#39 - Adds support for types with generic parameters

blackbox-test/src/main/java/org/example/customer/generics/MyGenericHolder.java

@@ -0,0 +1,38 @@
+package org.example.customer.generics;
+
+import io.avaje.jsonb.Json;
+
+@Json
+public class MyGenericHolder<T> {
+
+  String title;
+  String author;
+  T document;
+
+  public String getTitle() {
+    return title;
+  }
+
+  public MyGenericHolder<T> setTitle(String title) {
+    this.title = title;
+    return this;
+  }
+
+  public String getAuthor() {
+    return author;
+  }
+
+  public MyGenericHolder<T> setAuthor(String author) {
+    this.author = author;
+    return this;
+  }
+
+  public T getDocument() {
+    return document;
+  }
+
+  public MyGenericHolder<T> setDocument(T document) {
+    this.document = document;
+    return this;
+  }
+}

blackbox-test/src/main/java/org/example/customer/generics/MyGenericPageResult.java

@@ -0,0 +1,50 @@
+package org.example.customer.generics;
+
+import io.avaje.jsonb.Json;
+
+import java.util.List;
+
+@Json
+public class MyGenericPageResult<T> {
+
+  int page;
+  int pageSize;
+  int totalPageCount;
+  List<? extends T> results;
+
+  public int getPage() {
+    return page;
+  }
+
+  public MyGenericPageResult<T> setPage(int page) {
+    this.page = page;
+    return this;
+  }
+
+  public int getPageSize() {
+    return pageSize;
+  }
+
+  public MyGenericPageResult<T> setPageSize(int pageSize) {
+    this.pageSize = pageSize;
+    return this;
+  }
+
+  public int getTotalPageCount() {
+    return totalPageCount;
+  }
+
+  public MyGenericPageResult<T> setTotalPageCount(int totalPageCount) {
+    this.totalPageCount = totalPageCount;
+    return this;
+  }
+
+  public List<? extends T> getResults() {
+    return results;
+  }
+
+  public MyGenericPageResult<T> setResults(List<? extends T> results) {
+    this.results = results;
+    return this;
+  }
+}

blackbox-test/src/test/java/org/example/customer/generics/MyGenericHolderTest.java

@@ -0,0 +1,75 @@
+package org.example.customer.generics;
+
+import io.avaje.jsonb.JsonType;
+import io.avaje.jsonb.JsonView;
+import io.avaje.jsonb.Jsonb;
+import io.avaje.jsonb.Types;
+import org.example.customer.Address;
+import org.junit.jupiter.api.Test;
+
+import java.util.LinkedHashMap;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class MyGenericHolderTest {
+
+  Jsonb jsonb = Jsonb.builder().build();
+
+  private static MyGenericHolder<Address> createTestData() {
+    var bean = new MyGenericHolder<Address>();
+    bean.setTitle("hello").setAuthor("art").setDocument(new Address(90L, "one"));
+    return bean;
+  }
+
+  @SuppressWarnings({"rawtypes"})
+  @Test
+  void toJson() {
+    MyGenericHolder<Address> bean = createTestData();
+
+    var type = jsonb.type(MyGenericHolder.class);
+
+    String asJson = type.toJson(bean);
+    assertThat(asJson).isEqualTo("{\"title\":\"hello\",\"author\":\"art\",\"document\":{\"id\":90,\"street\":\"one\"}}");
+    assertThat(jsonb.toJson(bean)).isEqualTo(asJson);
+
+    MyGenericHolder pageResult = type.fromJson(asJson);
+    Object document = pageResult.getDocument();
+    // reading via Object means the list contains LinkedHashMap
+    assertThat(document).isInstanceOf(LinkedHashMap.class);
+    LinkedHashMap asMap = (LinkedHashMap)document;
+    assertThat(asMap.get("street")).isEqualTo("one");
+
+    JsonView<MyGenericHolder> view = type.view("author,document(id)");
+    String partialJson2 = view.toJson(bean);
+    // not supporting partial on the generic object (output includes street)
+    assertThat(partialJson2).isEqualTo("{\"author\":\"art\",\"document\":{\"id\":90,\"street\":\"one\"}}");
+  }
+
+
+  @Test
+  void toJson_withGenericParam() {
+    MyGenericHolder<Address> bean = createTestData();
+
+    Jsonb jsonb = Jsonb.builder().build();
+    JsonType<MyGenericHolder<Address>> type = jsonb.type(Types.newParameterizedType(MyGenericHolder.class, Address.class));
+
+    String asJson = type.toJson(bean);
+    assertThat(asJson).isEqualTo("{\"title\":\"hello\",\"author\":\"art\",\"document\":{\"id\":90,\"street\":\"one\"}}");
+    assertThat(jsonb.toJson(bean)).isEqualTo(asJson);
+
+    MyGenericHolder<Address> genericResult = type.fromJson(asJson);
+    Address document = genericResult.getDocument();
+
+    assertThat(document.getId()).isEqualTo(90L);
+    assertThat(document.getStreet()).isEqualTo("one");
+
+
+    JsonView<MyGenericHolder<Address>> partial = type.view("author,document(*)");
+    String partialJson = partial.toJson(bean);
+    assertThat(partialJson).isEqualTo("{\"author\":\"art\",\"document\":{\"id\":90,\"street\":\"one\"}}");
+
+    JsonView<MyGenericHolder<Address>> partial2 = type.view("author,document(id)");
+    String partialJson2 = partial2.toJson(bean);
+    assertThat(partialJson2).isEqualTo("{\"author\":\"art\",\"document\":{\"id\":90}}");
+  }
+}

blackbox-test/src/test/java/org/example/customer/generics/MyGenericPageResultTest.java

@@ -0,0 +1,75 @@
+package org.example.customer.generics;
+
+import io.avaje.jsonb.JsonType;
+import io.avaje.jsonb.JsonView;
+import io.avaje.jsonb.Jsonb;
+import io.avaje.jsonb.Types;
+import org.example.customer.Address;
+import org.junit.jupiter.api.Test;
+
+import java.util.LinkedHashMap;
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class MyGenericPageResultTest {
+
+  Jsonb jsonb = Jsonb.builder().build();
+
+  private static MyGenericPageResult<Address> createPageTestData() {
+    var bean = new MyGenericPageResult<Address>();
+    bean.setPage(42).setPageSize(10).setResults(List.of(new Address(90L, "one"), new Address(91L, "two")));
+    return bean;
+  }
+
+  @SuppressWarnings({"rawtypes"})
+  @Test
+  void toJson() {
+    MyGenericPageResult<Address> bean = createPageTestData();
+
+    var type = jsonb.type(MyGenericPageResult.class);
+
+    String asJson = type.toJson(bean);
+    assertThat(asJson).isEqualTo("{\"page\":42,\"pageSize\":10,\"totalPageCount\":0,\"results\":[{\"id\":90,\"street\":\"one\"},{\"id\":91,\"street\":\"two\"}]}");
+    assertThat(jsonb.toJson(bean)).isEqualTo(asJson);
+
+    MyGenericPageResult pageResult = type.fromJson(asJson);
+    List list = pageResult.getResults();
+    assertThat(list).hasSize(2);
+    // reading via Object means the list contains LinkedHashMap
+    assertThat(list.get(0)).isInstanceOf(LinkedHashMap.class);
+
+    JsonView<MyGenericPageResult> partial2 = type.view("page,results(id)");
+    String partialJson2 = partial2.toJson(bean);
+    // not supporting partial on the generic list of object (output includes street)
+    assertThat(partialJson2).isEqualTo("{\"page\":42,\"results\":[{\"id\":90,\"street\":\"one\"},{\"id\":91,\"street\":\"two\"}]}");
+  }
+
+
+  @Test
+  void toJson_withGenericParam() {
+    MyGenericPageResult<Address> bean = createPageTestData();
+
+    Jsonb jsonb = Jsonb.builder().build();
+
+    JsonType<MyGenericPageResult<Address>> type = jsonb.type(Types.newParameterizedType(MyGenericPageResult.class, Address.class));
+
+    String asJson = type.toJson(bean);
+    assertThat(asJson).isEqualTo("{\"page\":42,\"pageSize\":10,\"totalPageCount\":0,\"results\":[{\"id\":90,\"street\":\"one\"},{\"id\":91,\"street\":\"two\"}]}");
+    assertThat(jsonb.toJson(bean)).isEqualTo(asJson);
+
+    MyGenericPageResult<Address> genericResult = type.fromJson(asJson);
+    List<? extends Address> addresses = genericResult.getResults();
+
+    assertThat(addresses).hasSize(2);
+    assertThat(addresses.get(0)).isInstanceOf(Address.class);
+
+    JsonView<MyGenericPageResult<Address>> partial = type.view("page,results(*)");
+    String partialJson = partial.toJson(bean);
+    assertThat(partialJson).isEqualTo("{\"page\":42,\"results\":[{\"id\":90,\"street\":\"one\"},{\"id\":91,\"street\":\"two\"}]}");
+
+    JsonView<MyGenericPageResult<Address>> partial2 = type.view("page,results(id)");
+    String partialJson2 = partial2.toJson(bean);
+    assertThat(partialJson2).isEqualTo("{\"page\":42,\"results\":[{\"id\":90},{\"id\":91}]}");
+  }
+}

jsonb-generator/src/main/java/io/avaje/jsonb/generator/BeanReader.java

@@ -57,6 +57,10 @@ public BeanReader(TypeElement beanType, TypeElement mixInElement, ProcessingCont
     this.constructor = typeReader.constructor();
   }
 
+  int genericTypeParamsCount() {
+    return typeReader.genericTypeParamsCount();
+  }
+
   @Override
   public String toString() {
     return beanType.toString();
@@ -106,6 +110,10 @@ private String shortName(Element element) {
   }
 
   private Set<String> importTypes() {
+    if (genericTypeParamsCount() > 0) {
+      importTypes.add(Constants.REFLECT_TYPE);
+      importTypes.add(Constants.PARAMETERIZED_TYPE);
+    }
     importTypes.add(Constants.JSONB_WILD);
     importTypes.add(Constants.IOEXCEPTION);
     importTypes.add(Constants.JSONB_SPI);

jsonb-generator/src/main/java/io/avaje/jsonb/generator/ComponentMetaData.java

@@ -5,6 +5,7 @@
 class ComponentMetaData {
 
   private final List<String> allTypes = new ArrayList<>();
+  private final List<String> factoryTypes = new ArrayList<>();
   private String fullName;
 
   @Override
@@ -27,6 +28,10 @@ void add(String type) {
     allTypes.add(type);
   }
 
+  void addFactory(String fullName) {
+    factoryTypes.add(fullName);
+  }
+
   void setFullName(String fullName) {
     this.fullName = fullName;
   }
@@ -50,6 +55,10 @@ List<String> all() {
     return allTypes;
   }
 
+  List<String> allFactories() {
+    return factoryTypes;
+  }
+
   /**
    * Return the package imports for the JsonAdapters and related types.
    */

jsonb-generator/src/main/java/io/avaje/jsonb/generator/ComponentReader.java

@@ -19,6 +19,7 @@
 class ComponentReader {
 
   private static final String META_DATA = "io.avaje.jsonb.spi.MetaData";
+  private static final String META_DATA_FACTORY = "io.avaje.jsonb.spi.MetaData.Factory";
   private final ProcessingContext ctx;
   private final ComponentMetaData componentMetaData;
 
@@ -44,13 +45,21 @@ void read() {
   private void readMetaData(TypeElement moduleType) {
     for (AnnotationMirror annotationMirror : moduleType.getAnnotationMirrors()) {
       if (META_DATA.equals(annotationMirror.getAnnotationType().toString())) {
-        for (Map.Entry<? extends ExecutableElement, ? extends AnnotationValue> entry : annotationMirror.getElementValues().entrySet()) {
-          for (Object adapterEntry : (List<?>) entry.getValue().getValue()) {
-            componentMetaData.add(adapterNameFromEntry(adapterEntry));
-          }
-        }
+        readValues(annotationMirror).forEach(componentMetaData::add);
+      } else if (META_DATA_FACTORY.equals(annotationMirror.getAnnotationType().toString())) {
+        readValues(annotationMirror).forEach(componentMetaData::addFactory);
+      }
+    }
+  }
+
+  private List<String> readValues(AnnotationMirror annotationMirror) {
+    List<String> adapterClasses = new ArrayList<>();
+    for (Map.Entry<? extends ExecutableElement, ? extends AnnotationValue> entry : annotationMirror.getElementValues().entrySet()) {
+      for (Object adapterEntry : (List<?>) entry.getValue().getValue()) {
+        adapterClasses.add(adapterNameFromEntry(adapterEntry));
       }
     }
+    return adapterClasses;
   }
 
   private String adapterNameFromEntry(Object adapterEntry) {

jsonb-generator/src/main/java/io/avaje/jsonb/generator/Constants.java

@@ -8,5 +8,7 @@ class Constants {
   static final String JSONB = "io.avaje.jsonb.Jsonb";
   static final String IOEXCEPTION = "java.io.IOException";
   static final String METHODHANDLE = "java.lang.invoke.MethodHandle";
+  static final String REFLECT_TYPE = "java.lang.reflect.Type";
+  static final String PARAMETERIZED_TYPE = "java.lang.reflect.ParameterizedType";
 
 }