（注：このブログはもう更新していません）この日記は私的なものであり所属会社の見解とは無関係です。 GitHub: takahashikzn

[クラウド帳票エンジンDocurain]

Spring4.0.0が出た

Java

…しかしStackOverflowで動かなかった!！（ドラクエ風に）

...
at org.springframework.core.ResolvableType.hashCode(ResolvableType.java:693) ~[spring-core-4.0.0.RELEASE.jar:4.0.0.RELEASE]
at org.springframework.util.ObjectUtils.nullSafeHashCode(ObjectUtils.java:336) ~[spring-core-4.0.0.RELEASE.jar:4.0.0.RELEASE]
at org.springframework.core.ResolvableType.hashCode(ResolvableType.java:693) ~[spring-core-4.0.0.RELEASE.jar:4.0.0.RELEASE]
at org.springframework.util.ObjectUtils.nullSafeHashCode(ObjectUtils.java:336) ~[spring-core-4.0.0.RELEASE.jar:4.0.0.RELEASE]
at org.springframework.core.ResolvableType.hashCode(ResolvableType.java:693) ~[spring-core-4.0.0.RELEASE.jar:4.0.0.RELEASE]
at org.springframework.util.ObjectUtils.nullSafeHashCode(ObjectUtils.java:336) ~[spring-core-4.0.0.RELEASE.jar:4.0.0.RELEASE]
at org.springframework.core.ResolvableType.hashCode(ResolvableType.java:693) ~[spring-core-4.0.0.RELEASE.jar:4.0.0.RELEASE]
at org.springframework.util.ObjectUtils.nullSafeHashCode(ObjectUtils.java:336) ~[spring-core-4.0.0.RELEASE.jar:4.0.0.RELEASE]
at org.springframework.core.ResolvableType.hashCode(ResolvableType.java:693) ~[spring-core-4.0.0.RELEASE.jar:4.0.0.RELEASE]
at org.springframework.util.ObjectUtils.nullSafeHashCode(ObjectUtils.java:336) ~[spring-core-4.0.0.RELEASE.jar:4.0.0.RELEASE]
at org.springframework.core.ResolvableType.hashCode(ResolvableType.java:693) ~[spring-core-4.0.0.RELEASE.jar:4.0.0.RELEASE]
at org.springframework.util.ObjectUtils.nullSafeHashCode(ObjectUtils.java:336) ~[spring-core-4.0.0.RELEASE.jar:4.0.0.RELEASE]
at org.springframework.core.ResolvableType.hashCode(ResolvableType.java:693) ~[spring-core-4.0.0.RELEASE.jar:4.0.0.RELEASE]
at org.springframework.util.ObjectUtils.nullSafeHashCode(ObjectUtils.java:336) ~[spring-core-4.0.0.RELEASE.jar:4.0.0.RELEASE]
at org.springframework.core.ResolvableType.hashCode(ResolvableType.java:693) ~[spring-core-4.0.0.RELEASE.jar:4.0.0.RELEASE]
at org.springframework.util.ObjectUtils.nullSafeHashCode(ObjectUtils.java:336) ~[spring-core-4.0.0.RELEASE.jar:4.0.0.RELEASE]
at org.springframework.core.ResolvableType.hashCode(ResolvableType.java:693) ~[spring-core-4.0.0.RELEASE.jar:4.0.0.RELEASE]
...

なんやねん

該当の箇所を見てみたらこの通り。

ResolvableType.java

@Override
public int hashCode() {
    int hashCode = ObjectUtils.nullSafeHashCode(this.type);
    hashCode = hashCode * 31 + ObjectUtils.nullSafeHashCode( // ←693行目はココ
            this.variableResolver == null ? null : this.variableResolver.getSource()); 
    hashCode = hashCode * 31 + ObjectUtils.nullSafeHashCode(this.componentType);
    return hashCode;
}


ObjectUtils.java

public static int nullSafeHashCode(Object obj) {
    if (obj == null) {
        return 0;
    }
    if (obj.getClass().isArray()) {
        if (obj instanceof Object[]) {
            return nullSafeHashCode((Object[]) obj);
        }
        if (obj instanceof boolean[]) {
            return nullSafeHashCode((boolean[]) obj);
        }
        if (obj instanceof byte[]) {
            return nullSafeHashCode((byte[]) obj);
        }
        if (obj instanceof char[]) {
            return nullSafeHashCode((char[]) obj);
        }
        if (obj instanceof double[]) {
            return nullSafeHashCode((double[]) obj);
        }
        if (obj instanceof float[]) {
            return nullSafeHashCode((float[]) obj);
        }
        if (obj instanceof int[]) {
            return nullSafeHashCode((int[]) obj);
        }
        if (obj instanceof long[]) {
            return nullSafeHashCode((long[]) obj);
        }
        if (obj instanceof short[]) {
            return nullSafeHashCode((short[]) obj);
        }
    }
    return obj.hashCode(); // ←336行目はココ
}


パッと見た感じ、ResolvableType#hashCodeの

    hashCode = hashCode * 31 + ObjectUtils.nullSafeHashCode(
            this.variableResolver == null ? null : this.variableResolver.getSource());

において、三項演算子のfalse側の式が評価されていて、かつ

this.variableResolver.getSource() == this

という循環参照になっているのではないかと。