计算ArrayList中给定字符串的出现次数

计算ArrayList中给定字符串的出现次数，可以使用以下方法：

遍历ArrayList，使用String的equals()方法比较每个元素是否与给定字符串相等，如果相等则计数器加1。
使用Java 8的Stream API，可以更简洁地实现相同的功能。

以下是示例代码：

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class ArrayListStringCount {
    public static void main(String[] args) {
        List<String> list = new ArrayList<>(Arrays.asList("apple", "banana", "orange", "apple", "orange", "banana"));
        String target = "banana";
        int count = countOccurrences(list, target);
        System.out.println("The target string \"" + target + "\" appears " + count + " times in the ArrayList.");
    }

    public static int countOccurrences(List<String> list, String target) {
        int count = 0;
        for (String s : list) {
            if (s.equals(target)) {
                count++;
            }
        }
        return count;
    }
}

输出结果：

The target string "banana" appears 2 times in the ArrayList.

使用Java 8的Stream API实现：

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;

public class ArrayListStringCount {
    public static void main(String[] args) {
        List<String> list = new ArrayList<>(Arrays.asList("apple", "banana", "orange", "apple", "orange", "banana"));
        String target = "banana";
        int count = countOccurrences(list, target);
        System.out.println("The target string \"" + target + "\" appears " + count + " times in the ArrayList.");
    }

    public static int countOccurrences(List<String> list, String target) {
        return (int) list.stream().filter(target::equals).count();
    }
}

输出结果与上述示例相同。