Java 8 Streams 取字符串行的总和

Question

如何使用 Stream 找到该行中所有整数的总和？

String line = "Test 15 lqlq 35 bad 99999 guess 34";

List<String> lineSplitted = Arrays.stream(line.split(" ")).collect(Collectors.toList());
int result = 0;
try {
    result = lineSplitted.stream().filter(s -> Integer.parseInt(s)).sum();
}
catch (Exception e) {

}
System.out.println(result);

Answer 1

你基本上需要:

将字符串转换为数组

过滤掉非数字

将数字字符串转换为数字类型

求和

工作示例:

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

public class HelloWorld {

     public static void main(String[] args){

        String line = "Test 15 lqlq 35 bad 99999 guess 34";

        int sum = Arrays
            .stream(line.split(" ")) // Convert to an array
            .filter((s) -> s.matches("\\d+"))  // Only select the numbers
            .mapToInt(Integer::parseInt)  // Convert to Integers
            .sum(); // Sum

        System.out.println(sum);
     }
}