问题
This is how you overload the toString() method:
public class Person extends Object {
@Override
public final String toString() {
Gson gson = new GsonBuilder().serializeNulls().create();
return (gson.toJson(this));
}
}
In this example I get a JSON string when calling the toString() method of Person instead of the default string representation of an Object.
But what if I have an array of Person like:
Person[] persons = new Person[3];
System.out.println(persons.toString());
What do I have to do or which method(s) do I have to override in that case?
回答1:
You cannot override default array's toString. If you want to convert an array of objects into the string, use Arrays.toString().
回答2:
You can't override the "array" version as their is no array version. What really happens is that the Array has a toString method which will be called.
If you had used a Java Collection as opposed to an Array, it would print out your Person#toString method 3 times as the Collection#toString iterates over each object in the collection.
回答3:
You cannot override method toString on array but you can use Arrays.toString(Object[]) to print array.
回答4:
First of all, you don't need to extend Object, it is there by default.
To print the array content you can use:
Person[] persons = new Person[3];
System.out.println(Arrays.toString(persons));
来源：https://stackoverflow.com/questions/16970488/java-overloading-tostring-method-when-array-of-class-is-given