[Java][Spring][#2901] remove unused import from spring template

[bilak]

closes #2901

[bilak]

@wing328 is it possible to add this pr to upcoming release?

[bilak]

cc @bbdouglas (2017/07) @sreeshas (2017/08) @jfiala (2017/08) @lukoyanov (2017/09) @cbornet (2017/09) @jeff9finger (2018/01) @karismann (2019/03) @Zomzog (2019/04)

[jimschubert]

This will break the JavaSpring templates… for example:

• openapi-generator/modules/openapi-generator/src/main/resources/JavaSpring/nullableDataType.mustache

  Line 1 in 0fca901

  {{#isNullable}}JsonNullable<{{{datatypeWithEnum}}}>{{/isNullable}}{{^isNullable}}{{{datatypeWithEnum}}}{{/isNullable}}

• openapi-generator/modules/openapi-generator/src/main/resources/Java/pojo.mustache

  Line 59 in 87727de

  private JsonNullable<{{{datatypeWithEnum}}}> {{name}} = JsonNullable.<{{{datatypeWithEnum}}}>undefined();

Maybe a good way around this, since the template modified in this PR is used by multiple library options which apparently provide their own build scripts… would be to fully qualify the occurrences of JsonNullable (change JsonNullable to org.openapitools.jackson.nullable.JsonNullable).

@cbornet does that seem like a valid fix to get the import out of the shared template?

For anyone affected by this in an already released version, you can create a new directory with a single file called model.mustache and the contents of this PR's fix:

package {{package}};

import java.util.Objects;
{{#imports}}import {{import}};
{{/imports}}
{{#serializableModel}}
import java.io.Serializable;
{{/serializableModel}}
{{#useBeanValidation}}
import javax.validation.Valid;
import javax.validation.constraints.*;
{{/useBeanValidation}}
{{#performBeanValidation}}
import org.hibernate.validator.constraints.*;
{{/performBeanValidation}}
{{#jackson}}
{{#withXml}}
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlRootElement;
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlProperty;
{{/withXml}}
{{/jackson}}
{{#withXml}}
import javax.xml.bind.annotation.*;
{{/withXml}}
{{^parent}}
{{#hateoas}}
import org.springframework.hateoas.ResourceSupport;
{{/hateoas}}
{{/parent}}

{{#models}}
{{#model}}
{{#isEnum}}
{{>enumOuterClass}}
{{/isEnum}}
{{^isEnum}}
{{>pojo}}
{{/isEnum}}
{{/model}}
{{/models}}

During generation, pass the new folder to the template directory option for your tool:

• CLI: -t
• gradle plugin: templateDir
• maven plugin: templateDirectory

The generator should fall back to embedded templates for any not found in the target directory.

[mateusz-nalepa]

Hi @jimschubert ,

What about solution like this?
{{#isNullable}}import org.openapitools.jackson.nullable.JsonNullable;{{/isNullable}}

@jmini @cbornet does this looks like a valid solution?

[RockyMM]

To be honest looks fine to me. To be honest #6154 looks more complete.

[jimschubert]

Following up for visibility… 

What about solution like this?
{{#isNullable}}import org.openapitools.jackson.nullable.JsonNullable;{{/isNullable}}

This would be an excellent option, and users can do this for any version of the tool by extending the templates.

Since this PR would be a breaking change and that hasn't been addressed, I think we'll move forward with #6154 as this would accomplish the same while also moving us toward more vanilla output by default (without the JSON Nullable library).

[jimschubert]

Thanks again for the PR. We've merged #6154 so the issue should be addressed in a way that allows for both scenarios.