如何以特定布局输出到控制台？

Question

我正在做一个小项目，该项目在一行上接受用户输入（匹配结果），拆分输入并以不同格式输出相同的数据。我正在努力寻找一种以特定格式输出数据的方法。除了玩的总游戏数之外，我希望我的程序生成一个类似于输出格式的图表

home_name [home_score] | away_name [away_score]

这是我目前拥有的代码，它允许用户按以下格式逐行输入结果

home_name : away_name : home_score : away_score

直到他们进入停止，这会打破循环（并希望很快输出数据）。

import java.util.*;
public class results {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int totalGames = 0;
        String input = null;
        System.out.println("Please enter results in the following format"
                + " home_name : away_name : home_score : away_score"
                + ", or enter stop to quit");

        while (null != (input = scan.nextLine())){
            if ("stop".equals(input)){
                break;
            }
            String results[] = input.split(" : ");
            for (int x = 0; x < results.length; x++) {

            }       
        totalGames++;
        }
        System.out.println("Total games played is " + totalGames);  
    }
}

Answer 1

你可以看到here。

您可以根据需要设置文本格式。

一般语法是 %[arg_index$][flags][width][.precision]conversion char  参数 编号从 1（不是 0）开始。所以要打印第一个参数，你 应该使用 1$（如果您使用显式排序）。

Answer 2

您可以使用正则表达式来解析该行：

(\w)\s(\w)\s|\s(\w)\s(\w)

基于来自（来自http://tutorials.jenkov.com/java-regex/matcher.html）的 Java 代码

import java.util.regex.Pattern;
import java.util.regex.Matcher;

    public class MatcherFindStartEndExample{

        public static void main(String[] args){

            String text = "Belenenses 6 | Benfica 0";

            String patternString = "(\\w+)\\s(\\w+)\\s\\|\\s(\\w+)\\s(\\w+)";

            Pattern pattern = Pattern.compile(patternString);
            Matcher matcher = pattern.matcher(text);


            while (matcher.find()){
                    System.out.println("found: " + matcher.group(1));
                    System.out.println("found: " + matcher.group(2));
                    System.out.println("found: " + matcher.group(3));
                    System.out.println("found: " + matcher.group(4));
            }
        }}

使用此代码代替您的

 String results[] = input.split(" : ");
            for (int x = 0; x < results.length; x++) {

            }

Answer 3

你应该分两次做事：

1) 检索用户输入的信息并将其存储在自定义类的实例中：PlayerResult。

2) 根据预期的格式执行输出。您还应该在创建图形表之前计算每列的最大大小。
否则你可能会得到一个丑陋的渲染。

第一步：

List<PlayerResult> playerResults = new ArrayList<PlayerResult>();

...
String[4] results = input.split(" : "); 
playerResults.add(new PlayerResult(results[0],results[1],results[2],results[3])

第二步：

// compute length of column
int[] lengthByColumn = computeLengthByColumn(results);
int lengthHomeColumn = lengthByColumn[0];
int lengthAwayColumn = lengthByColumn[1];

// render header
System.out.print(adjustLength("home_name [home_score]", lengthHomeColumn));
System.out.println(adjustLength("away_name [away_score]", lengthAwayColumn));

// render data
for (PlayerResult playerResult : playerResults){
   System.out.print(adjustLength(playerResult.getHomeName() + "[" + playerResult.getHomeName() + "]", lengthHomeColumn));
   System.out.println(adjustLength(playerResult.getAwayName() + "[" + playerResult.getAwayScore() + "]", lengthAwayColumn));
 }

Answer 4

您可以通过将results 数组值添加到finalResults ArrayList 来保留游戏统计信息。然后将其结果输出为输入stop。
对于计算每个团队的总结果，HashMap<String, Integer> 是最佳选择。

为了清楚起见，这里是带有 cmets 的完整代码：

import java.util.*;

// following the naming conventions class name must start with a capital letter
public class Results {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int totalGames = 0;
        String input;
        System.out.println("Please enter results in the following format: \n"
                + "'HOME_NAME : AWAY_NAME : HOME_SCORE : AWAY_SCORE' \n"
                + "or enter 'stop' to quit");

        // HashMap to keep team name as a key and its total score as value
        Map<String, Integer> scoreMap = new HashMap<>();
        // ArrayList for storing game history
        List<String> finalResults = new ArrayList<>();
        // don't compare null to value. Read more http://stackoverflow.com/questions/6883646/obj-null-vs-null-obj
        while ((input = scan.nextLine()) != null) {
            if (input.equalsIgnoreCase("stop")) {   // 'Stop', 'STOP' and 'stop' are all OK
                scan.close(); // close Scanner object
                break;
            }
            String[] results = input.split(" : ");

            // add result as String.format. Read more https://examples.javacodegeeks.com/core-java/lang/string/java-string-format-example/
            finalResults.add(String.format("%s [%s] | %s [%s]", results[0], results[2], results[1], results[3]));

            // check if the map already contains the team
            // results[0] and results[1] are team names, results[2] and results[3] are their scores
            for (int i = 0; i < 2; i++) {
                // here is used the Ternary operator. Read more http://alvinalexander.com/java/edu/pj/pj010018
                scoreMap.put(results[i], !scoreMap.containsKey(results[i]) ?
                        Integer.valueOf(results[i + 2]) :
                        Integer.valueOf(scoreMap.get(results[i]) + Integer.valueOf(results[i + 2])));
            }
            totalGames++; // increment totalGames
        }

        System.out.printf("%nTotal games played: %d.%n", totalGames); // output the total played games

        // output the games statistics from ArrayList finalResults
        for (String finalResult : finalResults) {
            System.out.println(finalResult);
        }

        // output the score table from HashMap scoreMap
        System.out.println("\nScore table:");
        for (Map.Entry<String, Integer> score : scoreMap.entrySet()) {
            System.out.println(score.getKey() + " : " + score.getValue());
        }
    }
}

现在测试输入：

team1 : team2 : 1 : 0
team3 : team1 : 3 : 2
team3 : team2 : 2 : 2
sToP

输出是：

Total games played: 3.

team1 [1] | team2 [0]
team3 [3] | team1 [2]
team3 [2] | team2 [2]

Score table:
team3 : 5
team1 : 3
team2 : 2