From 5965fddcd0877a4a07118844dd258d8a12f69dcd Mon Sep 17 00:00:00 2001
From: Carsten Wickner <11309681+CarstenWickner@users.noreply.github.com>
Date: Sun, 4 Jun 2023 07:58:13 +0200
Subject: [PATCH] chore(example): show-case reflection based subtype resolution
(#356)
---
jsonschema-examples/pom.xml | 5 +
.../examples/SubtypeLookUpExample.java | 122 ++++++++++++++++++
.../jsonschema/examples/ExampleTest.java | 3 +-
.../examples/SubtypeLookUpExample-result.json | 37 ++++++
4 files changed, 166 insertions(+), 1 deletion(-)
create mode 100644 jsonschema-examples/src/main/java/com/github/victools/jsonschema/examples/SubtypeLookUpExample.java
create mode 100644 jsonschema-examples/src/test/resources/com/github/victools/jsonschema/examples/SubtypeLookUpExample-result.json
diff --git a/jsonschema-examples/pom.xml b/jsonschema-examples/pom.xml
index 66e509aa..6b118ddd 100644
--- a/jsonschema-examples/pom.xml
+++ b/jsonschema-examples/pom.xml
@@ -64,6 +64,11 @@
io.swagger.core.v3
swagger-annotations
+
+ io.github.classgraph
+ classgraph
+ 4.8.149
+
diff --git a/jsonschema-examples/src/main/java/com/github/victools/jsonschema/examples/SubtypeLookUpExample.java b/jsonschema-examples/src/main/java/com/github/victools/jsonschema/examples/SubtypeLookUpExample.java
new file mode 100644
index 00000000..a2b9f255
--- /dev/null
+++ b/jsonschema-examples/src/main/java/com/github/victools/jsonschema/examples/SubtypeLookUpExample.java
@@ -0,0 +1,122 @@
+/*
+ * Copyright 2023 VicTools.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.github.victools.jsonschema.examples;
+
+import com.fasterxml.classmate.ResolvedType;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import com.github.victools.jsonschema.generator.Option;
+import com.github.victools.jsonschema.generator.OptionPreset;
+import com.github.victools.jsonschema.generator.SchemaGenerationContext;
+import com.github.victools.jsonschema.generator.SchemaGenerator;
+import com.github.victools.jsonschema.generator.SchemaGeneratorConfig;
+import com.github.victools.jsonschema.generator.SchemaGeneratorConfigBuilder;
+import com.github.victools.jsonschema.generator.SchemaVersion;
+import com.github.victools.jsonschema.generator.SubtypeResolver;
+import com.github.victools.jsonschema.generator.TypeContext;
+import io.github.classgraph.ClassGraph;
+import io.github.classgraph.ClassInfo;
+import io.github.classgraph.ClassInfoList;
+import io.github.classgraph.ScanResult;
+import java.util.List;
+import java.util.stream.Collectors;
+
+/**
+ * Example created to show-case generic subtype look-up.
+ *
+ * Using classgraph for determining type hierarchy.
+ */
+public class SubtypeLookUpExample implements SchemaGenerationExampleInterface {
+
+ @Override
+ public ObjectNode generateSchema() {
+ SchemaGeneratorConfigBuilder configBuilder = new SchemaGeneratorConfigBuilder(SchemaVersion.DRAFT_2020_12, OptionPreset.PLAIN_JSON);
+ configBuilder.with(Option.DEFINITIONS_FOR_ALL_OBJECTS, Option.DEFINITIONS_FOR_MEMBER_SUPERTYPES);
+ configBuilder.forTypesInGeneral()
+ .withSubtypeResolver(new ClassGraphSubtypeResolver());
+ SchemaGeneratorConfig config = configBuilder.build();
+ SchemaGenerator generator = new SchemaGenerator(config);
+ return generator.generateSchema(Example.class);
+ }
+
+ /**
+ * Simple implementation of a reflection based subtype resolver, considering only subtypes from a certain package.
+ */
+ static class ClassGraphSubtypeResolver implements SubtypeResolver {
+
+ private final ClassGraph classGraphConfig;
+ private ScanResult scanResult;
+
+ ClassGraphSubtypeResolver() {
+ this.classGraphConfig = new ClassGraph()
+ .enableClassInfo()
+ .enableInterClassDependencies()
+ // in this example, only consider a certain set of potential subtypes
+ .acceptPackages("com.github.victools.jsonschema.examples");
+ }
+
+ private ScanResult getScanResult() {
+ if (this.scanResult == null) {
+ this.scanResult = this.classGraphConfig.scan();
+ }
+ return this.scanResult;
+ }
+
+ @Override
+ public void resetAfterSchemaGenerationFinished() {
+ if (this.scanResult != null) {
+ this.scanResult.close();
+ this.scanResult = null;
+ }
+ }
+
+ @Override
+ public List findSubtypes(ResolvedType declaredType, SchemaGenerationContext context) {
+ if (declaredType.getErasedType() == Object.class) {
+ return null;
+ }
+ ClassInfoList subtypes;
+ if (declaredType.isInterface()) {
+ subtypes = this.getScanResult().getClassesImplementing(declaredType.getErasedType());
+ } else {
+ subtypes = this.getScanResult().getSubclasses(declaredType.getErasedType());
+ }
+ if (!subtypes.isEmpty()) {
+ TypeContext typeContext = context.getTypeContext();
+ return subtypes.loadClasses(true)
+ .stream()
+ .map(subclass -> typeContext.resolveSubtype(declaredType, subclass))
+ .collect(Collectors.toList());
+ }
+ return null;
+ }
+ }
+
+ static class Example {
+ public BaseType declaredAsBaseType;
+ }
+
+ interface BaseType {
+ }
+
+ static class SubType1 implements BaseType {
+ public String text;
+ }
+
+ static class SubType2 implements BaseType {
+ public List nested;
+ }
+}
diff --git a/jsonschema-examples/src/test/java/com/github/victools/jsonschema/examples/ExampleTest.java b/jsonschema-examples/src/test/java/com/github/victools/jsonschema/examples/ExampleTest.java
index 1bd1dc42..2095bc07 100644
--- a/jsonschema-examples/src/test/java/com/github/victools/jsonschema/examples/ExampleTest.java
+++ b/jsonschema-examples/src/test/java/com/github/victools/jsonschema/examples/ExampleTest.java
@@ -37,7 +37,8 @@ public class ExampleTest {
IfThenElseExample.class,
JacksonDescriptionAsTitleExample.class,
JacksonSubtypeDefinitionExample.class,
- StrictTypeInfoExample.class
+ StrictTypeInfoExample.class,
+ SubtypeLookUpExample.class
})
public void testExample(Class extends SchemaGenerationExampleInterface> exampleType) throws Exception {
SchemaGenerationExampleInterface exampleImplementation = exampleType.getDeclaredConstructor().newInstance();
diff --git a/jsonschema-examples/src/test/resources/com/github/victools/jsonschema/examples/SubtypeLookUpExample-result.json b/jsonschema-examples/src/test/resources/com/github/victools/jsonschema/examples/SubtypeLookUpExample-result.json
new file mode 100644
index 00000000..80a5a1b8
--- /dev/null
+++ b/jsonschema-examples/src/test/resources/com/github/victools/jsonschema/examples/SubtypeLookUpExample-result.json
@@ -0,0 +1,37 @@
+{
+ "$schema" : "https://json-schema.org/draft/2020-12/schema",
+ "$defs" : {
+ "BaseType" : {
+ "anyOf" : [ {
+ "$ref" : "#/$defs/SubType1"
+ }, {
+ "$ref" : "#/$defs/SubType2"
+ } ]
+ },
+ "SubType1" : {
+ "type" : "object",
+ "properties" : {
+ "text" : {
+ "type" : "string"
+ }
+ }
+ },
+ "SubType2" : {
+ "type" : "object",
+ "properties" : {
+ "nested" : {
+ "type" : "array",
+ "items" : {
+ "$ref" : "#/$defs/BaseType"
+ }
+ }
+ }
+ }
+ },
+ "type" : "object",
+ "properties" : {
+ "declaredAsBaseType" : {
+ "$ref" : "#/$defs/BaseType"
+ }
+ }
+}