Openapi-generator: [JAVA] incorrect import mapping of DateTime

[guidoschreuder]

Description

Generation of java components fails when joda is not used due to incorrect mapping of imports

openapi-generator version

3.3.2-SNAPSHOT

OpenAPI declaration file content or url

---
components:
  schemas:
    Dummy:
      type: object
      properties:
        dt:
          type: date
        ts:
          type: date-time

Command line used for generation

Steps to reproduce

Generate with any Java generator with dateLibrary other then joda

Related issues/PRs

https://github.com/OpenAPITools/openapi-generator/pull/1313

Suggest a fix/enhancement

diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java
index c119400db..15458ccb7 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java
@@ -486,7 +486,7 @@ public abstract class AbstractJavaCodegen extends DefaultCodegen implements Code
             typeMapping.put("date", "LocalDate");
             typeMapping.put("DateTime", "OffsetDateTime");
             importMapping.put("LocalDate", "org.threeten.bp.LocalDate");
-            importMapping.put("OffsetDateTime", "org.threeten.bp.OffsetDateTime");
+            importMapping.put("DateTime", "org.threeten.bp.OffsetDateTime");
         } else if ("joda".equals(dateLibrary)) {
             additionalProperties.put("joda", "true");
             typeMapping.put("date", "LocalDate");
@@ -500,10 +500,10 @@ public abstract class AbstractJavaCodegen extends DefaultCodegen implements Code
             importMapping.put("LocalDate", "java.time.LocalDate");
             if ("java8-localdatetime".equals(dateLibrary)) {
                 typeMapping.put("DateTime", "LocalDateTime");
-                importMapping.put("LocalDateTime", "java.time.LocalDateTime");
+                importMapping.put("DateTime", "java.time.LocalDateTime");
             } else {
                 typeMapping.put("DateTime", "OffsetDateTime");
-                importMapping.put("OffsetDateTime", "java.time.OffsetDateTime");
+                importMapping.put("DateTime", "java.time.OffsetDateTime");
             }
         } else if (dateLibrary.equals("legacy")) {
             additionalProperties.put("legacyDates", "true");

[cbornet]

The type DateTime is mapped to another type (eg. OffsetDateTime) so I don't see why we need an import for DateTime. Do you have a failing example ?

[cbornet]

The samples look good to me : https://github.com/OpenAPITools/openapi-generator/blob/master/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Order.java#L23
OffsetDateTime is used as type for date-time and the import is there.

[guidoschreuder]

Hi @cbornet

with this pom

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>org.openapitools</groupId>
  <artifactId>failing-date-time</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>pom</packaging>

  <build>
    <plugins>
      <plugin>
        <groupId>org.openapitools</groupId>
        <artifactId>openapi-generator-maven-plugin</artifactId>
        <version>3.3.2-SNAPSHOT</version>
        <executions>
          <execution>
            <id>Generate CRM</id>
            <goals>
              <goal>generate</goal>
            </goals>
            <configuration>
              <inputSpec>src/main/resources/dummy.yaml</inputSpec>
              <validateSpec>true</validateSpec>
              <generatorName>java</generatorName>
              <configOptions>
                <interfaceOnly>true</interfaceOnly>
                <library>webclient</library>
                <dateLibrary>java8</dateLibrary>
              </configOptions>
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
</project>

and this specification:

---
openapi: 3.0.0
info:
  title: Dummy test
  version: 0.0.1
paths:
  "/dummy":
    get:
      responses:
        '200':
          description: successful operation
          content:
            application/json:
              schema:
                "$ref": "#/components/schemas/VersionResponse"
components:
  schemas:
    Dummy:
      type: object
      properties:
        dt:
          type: date
        ts:
          type: date-time

the generated model has this import section

import java.util.Objects;
import java.util.Arrays;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonValue;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import java.time.LocalDate;
import org.joda.time.*;

as you can see, OffsetDateTime is not correctly imported

[guidoschreuder]

the same happens for instance with jaxrs-spec generator

[cbornet]

Strange : it doesn't seem to affect the samples https://github.com/OpenAPITools/openapi-generator/blob/master/samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/model/Order.java#L23 ...

[guidoschreuder]

strange indeed, but this is blocking

[cbornet]

What I find surprising is that you get joda and not threetenbp which is the default. Also from what I see in the code, specifying java8 for webclient shouldn't be necessary. What does it give if you remove <dateLibrary>java8</dateLibrary> ?

[guidoschreuder]

with dateLibrary removed i get:

import java.util.Objects;
import java.util.Arrays;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonValue;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import org.joda.time.*;
import org.threeten.bp.LocalDate;

[guidoschreuder]

When the CLI generator does not show this behaviour, could the issue be in the wiring of CodeGenMojo?

[cbornet]

Oh, actually it's because your DateTime is not remapped to OffsetDateTime

[guidoschreuder]

i was thinking along the same path, but have not found where the remapping should happen or why it fails, the codebase is rather new to me

[cbornet]

BTW you can remove interfaceOnly as it's not a java client option. And also java8 as Webclient sets java8 by default.

[cbornet]

I reproduce your issue.

[guidoschreuder]

ok , that's good.

I had already remove java8 before, the interfaceOnly was indeed a heritage of trying with another generator.

With interfaceOnly removed i still get

import java.util.Objects;
import java.util.Arrays;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonValue;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import org.joda.time.*;
import org.threeten.bp.LocalDate;

POM used:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>org.openapitools</groupId>
  <artifactId>failing-date-time</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>pom</packaging>

  <build>
    <plugins>
      <plugin>
        <groupId>org.openapitools</groupId>
        <artifactId>openapi-generator-maven-plugin</artifactId>
        <version>3.3.2-SNAPSHOT</version>
        <executions>
          <execution>
            <goals>
              <goal>generate</goal>
            </goals>
            <configuration>
              <inputSpec>src/main/resources/dummy.yaml</inputSpec>
              <validateSpec>true</validateSpec>
              <generatorName>java</generatorName>
              <configOptions>
                <library>webclient</library>
              </configOptions>
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
</project>

[cbornet]

I get it : your OAS is wrong.
The type of dt and ts should be string with format: date and format: date-time respectively.
Now there remains 2 issues:

• You have validateSpec=true so it should have failed the generation
• When I generate with the maven-plugin after fixing the OAS, I get threetenbp imports instead of java.time ones. This doesn't happen when generating from the CLI.

cc @jimschubert for the maven plugin

[cbornet]

@guidoschreuder you can workaround the second issue by forcing dateLibrary=java8

[guidoschreuder]

@cbornet thank you, i totally missed that issue in the specification, good catch

can't believe this had me stumped for so long

generation indeed now works with java8 with

        dt:
          type: string
          format: date
        ts:
          type: string
          format: date-time

[guidoschreuder]

i've closed the PR

[cbornet]

About the spec validation, the issue is also present with the CLI.

[guidoschreuder]

that makes sense as the validation messages come from io.swagger.v3.parser.OpenAPIV3Parser

[cbornet]

so that's not us. We should open an issue in swagger-parser