From 8aa741301310079b3093878cb8eb092d5c9a5207 Mon Sep 17 00:00:00 2001
From: Jens-Otto Larsen <jens-otto.larsen@nav.no>
Date: Sun, 16 Aug 2026 21:01:34 +0200
Subject: [PATCH 1/2] Module for Jackson 3

---
 handlebars-jackson3/pom.xml                   |  61 +++++
 .../handlebars/jackson/JacksonHelper.java     | 177 ++++++++++++++
 .../jackson/JsonNodeValueResolver.java        | 155 ++++++++++++
 .../src/main/java/module-info.java            |   9 +
 .../jknack/handlebars/jackson/Blog.java       |  63 +++++
 .../jknack/handlebars/jackson/Comment.java    |   9 +
 .../handlebars/jackson/JacksonHelperTest.java | 160 ++++++++++++
 .../jackson/JsonNodeValueResolverTest.java    | 231 ++++++++++++++++++
 8 files changed, 865 insertions(+)
 create mode 100644 handlebars-jackson3/pom.xml
 create mode 100644 handlebars-jackson3/src/main/java/com/github/jknack/handlebars/jackson/JacksonHelper.java
 create mode 100644 handlebars-jackson3/src/main/java/com/github/jknack/handlebars/jackson/JsonNodeValueResolver.java
 create mode 100644 handlebars-jackson3/src/main/java/module-info.java
 create mode 100644 handlebars-jackson3/src/test/java/com/github/jknack/handlebars/jackson/Blog.java
 create mode 100644 handlebars-jackson3/src/test/java/com/github/jknack/handlebars/jackson/Comment.java
 create mode 100644 handlebars-jackson3/src/test/java/com/github/jknack/handlebars/jackson/JacksonHelperTest.java
 create mode 100644 handlebars-jackson3/src/test/java/com/github/jknack/handlebars/jackson/JsonNodeValueResolverTest.java

diff --git a/handlebars-jackson3/pom.xml b/handlebars-jackson3/pom.xml
new file mode 100644
index 00000000..c02a8c4a
--- /dev/null
+++ b/handlebars-jackson3/pom.xml
@@ -0,0 +1,61 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+
+  <parent>
+    <groupId>com.github.jknack</groupId>
+    <artifactId>handlebars.java</artifactId>
+    <version>4.5.4</version>
+  </parent>
+
+  <modelVersion>4.0.0</modelVersion>
+  <artifactId>handlebars-jackson3</artifactId>
+
+  <name>JSON Jackson helpers</name>
+
+  <dependencies>
+    <dependency>
+      <groupId>com.github.jknack</groupId>
+      <artifactId>handlebars</artifactId>
+      <version>${project.version}</version>
+    </dependency>
+
+    <dependency>
+      <groupId>tools.jackson.core</groupId>
+      <artifactId>jackson-databind</artifactId>
+    </dependency>
+
+    <!-- Test dependencies -->
+    <dependency>
+      <groupId>com.github.jknack</groupId>
+      <artifactId>handlebars</artifactId>
+      <version>${project.version}</version>
+      <scope>test</scope>
+      <classifier>tests</classifier>
+    </dependency>
+
+    <dependency>
+      <groupId>ch.qos.logback</groupId>
+      <artifactId>logback-classic</artifactId>
+      <scope>test</scope>
+    </dependency>
+
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter-engine</artifactId>
+      <scope>test</scope>
+    </dependency>
+
+    <dependency>
+      <groupId>org.hamcrest</groupId>
+      <artifactId>hamcrest</artifactId>
+      <scope>test</scope>
+    </dependency>
+
+    <dependency>
+      <groupId>org.mockito</groupId>
+      <artifactId>mockito-core</artifactId>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+
+</project>
diff --git a/handlebars-jackson3/src/main/java/com/github/jknack/handlebars/jackson/JacksonHelper.java b/handlebars-jackson3/src/main/java/com/github/jknack/handlebars/jackson/JacksonHelper.java
new file mode 100644
index 00000000..c9fadb76
--- /dev/null
+++ b/handlebars-jackson3/src/main/java/com/github/jknack/handlebars/jackson/JacksonHelper.java
@@ -0,0 +1,177 @@
+/*
+ * Handlebars.java: https://github.com/jknack/handlebars.java
+ * Apache License Version 2.0 http://www.apache.org/licenses/LICENSE-2.0
+ * Copyright (c) 2012 Edgar Espina
+ */
+package com.github.jknack.handlebars.jackson;
+
+import com.github.jknack.handlebars.Handlebars;
+import com.github.jknack.handlebars.Helper;
+import com.github.jknack.handlebars.Options;
+import tools.jackson.core.SerializableString;
+import tools.jackson.core.io.CharacterEscapes;
+import tools.jackson.databind.ObjectMapper;
+import tools.jackson.databind.ObjectWriter;
+import tools.jackson.databind.json.JsonMapper;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import static java.util.Objects.requireNonNull;
+
+/**
+ * A Jackson 3.x helper.
+ *
+ * <p>Basic usage:
+ *
+ * <pre>
+ *  Handlebars hbs = new Handlebars();
+ *
+ *  hbs.registerHelper("json", JacksonHelper.INSTANCE);
+ *
+ *  ...
+ *
+ *  {{json model}}
+ * </pre>
+ *
+ * <p>If <code>model</code> is null an empty string is returned.
+ *
+ * <p>You can change this using the <code>default</code> option:
+ *
+ * <pre>
+ *  {{json model default="{}"}}
+ * </pre>
+ *
+ * <p>Using a view class:
+ *
+ * <pre>
+ *  {{json model view="foo.MyView"}}
+ * </pre>
+ *
+ * <p>Using alias for views:
+ *
+ * <pre>
+ *  {{json model view="myView"}}
+ * </pre>
+ *
+ * <p>Escape HTML chars:
+ *
+ * <pre>
+ *  {{json model escapeHTML=true}}
+ * </pre>
+ *
+ * <p>Pretty printer:
+ *
+ * <pre>
+ *  {{json model pretty=true}}
+ * </pre>
+ *
+ * @author edgar.espina, jolarsen
+ * @since 4.5.5
+ */
+public class JacksonHelper implements Helper<Object> {
+
+  /**
+   * Escape HTML chars from JSON content. See
+   * http://www.cowtowncoder.com/blog/archives/2012/08/entry_476.html
+   *
+   * @author edgar.espina, jolarsen
+   * @since 4.5.5
+   */
+  @SuppressWarnings("serial")
+  private static class HtmlEscapes extends CharacterEscapes {
+
+    /** The escape table. */
+    private final int[] escapeTable;
+
+    {
+      // Start with set of characters known to require escaping (double-quote,
+      // backslash etc)
+      escapeTable = CharacterEscapes.standardAsciiEscapesForJSON();
+      // and force escaping of a few others:
+      escapeTable['<'] = CharacterEscapes.ESCAPE_STANDARD;
+      escapeTable['>'] = CharacterEscapes.ESCAPE_STANDARD;
+      escapeTable['&'] = CharacterEscapes.ESCAPE_STANDARD;
+      escapeTable['\''] = CharacterEscapes.ESCAPE_STANDARD;
+    }
+
+    @Override
+    public int[] getEscapeCodesForAscii() {
+      return escapeTable;
+    }
+
+    @Override
+    public SerializableString getEscapeSequence(final int ch) {
+      return null;
+    }
+  }
+
+  /** A singleton version of {@link JacksonHelper}. */
+  public static final Helper<Object> INSTANCE = new JacksonHelper();
+
+  /** The JSON parser. */
+  private final ObjectMapper mapper;
+
+  /** Class alias registry. */
+  private final Map<String, Class<?>> alias = new HashMap<String, Class<?>>();
+
+  /**
+   * Creates a new {@link JacksonHelper}.
+   *
+   * @param objectMapper The object's mapper. Required.
+   */
+  public JacksonHelper(final ObjectMapper objectMapper) {
+    mapper = requireNonNull(objectMapper, "The object mapper is required.");
+  }
+
+  /** Creates a new {@link JacksonHelper}. */
+  private JacksonHelper() {
+    this(JsonMapper.builder().build());
+  }
+
+  @Override
+  public Object apply(final Object context, final Options options) {
+    if (context == null) {
+      return options.hash("default", "");
+    }
+
+    final String viewName = options.hash("view", "");
+    try {
+      final Class<?> viewClass = alias.get(viewName);
+      final ObjectWriter viewWriter = Handlebars.Utils.isEmpty(viewName)
+              ? mapper.writer()
+              : mapper.writerWithView(viewClass != null
+                                      ? viewClass
+                                      : getClass().getClassLoader().loadClass(viewName));
+
+      final boolean escapeHtml = options.hash("escapeHTML", false);
+      final boolean pretty = options.hash("pretty", false);
+
+      final ObjectWriter writer = pretty
+              ? viewWriter.withDefaultPrettyPrinter()
+              : viewWriter;
+
+      final ObjectWriter configuredWriter = escapeHtml
+              ? writer.with(new HtmlEscapes())
+              : writer;
+
+      return new Handlebars.SafeString(configuredWriter.writeValueAsString(context));
+    } catch (ClassNotFoundException|NoClassDefFoundError ex) {
+      throw new IllegalArgumentException(viewName, ex);
+    }
+  }
+
+  /**
+   * Add an alias for the given view class.
+   *
+   * @param alias The view alias. Required.
+   * @param viewClass The view class. Required.
+   * @return This helper.
+   */
+  public JacksonHelper viewAlias(final String alias, final Class<?> viewClass) {
+    this.alias.put(
+        requireNonNull(alias, "A view alias is required."),
+        requireNonNull(viewClass, "A view class is required."));
+    return this;
+  }
+}
diff --git a/handlebars-jackson3/src/main/java/com/github/jknack/handlebars/jackson/JsonNodeValueResolver.java b/handlebars-jackson3/src/main/java/com/github/jknack/handlebars/jackson/JsonNodeValueResolver.java
new file mode 100644
index 00000000..5d9d7ca7
--- /dev/null
+++ b/handlebars-jackson3/src/main/java/com/github/jknack/handlebars/jackson/JsonNodeValueResolver.java
@@ -0,0 +1,155 @@
+/*
+ * Handlebars.java: https://github.com/jknack/handlebars.java
+ * Apache License Version 2.0 http://www.apache.org/licenses/LICENSE-2.0
+ * Copyright (c) 2012 Edgar Espina
+ */
+package com.github.jknack.handlebars.jackson;
+
+import com.github.jknack.handlebars.ValueResolver;
+import tools.jackson.databind.JsonNode;
+import tools.jackson.databind.node.ArrayNode;
+import tools.jackson.databind.node.BigIntegerNode;
+import tools.jackson.databind.node.BinaryNode;
+import tools.jackson.databind.node.BooleanNode;
+import tools.jackson.databind.node.DecimalNode;
+import tools.jackson.databind.node.DoubleNode;
+import tools.jackson.databind.node.IntNode;
+import tools.jackson.databind.node.LongNode;
+import tools.jackson.databind.node.NullNode;
+import tools.jackson.databind.node.ObjectNode;
+import tools.jackson.databind.node.POJONode;
+import tools.jackson.databind.node.StringNode;
+
+import java.util.AbstractMap;
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Set;
+
+/**
+ * Resolve a context stack value from {@link JsonNode}.
+ *
+ * @author edgar.espina, jolarsen
+ * @since 4.5.5
+ */
+public enum JsonNodeValueResolver implements ValueResolver {
+
+  /** The singleton instance. */
+  INSTANCE;
+
+  @Override
+  public Object resolve(final Object context, final String name) {
+    Object value = null;
+    if (context instanceof ArrayNode arrayNode) {
+      try {
+        if (name.equals("length")) {
+          return arrayNode.size();
+        }
+        value = resolve(arrayNode.get(Integer.parseInt(name)));
+      } catch (NumberFormatException ex) {
+        // ignore undefined key and move on, see
+        // https://github.com/jknack/handlebars.java/pull/280
+      }
+    } else if (context instanceof JsonNode jsonNode) {
+      value = resolve(jsonNode.get(name));
+    }
+    return value == null ? UNRESOLVED : value;
+  }
+
+  @Override
+  public Object resolve(final Object context) {
+    if (context instanceof JsonNode jsonNode) {
+      return resolve(jsonNode);
+    }
+    return UNRESOLVED;
+  }
+
+  /**
+   * Resolve a {@link JsonNode} object to a primitive value.
+   *
+   * @param node A {@link JsonNode} object.
+   * @return A primitive value, json object, json array or null.
+   */
+  private static Object resolve(final JsonNode node) {
+    // binary node
+    if (node instanceof BinaryNode binaryNode) {
+      return binaryNode.binaryValue();
+    }
+    // boolean node
+    if (node instanceof BooleanNode booleanNode) {
+      return booleanNode.booleanValue();
+    }
+    // null node
+    if (node instanceof NullNode) {
+      return null;
+    }
+    // numeric nodes
+    if (node instanceof BigIntegerNode bigIntegerNode) {
+      return bigIntegerNode.bigIntegerValue();
+    }
+    if (node instanceof DecimalNode decimalNode) {
+      return decimalNode.decimalValue();
+    }
+    if (node instanceof DoubleNode doubleNode) {
+      return doubleNode.doubleValue();
+    }
+    if (node instanceof IntNode intNode) {
+      return intNode.intValue();
+    }
+    if (node instanceof LongNode longNode) {
+      return longNode.longValue();
+    }
+    // pojo
+    if (node instanceof POJONode pojoNode) {
+      return pojoNode.getPojo();
+    }
+    // string
+    if (node instanceof StringNode stringNode) {
+      return stringNode.stringValue();
+    }
+    // object node to map
+    if (node instanceof ObjectNode objectNode) {
+      return toMap(objectNode);
+    }
+    // container, array or null
+    return node;
+  }
+
+  /**
+   * @param node A json node.
+   * @return A map from a json node.
+   */
+  private static Map<String, Object> toMap(final ObjectNode node) {
+    return new AbstractMap<String, Object>() {
+      @Override
+      public Object get(final Object key) {
+        return resolve(node.get((String) key));
+      }
+
+      @Override
+      public int size() {
+        return node.size();
+      }
+
+      @SuppressWarnings({"unchecked", "rawtypes"})
+      @Override
+      public Set<Entry<String, Object>> entrySet() {
+        Set set = new LinkedHashSet<Map.Entry<String, Object>>();
+        node.propertyStream().forEach(set::add);
+        return set;
+      }
+    };
+  }
+
+  @Override
+  public Set<Entry<String, Object>> propertySet(final Object context) {
+    if (context instanceof ObjectNode node) {
+      Map<String, Object> result = new LinkedHashMap<>();
+      node.propertyNames().forEach(name -> result.put(name, resolve(node.get(name))));
+      return result.entrySet();
+    }
+    return Collections.emptySet();
+  }
+}
diff --git a/handlebars-jackson3/src/main/java/module-info.java b/handlebars-jackson3/src/main/java/module-info.java
new file mode 100644
index 00000000..cc47d90e
--- /dev/null
+++ b/handlebars-jackson3/src/main/java/module-info.java
@@ -0,0 +1,9 @@
+/** handlebars jackson3. */
+module com.github.jknack.handlebars.jackson {
+  exports com.github.jknack.handlebars.jackson;
+
+  requires org.slf4j;
+  requires com.github.jknack.handlebars;
+  requires tools.jackson.core;
+  requires tools.jackson.databind;
+}
diff --git a/handlebars-jackson3/src/test/java/com/github/jknack/handlebars/jackson/Blog.java b/handlebars-jackson3/src/test/java/com/github/jknack/handlebars/jackson/Blog.java
new file mode 100644
index 00000000..de199552
--- /dev/null
+++ b/handlebars-jackson3/src/test/java/com/github/jknack/handlebars/jackson/Blog.java
@@ -0,0 +1,63 @@
+/*
+ * Handlebars.java: https://github.com/jknack/handlebars.java
+ * Apache License Version 2.0 http://www.apache.org/licenses/LICENSE-2.0
+ * Copyright (c) 2012 Edgar Espina
+ */
+package com.github.jknack.handlebars.jackson;
+
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+import com.fasterxml.jackson.annotation.JsonView;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@JsonPropertyOrder({"title", "body", "comments"})
+public class Blog {
+
+  public static class Views {
+    public static class Public {}
+  }
+
+  @JsonView(Views.Public.class)
+  private String title;
+
+  private String body;
+
+  private List<Comment> comments = new ArrayList<Comment>();
+
+  public Blog(final String title, final String body) {
+    this.title = title;
+    this.body = body;
+  }
+
+  public Blog() {}
+
+  public String getTitle() {
+    return title;
+  }
+
+  public String getBody() {
+    return body;
+  }
+
+  public Blog add(final Comment comment) {
+    comments.add(comment);
+    return this;
+  }
+
+  public List<Comment> getComments() {
+    return comments;
+  }
+
+  public void setBody(final String body) {
+    this.body = body;
+  }
+
+  public void setComments(final List<Comment> comments) {
+    this.comments = comments;
+  }
+
+  public void setTitle(final String title) {
+    this.title = title;
+  }
+}
diff --git a/handlebars-jackson3/src/test/java/com/github/jknack/handlebars/jackson/Comment.java b/handlebars-jackson3/src/test/java/com/github/jknack/handlebars/jackson/Comment.java
new file mode 100644
index 00000000..5e6803c1
--- /dev/null
+++ b/handlebars-jackson3/src/test/java/com/github/jknack/handlebars/jackson/Comment.java
@@ -0,0 +1,9 @@
+/*
+ * Handlebars.java: https://github.com/jknack/handlebars.java
+ * Apache License Version 2.0 http://www.apache.org/licenses/LICENSE-2.0
+ * Copyright (c) 2012 Edgar Espina
+ */
+package com.github.jknack.handlebars.jackson;
+
+public record Comment(String author, String comment) {
+}
diff --git a/handlebars-jackson3/src/test/java/com/github/jknack/handlebars/jackson/JacksonHelperTest.java b/handlebars-jackson3/src/test/java/com/github/jknack/handlebars/jackson/JacksonHelperTest.java
new file mode 100644
index 00000000..cc40b923
--- /dev/null
+++ b/handlebars-jackson3/src/test/java/com/github/jknack/handlebars/jackson/JacksonHelperTest.java
@@ -0,0 +1,160 @@
+/*
+ * Handlebars.java: https://github.com/jknack/handlebars.java
+ * Apache License Version 2.0 http://www.apache.org/licenses/LICENSE-2.0
+ * Copyright (c) 2012 Edgar Espina
+ */
+package com.github.jknack.handlebars.jackson;
+
+import com.github.jknack.handlebars.Handlebars;
+import com.github.jknack.handlebars.HandlebarsException;
+import com.github.jknack.handlebars.Template;
+import com.github.jknack.handlebars.jackson.Blog.Views.Public;
+import org.hamcrest.Description;
+import org.hamcrest.TypeSafeMatcher;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+import tools.jackson.databind.ObjectMapper;
+import tools.jackson.databind.json.JsonMapper;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+
+import static com.github.jknack.handlebars.jackson.JacksonHelperTest.IgnoreWindowsLineMatcher.equalsToStringIgnoringWindowsNewLine;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+/**
+ * Unit test for {@link JacksonHelper}.
+ *
+ * @author edgar.espina, jolarsen
+ * @since 4.5.5
+ */
+class JacksonHelperTest {
+
+  @Test
+  void toJSON() throws IOException {
+    Handlebars handlebars = new Handlebars();
+    handlebars.registerHelper("@json", JacksonHelper.INSTANCE);
+
+    Template template = handlebars.compileInline("{{@json this}}");
+
+    assertThat(
+        template.apply(new Blog("First Post", "...")),
+        equalsToStringIgnoringWindowsNewLine(
+            "{\"title\":\"First Post\",\"body\":\"...\",\"comments\":[]}"));
+  }
+
+  @Test
+  void toPrettyJSON() throws IOException {
+    Handlebars handlebars = new Handlebars();
+    handlebars.registerHelper("@json", JacksonHelper.INSTANCE);
+
+    Template template = handlebars.compileInline("{{@json this pretty=true}}");
+
+    assertThat(
+        template.apply(new Blog("First Post", "...")),
+        equalsToStringIgnoringWindowsNewLine(
+            """
+                {
+                  "title" : "First Post",
+                  "body" : "...",
+                  "comments" : [ ]
+                }"""));
+  }
+
+  @Test
+  void toJSONViewExclusive() throws IOException {
+    Handlebars handlebars = new Handlebars();
+
+    handlebars.registerHelper("@json", JacksonHelper.INSTANCE);
+
+    Template template =
+        handlebars.compileInline(
+            "{{@json this view=\"com.github.jknack.handlebars.jackson.Blog$Views$Public\"}}");
+
+    assertThat(
+        template.apply(new Blog("First Post", "...")),
+        equalsToStringIgnoringWindowsNewLine("{\"title\":\"First Post\"}"));
+  }
+
+  @Test
+  void toJSONAliasViewExclusive() throws IOException {
+    Handlebars handlebars = new Handlebars();
+
+    ObjectMapper mapper = JsonMapper.builder().build();
+
+    handlebars.registerHelper("@json", new JacksonHelper(mapper).viewAlias("myView", Public.class));
+
+    Template template = handlebars.compileInline("{{@json this view=\"myView\"}}");
+
+    assertThat(
+        template.apply(new Blog("First Post", "...")),
+        equalsToStringIgnoringWindowsNewLine("{\"title\":\"First Post\"}"));
+  }
+
+  @Test
+  void jsonViewNotFound() {
+    Assertions.assertThrows(
+        HandlebarsException.class,
+        () -> {
+          Handlebars handlebars = new Handlebars();
+
+          ObjectMapper mapper = JsonMapper.builder().build();
+
+          handlebars.registerHelper("@json", new JacksonHelper(mapper));
+
+          Template template = handlebars.compileInline("{{@json this view=\"missing.ViewClass\"}}");
+
+          assertThat(
+              template.apply(new Blog("First Post", "...")),
+              equalsToStringIgnoringWindowsNewLine("{\"title\":\"First Post\"}"));
+        });
+  }
+
+  @Test
+  void escapeHtml() throws IOException {
+    Handlebars handlebars = new Handlebars();
+    handlebars.registerHelper("@json", JacksonHelper.INSTANCE);
+
+    Map<String, String> model = new HashMap<String, String>();
+    model.put("script", "<script text=\"text/javascript\"></script>");
+
+    assertThat(
+        handlebars.compileInline("{{@json this}}").apply(model),
+        equalsToStringIgnoringWindowsNewLine(
+            "{\"script\":\"<script text=\\\"text/javascript\\\"></script>\"}"));
+
+    assertThat(
+        handlebars.compileInline("{{@json this escapeHTML=true}}").apply(model),
+        equalsToStringIgnoringWindowsNewLine(
+            "{\"script\":\"\\u003Cscript"
+                + " text=\\\"text/javascript\\\"\\u003E\\u003C/script\\u003E\"}"));
+  }
+
+  static class IgnoreWindowsLineMatcher extends TypeSafeMatcher<String> {
+
+    private final String value;
+
+    private IgnoreWindowsLineMatcher(String value) {
+      this.value = value;
+    }
+
+    static IgnoreWindowsLineMatcher equalsToStringIgnoringWindowsNewLine(String value) {
+      return new IgnoreWindowsLineMatcher(value);
+    }
+
+    @Override
+    protected boolean matchesSafely(String item) {
+      return item.replace("\r\n", "\n").equals(value);
+    }
+
+    @Override
+    public void describeTo(Description description) {
+      description
+              .appendText("a string ")
+              .appendText("ignoring \\r")
+              .appendText(" ")
+              .appendValue(value);
+    }
+  }
+}
diff --git a/handlebars-jackson3/src/test/java/com/github/jknack/handlebars/jackson/JsonNodeValueResolverTest.java b/handlebars-jackson3/src/test/java/com/github/jknack/handlebars/jackson/JsonNodeValueResolverTest.java
new file mode 100644
index 00000000..d5adeb53
--- /dev/null
+++ b/handlebars-jackson3/src/test/java/com/github/jknack/handlebars/jackson/JsonNodeValueResolverTest.java
@@ -0,0 +1,231 @@
+/*
+ * Handlebars.java: https://github.com/jknack/handlebars.java
+ * Apache License Version 2.0 http://www.apache.org/licenses/LICENSE-2.0
+ * Copyright (c) 2012 Edgar Espina
+ */
+package com.github.jknack.handlebars.jackson;
+
+import com.github.jknack.handlebars.Context;
+import com.github.jknack.handlebars.Handlebars;
+import com.github.jknack.handlebars.ValueResolver;
+import com.github.jknack.handlebars.context.MapValueResolver;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+import tools.jackson.databind.JsonNode;
+import tools.jackson.databind.json.JsonMapper;
+import tools.jackson.databind.node.BigIntegerNode;
+import tools.jackson.databind.node.BinaryNode;
+import tools.jackson.databind.node.DecimalNode;
+import tools.jackson.databind.node.LongNode;
+import tools.jackson.databind.node.NullNode;
+import tools.jackson.databind.node.POJONode;
+
+import java.io.IOException;
+import java.math.BigDecimal;
+import java.math.BigInteger;
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Set;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+class JsonNodeValueResolverTest {
+
+  @Test
+  void resolveValueNode() throws IOException {
+    Handlebars handlebars = new Handlebars();
+
+    Map<String, Object> root = new LinkedHashMap<String, Object>();
+    root.put("string", "abc");
+    root.put("int", 678);
+    root.put("long", 6789L);
+    root.put("float", 7.13f);
+    root.put("double", 3.14d);
+    root.put("bool", true);
+
+    assertEquals(
+        "abc 678 6789 7.13 3.14 true",
+        handlebars
+            .compileInline("{{string}} {{int}} {{long}} {{float}} {{double}} {{bool}}")
+            .apply(context(root)));
+  }
+
+  @Test
+  void nullMustBeResolvedToUnresolved() {
+    Assertions.assertEquals(
+        ValueResolver.UNRESOLVED, JsonNodeValueResolver.INSTANCE.resolve(null, "nothing"));
+  }
+
+  @Test
+  void resolveBinaryNode() {
+    String name = "binary";
+    byte[] result = new byte[] {1};
+
+    JsonNode node = mock(JsonNode.class);
+    BinaryNode value = BinaryNode.valueOf(result);
+    when(node.get(name)).thenReturn(value);
+
+    Assertions.assertEquals(result, JsonNodeValueResolver.INSTANCE.resolve(node, name));
+
+    verify(node).get(name);
+  }
+
+  @Test
+  void resolveNullNode() {
+    String name = "null";
+    Object result = ValueResolver.UNRESOLVED;
+
+    JsonNode node = mock(JsonNode.class);
+    NullNode value = NullNode.instance;
+    when(node.get(name)).thenReturn(value);
+
+    Assertions.assertEquals(result, JsonNodeValueResolver.INSTANCE.resolve(node, name));
+
+    verify(node).get(name);
+  }
+
+  @Test
+  void resolveBigIntegerNode() {
+    String name = "bigInt";
+    BigInteger result = BigInteger.ONE;
+
+    JsonNode node = mock(JsonNode.class);
+    JsonNode value = BigIntegerNode.valueOf(result);
+    when(node.get(name)).thenReturn(value);
+
+    Assertions.assertEquals(result, JsonNodeValueResolver.INSTANCE.resolve(node, name));
+
+    verify(node).get(name);
+  }
+
+  @Test
+  void resolveDecimalNode() {
+    String name = "decimal";
+    BigDecimal result = BigDecimal.TEN;
+
+    JsonNode node = mock(JsonNode.class);
+    JsonNode value = DecimalNode.valueOf(result);
+    when(node.get(name)).thenReturn(value);
+
+    Assertions.assertEquals(result, JsonNodeValueResolver.INSTANCE.resolve(node, name));
+
+    verify(node).get(name);
+  }
+
+  @Test
+  void resolveLongNode() {
+    String name = "long";
+    long result = 678L;
+
+    JsonNode node = mock(JsonNode.class);
+    JsonNode value = LongNode.valueOf(result);
+    when(node.get(name)).thenReturn(value);
+
+    Assertions.assertEquals(result, JsonNodeValueResolver.INSTANCE.resolve(node, name));
+
+    verify(node).get(name);
+  }
+
+  @Test
+  void resolvePojoNode() {
+    String name = "pojo";
+    Object result = new Object();
+
+    JsonNode node = mock(JsonNode.class);
+    JsonNode value = new POJONode(result);
+    when(node.get(name)).thenReturn(value);
+
+    Assertions.assertEquals(result, JsonNodeValueResolver.INSTANCE.resolve(node, name));
+
+    verify(node).get(name);
+  }
+
+  @Test
+  void propertySet() {
+    Map<String, Object> root = new LinkedHashMap<String, Object>();
+    root.put("string", "abc");
+    root.put("int", 678);
+    root.put("double", 3.14d);
+    root.put("bool", true);
+
+    Assertions.assertEquals(
+        root.entrySet(), JsonNodeValueResolver.INSTANCE.propertySet(node(root)));
+  }
+
+  @Test
+  void emptyPropertySet() {
+    Set<Entry<String, Object>> propertySet =
+        JsonNodeValueResolver.INSTANCE.propertySet(new Object());
+    assertNotNull(propertySet);
+    assertEquals(0, propertySet.size());
+  }
+
+  @Test
+  void resolveObjectNode() throws IOException {
+    Handlebars handlebars = new Handlebars();
+    Object item =
+        new Object() {
+          @SuppressWarnings("unused")
+          public String getKey() {
+            return "pojo";
+          }
+        };
+
+    Map<String, Object> root = new HashMap<String, Object>();
+    root.put("pojo", item);
+
+    assertEquals("pojo", handlebars.compileInline("{{pojo.key}}").apply(context(root)));
+  }
+
+  @Test
+  void resolveSimpleArrayNode() throws IOException {
+    Handlebars handlebars = new Handlebars();
+
+    Map<String, Object> root = new HashMap<String, Object>();
+    root.put("array", new Object[] {1, 2, 3});
+
+    assertEquals(
+        "123",
+        handlebars.compileInline("{{array.[0]}}{{array.[1]}}{{array.[2]}}").apply(context(root)));
+    assertEquals(
+        "123", handlebars.compileInline("{{#array}}{{this}}{{/array}}").apply(context(root)));
+  }
+
+  @Test
+  void resolveArrayNode() throws IOException {
+    Handlebars handlebars = new Handlebars();
+
+    Object item =
+        new Object() {
+          @SuppressWarnings("unused")
+          public String getKey() {
+            return "pojo";
+          }
+        };
+
+    Map<String, Object> root = new HashMap<String, Object>();
+    root.put("array", new Object[] {item});
+
+    assertEquals("pojo", handlebars.compileInline("{{array.[0].key}}").apply(context(root)));
+    assertEquals(
+        "pojo", handlebars.compileInline("{{#array}}{{key}}{{/array}}").apply(context(root)));
+  }
+
+  public static JsonNode node(final Object object) {
+    JsonMapper mapper = JsonMapper.builder().build();
+    JsonNode node = mapper.readTree(mapper.writeValueAsString(object));
+    return node;
+  }
+
+  public static Context context(final Object object) {
+    return Context.newBuilder(node(object))
+        .resolver(MapValueResolver.INSTANCE, JsonNodeValueResolver.INSTANCE)
+        .build();
+  }
+}

From 944ad982853f5da526392d87da6dc44a395423a6 Mon Sep 17 00:00:00 2001
From: Jens-Otto Larsen <jens-otto.larsen@nav.no>
Date: Sun, 16 Aug 2026 21:01:54 +0200
Subject: [PATCH 2/2] Module for Jackson 3, root

---
 pom.xml | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/pom.xml b/pom.xml
index 406e7714..6ddd598f 100644
--- a/pom.xml
+++ b/pom.xml
@@ -17,6 +17,7 @@
     <module>handlebars-helpers</module>
     <module>handlebars-springmvc</module>
     <module>handlebars-jackson</module>
+    <module>handlebars-jackson3</module>
     <module>handlebars-guava-cache</module>
     <module>handlebars-caffeine</module>
     <module>handlebars-maven-plugin</module>
@@ -107,6 +108,13 @@
         <version>${jackson2-version}</version>
       </dependency>
 
+      <!-- Jackson 3.x -->
+      <dependency>
+        <groupId>tools.jackson.core</groupId>
+        <artifactId>jackson-databind</artifactId>
+        <version>${jackson3-version}</version>
+      </dependency>
+
       <!-- Test dependencies -->
       <dependency>
         <groupId>ch.qos.logback</groupId>
@@ -493,6 +501,7 @@
     <!-- Encoding UTF-8 -->
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <jackson2-version>2.22.1</jackson2-version>
+    <jackson3-version>3.2.1</jackson3-version>
     <spring.version>6.2.9</spring.version>
     <jacoco.version>0.8.12</jacoco.version>
     <antlr-version>4.13.2</antlr-version>