strings - Unintended Recursion

最新推荐文章于 2022-07-31 01:11:20 发布

原创最新推荐文章于 2022-07-31 01:11:20 发布 · 165 阅读

0 ·

CC 4.0 BY-SA版权

Thinking in Java 专栏收录该内容

155 篇文章

订阅专栏

博客给出Java异常示例，解决方案是使用super.toString()替代this，还给出输出情况，并列出参考资料，包括《On Java 8 - Bruce Eckel》及相关GitHub链接。

// strings/InfiniteRecursion.java
// (c)2017 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
// Accidental recursion
// {ThrowsException}
// {VisuallyInspectOutput} Throws very long exception

import java.util.*;
import java.util.stream.*;

public class InfiniteRecursion {
  @Override
  public String toString() {
    return " InfiniteRecursion address: " + this + "\n";// Throws very long exception
  }

  public static void main(String[] args) {
    Stream.generate(InfiniteRecursion::new).limit(10).forEach(System.out::println);
  }
}

the exception example is

…………………………………………
        at java.lang.StringBuilder.append(StringBuilder.java:131)
        at InfiniteRecursion.toString(InfiniteRecursion.java:15)
        at java.lang.String.valueOf(String.java:2994)
        at java.lang.StringBuilder.append(StringBuilder.java:131)
        at InfiniteRecursion.toString(InfiniteRecursion.java:15)

        at java.lang.String.valueOf(String.java:2994)
        at java.lang.StringBuilder.append(StringBuilder.java:131)
        at InfiniteRecursion.toString(InfiniteRecursion.java:15)

The solution is using super.toString() instead of this.

then it outputs

 InfiniteRecursion address: InfiniteRecursion@1b28cdfa

 InfiniteRecursion address: InfiniteRecursion@eed1f14

 InfiniteRecursion address: InfiniteRecursion@7229724f

 InfiniteRecursion address: InfiniteRecursion@4c873330

 InfiniteRecursion address: InfiniteRecursion@119d7047

 InfiniteRecursion address: InfiniteRecursion@776ec8df


 InfiniteRecursion address: InfiniteRecursion@4eec7777

 InfiniteRecursion address: InfiniteRecursion@3b07d329

 InfiniteRecursion address: InfiniteRecursion@41629346

 InfiniteRecursion address: InfiniteRecursion@404b9385

references:

1. On Java 8 - Bruce Eckel

2. https://github.com/wangbingfeng/OnJava8-Examples/blob/master/strings/InfiniteRecursion.java