jade-recipe-11-17-wrapper-valueof — the wrapper constructors are on the way out

JEP 390 designated the primitive wrapper classes as value-based and deprecated their constructors for removal. The JDK 16 release note is explicit: "Programmers are strongly discouraged from calling the wrapper class constructors, which are now deprecated for removal."

Nothing is broken on JDK 17 — the code compiles and runs. What the rule buys is that this is JADE's largest terminally-deprecated surface: 144 sites confirmed by javac itself (-Xlint:removal -Xmaxwarns 100000), spread over 52 files.

Scope of one task

You receive a shard contract. This rule is blast_class: body-local (parallel_safe: true), planned into 12 shards. Edit only that shard's editable_files; read_only_context is read-only.

The transform

new Boolean(x)   ->  Boolean.valueOf(x)
new Integer(x)   ->  Integer.valueOf(x)
new Long(x)      ->  Long.valueOf(x)
new Double(x)    ->  Double.valueOf(x)
new Float(x)     ->  Float.valueOf(x)
new Character(c) ->  Character.valueOf(c)

Both the primitive and the String overloads are covered — Integer.valueOf(String) and Long.valueOf(String) exist and parse identically. Fully-qualified receivers (new java.lang.Long(...)) keep their qualification: java.lang.Long.valueOf(...).

The static type of the expression is unchanged, so no field type, method signature or return type moves. That is what makes this body-local.

The one thing that can go wrong

valueOf may return a cached, shared instance where the constructor always returned a fresh one. Boolean.valueOf always returns Boolean.TRUE or Boolean.FALSE; Integer.valueOf, Long.valueOf, Short.valueOf and Byte.valueOf intern -128..127; Character.valueOf interns 0..127.

Before converting a site, check what happens to the resulting object:

• compared with == or != against another wrapper
• used as a synchronized monitor
• used as a key in an IdentityHashMap, or passed to System.identityHashCode
• relied on for wait/notify

Any of those makes the conversion a behaviour change. Leave the site as it is, keep its // JADE-FLAG: marker, and report it in the shard result. Converting an identity-sensitive site is worse than leaving a deprecation warning.

.equals comparison, .intValue()/.booleanValue() unwrapping, storage in a collection, and use as a method argument are all safe.

What the agent may not do

• Do not "simplify" further by removing the boxing altogether (new Integer(x) -> x). Autoboxing has different overload-resolution behaviour and this rule is not a refactor.
• Do not edit a site inside a comment or a string literal. The scanner's line filter is prefix-based and its population (147) is three larger than javac's live count (144); the difference is code sitting inside block comments such as MMCanvas.java:427-469. Check with java_source.is_live_code() before every edit.
• Do not touch #PJAVA_INCLUDE, #DOTNET_INCLUDE or #MIDP_EXCLUDE blocks. They are comment text, not code.

Verification

Recompiling in jade-ant:17 with -Xlint:removal -Xmaxwarns 100000 reports zero [removal] ... in Boolean/Integer/Long/Double/Float/Character has been deprecated and marked for removal warnings, down from 144. Any site deliberately left behind is named in the shard result with its reason. The build exits 0 and all consumers PASS.