JIRA: https://jira.spring.io/browse/INT-3698
The `HttpRequestExecutingMessageHandler` added two internal `Converters` to the `ConversionService` before.
In case of parent-child environment it causes memory leak: closing of child context doesn't release
`HttpRequestExecutingMessageHandler` instances, because those internal `Converters` aren't `static`, hence bounded to outer instance.
Actually after introduction since `4.0` version to the `HttpRequestExecutingMessageHandler` the code like:
```
Assert.isTrue(expectedResponseType instanceof Class<?>
|| expectedResponseType instanceof String
|| expectedResponseType instanceof ParameterizedTypeReference,
"'expectedResponseType' can be an instance of 'Class<?>', 'String' or 'ParameterizedTypeReference<?>'.");
if (expectedResponseType instanceof String && StringUtils.hasText((String) expectedResponseType)){
expectedResponseType = ClassUtils.forName((String) expectedResponseType, ClassUtils.getDefaultClassLoader());
}
```
These converters are redundant.
In addition remove the `expected type` for the `uriVariablesExpression` evaluation to avoid `MapToMapConverter`.
**Cherry-pick to 4.1.x, 4.0.x**
INT-3698: Provide robust logic for the `uriExpression` and `httpMethodExpression`
Make some polishing around `Assert`s, when `IllegalStateException` must be presented instead of `IllegalArgumentException`
for the expression evaluation results.
Polishing
2aac4414df