support non-lenient constructor injection [SPR-5816]

[spring-projects-issues]

Costin Leau opened SPR-5816 and commented

Currently, for constructor injection the container assumes a default type of String for values injected. Consider the following class:

Foo(String s) {}
Foo(Boolean b) {}
<bean class="Foo">
<constructor-arg value="true"/>
</bean>

Currently Spring will pick the first (String) constructor - arguably the second one is also valid. It would be useful to have a flag or some means (even programatically) to change this behaviour so when more then one constructor are found suitable, an exception is raised.

---

Affects: 3.0 M3

Issue Links:

• primitive vs wrapper objects abiguity inside the container [SPR-5881] #10550 primitive vs wrapper objects abiguity inside the container

Referenced from: commits 8e27971, a9254b3

[spring-projects-issues]

Costin Leau commented

Based on our discussion, this could be implemented (in a backwards compatible way) by taking into account the defaultType of the TypedStringValue. By default this would be set to java.lang.String (for compatibility reason) but implementations could just change it into null or maybe java.lang.Object which prevent any String assignment from happening.

[spring-projects-issues]

Juergen Hoeller commented

Introduced "lenientConstructorResolution" flag at the BeanDefinition level, as discussed.

Juergen