在组成该文本的片段数组列表上查找文本片段（文本中的选择）的最佳方法是什么？

Question

我在查找 arraylist 上的文本巧合时遇到了麻烦。我有这个结构：

public class Fragment {
    private int id;
    private Date date;
    private String text;
    private Profile profile;
}

我有一个从 API 获取片段列表并将它们放在ArrayList<Fragment> 上的活动。它还创建了一个包含所有片段的 TextView。然后我有一个自定义的ActionMode.Callback 用于显示上下文菜单选项，例如“搜索”。

单击“搜索”菜单选项时，我想在该片段列表中搜索与所选文本的重合，但该文本不能是完全重合的片段。例如，将这个片段放在列表中：

fragments.get(0).getText() //returns "Hi"
fragments.get(1).getText() //returns ", Mi name is Peter"
fragments.get(2).getText() //returns ", how are you?"

而选中的文字是“is peter, how are”

感谢您的建议！

Answer 1

下面是一个示例，说明您可以如何做到这一点。它基本上创建了一个基于全文匹配发生的边界，并找到与该边界重叠的片段。我添加了一些 cmets 以进行澄清。

//Set up an example arraylist
ArrayList<Fragment> fragments = new ArrayList<>();
fragments.add(new Fragment("Hi"));
fragments.add(new Fragment(", My name is Peter"));
fragments.add(new Fragment(", how are you?"));

//Create a full string of all fragments together
String total = fragments.stream().map(Fragment::getText).collect(Collectors.joining());
String toMatch = "Peter, how";

//Search and check for a match in the full string, store the index where the match starts
int matchIndex = total.indexOf(toMatch);
if (matchIndex >= 0) {
    //Store the index where the match ends
    int maxMatchIndex = matchIndex + toMatch.length();
    ArrayList<Fragment> overlap = new ArrayList<>();
    //Keep track of the current character index we're at compared to the full string
    int processed = 0;
    for (Fragment fragment : fragments) {
        //Add any fragments that lie between the start and end index of the match to the overlap arraylist
        if(processed + fragment.getText().length() >= matchIndex && processed < maxMatchIndex) {
            overlap.add(fragment);
        }
        //Add the length of the processed fragment to update the "full string index" for the next check
        processed += fragment.getText().length();
    }

    //Do something with the match, here we just print the text
    for (Fragment l : overlap) {
        System.out.println("Fragment match: " + l.getText());
        //Prints:
        //  Fragment match: , My name is Peter
        //  Fragment match: , how are you?
    }
}

请注意，我创建了一个用于插入文本的基本构造函数和一个用于比较文本的 getter。