1 files changed, 74 insertions, 0 deletions
diff --git a/javaparser-core/src/main/java/com/github/javaparser/printer/JsonPrinter.java b/javaparser-core/src/main/java/com/github/javaparser/printer/JsonPrinter.java
new file mode 100644
index 000000000..237051265
--- /dev/null
+++ b/javaparser-core/src/main/java/com/github/javaparser/printer/JsonPrinter.java
@@ -0,0 +1,74 @@
+package com.github.javaparser.printer;
+
+import com.github.javaparser.ast.Node;
+import com.github.javaparser.ast.NodeList;
+import com.github.javaparser.metamodel.NodeMetaModel;
+import com.github.javaparser.metamodel.PropertyMetaModel;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static com.github.javaparser.utils.Utils.assertNotNull;
+import static java.util.stream.Collectors.toList;
+
+/**
+ * Outputs a JSON file containing the AST meant for inspecting it.
+ */
+public class JsonPrinter {
+    private final boolean outputNodeType;
+
+    public JsonPrinter(boolean outputNodeType) {
+        this.outputNodeType = outputNodeType;
+    }
+
+    public String output(Node node) {
+        return output(node, null, 0);
+    }
+
+    public String output(Node node, String name, int level) {
+        assertNotNull(node);
+        NodeMetaModel metaModel = node.getMetaModel();
+        List<PropertyMetaModel> allPropertyMetaModels = metaModel.getAllPropertyMetaModels();
+        List<PropertyMetaModel> attributes = allPropertyMetaModels.stream().filter(PropertyMetaModel::isAttribute).filter(PropertyMetaModel::isSingular).collect(toList());
+        List<PropertyMetaModel> subNodes = allPropertyMetaModels.stream().filter(PropertyMetaModel::isNode).filter(PropertyMetaModel::isSingular).collect(toList());
+        List<PropertyMetaModel> subLists = allPropertyMetaModels.stream().filter(PropertyMetaModel::isNodeList).collect(toList());
+
+        final List<String> content = new ArrayList<>();
+
+        if (outputNodeType) {
+            content.add(q("type") + ":" + q(metaModel.getTypeName()));
+        }
+
+        for (PropertyMetaModel attributeMetaModel : attributes) {
+            content.add(q(attributeMetaModel.getName()) + ":" + q(attributeMetaModel.getValue(node).toString()));
+        }
+
+        for (PropertyMetaModel subNodeMetaModel : subNodes) {
+            Node value = (Node) subNodeMetaModel.getValue(node);
+            if (value != null) {
+                content.add(output(value, subNodeMetaModel.getName(), level + 1));
+            }
+        }
+
+        for (PropertyMetaModel subListMetaModel : subLists) {
+            NodeList<? extends Node> subList = (NodeList<? extends Node>) subListMetaModel.getValue(node);
+            if (subList != null && !subList.isEmpty()) {
+                final List<String> listContent = new ArrayList<>();
+                for (Node subListNode : subList) {
+                    listContent.add(output(subListNode, null, level + 1));
+                }
+                content.add(listContent.stream().collect(Collectors.joining(",", q(subListMetaModel.getName()) + ":[", "]")));
+            }
+        }
+
+        if (name == null) {
+            return content.stream().collect(Collectors.joining(",", "{", "}"));
+        }
+        return content.stream().collect(Collectors.joining(",", q(name) + ":{", "}"));
+    }
+
+    private static String q(String value) {
+        return "\"" + value.replace("\"", "\\\"").replace("\n", "\\n").replace("\r", "\\r") + "\"";
+    }
+}