[json-core] Add helper toJson() fromJson() methods that use JsonReade…

…r JsonWriter

This makes it more trivially obvious when using SimpleMapper or JsonNodeMapper to implement a JsonAdapter [where the API uses JsonReader and JsonWriter]

json-core/src/main/java/io/avaje/json/simple/DSimpleMapper.java

@@ -1,6 +1,8 @@
 package io.avaje.json.simple;
 
 import io.avaje.json.JsonAdapter;
+import io.avaje.json.JsonReader;
+import io.avaje.json.JsonWriter;
 import io.avaje.json.PropertyNames;
 import io.avaje.json.core.CoreTypes;
 import io.avaje.json.stream.JsonStream;
@@ -52,11 +54,26 @@ public String toJson(Object object) {
     return objectType.toJson(object);
   }
 
+  @Override
+  public void toJson(Object object, JsonWriter jsonWriter) {
+    objectType.toJson(object, jsonWriter);
+  }
+
   @Override
   public Object fromJson(String json) {
     return objectType.fromJson(json);
   }
 
+  @Override
+  public Object fromJson(JsonReader jsonReader) {
+    return objectType.fromJson(jsonReader);
+  }
+
+  @Override
+  public Map<String, Object> fromJsonObject(JsonReader jsonReader) {
+    return mapType.fromJson(jsonReader);
+  }
+
   @Override
   public Map<String,Object> fromJsonObject(String json) {
     return mapType.fromJson(json);
@@ -66,4 +83,9 @@ public Map<String,Object> fromJsonObject(String json) {
   public List<Object> fromJsonArray(String json) {
     return listType.fromJson(json);
   }
+
+  @Override
+  public List<Object> fromJsonArray(JsonReader jsonReader) {
+    return listType.fromJson(jsonReader);
+  }
 }

json-core/src/main/java/io/avaje/json/simple/SimpleMapper.java

@@ -73,25 +73,52 @@ static Builder builder() {
    */
   String toJson(Object object);
 
+  /**
+   * Write the object to JsonWriter.
+   * <p>
+   * For options to write json content to OutputStream, Writer etc
+   * use {@link Type}.
+   */
+  void toJson(Object object, JsonWriter jsonWriter);
+
   /**
    * Read the object from JSON string.
    */
   Object fromJson(String json);
 
+  /**
+   * Read the object from JSON.
+   */
+  Object fromJson(JsonReader jsonReader);
+
   /**
    * Read a Map from JSON OBJECT string.
    * <p>
    * Use {@link #map()} for more reading options.
    */
   Map<String, Object> fromJsonObject(String json);
 
+  /**
+   * Read a Map from JSON OBJECT.
+   * <p>
+   * Use {@link #map()} for more reading options.
+   */
+  Map<String, Object> fromJsonObject(JsonReader jsonReader);
+
   /**
    * Read a List from JSON ARRAY string.
    * <p>
    * Use {@link #list()} for more reading options.
    */
   List<Object> fromJsonArray(String json);
 
+  /**
+   * Read a List from JSON ARRAY.
+   * <p>
+   * Use {@link #list()} for more reading options.
+   */
+  List<Object> fromJsonArray(JsonReader jsonReader);
+
   /**
    * Return the property names as PropertyNames.
    * <p>

json-core/src/test/java/io/avaje/json/simple/SimpleMapperTest.java

@@ -1,6 +1,9 @@
 package io.avaje.json.simple;
 
 
+import io.avaje.json.JsonReader;
+import io.avaje.json.stream.BufferedJsonWriter;
+import io.avaje.json.stream.JsonStream;
 import org.junit.jupiter.api.Test;
 
 import java.util.LinkedHashMap;
@@ -30,14 +33,52 @@ void mapToJsonFromJson() {
 
     Map<String, Object> mapFromJson2 = simpleMapper.map().fromJson(asJson);
     assertThat(mapFromJson2).isEqualTo(mapFromJson);
+
+    JsonStream jsonStream = JsonStream.builder().build();
+    try (JsonReader reader = jsonStream.reader(asJson)) {
+      Map<String, Object> mapFromJson3 = simpleMapper.fromJsonObject(reader);
+      assertThat(mapFromJson3).isEqualTo(mapFromJson);
+    }
+  }
+
+  @Test
+  void toJsonWriter_scalar() {
+    JsonStream jsonStream = JsonStream.builder().build();
+    BufferedJsonWriter writer0 = jsonStream.bufferedWriter();
+    simpleMapper.toJson("hi", writer0);
+    assertThat(writer0.result()).isEqualTo("\"hi\"");
+  }
+
+  @Test
+  void toJsonWriter_map() {
+    JsonStream jsonStream = JsonStream.builder().build();
+    BufferedJsonWriter writer0 = jsonStream.bufferedWriter();
+    simpleMapper.toJson(Map.of("key", 0), writer0);
+    assertThat(writer0.result()).isEqualTo("{\"key\":0}");
+  }
+
+  @Test
+  void toJsonWriter_list() {
+    JsonStream jsonStream = JsonStream.builder().build();
+    BufferedJsonWriter writer0 = jsonStream.bufferedWriter();
+    simpleMapper.toJson(List.of("a", 0), writer0);
+    assertThat(writer0.result()).isEqualTo("[\"a\",0]");
   }
 
   @Test
   void nullDirectly() {
-   var mapFromJson = simpleMapper.fromJson("null");
+    var mapFromJson = simpleMapper.fromJson("null");
     assertThat(mapFromJson).isNull();
   }
 
+  @Test
+  void objectJsonReader() {
+    try (var reader = JsonStream.builder().build().reader("\"hi\"")) {
+      var fromJson = simpleMapper.fromJson(reader);
+      assertThat(fromJson).isEqualTo("hi");
+    }
+  }
+
   @Test
   void mapWithNull() {
     Map<String, Object> mapFromJson = simpleMapper.fromJsonObject("{\"one\":1,\"two\":null,\"three\":3}");
@@ -58,6 +99,16 @@ void listWithNull() {
     assertThat(simpleMapper.toJson(listFromJson)).isEqualTo("[1,3]");
   }
 
+  @Test
+  void listWithReader() {
+    try (JsonReader reader = JsonStream.builder().build().reader("[1,2]")) {
+      List<Object> listFromJson = simpleMapper.fromJsonArray(reader);
+
+      assertThat(listFromJson).hasSize(2);
+      assertThat(simpleMapper.toJson(listFromJson)).isEqualTo("[1,2]");
+    }
+  }
+
   @Test
   void arrayToJsonFromJson() {
 

json-node/src/main/java/io/avaje/json/node/JsonNodeMapper.java

@@ -1,6 +1,8 @@
 package io.avaje.json.node;
 
 import io.avaje.json.JsonAdapter;
+import io.avaje.json.JsonReader;
+import io.avaje.json.JsonWriter;
 import io.avaje.json.PropertyNames;
 import io.avaje.json.node.adapter.NodeAdapterBuilder;
 import io.avaje.json.simple.SimpleMapper;
@@ -87,6 +89,17 @@ static Builder builder() {
    */
   String toJson(JsonNode node);
 
+  /**
+   * Write the node to JSON.
+   * <p>
+   * For options to write json content to OutputStream, Writer etc
+   * use {@link #nodeMapper()}.
+   *
+   * @see SimpleMapper.Type#toJson(Object, OutputStream)
+   * @see SimpleMapper.Type#toJson(Object, Writer)
+   */
+  void toJson(JsonNode node, JsonWriter jsonWriter);
+
   /**
    * Read any json content returning a JsonNode.
    * <p>
@@ -104,6 +117,17 @@ static Builder builder() {
    */
   JsonNode fromJson(String json);
 
+  /**
+   * Read any json content returning a JsonNode.
+   * <p>
+   * For options to read json content from InputStream, Reader etc
+   * use the fromJson methods on {@link SimpleMapper.Type}.
+   *
+   * @see SimpleMapper.Type#fromJson(Reader)
+   * @see SimpleMapper.Type#fromJson(InputStream)
+   */
+  JsonNode fromJson(JsonReader jsonReader);
+
   /**
    * Read a JsonObject from json string content.
    * <p>
@@ -114,6 +138,13 @@ static Builder builder() {
    */
   JsonObject fromJsonObject(String json);
 
+  /**
+   * Read a JsonObject from json string content.
+   * <p>
+   * Use this when we know that the json content is a JsonObject.
+   */
+  JsonObject fromJsonObject(JsonReader jsonReader);
+
   /**
    * Read a JsonArray from json string content.
    * <p>
@@ -124,6 +155,13 @@ static Builder builder() {
    */
   JsonArray fromJsonArray(String json);
 
+  /**
+   * Read a JsonArray from json string content.
+   * <p>
+   * Use this when we know that the json content is a JsonArray.
+   */
+  JsonArray fromJsonArray(JsonReader jsonReader);
+
   /**
    * Helper method to read JSON with an expected JsonNode type.
    *

json-node/src/main/java/io/avaje/json/node/adapter/DJsonNodeMapper.java

@@ -2,6 +2,7 @@
 
 import io.avaje.json.JsonAdapter;
 import io.avaje.json.JsonReader;
+import io.avaje.json.JsonWriter;
 import io.avaje.json.PropertyNames;
 import io.avaje.json.node.*;
 import io.avaje.json.simple.SimpleMapper;
@@ -63,6 +64,11 @@ public String toJson(JsonNode node) {
     return writer.result();
   }
 
+  @Override
+  public void toJson(JsonNode node, JsonWriter jsonWriter) {
+    nodeAdapter.toJson(jsonWriter, node);
+  }
+
   @Override
   public JsonNode fromJson(String json) {
     try (JsonReader reader = jsonStream.reader(json)) {
@@ -84,6 +90,21 @@ public JsonArray fromJsonArray(String json) {
     }
   }
 
+  @Override
+  public JsonNode fromJson(JsonReader jsonReader) {
+    return nodeAdapter.fromJson(jsonReader);
+  }
+
+  @Override
+  public JsonObject fromJsonObject(JsonReader jsonReader) {
+    return objectAdapter.fromJson(jsonReader);
+  }
+
+  @Override
+  public JsonArray fromJsonArray(JsonReader jsonReader) {
+    return arrayAdapter.fromJson(jsonReader);
+  }
+
   @Override
   public <T extends JsonNode> T fromJson(Class<T> type, String json) {
     JsonAdapter<T> adapter = adapter(type);

json-node/src/test/java/io/avaje/json/node/adapter/JsonNodeAdaptersTest.java

@@ -4,6 +4,7 @@
 import io.avaje.json.JsonReader;
 import io.avaje.json.node.*;
 import io.avaje.json.simple.SimpleMapper;
+import io.avaje.json.stream.BufferedJsonWriter;
 import io.avaje.json.stream.JsonStream;
 import org.junit.jupiter.api.Test;
 
@@ -102,6 +103,36 @@ void create_JsonString_expect_sameInstance() {
     assertThat(jsonAdapter).isSameAs(adapter);
   }
 
+  @Test
+  void toJsonWriter() {
+    BufferedJsonWriter writer = stream.bufferedWriter();
+    mapper.toJson(JsonArray.create().add(1).add(2), writer);
+    assertThat(writer.result()).isEqualTo("[1,2]");
+  }
+
+  @Test
+  void fromJson_usingReader() {
+    try (var reader = stream.reader("[42, \"foo\"]")) {
+      JsonNode node = mapper.fromJson(reader);
+      assertThat(node).isEqualTo(JsonArray.create().add(42L).add("foo"));
+    }
+  }
+
+  @Test
+  void fromJsonArray_usingReader() {
+    try (var reader = stream.reader("[42, \"foo\"]")) {
+      JsonArray node = mapper.fromJsonArray(reader);
+      assertThat(node).isEqualTo(JsonArray.create().add(42L).add("foo"));
+    }
+  }
+
+  @Test
+  void fromJsonObject_usingReader() {
+    try (var reader = stream.reader("{\"a\":1,\"b\":2}")) {
+      JsonObject node = mapper.fromJsonObject(reader);
+      assertThat(node).isEqualTo(JsonObject.create().add("a", 1L).add("b", 2L));
+    }
+  }
 
   @Test
   void arrayCreateOfMixed_defaultStream() {