitArrayMember(JsonArray parent, JsonPrimitive member, boolean isFirst) {
+  public void visitArrayMember(JsonArray parent, JsonPrimitive member, 
+      boolean isFirst) throws IOException {
     super.visitArrayMember(parent, escapeJsonPrimitive(member), isFirst);
   }
 
   @Override
-  public void visitObjectMember(
-      JsonObject parent, String memberName, JsonPrimitive member, boolean isFirst) {
+  public void visitObjectMember(JsonObject parent, String memberName, JsonPrimitive member, 
+      boolean isFirst) throws IOException {
     super.visitObjectMember(parent, memberName, escapeJsonPrimitive(member), isFirst);
   }
 
   @Override
-  public void visitPrimitive(JsonPrimitive primitive) {
+  public void visitPrimitive(JsonPrimitive primitive) throws IOException {
     super.visitPrimitive(escapeJsonPrimitive(primitive));
   }
 
diff --git a/gson/src/main/java/com/google/gson/JsonFormatter.java b/gson/src/main/java/com/google/gson/JsonFormatter.java
index 66e01a1b..6590b6e3 100644
--- a/gson/src/main/java/com/google/gson/JsonFormatter.java
+++ b/gson/src/main/java/com/google/gson/JsonFormatter.java
@@ -16,7 +16,7 @@
 
 package com.google.gson;
 
-import java.io.PrintWriter;
+import java.io.IOException;
 
 /**
  * Common interface for a formatter for Json. 
@@ -33,5 +33,6 @@ interface JsonFormatter {
    * @param writer the writer to output the formatter JSON to.
    * @param serializeNulls serialize null values in the output.
    */
-  public void format(JsonElement root, PrintWriter writer, boolean serializeNulls);
+  public void format(JsonElement root, Appendable writer, 
+      boolean serializeNulls) throws IOException;
 }
diff --git a/gson/src/main/java/com/google/gson/JsonPrintFormatter.java b/gson/src/main/java/com/google/gson/JsonPrintFormatter.java
index b7194e89..6f747fd4 100644
--- a/gson/src/main/java/com/google/gson/JsonPrintFormatter.java
+++ b/gson/src/main/java/com/google/gson/JsonPrintFormatter.java
@@ -16,7 +16,7 @@
 
 package com.google.gson;
 
-import java.io.PrintWriter;
+import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -48,10 +48,10 @@ final class JsonPrintFormatter implements JsonFormatter {
   }
 
   private class JsonWriter {
-    private final PrintWriter writer;
+    private final Appendable writer;
     private StringBuilder line;
     private int level;
-    JsonWriter(PrintWriter writer) {
+    JsonWriter(Appendable writer) {
       this.writer = writer;
       level = 0;
       line = new StringBuilder();
@@ -67,17 +67,17 @@ final class JsonPrintFormatter implements JsonFormatter {
       getLine().append(value);
     }
 
-    void fieldSeparator() {
+    void fieldSeparator() throws IOException {
       getLine().append(':');
       breakLineIfNeeded();
     }
 
-    void elementSeparator() {
+    void elementSeparator() throws IOException {
       getLine().append(',');
       breakLineIfNeeded();
     }
 
-    void beginObject() {
+    void beginObject() throws IOException {
       ++level;
       breakLineIfNeeded();
       getLine().append('{');
@@ -88,7 +88,7 @@ final class JsonPrintFormatter implements JsonFormatter {
       --level;
     }
 
-    void beginArray() {
+    void beginArray() throws IOException {
       ++level;
       breakLineIfNeeded();
       getLine().append('[');
@@ -99,13 +99,13 @@ final class JsonPrintFormatter implements JsonFormatter {
       --level;
     }
 
-    private void breakLineIfNeeded() {
+    private void breakLineIfNeeded() throws IOException {
       if (getLine().length() > printMargin - rightMargin) {
         finishLine();
       }
     }
 
-    private void finishLine() {
+    private void finishLine() throws IOException {
       if (line != null) {
         writer.append(line).append("\n");
       }
@@ -143,7 +143,7 @@ final class JsonPrintFormatter implements JsonFormatter {
       this.firstObjectMember = new HashMap<Integer, Boolean>();
     }
 
-    private void addCommaCheckingFirst(Map<Integer, Boolean> first) {
+    private void addCommaCheckingFirst(Map<Integer, Boolean> first) throws IOException {
       if (first.get(level) != Boolean.FALSE) {
         first.put(level, false);
       } else {
@@ -151,25 +151,28 @@ final class JsonPrintFormatter implements JsonFormatter {
       }
     }
 
-    public void startArray(JsonArray array) {
+    public void startArray(JsonArray array) throws IOException {
       firstArrayElement.put(++level, true);
       writer.beginArray();
     }
 
-    public void visitArrayMember(JsonArray parent, JsonPrimitive member, boolean isFirst) {
+    public void visitArrayMember(JsonArray parent, JsonPrimitive member, 
+        boolean isFirst) throws IOException {
       addCommaCheckingFirst(firstArrayElement);
       writer.value(member.toString());
     }
 
-    public void visitArrayMember(JsonArray parent, JsonArray member, boolean first) {
+    public void visitArrayMember(JsonArray parent, JsonArray member, 
+        boolean first) throws IOException {
       addCommaCheckingFirst(firstArrayElement);
     }
 
-    public void visitArrayMember(JsonArray parent, JsonObject member, boolean first) {
+    public void visitArrayMember(JsonArray parent, JsonObject member, 
+        boolean first) throws IOException {
       addCommaCheckingFirst(firstArrayElement);
     }
 
-    public void visitNullArrayMember(JsonArray parent, boolean isFirst) {
+    public void visitNullArrayMember(JsonArray parent, boolean isFirst) throws IOException {
       addCommaCheckingFirst(firstArrayElement);
     }
 
@@ -178,13 +181,13 @@ final class JsonPrintFormatter implements JsonFormatter {
       writer.endArray();
     }
 
-    public void startObject(JsonObject object) {
+    public void startObject(JsonObject object) throws IOException {
       firstObjectMember.put(level, true);
       writer.beginObject();
     }
 
     public void visitObjectMember(JsonObject parent, String memberName, JsonPrimitive member, 
-        boolean isFirst) {
+        boolean isFirst) throws IOException {
       addCommaCheckingFirst(firstObjectMember);
       writer.key(memberName);
       writer.fieldSeparator();
@@ -192,20 +195,21 @@ final class JsonPrintFormatter implements JsonFormatter {
     }
 
     public void visitObjectMember(JsonObject parent, String memberName, JsonArray member, 
-        boolean isFirst) {
+        boolean isFirst) throws IOException {
       addCommaCheckingFirst(firstObjectMember);
       writer.key(memberName);
       writer.fieldSeparator();
     }
 
     public void visitObjectMember(JsonObject parent, String memberName, JsonObject member, 
-        boolean isFirst) {
+        boolean isFirst) throws IOException {
       addCommaCheckingFirst(firstObjectMember);
       writer.key(memberName);
       writer.fieldSeparator();
     }
 
-    public void visitNullObjectMember(JsonObject parent, String memberName, boolean isFirst) {
+    public void visitNullObjectMember(JsonObject parent, String memberName, 
+        boolean isFirst) throws IOException {
       if (serializeNulls) {
         visitObjectMember(parent, memberName, (JsonObject) null, isFirst);
       }
@@ -224,7 +228,8 @@ final class JsonPrintFormatter implements JsonFormatter {
     }
   }
 
-  public void format(JsonElement root, PrintWriter writer, boolean serializeNulls) {
+  public void format(JsonElement root, Appendable writer, 
+      boolean serializeNulls) throws IOException {
     if (root == null) {
       return;
     }
diff --git a/gson/src/main/java/com/google/gson/JsonTreeNavigator.java b/gson/src/main/java/com/google/gson/JsonTreeNavigator.java
index 945f2a30..88d5977e 100644
--- a/gson/src/main/java/com/google/gson/JsonTreeNavigator.java
+++ b/gson/src/main/java/com/google/gson/JsonTreeNavigator.java
@@ -16,6 +16,7 @@
 
 package com.google.gson;
 
+import java.io.IOException;
 import java.util.Map;
 
 /**
@@ -32,7 +33,7 @@ final class JsonTreeNavigator {
     this.visitNulls = visitNulls;
   }
   
-  public void navigate(JsonElement element) {
+  public void navigate(JsonElement element) throws IOException {
     if (element == null || element.isJsonNull()) {
       visitor.visitNull();
     } else if (element.isJsonArray()) {
@@ -66,7 +67,7 @@ final class JsonTreeNavigator {
    * Returns true if the child was visited, false if it was skipped.
    */
   private boolean visitChild(JsonObject parent, String childName, JsonElement child, 
-      boolean isFirst) {
+      boolean isFirst) throws IOException {
     if (child != null) { 
       if (child.isJsonNull()) {
         if (visitNulls) {
@@ -93,7 +94,7 @@ final class JsonTreeNavigator {
   /**
    * Returns true if the child was visited, false if it was skipped.
    */
-  private void visitChild(JsonArray parent, JsonElement child, boolean isFirst) {
+  private void visitChild(JsonArray parent, JsonElement child, boolean isFirst) throws IOException {
     if (child == null || child.isJsonNull()) {
       visitor.visitNullArrayMember(parent, isFirst);
       navigate(null);