Java: 通过引用传递 int 的最佳方式

我有一个解析函数，它解析字节缓冲区中的编码长度，它返回解析后的长度为 int，并将一个索引作为整数 arg 放入缓冲区。我希望函数根据它解析的内容来更新索引，也就是说，希望通过引用传递索引。C 我刚刚通过了 int *。 在 Java 中最干净的方法是什么？ 我目前正在寻找传递的索引参数。作为一个 int[]，但它有点丑陋。

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最佳答案

You can try using org.apache.commons.lang.mutable.MutableInt from Apache Commons library. There is no direct way of doing this in the language itself.

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You cannot pass arguments by reference in Java.

What you can do is wrap your integer value in a mutable object. Using Apache Commons' MutableInt is a good option. Another, slightly more obfuscated way, is to use an int[] like you suggested. I wouldn't use it as it is unclear as to why you are wrapping an int in a single-celled array.

Note that java.lang.Integer is immutable.

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This isn't possible in Java. As you've suggested one way is to pass an int[]. Another would be do have a little class e.g. IntHolder that wrapped an int.

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Wrap the byte buffer and index into a ByteBuffer object. A ByteBuffer encapsulates the concept of a buffer+position and allows you to read and write from the indexed position, which it updates as you go along.

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You can design new class like this:

public class Inte{
public int x=0;
}

later you can create object of this class :

Inte inte=new Inte();

then you can pass inte as argument where you want to pass an integer variable:

public void function(Inte inte) {
some code
}

so for update the integer value:

inte.x=value;

for getting value:

Variable=inte.x;
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You can use java.util.concurrent.atomic.AtomicInteger.

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You can create a Reference class to wrap primitives:

public class Ref<T>
{
public T Value;


public Ref(T value)
{
Value = value;
}
}

Then you can create functions that take a Reference as a parameters:

public class Utils
{
public static <T> void Swap(Ref<T> t1, Ref<T> t2)
{
T temp = t1.Value;
t1.Value = t2.Value;
t2.Value = temp;
}
}

Usage:

Ref<Integer> x = 2;
Ref<Integer> y = 9;
Utils.Swap(x, y);


System.out.println("x is now equal to " + x.Value + " and y is now equal to " + y.Value";
// Will print: x is now equal to 9 and y is now equal to 2

Hope this helps.


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