Object instantiation inside 'equals()' or 'hashCode()'
Reports construction of (temporary) new objects inside equals()
, hashCode()
, compareTo()
, and Comparator.compare()
methods.
Besides constructor invocations, new objects can also be created by autoboxing or iterator creation inside a foreach
statement. This can cause performance problems, for example, when objects are added to a Set
or Map
, where these methods will be called often.
The inspection will not report when the objects are created in a throw
or assert
statement.
Example:
class Person {
private String name;
private int age;
public boolean equals(Object o) {
return Arrays.equals(new Object[] {name, age}, new Object[] {((Foo)o).name, ((Foo)o).age});
}
public int hashCode() {
return (name + age).hashCode();
}
}
In this example, two additional arrays are created inside equals()
, usages of age
field require boxing, and name + age
implicitly creates a new string.
- By ID
Can be used to locate inspection in e.g. Qodana configuration files, where you can quickly enable or disable it, or adjust its settings.
ObjectInstantiationInEqualsHashCode
Inspection Details | |
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By default bundled with: | |
Can be installed with plugin: | Java, 243.23126 |
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