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社区首页 >问答首页 >带数字的Java排序算法字符串

带数字的Java排序算法字符串
EN

Stack Overflow用户
提问于 2012-06-29 15:08:57
回答 4查看 732关注 0票数 0

我有一个字符串列表。EXAMPLE_1,EXAMPLE_2,EXAMPLE_3 ...EXAMPLE_99这里最好的排序算法是什么?

有没有可能使用排序器?这是我目前的程序,但我想可能有更好的方法:

代码语言:javascript
复制
public class Example implements Comparable<Example> {
    private final String id;

    public getId() {
        return id;
    }

    private Integer getIdNo() {
        try {
            return Integer.parseInt(getId().replaceAll("[\\D]", ""));
        } catch (NumberFormatException e) {
            return null;
        }
    }

    @Override
    public int compareTo(Example o) {
        if ((getIdNo() == null && getIdNo() != null) || (getProductFeatureId_sizeNo() < o.getProductFeatureId_sizeNo())) {
            return -1;
        } else if (o.getIdNo() == null || getIdNo() > o.getIdNo()) {
            return 1;
        }

        return 0;
    }
}
EN

回答 4

Stack Overflow用户

回答已采纳

发布于 2012-06-29 15:35:59

这是更好的替代方案- AlphanumComparator.java

复制代码以备参考-

代码语言:javascript
复制
public class AlphanumComparator implements Comparator
{
    private final boolean isDigit(char ch)
    {
        return ch >= 48 && ch <= 57;
    }

    /** Length of string is passed in for improved efficiency (only need to calculate it once) **/
    private final String getChunk(String s, int slength, int marker)
    {
        StringBuilder chunk = new StringBuilder();
        char c = s.charAt(marker);
        chunk.append(c);
        marker++;
        if (isDigit(c))
        {
            while (marker < slength)
            {
                c = s.charAt(marker);
                if (!isDigit(c))
                    break;
                chunk.append(c);
                marker++;
            }
        } else
        {
            while (marker < slength)
            {
                c = s.charAt(marker);
                if (isDigit(c))
                    break;
                chunk.append(c);
                marker++;
            }
        }
        return chunk.toString();
    }

    public int compare(Object o1, Object o2)
    {
        if (!(o1 instanceof String) || !(o2 instanceof String))
        {
            return 0;
        }
        String s1 = (String)o1;
        String s2 = (String)o2;

        int thisMarker = 0;
        int thatMarker = 0;
        int s1Length = s1.length();
        int s2Length = s2.length();

        while (thisMarker < s1Length && thatMarker < s2Length)
        {
            String thisChunk = getChunk(s1, s1Length, thisMarker);
            thisMarker += thisChunk.length();

            String thatChunk = getChunk(s2, s2Length, thatMarker);
            thatMarker += thatChunk.length();

            // If both chunks contain numeric characters, sort them numerically
            int result = 0;
            if (isDigit(thisChunk.charAt(0)) && isDigit(thatChunk.charAt(0)))
            {
                // Simple chunk comparison by length.
                int thisChunkLength = thisChunk.length();
                result = thisChunkLength - thatChunk.length();
                // If equal, the first different number counts
                if (result == 0)
                {
                    for (int i = 0; i < thisChunkLength; i++)
                    {
                        result = thisChunk.charAt(i) - thatChunk.charAt(i);
                        if (result != 0)
                        {
                            return result;
                        }
                    }
                }
            } else
            {
                result = thisChunk.compareTo(thatChunk);
            }

            if (result != 0)
                return result;
        }

        return s1Length - s2Length;
    }
}

注意:如果使用java 1.5+,则应泛化此类

票数 2
EN

Stack Overflow用户

发布于 2012-06-29 15:23:43

代码语言:javascript
复制
private Integer getIdNo() {
        try {
            return Integer.parseInt(getId().replaceAll("[\\D]", ""));
        } catch (NumberFormatException e) {
            return 0;
        }
    }

@Override
public int compareTo(Example o) {
    if(o == null) {
        return 1;
    }
    return getIdNo().compareTo(o.getIdNo());
}
票数 1
EN

Stack Overflow用户

发布于 2012-06-29 15:31:33

要构建@Jeshuruns答案,您可以跳过所有数字解析,如下所示:

代码语言:javascript
复制
  @Override
  public int compareTo(Example o) {
      if (o == null) {
          return 1;
      }
      if (getId().length() != o.getId().length() {
          return (getId().length() - o.getId().length());
      } else {
          return getId().compareTo(o.getId());
      }
  }
票数 1
EN
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接:

https://stackoverflow.com/questions/11257531

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