feat: Add complex type support for JSON mappings.

src/main/java/io/github/nstdio/http/ext/spi/GsonJsonMapping.java

@@ -23,6 +23,7 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
+import java.lang.reflect.Type;
 import java.util.Objects;
 
 import static java.nio.charset.StandardCharsets.UTF_8;
@@ -48,8 +49,22 @@ public <T> T read(InputStream in, Class<T> targetType) throws IOException {
     }
   }
 
+  @Override
+  public <T> T read(InputStream in, Type targetType) throws IOException {
+    try (var reader = new InputStreamReader(in, UTF_8)) {
+      return gson.fromJson(reader, targetType);
+    } catch (JsonParseException e) {
+      throw new IOException(e);
+    }
+  }
+
   @Override
   public <T> T read(byte[] bytes, Class<T> targetType) throws IOException {
     return read(new ByteArrayInputStream(bytes), targetType);
   }
+
+  @Override
+  public <T> T read(byte[] bytes, Type targetType) throws IOException {
+    return read(new ByteArrayInputStream(bytes), targetType);
+  }
 }

src/main/java/io/github/nstdio/http/ext/spi/JacksonJsonMapping.java

@@ -16,10 +16,12 @@
 
 package io.github.nstdio.http.ext.spi;
 
+import com.fasterxml.jackson.databind.JavaType;
 import com.fasterxml.jackson.databind.ObjectMapper;
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.lang.reflect.Type;
 
 public class JacksonJsonMapping implements JsonMapping {
   private final ObjectMapper mapper;
@@ -40,8 +42,25 @@ public <T> T read(InputStream in, Class<T> targetType) throws IOException {
     }
   }
 
+  @Override
+  public <T> T read(InputStream in, Type targetType) throws IOException {
+    try (var stream = in) {
+      return mapper.readValue(stream, constructType(targetType));
+    }
+  }
+
   @Override
   public <T> T read(byte[] bytes, Class<T> targetType) throws IOException {
     return mapper.readValue(bytes, targetType);
   }
+
+  @Override
+  public <T> T read(byte[] bytes, Type targetType) throws IOException {
+    return mapper.readValue(bytes, constructType(targetType));
+  }
+
+
+  private JavaType constructType(Type targetType) {
+    return mapper.constructType(targetType);
+  }
 }

src/main/java/io/github/nstdio/http/ext/spi/JsonMapping.java

@@ -18,6 +18,7 @@
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.lang.reflect.Type;
 
 /**
  * The simple strategy for binding JSON to Java objects.
@@ -37,6 +38,20 @@ public interface JsonMapping {
    */
   <T> T read(InputStream in, Class<T> targetType) throws IOException;
 
+  /**
+   * Reads JSON data from the {@code in} and creates mapped object of type {@code targetType}. Note that {@code in}
+   * might not be closed by the underlying implementation and caller should try to close {@code in}.
+   *
+   * @param in         The input source.
+   * @param targetType The required type.
+   * @param <T>        The type of object to create.
+   *
+   * @return The object created from JSON.
+   *
+   * @throws IOException When there is a JSON parsing or binding error or I/O error occurred.
+   */
+  <T> T read(InputStream in, Type targetType) throws IOException;
+
   /**
    * Reads JSON data from the {@code bytes} and creates mapped object of type {@code targetType}.
    *
@@ -49,4 +64,17 @@ public interface JsonMapping {
    * @throws IOException When there is a JSON parsing or binding error or I/O error occurred.
    */
   <T> T read(byte[] bytes, Class<T> targetType) throws IOException;
+
+  /**
+   * Reads JSON data from the {@code bytes} and creates mapped object of type {@code targetType}.
+   *
+   * @param bytes      The input source.
+   * @param targetType The required type.
+   * @param <T>        The type of object to create.
+   *
+   * @return The object created from JSON.
+   *
+   * @throws IOException When there is a JSON parsing or binding error or I/O error occurred.
+   */
+  <T> T read(byte[] bytes, Type targetType) throws IOException;
 }

src/spiTest/java/io/github/nstdio/http/ext/spi/GsonJsonMappingTest.java

@@ -17,57 +17,13 @@
 package io.github.nstdio.http.ext.spi;
 
 import io.github.nstdio.http.ext.jupiter.EnabledIfOnClasspath;
-import org.junit.jupiter.api.Test;
-
-import java.io.ByteArrayInputStream;
-import java.io.IOException;
-import java.nio.charset.StandardCharsets;
 
 import static io.github.nstdio.http.ext.OptionalDependencies.GSON;
-import static org.assertj.core.api.Assertions.assertThat;
-import static org.assertj.core.api.Assertions.assertThatIOException;
-import static org.mockito.Mockito.spy;
-import static org.mockito.Mockito.verify;
 
 @EnabledIfOnClasspath(GSON)
-class GsonJsonMappingTest {
-
-  @Test
-  void shouldThrowIOExceptionWhenParsingException() {
-    //given
-    var bytes = "{".getBytes(StandardCharsets.UTF_8);
-    var mapping = new GsonJsonMapping();
-
-    //when
-    assertThatIOException()
-        .isThrownBy(() -> mapping.read(bytes, Object.class))
-        .havingCause();
-  }
-
-  @Test
-  void shouldCloseInputStream() throws IOException {
-    //given
-    var inSpy = spy(new ByteArrayInputStream("{}".getBytes(StandardCharsets.UTF_8)));
-    var mapping = new GsonJsonMapping();
-
-    //when
-    Object read = mapping.read(inSpy, Object.class);
-
-    //then
-    assertThat(read).isNotNull();
-    verify(inSpy).close();
-  }
-
-  @Test
-  void shouldReadFromByteArray() throws IOException {
-    //given
-    var bytes = "{}".getBytes(StandardCharsets.UTF_8);
-    var mapping = new GsonJsonMapping();
-
-    //when
-    Object read = mapping.read(bytes, Object.class);
-
-    //then
-    assertThat(read).isNotNull();
+public class GsonJsonMappingTest implements JsonMappingContract {
+  @Override
+  public JsonMapping get() {
+    return new GsonJsonMapping();
   }
-}
+}

src/spiTest/java/io/github/nstdio/http/ext/spi/JacksonJsonMappingTest.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright (C) 2022 Edgar Asatryan
+ *
+ * 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 io.github.nstdio.http.ext.spi;
+
+import io.github.nstdio.http.ext.jupiter.EnabledIfOnClasspath;
+
+import static io.github.nstdio.http.ext.OptionalDependencies.JACKSON;
+
+@EnabledIfOnClasspath(JACKSON)
+public class JacksonJsonMappingTest implements JsonMappingContract {
+  @Override
+  public JsonMapping get() {
+    return new JacksonJsonMapping();
+  }
+}

src/spiTest/java/io/github/nstdio/http/ext/spi/JsonMappingContract.java

@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2022 Edgar Asatryan
+ *
+ * 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 io.github.nstdio.http.ext.spi;
+
+import com.google.common.reflect.TypeToken;
+import org.junit.jupiter.api.Test;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.List;
+import java.util.Map;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.mockito.Mockito.*;
+
+interface JsonMappingContract {
+  JsonMapping get();
+
+  @Test
+  default void shouldThrowIOExceptionWhenParsingException() {
+    //given
+    var bytes = "{".getBytes(StandardCharsets.UTF_8);
+    var mapping = get();
+
+    //when
+    assertThrows(IOException.class, () -> mapping.read(bytes, Object.class));
+  }
+
+  @Test
+  default void shouldThrowIOExceptionWhenParsingExceptionWithComplexType() {
+    //given
+    var bytes = new ByteArrayInputStream("{".getBytes(StandardCharsets.UTF_8));
+    var mapping = get();
+    var targetType = new TypeToken<List<String>>() {}.getType();
+
+    //when
+    assertThrows(IOException.class, () -> mapping.read(bytes, targetType));
+  }
+
+  @Test
+  default void shouldCloseInputStream() throws IOException {
+    //given
+    byte[] jsonBytes = "{}".getBytes(StandardCharsets.UTF_8);
+    var inSpy = spy(new ByteArrayInputStream(jsonBytes));
+    var mapping = get();
+
+    //when
+    Object read = mapping.read(inSpy, Object.class);
+
+    //then
+    assertThat(read).isNotNull();
+    verify(inSpy, atLeastOnce()).close();
+  }
+
+  @Test
+  default void shouldReadFromByteArray() throws IOException {
+    //given
+    var jsonBytes = "{}".getBytes(StandardCharsets.UTF_8);
+    var mapping = get();
+
+    //when
+    Object read = mapping.read(jsonBytes, Object.class);
+
+    //then
+    assertThat(read).isNotNull();
+  }
+
+  @Test
+  default void shouldReadFromByteArrayUsingComplexType() throws IOException {
+    //given
+    var jsonBytes = "{\"a\": 1, \"b\": 2}".getBytes(StandardCharsets.UTF_8);
+    var mapping = get();
+    var targetType = new TypeToken<Map<String, Integer>>() {
+    }.getType();
+
+    //when
+    Map<String, Integer> read = mapping.read(jsonBytes, targetType);
+
+    //then
+    assertThat(read)
+        .hasSize(2)
+        .containsEntry("a", 1)
+        .containsEntry("b", 2);
+  }
+
+  @Test
+  default void shouldReadFromInputStreamUsingComplexType() throws IOException {
+    //given
+    var jsonBytes = new ByteArrayInputStream("{\"a\": 1, \"b\": 2}".getBytes(StandardCharsets.UTF_8));
+    var mapping = get();
+    var targetType = new TypeToken<Map<String, Integer>>() {
+    }.getType();
+
+    //when
+    Map<String, Integer> read = mapping.read(jsonBytes, targetType);
+
+    //then
+    assertThat(read)
+        .hasSize(2)
+        .containsEntry("a", 1)
+        .containsEntry("b", 2);
+  }
+}