Fix java test failure (#247)

* Fixes test for java 21

* Adds higher java

* Changes to java 20

* Changes to docker convenience image

* Changes to docker convenience image, fix

* FIxes refs to nonexistant file

* Fix yaml file extension

* Comments out test

* Comments out test

* Changes docker image for java 20

* Updates docker image

* Adds maven docker image

* Reverts two files

Author: spacether

samples/meta-codegen/lib/src/test/java/com/my/company/codegen/MyclientcodegenGeneratorTest.java

@@ -25,8 +25,8 @@ public void launchCodeGenerator() {
     // https://github.com/OpenAPITools/openapi-generator/blob/master/modules/openapi-generator-cli/src/main/java/org/openapijsonschematools/codegen/cmd/Generate.java
     final CodegenConfigurator configurator = new CodegenConfigurator()
               .setGeneratorName("myClientCodegen") // use this codegen library
-              .setInputSpec("../../../modules/openapi-generator/src/test/resources/2_0/petstore.yaml") // sample OpenAPI file
-              // .setInputSpec("https://raw.githubusercontent.com/openapi-json-schema-tools/openapi-json-schema-generator/master/modules/openapi-generator/src/test/resources/2_0/petstore.yaml") // or from the server
+              .setInputSpec("../../../modules/openapi-generator/src/test/resources/2_0/sample_spec.yml") // sample OpenAPI file
+              // .setInputSpec("https://raw.githubusercontent.com/openapi-json-schema-tools/openapi-json-schema-generator/master/modules/openapi-generator/src/test/resources/2_0/sample_spec.yml") // or from the server
               .setOutputDir("out/myClientCodegen"); // output directory
 
     final ClientOptInput clientOptInput = configurator.toClientOptInput();

src/test/java/org/openapijsonschematools/codegen/common/URLPathUtilsTest.java

@@ -111,8 +111,8 @@ public void testGetServerURLWithVariables() {
 
         Server s9 = new Server().url("https://{user}.example.com/{version}").variables(
                     new ServerVariables().addServerVariable("version", new ServerVariable()._default("v1"))
-                        .addServerVariable("user", new ServerVariable()._default("{user}")));
-        Assert.assertEquals(URLPathUtils.getServerURL(s9, null).toString(), "https://{user}.example.com/v1");
+                        .addServerVariable("user", new ServerVariable()._default("%7Buser%7D")));
+        Assert.assertEquals(URLPathUtils.getServerURL(s9, null).toString(), "https://%7Buser%7D.example.com/v1");
     }
 
     private ServerVariables serverVariables(String... entries) {

src/test/java/org/openapijsonschematools/codegen/generators/PythonClientGeneratorTest.java

@@ -63,7 +63,7 @@ public void testRecursiveExampleValueWithCycle() throws Exception {
 
     @Test(expectedExceptions = RuntimeException.class)
     public void testSpecWithTooLowVersionThrowsException() {
-        final OpenAPI openAPI = TestUtils.parseSpec("src/test/resources/2_0/petstore.yaml");
+        final OpenAPI openAPI = TestUtils.parseSpec("src/test/resources/2_0/sample_spec.yml");
         final PythonClientGenerator codegen = new PythonClientGenerator();
         codegen.preprocessOpenAPI(openAPI);
     }