XCOMMONS-130: Upgrade to Json-lib 2.4

XCOMMONS-131: Add a Velocity tool to serialize Java objects to JSON format

pom.xml

@@ -194,6 +194,14 @@
         <version>1.4.2</version>
       </dependency>
 
+      <!-- Used in both commons and platform -->
+      <dependency>
+        <groupId>net.sf.json-lib</groupId>
+        <artifactId>json-lib</artifactId>
+        <version>2.4</version>
+        <classifier>jdk15</classifier>
+      </dependency>
+
       <!-- Everybody logs -->
       <dependency>
         <groupId>org.slf4j</groupId>

xwiki-commons-core/xwiki-commons-velocity/pom.xml

@@ -77,6 +77,12 @@
       <groupId>commons-codec</groupId>
       <artifactId>commons-codec</artifactId>
     </dependency>
+    <dependency>
+      <!-- Used by JSONTool -->
+      <groupId>net.sf.json-lib</groupId>
+      <artifactId>json-lib</artifactId>
+      <classifier>jdk15</classifier>
+    </dependency>
     <!-- Test Dependencies -->
     <dependency>
       <groupId>org.xwiki.commons</groupId>

xwiki-commons-core/xwiki-commons-velocity/src/main/java/org/xwiki/velocity/internal/DefaultVelocityConfiguration.java

@@ -41,6 +41,7 @@
 import org.xwiki.velocity.introspection.DeprecatedCheckUberspector;
 import org.xwiki.velocity.tools.CollectionsTool;
 import org.xwiki.velocity.tools.EscapeTool;
+import org.xwiki.velocity.tools.JSONTool;
 import org.xwiki.velocity.tools.RegexTool;
 
 /**
@@ -87,6 +88,7 @@ public void initialize() throws InitializationException
         this.defaultTools.setProperty("regextool", RegexTool.class.getName());
         this.defaultTools.setProperty("collectionstool", CollectionsTool.class.getName());
         this.defaultTools.setProperty("stringtool", StringUtils.class.getName());
+        this.defaultTools.setProperty("jsontool", JSONTool.class.getName());
 
         // Default Velocity properties
         this.defaultProperties.setProperty("directive.set.null.allowed", Boolean.TRUE.toString());

xwiki-commons-core/xwiki-commons-velocity/src/main/java/org/xwiki/velocity/tools/JSONTool.java

@@ -0,0 +1,70 @@
+/*
+ * See the NOTICE file distributed with this work for additional
+ * information regarding copyright ownership.
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this software; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
+ */
+package org.xwiki.velocity.tools;
+
+import net.sf.json.JSON;
+import net.sf.json.JSONArray;
+import net.sf.json.JSONNull;
+import net.sf.json.JSONObject;
+import net.sf.json.util.JSONUtils;
+
+/**
+ * Velocity tool to facilitate serialization of Java objects to the JSON format.
+ * 
+ * @version $Id$
+ * @since 4.0M2
+ */
+public class JSONTool
+{
+    /**
+     * Serialize a Java object to the JSON format.
+     * <p>
+     * Examples:
+     * <ul>
+     * <li>numbers and boolean values: 23, 13.5, true, false</li>
+     * <li>strings: "one\"two'three" (quotes included)</li>
+     * <li>arrays and collections: [1, 2, 3]</li>
+     * <li>maps: {"number": 23, "boolean": false, "string": "value"}</li>
+     * <li>beans: {"enabled": true, "name": "XWiki"} for a bean that has #isEnabled() and #getName() getters</li>
+     * </ul>
+     * 
+     * @param object the object to be serialized to the JSON format
+     * @return the JSON-verified string representation of the given object
+     */
+    public String serialize(Object object)
+    {
+        JSON json = null;
+        if (object == null) {
+            json = JSONNull.getInstance();
+        } else if (object instanceof String) {
+            return JSONUtils.valueToString(object);
+        } else if (JSONUtils.isBoolean(object)) {
+            return object.toString();
+        } else if (JSONUtils.isNumber(object)) {
+            return JSONUtils.numberToString((Number) object);
+        } else if (JSONUtils.isArray(object)) {
+            json = JSONArray.fromObject(object);
+        } else {
+            json = JSONObject.fromObject(object);
+        }
+
+        return json.toString();
+    }
+}

xwiki-commons-core/xwiki-commons-velocity/src/test/java/org/xwiki/velocity/tools/JSONToolTest.java

@@ -0,0 +1,139 @@
+/*
+ * See the NOTICE file distributed with this work for additional
+ * information regarding copyright ownership.
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this software; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
+ */
+package org.xwiki.velocity.tools;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * Unit tests for {@link JSONTool}.
+ * 
+ * @version $Id$
+ * @since 4.0M2
+ */
+public class JSONToolTest
+{
+    public static class MockBean
+    {
+        public boolean isEnabled()
+        {
+            return true;
+        }
+
+        public int getAge()
+        {
+            return 28;
+        }
+
+        public double getGrade()
+        {
+            return 9.48;
+        }
+
+        public String getName()
+        {
+            return "XWiki";
+        }
+
+        public List<String> getItems()
+        {
+            return Arrays.asList("one");
+        }
+
+        public Map<String, String> getParameters()
+        {
+            return Collections.singletonMap("foo", "bar");
+        }
+    }
+
+    /**
+     * The object being tested.
+     */
+    private JSONTool tool = new JSONTool();
+
+    @Test
+    public void testSerializeMap()
+    {
+        Map<String, Object> map = new HashMap<String, Object>();
+        map.put("bool", false);
+        map.put("int", 13);
+        map.put("double", 0.78);
+        map.put("string", "foo");
+        map.put("array", new int[] {9, 8});
+        map.put("list", Arrays.asList("one", "two"));
+        map.put("map", Collections.singletonMap("level2", true));
+
+        String json = tool.serialize(map);
+        // We can't predict the order in the map.
+        Assert.assertTrue(json.contains("\"bool\":false"));
+        Assert.assertTrue(json.contains("\"int\":13"));
+        Assert.assertTrue(json.contains("\"double\":0.78"));
+        Assert.assertTrue(json.contains("\"string\":\"foo\""));
+        Assert.assertTrue(json.contains("\"array\":[9,8]"));
+        Assert.assertTrue(json.contains("\"list\":[\"one\",\"two\"]"));
+        Assert.assertTrue(json.contains("\"map\":{\"level2\":true}"));
+    }
+
+    @Test
+    public void testSerializeList()
+    {
+        Assert.assertEquals("[1,2]", tool.serialize(Arrays.asList(1, 2)));
+        Assert.assertEquals("[1.3,2.4]", tool.serialize(new double[] {1.3, 2.4}));
+    }
+
+    @Test
+    public void testSerializeNumber()
+    {
+        Assert.assertEquals("27", tool.serialize(27));
+        Assert.assertEquals("2.7", tool.serialize(2.7));
+    }
+
+    @Test
+    public void testSerializeBoolean()
+    {
+        Assert.assertEquals("false", tool.serialize(false));
+        Assert.assertEquals("true", tool.serialize(true));
+    }
+
+    @Test
+    public void testSerializeString()
+    {
+        Assert.assertEquals("\"\\\"te'st\\\"\"", tool.serialize("\"te'st\""));
+    }
+
+    @Test
+    public void testSerializeBean()
+    {
+        String json = tool.serialize(new MockBean());
+        // We can't predict the order in the map.
+        Assert.assertTrue(json.contains("\"age\":28"));
+        Assert.assertTrue(json.contains("\"enabled\":true"));
+        Assert.assertTrue(json.contains("\"grade\":9.48"));
+        Assert.assertTrue(json.contains("\"items\":[\"one\"]"));
+        Assert.assertTrue(json.contains("\"name\":\"XWiki\""));
+        Assert.assertTrue(json.contains("\"parameters\":{\"foo\":\"bar\"}"));
+    }
+}