How to code generate nested array property using swagger-code-gen client

[vijayrcse]

I have a property which is List<List>

I tried to add the below in my .json file( using swaggercode gen cli - 2.1.2 )

"listOfListOfClassA": {
"type": "array",
"description": "description 1",
"items": {
"type": "array",
"description": "description 2",
"items": {
"$ref": "ClassA"
}
}
}

"ClassA": {
"id": "class_id",
"description": "Description for class A",
"properties": {
"propertyName1": {
"type": "string",
"description": "Property Name 1"
},
"propertyName2": {
"type": "string",
"description": "Property Name 1"
},
}
},

But I am getting the below exception
java.lang.NullPointerException
at java.util.regex.Matcher.getTextLength(Matcher.java:1283)
at java.util.regex.Matcher.reset(Matcher.java:309)
at java.util.regex.Matcher.(Matcher.java:229)
at java.util.regex.Pattern.matcher(Pattern.java:1093)
at io.swagger.codegen.DefaultCodegen.camelize(DefaultCodegen.java:1237)
at io.swagger.codegen.DefaultCodegen.camelize(DefaultCodegen.java:1212)
at io.swagger.codegen.languages.JavaClientCodegen.toModelName(JavaClientCodegen.java:179)
at io.swagger.codegen.languages.JavaClientCodegen.getSwaggerType(JavaClientCodegen.java:215)
at io.swagger.codegen.DefaultCodegen.getTypeDeclaration(DefaultCodegen.java:490)

Could you please advise ?

[wing328]

@vijayrcse would be nice if you can share the full swagger spec definition with us (assuming it can be shared publicly) and also I wonder if you can do a test with the latest develop_2.0 branch to see if the exception still occurs.

[vijayrcse]

wing328

This was the original .json file

{"apiVersion": "1.0", "swaggerVersion": "1.2", "basePath": "/", "resourcePath": "/service-v1", "produces": ["application/json"], "consumes": ["application/json"], "apis": [
    {
        "path": "/service-v1/evaluate",
        "operations": [
            {
                "method": "POST",
                "summary": "Summary",
                "notes": "notes",
                "type": "Response",
                "nickname": "evaluate",
                "produces": ["application/json"],
                "parameters": [
                    {
                        "name": "body",
                        "description": "Request description",
                        "required": true,
                        "type": "array",
                        "items": {
                            "$ref": "Request"
                        },
                        "paramType": "body",
                        "allowMultiple": false
                    }
                ],
                "responseMessages": [
                    {
                        "code": 200,
                        "message": "Successful evaluation",
                        "responseModel": "Response"
                    },
                    {
                        "code": 404,
                        "message": "service does not exist"
                    },
                    {
                        "code": 500,
                        "message": "Internal service error"
                    }
                ]
            }
        ]
    }
], "models": {
    "Attribute": {
        "id": "Attribute",
        "description": "Attribute representation",
        "properties": {
            "id": {
                "type": "integer",
                "format": "int32",
                "description": "Id"
            },
            "attributeId": {
                "type": "integer",
                "format": "int32",
                "description": "Attribute Id"
            },
            "attributeName": {
                "type": "string",
                "description": "Attribute Name"
            },
            "attributeValue": {
                "type": "string",
                "description": "Attribute Value"
            },
            "attributeValueCode": {
                "type": "string",
                "description": "Attribute Value Code"
            }
        }
    },
    "Response": {
        "id": "Response",
        "description": "response representation",
        "required": ["id", "exceptionType", "chains"],
        "properties": {
            "requestId": {
                "type": "string",
                "description": "Unique ID for mapping input and output"
            },
            "id": {
                "type": "integer",
                "format": "int32",
                "description": "ID"
            },
            "exceptionType": {
                "type": "string",
                "description": "Exception Type description"
            },
            "exceptionDetail": {
                "type": "string",
                "description": "Exception Details description"
            },
            "chains": {
                "$ref": "List[List[Descriptor]]",
                "description": "Ordered collection of Descriptor"
            }
        }
    },
    "Request": {
        "id": "Request",
        "description": "request representation",
        "required": ["id"],
        "properties": {
            "requestId": {
                "type": "string",
                "description": "Unique ID for mapping input and output"
            },
            "id": {
                "type": "integer",
                "format": "int32",
                "description": "ID"
            },
            "allAttribute": {
                "type": "array",
                "description": "Attributes",
                "items": {
                    "$ref": "Attribute"
                }
            }
        }
    }
}}

This doesn't complie while i try to generate code using swaggercode gen cli - 2.1.2. I noticed that List Of List of decriptor is not generated properly( java List<List<Descriptor>> )

So i edited to below

{"apiVersion": "1.0", "swaggerVersion": "1.2", "basePath": "/", "resourcePath": "/service-v1", "produces": ["application/json"], "consumes": ["application/json"], "apis": [
    {
        "path": "/service-v1/evaluate",
        "operations": [
            {
                "method": "POST",
                "summary": "Summary",
                "notes": "notes",
                "type": "Response",
                "nickname": "evaluate",
                "produces": ["application/json"],
                "parameters": [
                    {
                        "name": "body",
                        "description": "Request description",
                        "required": true,
                        "type": "array",
                        "items": {
                            "$ref": "Request"
                        },
                        "paramType": "body",
                        "allowMultiple": false
                    }
                ],
                "responseMessages": [
                    {
                        "code": 200,
                        "message": "Successful evaluation",
                        "responseModel": "Response"
                    },
                    {
                        "code": 404,
                        "message": "service does not exist"
                    },
                    {
                        "code": 500,
                        "message": "Internal service error"
                    }
                ]
            }
        ]
    }
], "models": {
    "Attribute": {
        "id": "Attribute",
        "description": "Attribute representation",
        "properties": {
            "id": {
                "type": "integer",
                "format": "int32",
                "description": "Id"
            },
            "attributeId": {
                "type": "integer",
                "format": "int32",
                "description": "Attribute Id"
            },
            "attributeName": {
                "type": "string",
                "description": "Attribute Name"
            },
            "attributeValue": {
                "type": "string",
                "description": "Attribute Value"
            },
            "attributeValueCode": {
                "type": "string",
                "description": "Attribute Value Code"
            }
        }
    },
    "Descriptor": {
    "id": "class_id",
    "description": "Description for Descriptor",
    "properties": {
    "propertyName1": {
    "type": "string",
    "description": "Property Name 1"
    },
    "propertyName2": {
    "type": "string",
    "description": "Property Name 1"
    }
    }
    },
    "Response": {
        "id": "Response",
        "description": "response representation",
        "required": ["id", "exceptionType", "chains"],
        "properties": {
            "requestId": {
                "type": "string",
                "description": "Unique ID for mapping input and output"
            },
            "id": {
                "type": "integer",
                "format": "int32",
                "description": "ID"
            },
            "exceptionType": {
                "type": "string",
                "description": "Exception Type description"
            },
            "exceptionDetail": {
                "type": "string",
                "description": "Exception Details description"
            },
            "chains": {
                "type": "array",
                "description": "description 1",
                "items": {
                "type": "array",
                "description": "description 2",
                "items": {
                "$ref": "Descriptor"
                }
                }
            }
        }
    },
    "Request": {
        "id": "Request",
        "description": "request representation",
        "required": ["id"],
        "properties": {
            "requestId": {
                "type": "string",
                "description": "Unique ID for mapping input and output"
            },
            "id": {
                "type": "integer",
                "format": "int32",
                "description": "ID"
            },
            "allAttribute": {
                "type": "array",
                "description": "Attributes",
                "items": {
                    "$ref": "Attribute"
                }
            }
        }
    }
}}

Now i get the below exception
java.lang.NullPointerException
    at java.util.regex.Matcher.getTextLength(Matcher.java:1283)
    at java.util.regex.Matcher.reset(Matcher.java:309)
    at java.util.regex.Matcher.<init>(Matcher.java:229)
    at java.util.regex.Pattern.matcher(Pattern.java:1093)
    at io.swagger.codegen.DefaultCodegen.camelize(DefaultCodegen.java:1237)
    at io.swagger.codegen.DefaultCodegen.camelize(DefaultCodegen.java:1212)
    at io.swagger.codegen.languages.JavaClientCodegen.toModelName(JavaClientCodegen.java:179)
    at io.swagger.codegen.languages.JavaClientCodegen.getSwaggerType(JavaClientCodegen.java:215)
    at io.swagger.codegen.DefaultCodegen.getTypeDeclaration(DefaultCodegen.java:490)
    at io.swagger.codegen.languages.JavaClientCodegen.getTypeDeclaration(JavaClientCodegen.java:200)
    at io.swagger.codegen.languages.JavaClientCodegen.getTypeDeclaration(JavaClientCodegen.java:193)
    at io.swagger.codegen.languages.JavaClientCodegen.getTypeDeclaration(JavaClientCodegen.java:193)
    at io.swagger.codegen.DefaultCodegen.fromProperty(DefaultCodegen.java:606)
    at io.swagger.codegen.DefaultCodegen.addVars(DefaultCodegen.java:1191)
    at io.swagger.codegen.DefaultCodegen.fromModel(DefaultCodegen.java:540)
    at io.swagger.codegen.DefaultGenerator.processModels(DefaultGenerator.java:451

is this becoz of swagger spec 1.2 being used to generate .json file ?

I am using swagger code gen 2.1.2 at client side but service is owned by different team where they provide .json file to us.

Please help how to proceed .

[wing328]

Swagger spec 1.2 does not support nested array. Would you consider converting the spec to the latest Swagger spec 2.0, which supports nested array ?

[vijayrcse]

Yes. I am following this to move to swagger spec 2.0 please let me know if this is correct
https://github.com/swagger-api/swagger-core/wiki/1.3--1.5-Migration

[vijayrcse]

I have converted to 2.0 spec but i am getting below code generated at client side which doesn't compile

private List<List<Descriptor>> chains = new ArrayList<List>() ;

how should we get past this issue ?

generated json snippet

"chains": {
                "type": "array",
                "description": "Ordered descriptor chains",
                "items": {
                    "type": "array",

                    "items": {
                        "$ref": "#/definitions/Descriptor"
                    }
                }
            }

[fehguy]

This is simply not supported in codegen right now. Is there another way you can describe the data other than [[{ /* descriptor */ }]]?

[vijayrcse]

if this is not supported the only option is change the response not to contain

List<List<Descriptor>>

if spec 2.0 supports nested array , would like to know why code gen is not supporting that

other option for us to change as follows

List<DescriptorList>
class DescriptorList
{
    List<Descriptor> descriptor;
}

but this is going to change more things at service side
any thoughts if this can be supported ?

[xhh]

Hi @vijayrcse, were you using the latest code from the develop_2.0 branch when you tried it?
I just tried it and it works for me, generating code of model properties like this:

private List<List<Descriptor>> chains = new ArrayList<List<Descriptor>>();

[vijayrcse]

could you please tell me what is the certified version that needs to be used ? I am using the below version

<dependency>
            <groupId>io.swagger</groupId>
            <artifactId>swagger-codegen-cli</artifactId>
            <version>2.1.2</version>
        </dependency>

[wing328]

develop_2.0 branch is the latest version which contains bug fixes and enhancements. Please give it a try as it might have addressed the issue you reported.

[vijayrcse]

I cannot build using develop_2.0 branch. It is prohibited and i can only use a certified maven release.
Do you have certified maven release version that contains the fix ?

[wing328]

If that's the case, I'm afraid you've to wait for the next major release (no date has been set).

Maybe you can ask for an exception ?