Improved exception handling.

json-path/src/main/java/com/jayway/jsonpath/internal/filter/ArrayIndexFilter.java

@@ -14,6 +14,7 @@
  */
 package com.jayway.jsonpath.internal.filter;
 
+import com.jayway.jsonpath.PathNotFoundException;
 import com.jayway.jsonpath.spi.JsonProvider;
 
 import java.util.regex.Pattern;
@@ -95,8 +96,8 @@ public class ArrayIndexFilter extends PathTokenFilter {
         } else {
             String[] indexArr = COMMA.split(trimmedCondition);
 
-            if(jsonProvider.length(obj) == 0){
-                return result;
+            if(obj == null || jsonProvider.length(obj) == 0){
+                throw new PathNotFoundException("Failed to access array index: '" + condition + "' since the array is null or empty");
             }
 
             if (indexArr.length == 1) {

json-path/src/main/java/com/jayway/jsonpath/internal/filter/FieldFilter.java

@@ -89,7 +89,7 @@ public class FieldFilter extends PathTokenFilter {
                 }
             }
         } else {
-            throw new PathNotFoundException("Failed to access property: " + condition + " on object " + obj);
+            throw new PathNotFoundException("Failed to access property: '" + condition + "' on object " + obj);
         }
     }
 

json-path/src/test/java/com/jayway/jsonpath/DocumentationPageTests.java

@@ -0,0 +1,88 @@
+package com.jayway.jsonpath;
+
+import org.junit.Test;
+
+/**
+ * User: kalle
+ * Date: 8/23/13
+ * Time: 10:58 AM
+ */
+public class DocumentationPageTests {
+
+
+    public static final String JSON = "{ \n" +
+            "    \"store\": {\n" +
+            "        \"book\": [ \n" +
+            "            { \n" +
+            "                \"category\": \"reference\",\n" +
+            "                \"author\": \"Nigel Rees\",\n" +
+            "                \"title\": \"Sayings of the Century\",\n" +
+            "                \"price\": 8.95\n" +
+            "            },\n" +
+            "            { \n" +
+            "                \"category\": \"fiction\",\n" +
+            "                \"author\": \"Evelyn Waugh\",\n" +
+            "                \"title\": \"Sword of Honour\",\n" +
+            "                \"price\": 12.99\n" +
+            "            },\n" +
+            "            { \n" +
+            "                \"category\": \"fiction\",\n" +
+            "                \"author\": \"Herman Melville\",\n" +
+            "                \"title\": \"Moby Dick\",\n" +
+            "                \"isbn\": \"0-553-21311-3\",\n" +
+            "                \"price\": 8.99\n" +
+            "            },\n" +
+            "            { \n" +
+            "                \"category\": null,\n" +
+            "                \"author\": \"J. R. R. Tolkien\",\n" +
+            "                \"title\": \"The Lord of the Rings\",\n" +
+            "                \"isbn\": \"0-395-19395-8\",\n" +
+            "                \"price\": 22.99,\n" +
+            "                \"edition\": {\n" +
+            "                   \"release-date\": \"2013-01-22\"\n" +
+            "                }\n" +
+            "            }\n" +
+            "        ],\n" +
+            "        \"bicycle\": {\n" +
+            "            \"color\": \"red\",\n" +
+            "            \"price\": 19.95\n" +
+            "         }\n" +
+            "    }\n" +
+            "}";
+
+    @Test
+    public void test_1() {
+        System.out.println(JsonPath.read(JSON, "$.store.bicycle"));
+    }
+
+    @Test
+    public void test_2() {
+        System.out.println(JsonPath.read(JSON, "$.store.book[0]"));
+    }
+
+    @Test
+    public void test_3() {
+        System.out.println(JsonPath.read(JSON, "$.store.book[*].author"));
+    }
+
+    @Test
+    public void test_4() {
+        System.out.println(JsonPath.read(JSON, "$.store.book[-2:].author"));
+    }
+
+    @Test
+    public void test_5() {
+        System.out.println(JsonPath.read(JSON, "$.store.book[1:3].author"));
+    }
+
+    @Test
+    public void test_6() {
+        System.out.println(JsonPath.read(JSON, "$.store.book[0]['author', 'category']"));
+    }
+
+    @Test
+    public void test_7() {
+        System.out.println(JsonPath.read(JSON, "$..price"));
+    }
+
+}

json-path/src/test/java/com/jayway/jsonpath/JsonPathTest.java

@@ -78,7 +78,33 @@ public class JsonPathTest {
     private final static String ARRAY_EXPAND = "[{\"parent\": \"ONE\", \"child\": {\"name\": \"NAME_ONE\"}}, [{\"parent\": \"TWO\", \"child\": {\"name\": \"NAME_TWO\"}}]]";
 
 
+    @Test
+    public void null_object_in_path() {
+
+        String json = "{\n" +
+                "  \"success\": true,\n" +
+                "  \"data\": {\n" +
+                "    \"user\": 3,\n" +
+                "    \"own\": null,\n" +
+                "    \"passes\": null,\n" +
+                "    \"completed\": null\n" +
+                "  },\n" +
+                "  \"data2\": {\n" +
+                "    \"user\": 3,\n" +
+                "    \"own\": null,\n" +
+                "    \"passes\": [{\"id\":\"1\"}],\n" +
+                "    \"completed\": null\n" +
+                "  },\n" +
+                "  \"version\": 1371160528774\n" +
+                "}";
+
+        System.out.println(JsonPath.read(json, "$.data.passes[0].id"));
+        System.out.println(JsonPath.isPathDefinite("$.data.passes[0].id"));
+
+        System.out.println(JsonPath.read(json, "$.data2.passes[0].id"));
+        System.out.println(JsonPath.isPathDefinite("$.data2.passes[0].id"));
 
+    }
 
     @Test
     public void array_start_expands() throws Exception {