[Java] Issue with evaluating server URL (3.0.0-rc1)

[douglasbgray]

Description

When running code gen on an openapi 3.x document with a servers section, if you use a variable for the port, code gen throws an exception. The exception does not block the generation, but does generate a warning in the output. In addition method returns null in this circumstance. I not sure how this impacts downstream processes or the availability of servers for use in templates.

Error looks like:

java.net.MalformedURLException: For input string: "{port}"
	at java.net.URL.<init>(URL.java:627)
	at java.net.URL.<init>(URL.java:490)
	at java.net.URL.<init>(URL.java:439)
	at io.swagger.codegen.utils.URLPathUtil.getServerURL(URLPathUtil.java:30)
	at io.swagger.codegen.DefaultGenerator.configureGeneratorProperties(DefaultGenerator.java:211)
	...

Swagger-codegen version

3.0.0-rc1

Swagger declaration file content or url

servers:
  - url: 'http://localhost:{port}/sample'
    description: 'Development server running on localhost'
    variables:
      port:
        default: '8080'
        description: port number on which the server is running

Command line used for generation

Using the code generation plugin, so just a simple mvn clean compile

Steps to reproduce

I have created a sample project that shows the error and has steps to reproduce here: https://github.com/douglasbgray/code-gen-server-issue

Related issues/PRs

Did not find any open issues related to this

Suggest a fix/enhancement

Error is coming from URLPathUtil.java. Before checking if the url can be converted into a java.net.URL, it needs to perform the variable substitution, which would resolve the {port} and generate a URL that would be valid.

[haitongz]

can anyone give some suggestion for this issue

[b5l]

Bump, I am experiencing exactly the same issue using version 3.0.22:

Server configuration:

{
  "url": "http://{instance}:{port}/api/ext/{version}",
  "variables": {
    "instance": {
      "default": "localhost"
    },
    "port": {
      "enum": [
        "80",
        "443",
        "1356"
      ],
      "default": "1356"
    },
    "version": {
      "default": "1.0"
    }
  }
}

Output of java -jar swagger-codegen-cli-3.0.22.jar generate -i /tmp/swagger/api.json -l html:

13:41:38.914 [Thread-0] WARN  i.s.codegen.v3.utils.URLPathUtil - Not valid URL: http://{instance}:{port}/api/ext/{version}
java.net.MalformedURLException: Error at index 0 in: "{port}"
	at java.base/java.net.URL.<init>(URL.java:679)
	at java.base/java.net.URL.<init>(URL.java:541)
	at java.base/java.net.URL.<init>(URL.java:488)
	at io.swagger.codegen.v3.utils.URLPathUtil.getServerURL(URLPathUtil.java:70)
	at io.swagger.codegen.v3.DefaultGenerator.configureGeneratorProperties(DefaultGenerator.java:228)
	at io.swagger.codegen.v3.DefaultGenerator.generate(DefaultGenerator.java:773)
	at io.swagger.codegen.v3.cli.cmd.Generate.run(Generate.java:378)
	at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.lang.NumberFormatException: Error at index 0 in: "{port}"
	at java.base/java.lang.NumberFormatException.forCharSequence(NumberFormatException.java:81)
	at java.base/java.lang.Integer.parseInt(Integer.java:735)
	at java.base/java.net.URLStreamHandler.parseURL(URLStreamHandler.java:223)
	at java.base/java.net.URL.<init>(URL.java:674)
	... 7 common frames omitted
13:41:39.040 [Thread-0] WARN  i.s.codegen.v3.utils.URLPathUtil - Not valid URL: http://{instance}:{port}/api/ext/{version}
java.net.MalformedURLException: Error at index 0 in: "{port}"
	at java.base/java.net.URL.<init>(URL.java:679)
	at java.base/java.net.URL.<init>(URL.java:541)
	at java.base/java.net.URL.<init>(URL.java:488)
	at io.swagger.codegen.v3.utils.URLPathUtil.getServerURL(URLPathUtil.java:70)
	at io.swagger.codegen.v3.DefaultGenerator.buildSupportFileBundle(DefaultGenerator.java:723)
	at io.swagger.codegen.v3.DefaultGenerator.generate(DefaultGenerator.java:785)
	at io.swagger.codegen.v3.cli.cmd.Generate.run(Generate.java:378)
	at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.lang.NumberFormatException: Error at index 0 in: "{port}"
	at java.base/java.lang.NumberFormatException.forCharSequence(NumberFormatException.java:81)
	at java.base/java.lang.Integer.parseInt(Integer.java:735)
	at java.base/java.net.URLStreamHandler.parseURL(URLStreamHandler.java:223)
	at java.base/java.net.URL.<init>(URL.java:674)
	... 7 common frames omitted
13:41:39.040 [Thread-0] WARN  i.s.codegen.v3.utils.URLPathUtil - Not valid URL: http://{instance}:{port}/api/ext/{version}
java.net.MalformedURLException: Error at index 0 in: "{port}"
	at java.base/java.net.URL.<init>(URL.java:679)
	at java.base/java.net.URL.<init>(URL.java:541)
	at java.base/java.net.URL.<init>(URL.java:488)
	at io.swagger.codegen.v3.utils.URLPathUtil.getServerURL(URLPathUtil.java:33)
	at io.swagger.codegen.v3.utils.URLPathUtil.getScheme(URLPathUtil.java:79)
	at io.swagger.codegen.v3.DefaultGenerator.buildSupportFileBundle(DefaultGenerator.java:732)
	at io.swagger.codegen.v3.DefaultGenerator.generate(DefaultGenerator.java:785)
	at io.swagger.codegen.v3.cli.cmd.Generate.run(Generate.java:378)
	at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.lang.NumberFormatException: Error at index 0 in: "{port}"
	at java.base/java.lang.NumberFormatException.forCharSequence(NumberFormatException.java:81)
	at java.base/java.lang.Integer.parseInt(Integer.java:735)
	at java.base/java.net.URLStreamHandler.parseURL(URLStreamHandler.java:223)
	at java.base/java.net.URL.<init>(URL.java:674)
	... 8 common frames omitted
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by com.github.jknack.handlebars.context.MemberValueResolver (file:/tmp/swagger/swagger-codegen-cli-3.0.22.jar) to method java.util.Collections$EmptyMap.isEmpty()
WARNING: Please consider reporting this to the maintainers of com.github.jknack.handlebars.context.MemberValueResolver
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
13:41:39.243 [Thread-0] INFO  i.s.codegen.v3.AbstractGenerator - writing file /tmp/swagger/./index.html
13:41:39.247 [Thread-0] INFO  i.s.codegen.v3.AbstractGenerator - writing file /tmp/swagger/./.swagger-codegen/VERSION

[douglasbgray]

Saw that someone was looking for a fix, so I created one.

PR - #10565

[jaekim0312]

@douglasbgray thanks for the fix. This looks good to me. I was wondering you have any plan to merge your changes? Your branch was created a year ago, but not merged yet. I was wondering you have any plan for it. Thanks.

[douglasbgray]

Hi @jaekim0312 I am not an administrator for this project, so I do not have merge rights. I am not part of the project team, just thought I could help with a solution, since it seemed like my Issue was not being worked on. Only the owners can merge changes and I am not sure they are actively reviewing and merging changes from outside contributors right now.

[dchiang]

I am getting the exactly same issue when generating server stubs with python-flask locally using swagger-codegen version 3.0.32

[uri200]

Same here when using this command

swagger-codegen generate -i https://raw.githubusercontent.com/jdegre/5GC_APIs/master/TS29591_Nnef_EventExposure.yaml -l go -o client

It looks like that PR described before fixes that issue. @HugoMario , @frantuma could you please take a look at that PR please #10565

[HugoMario]

fixed by #10565