Java 8流将一个数组中的对象替换为另一个数组 [英] Java 8 stream replace object in one array from another

问题描述

我有两个对象数组。如果对象符合某个条件，我想用第二个数组中的更新对象更新一个数组。例如，我有这个：

I have two arrays of objects. I want to update one array with updated objects from the second array if the object matches a certain criteria. For example, I have this:

public class Foobar
{
   private String name;

   // Other methods here...

   public String getName() { return this.name; }
}

Foobar [] original = new Foobar[8];
// Instantiate them here and set their field values

Foobar [] updated = new Foobar[8];
// Instantiate them here and set their field values

/* Use Java8 stream operation here
*   - Check if name is the same in both arrays
*   - Replace original Foobar at index with updated Foobar
*
*   Arrays.stream(original).filter(a -> ...)
*/

我知道我可以为循环做一个简单的来执行此操作。我想知道是否可以使用流来完成此操作。我无法弄清楚要放入过滤器或之后的内容。

I know I can make a simple for loop to do this. I want to know if it's possible to do this using streams. I can't figure out what to put in filter or after that.

推荐答案

这里可以使用的一个巧妙的技巧是创建一个索引流并使用它们来评估相应的元素：

One neat trick you can use here is to create a stream of indexes and use them to evaluate the corresponding elements:

IntStream.range(0, original.length)
         .filter(i -> original[i].getName().equals(updated[i].getName()))
         .forEach(i -> original[i] = updated[i]);

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