swagger @ApiModelProperty example value for List<String> property

I have one class in which there is one property which is List<String>

public class MyClass {
    ....
    @ApiModelProperty(position = 2)
    private List<String> productIdentifiers;
    ....
}

This code generates the example values as following:

{
  "customerId": "1001",
  "productIdentifiers": [
    "string"
  ],
  "statuses": [
    "NEW"
  ]
}

The example values here shown are not valid. My expected example values should be like :

{
  "customerId": "1001",
  "productIdentifiers": [
    "PRD1",
    "PRD2",
    "PRD3"
  ],
  "statuses": [
    "NEW"
  ]
}

I have tried passing example attribute as following but it is not generating proper value:

@ApiModelProperty(position = 2, example = "PRD1, PRD2, PRD3")
// This generates -> "productIdentifiers": "PRD1, PRD2, PRD3" // Its not json array

@ApiModelProperty(position = 2, example = "[\"PRD1\", \"PRD2\", \"PRD3\"]")
// This generates -> "productIdentifiers": "[\"PRD1\", \"PRD2\", \"PRD3\"]" // Its too not json array

Is there any way I can generate proper example value for List property ?

Update :

I have tried the solutions suggested by @nullpointer and @Zeeshan Arif

@ApiModelProperty(position = 2, dataType="List", example = "PRD1, PRD2, PRD3")
private List<String> productIdentifiers;
//This generates -> `"productIdentifiers": "PRD1, PRD2, PRD3"`

Update 2 :

Tried following approach which did not generate proper response

@ApiModelProperty(position = 2, dataType="java.util.List<String>", example = "PRD1, PRD2, PRD3")
// This generates -> "productIdentifiers": "PRD1, PRD2, PRD3"


@ApiModelProperty(position = 2, dataType="String[]", example = "PRD1, PRD2, PRD3")
// This generates -> "productIdentifiers": "PRD1, PRD2, PRD3"

my maven dependency for swagger jar is :

<dependency>
    <groupId>io.springfox</groupId>
    <artifactId>springfox-swagger2</artifactId>
    <version>2.5.0</version>
    <exclusions>
        <exclusion>
            <artifactId>mapstruct</artifactId>
            <groupId>org.mapstruct</groupId>
        </exclusion>
    </exclusions>
</dependency>

Update github ticket for this issue

I managed to get this to work, generating a List of Strings.

Within the ApiModelProperty with springfox 2, write your example as follows:

example = "[\"AddLine1\",\"AddLine2\",\"AddLine3\",\"AddLine4\"]"

Here is my example:

@ApiModelProperty(value = "Address", name = "addLines", 
    example = "[\"AddLine1\",\"AddLine2\",\"AddLine3\",\"AddLine4\"]")

When I render the swagger page, I get the following output:

"addLines": [
      "AddLine1",
      "AddLine2",
      "AddLine3",
      "AddLine4"
    ],

TLDR: One of the contributers on Swagger-API has worked on this functionality to add this in version 3.0.0 but it's not sure yet when this will be released. For now it stands on the feature/3.0.0-rc2 branch at the Swagger-API GitHub

I've been working with Swagger for almost two months now and as our project progressed issues like this showed up. Now I did some research and read on the GitHub pages for the Swagger-API that this feature simply doesn't work (yet).

As described here and [here would be an other link but my reputation is not high enough to post more than 2 links] this feature has been requested several times since August 2015 with not much luck.

Now on this issue on the Swagger-API github, one of the contributors commented:

This takes a major refactoring of the models, which is on the way. 3 March 2017

which lead to a later comment:

Will be supported in 3.0.0 support, please see the feature/3.0.0-rc2 branch for details. 27 June 2017

And on 9 August 2017 someone asked when the release of version 3.0.0 would be with no further response.

So in conclusion, support for examples for arrays/Lists has been worked on and should be available in version 3.0.0 but no more news on when that would be released.

You just use Reflection notation. Using

@ApiModelProperty(dataType = "[Ljava.lang.String;")

works fine, but I can't put examples.

This is the result:

{
  "field": [
    "string"
  ]
}

Try to initialize @ApiModelProperty as follows:

public class MyClass {
    ....
    @ApiModelProperty(
        position = 2, datatype="List", example = "PRD1, PRD2, PRD3"
    )
    private List<String> productIdentifiers;
    ....
}

This seems to not be supported by the Swagger API. In the mean time you can use this Springfox Plugin to generate a singleton list example (one value list) https://github.com/aaitmouloud/springfox-collection-example-plugin

Just add this to you pom.xml

<dependency>
    <groupId>com.github.aaitmouloud</groupId>
    <artifactId>springfox-collection-example-plugin</artifactId>
    <version>2.9.2</version>
</dependency>

And import the right classes to your Spring context

@ComponentScan({"springfox.collection.example.plugins"})

You should then declares a single value example on your property and it will be transformed to a singleton list example by the plugin (works for all java.util.Collection classes)

@ApiModelProperty(value ="my property description", example = "2019-12-20T12:00:00")
@NotNull
private List<LocalDateTime> dates;

Disclaimer: I am the author of this plugin.