[java][okhttp-gson-nextgen] better oneOf implementation (#11146)

* add validJsonObject method

* add check for null

* fix list model generation

* fix optional fields validation

* add tests

* fix variable naming

* update tests

* add fromJson in oneOf, add tests

* convert JSON to static

* remove trailing space

* add fromString methods to all models

* add toJson, fix anyOf template

* remove workarounds

* undo changes to tests

* skip file schema test

* add new file

bin/configs/java-okhttp-gson-nextgen.yaml

@@ -1,8 +1,7 @@
 generatorName: java
 outputDir: samples/client/petstore/java/okhttp-gson-nextgen
 library: okhttp-gson-nextgen
-#inputSpec: modules/openapi-generator/src/test/resources/2_0/petstore-with-fake-endpoints-models-for-testing.yaml
-inputSpec: modules/openapi-generator/src/test/resources/3_0/java/petstore-with-fake-endpoints-models-for-testing-with-http-signature-okhttp-gson.yaml
+inputSpec: modules/openapi-generator/src/test/resources/3_0/java/petstore-with-fake-endpoints-models-for-testing-with-http-signature-okhttp-gson-nextgen.yaml
 templateDir: modules/openapi-generator/src/main/resources/Java
 additionalProperties:
   artifactId: petstore-okhttp-gson-nextgen

modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson-nextgen/JSON.mustache

@@ -50,19 +50,19 @@ import java.util.HashMap;
  *       backward-compatibility
  */
 public class JSON {
-    private Gson gson;
-    private boolean isLenientOnJson = false;
-    private DateTypeAdapter dateTypeAdapter = new DateTypeAdapter();
-    private SqlDateTypeAdapter sqlDateTypeAdapter = new SqlDateTypeAdapter();
+    private static Gson gson;
+    private static boolean isLenientOnJson = false;
+    private static DateTypeAdapter dateTypeAdapter = new DateTypeAdapter();
+    private static SqlDateTypeAdapter sqlDateTypeAdapter = new SqlDateTypeAdapter();
     {{#joda}}
-    private DateTimeTypeAdapter dateTimeTypeAdapter = new DateTimeTypeAdapter();
-    private LocalDateTypeAdapter localDateTypeAdapter = new LocalDateTypeAdapter();
+    private static DateTimeTypeAdapter dateTimeTypeAdapter = new DateTimeTypeAdapter();
+    private static LocalDateTypeAdapter localDateTypeAdapter = new LocalDateTypeAdapter();
     {{/joda}}
     {{#jsr310}}
-    private OffsetDateTimeTypeAdapter offsetDateTimeTypeAdapter = new OffsetDateTimeTypeAdapter();
-    private LocalDateTypeAdapter localDateTypeAdapter = new LocalDateTypeAdapter();
+    private static OffsetDateTimeTypeAdapter offsetDateTimeTypeAdapter = new OffsetDateTimeTypeAdapter();
+    private static LocalDateTypeAdapter localDateTypeAdapter = new LocalDateTypeAdapter();
     {{/jsr310}}
-    private ByteArrayAdapter byteArrayAdapter = new ByteArrayAdapter();
+    private static ByteArrayAdapter byteArrayAdapter = new ByteArrayAdapter();
 
     @SuppressWarnings("unchecked")
     public static GsonBuilder createGson() {
@@ -116,7 +116,7 @@ public class JSON {
         return clazz;
     }
 
-    public JSON() {
+    {
         gson = createGson()
             .registerTypeAdapter(Date.class, dateTypeAdapter)
             .registerTypeAdapter(java.sql.Date.class, sqlDateTypeAdapter)
@@ -146,7 +146,7 @@ public class JSON {
      *
      * @return Gson
      */
-    public Gson getGson() {
+    public static Gson getGson() {
         return gson;
     }
 
@@ -155,11 +155,11 @@ public class JSON {
      *
      * @param gson Gson
      */
-    public void setGson(Gson gson) {
-        this.gson = gson;
+    public static void setGson(Gson gson) {
+        JSON.gson = gson;
     }
 
-    public void setLenientOnJson(boolean lenientOnJson) {
+    public static void setLenientOnJson(boolean lenientOnJson) {
         isLenientOnJson = lenientOnJson;
     }
 
@@ -169,7 +169,7 @@ public class JSON {
      * @param obj Object
      * @return String representation of the JSON
      */
-    public String serialize(Object obj) {
+    public static String serialize(Object obj) {
         return gson.toJson(obj);
     }
 
@@ -182,7 +182,7 @@ public class JSON {
      * @return The deserialized Java object
      */
     @SuppressWarnings("unchecked")
-    public <T> T deserialize(String body, Type returnType) {
+    public static <T> T deserialize(String body, Type returnType) {
         try {
             if (isLenientOnJson) {
                 JsonReader jsonReader = new JsonReader(new StringReader(body));
@@ -206,7 +206,7 @@ public class JSON {
     /**
      * Gson TypeAdapter for Byte Array type
      */
-    public class ByteArrayAdapter extends TypeAdapter<byte[]> {
+    public static class ByteArrayAdapter extends TypeAdapter<byte[]> {
 
         @Override
         public void write(JsonWriter out, byte[] value) throws IOException {
@@ -235,7 +235,7 @@ public class JSON {
     /**
      * Gson TypeAdapter for Joda DateTime type
      */
-    public class DateTimeTypeAdapter extends TypeAdapter<DateTime> {
+    public static class DateTimeTypeAdapter extends TypeAdapter<DateTime> {
 
         private DateTimeFormatter formatter;
 
@@ -278,7 +278,7 @@ public class JSON {
     /**
      * Gson TypeAdapter for Joda LocalDate type
      */
-    public class LocalDateTypeAdapter extends TypeAdapter<LocalDate> {
+    public static class LocalDateTypeAdapter extends TypeAdapter<LocalDate> {
 
         private DateTimeFormatter formatter;
 
@@ -316,11 +316,11 @@ public class JSON {
         }
     }
 
-    public void setDateTimeFormat(DateTimeFormatter dateFormat) {
+    public static void setDateTimeFormat(DateTimeFormatter dateFormat) {
         dateTimeTypeAdapter.setFormat(dateFormat);
     }
 
-    public void setLocalDateFormat(DateTimeFormatter dateFormat) {
+    public static void setLocalDateFormat(DateTimeFormatter dateFormat) {
         localDateTypeAdapter.setFormat(dateFormat);
     }
 
@@ -329,7 +329,7 @@ public class JSON {
     /**
      * Gson TypeAdapter for JSR310 OffsetDateTime type
      */
-    public class OffsetDateTimeTypeAdapter extends TypeAdapter<OffsetDateTime> {
+    public static class OffsetDateTimeTypeAdapter extends TypeAdapter<OffsetDateTime> {
 
         private DateTimeFormatter formatter;
 
@@ -373,7 +373,7 @@ public class JSON {
     /**
      * Gson TypeAdapter for JSR310 LocalDate type
      */
-    public class LocalDateTypeAdapter extends TypeAdapter<LocalDate> {
+    public static class LocalDateTypeAdapter extends TypeAdapter<LocalDate> {
 
         private DateTimeFormatter formatter;
 
@@ -411,11 +411,11 @@ public class JSON {
         }
     }
 
-    public void setOffsetDateTimeFormat(DateTimeFormatter dateFormat) {
+    public static void setOffsetDateTimeFormat(DateTimeFormatter dateFormat) {
         offsetDateTimeTypeAdapter.setFormat(dateFormat);
     }
 
-    public void setLocalDateFormat(DateTimeFormatter dateFormat) {
+    public static void setLocalDateFormat(DateTimeFormatter dateFormat) {
         localDateTypeAdapter.setFormat(dateFormat);
     }
 
@@ -425,7 +425,7 @@ public class JSON {
      * If the dateFormat is null, a simple "yyyy-MM-dd" format will be used
      * (more efficient than SimpleDateFormat).
      */
-    public class SqlDateTypeAdapter extends TypeAdapter<java.sql.Date> {
+    public static class SqlDateTypeAdapter extends TypeAdapter<java.sql.Date> {
 
         private DateFormat dateFormat;
 
@@ -478,7 +478,7 @@ public class JSON {
      * Gson TypeAdapter for java.util.Date type
      * If the dateFormat is null, ISO8601Utils will be used.
      */
-    public class DateTypeAdapter extends TypeAdapter<Date> {
+    public static class DateTypeAdapter extends TypeAdapter<Date> {
 
         private DateFormat dateFormat;
 
@@ -531,11 +531,11 @@ public class JSON {
         }
     }
 
-    public void setDateFormat(DateFormat dateFormat) {
+    public static void setDateFormat(DateFormat dateFormat) {
         dateTypeAdapter.setFormat(dateFormat);
     }
 
-    public void setSqlDateFormat(DateFormat dateFormat) {
+    public static void setSqlDateFormat(DateFormat dateFormat) {
         sqlDateTypeAdapter.setFormat(dateFormat);
     }
 }

modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson-nextgen/anyof_model.mustache

@@ -90,22 +90,23 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
 
                     {{/discriminator}}
                     {{/useOneOfDiscriminatorLookup}}
-
                     {{#anyOf}}
                     // deserialize {{{.}}}
                     try {
-                        deserialized = adapter{{.}}.fromJsonTree(jsonObject);
+                        // validate the JSON object to see if any excpetion is thrown
+                        {{.}}.validateJsonObject(jsonObject);
                         log.log(Level.FINER, "Input data matches schema '{{{.}}}'");
                         {{classname}} ret = new {{classname}}();
-                        ret.setActualInstance(deserialized);
+                        ret.setActualInstance(adapter{{.}}.fromJsonTree(jsonObject));
                         return ret;
                     } catch (Exception e) {
                         // deserialization failed, continue
                         log.log(Level.FINER, "Input data does not match schema '{{{.}}}'", e);
                     }
 
                     {{/anyOf}}
-                    throw new IOException(String.format("Failed deserialization for {{classname}} as data doesn't match anyOf schmeas: {{#anyOf}}{{{.}}}{{^-last}}, {{/-last}}{{/anyOf}}. JSON: %s", jsonObject.toString()));
+
+                    throw new IOException(String.format("Failed deserialization for {{classname}}: no class matched. JSON: %s", jsonObject.toString()));
                 }
             }.nullSafe();
         }
@@ -188,4 +189,48 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
     }
 
     {{/anyOf}}
+
+ /**
+  * Validates the JSON Object and throws an exception if issues found
+  *
+  * @param jsonObj JSON Object
+  * @throws IOException if the JSON Object is invalid with respect to {{classname}}
+  */
+  public static void validateJsonObject(JsonObject jsonObj) throws IOException {
+    // validate anyOf schemas one by one
+    int validCount = 0;
+    {{#anyOf}}
+    // validate the json string with {{{.}}}
+    try {
+      {{{.}}}.validateJsonObject(jsonObj);
+      return; // return earlier as at least one schema is valid with respect to the Json object
+      //validCount++;
+    } catch (Exception e) {
+      // continue to the next one
+    }
+    {{/anyOf}}
+    if (validCount == 0) {
+      throw new IOException(String.format("The JSON string is invalid for {{classname}} with anyOf schemas: {{#anyOf}}{{{.}}}{{^-last}}, {{/-last}}{{/anyOf}}. JSON: %s", jsonObj.toString()));
+    }
+  }
+
+ /**
+  * Create an instance of {{classname}} given an JSON string
+  *
+  * @param jsonString JSON string
+  * @return An instance of {{classname}}
+  * @throws IOException if the JSON string is invalid with respect to {{classname}}
+  */
+  public static {{{classname}}} fromJson(String jsonString) throws IOException {
+    return JSON.getGson().fromJson(jsonString, {{{classname}}}.class);
+  }
+
+ /**
+  * Convert an instance of {{classname}} to an JSON string
+  *
+  * @return JSON string
+  */
+  public String toJson() {
+    return JSON.getGson().toJson(this);
+  }
 }

modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson-nextgen/oneof_model.mustache

@@ -91,11 +91,14 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
                     {{/discriminator}}
                     {{/useOneOfDiscriminatorLookup}}
                     int match = 0;
+                    TypeAdapter actualAdapter = elementAdapter;
 
                     {{#oneOf}}
                     // deserialize {{{.}}}
                     try {
-                        deserialized = adapter{{.}}.fromJsonTree(jsonObject);
+                        // validate the JSON object to see if any excpetion is thrown
+                        {{.}}.validateJsonObject(jsonObject);
+                        actualAdapter = adapter{{.}};
                         match++;
                         log.log(Level.FINER, "Input data matches schema '{{{.}}}'");
                     } catch (Exception e) {
@@ -106,7 +109,7 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
                     {{/oneOf}}
                     if (match == 1) {
                         {{classname}} ret = new {{classname}}();
-                        ret.setActualInstance(deserialized);
+                        ret.setActualInstance(actualAdapter.fromJsonTree(jsonObject));
                         return ret;
                     }
 
@@ -193,4 +196,47 @@ public class {{classname}} extends AbstractOpenApiSchema{{#vendorExtensions.x-im
     }
 
     {{/oneOf}}
+
+ /**
+  * Validates the JSON Object and throws an exception if issues found
+  *
+  * @param jsonObj JSON Object
+  * @throws IOException if the JSON Object is invalid with respect to {{classname}}
+  */
+  public static void validateJsonObject(JsonObject jsonObj) throws IOException {
+    // validate oneOf schemas one by one
+    int validCount = 0;
+    {{#oneOf}}
+    // validate the json string with {{{.}}}
+    try {
+      {{{.}}}.validateJsonObject(jsonObj);
+      validCount++;
+    } catch (Exception e) {
+      // continue to the next one
+    }
+    {{/oneOf}}
+    if (validCount != 1) {
+      throw new IOException(String.format("The JSON string is invalid for {{classname}} with oneOf schemas: {{#oneOf}}{{{.}}}{{^-last}}, {{/-last}}{{/oneOf}}. %d class(es) match the result, expected 1. JSON: %s", validCount, jsonObj.toString()));
+    }
+  }
+
+ /**
+  * Create an instance of {{classname}} given an JSON string
+  *
+  * @param jsonString JSON string
+  * @return An instance of {{classname}}
+  * @throws IOException if the JSON string is invalid with respect to {{classname}}
+  */
+  public static {{{classname}}} fromJson(String jsonString) throws IOException {
+    return JSON.getGson().fromJson(jsonString, {{{classname}}}.class);
+  }
+
+ /**
+  * Convert an instance of {{classname}} to an JSON string
+  *
+  * @return JSON string
+  */
+  public String toJson() {
+    return JSON.getGson().toJson(this);
+  }
 }