Closed as not planned
Description
When I was doing research for #42773, I came across two potential improvements for
MessageSourceMessageInterpolator:
- The logic around
MessageSource.setUseCodeAsDefaultMessage(true)Hibernate validation messages broken in spring boot 2.6.1 when setUseCodeAsDefaultMessage set to true #28930 could be
improved a little bit:
//Current test in MessageSourceMessageInterpolatorTests
@Test
void interpolateWhenParametersAreUnknownUsingCodeAsDefaultShouldLeaveThemUnchanged() {
this.messageSource.setUseCodeAsDefaultMessage(true);
this.messageSource.addMessage("top", Locale.getDefault(), "{child}+{child}");
assertThat(this.interpolator.interpolate("{foo}{top}{bar}", this.context))
.isEqualTo("{foo}{child}+{child}{bar}");
}
// Changed a little bit
@Test
void interpolateWhenParametersAreUnknownUsingCodeAsDefaultShouldLeaveThemUnchanged() {
this.messageSource.setUseCodeAsDefaultMessage(true);
this.messageSource.addMessage("top", Locale.getDefault(), "{child}+{child}");
this.messageSource.addMessage("foo", Locale.getDefault(), "foo");
this.messageSource.addMessage("bar", Locale.getDefault(), "bar");
// Actually, I expected the result to be "foo{child}+{child}bar"
// since I explicitly specified these values in the MessageSource.
// However, the test fails!
assertThat(this.interpolator.interpolate("{foo}{top}{bar}", this.context))
.isEqualTo("foo{child}+{child}bar");
}If MessageSource contains the searched parameter, it should be used, even if the value is identical to the parameter itself.
The solution for this is quite straightforward
private static final String DEFAULT_MESSAGE = MessageSourceMessageInterpolator.class.getName();
private String replaceParameter(String parameter, Locale locale, Set<String> visitedParameters) {
parameter = replaceParameters(parameter, locale, visitedParameters);
String value = this.messageSource.getMessage(parameter, null, DEFAULT_MESSAGE, locale);
if (value == null || value.equals(DEFAULT_MESSAGE)) {
return null;
}
return replaceParameters(value, locale, visitedParameters);
}- The message lookup for EL expressions like
${validatedValue}and for Bean Validation
attributes such as{max}could be skipped. For example:size.person.name=${validatedValue} must be between {min} and {max}. Currently,MessageSourceMessageInterpolatortries to resolve {validatedValue}, {min} and {max} viaMessageSource. Clearly, the first one is an EL expression, while the latter two are Bean Validation attributes.
EL expression can be handled by:
// EL Expression
if (buf.charAt(i) == '$' && next(buf, i, '{')) {
i++;
continue;
}Bean validation attributes:
private boolean isBeanValidationAttribute(String parameter, Context context) {
ConstraintDescriptor<?> constraintDescriptor = context.getConstraintDescriptor();
Map<String, Object> attributes = constraintDescriptor.getAttributes();
return attributes.containsKey(parameter);
}UPDATE: I changed the initial description to make it clearer.