java - 高效解析庞大的字符串响应

Question

我有一项服务可以按以下格式返回数据。为了便于理解，我已将其缩短，但总的来说，这是相当大的回应。格式总是一样的。

process=true
version=2
DataCenter=dc2
    Total:2
    prime:{0=1, 1=2, 2=3, 3=4, 4=1, 5=2}
    obvious:{0=6, 1=7, 2=8, 3=5, 4=6}
    mapping:{3=machineA.dc2.com, 2=machineB.dc2.com}
    Machine:[machineA.dc2.com, machineB.dc2.com]
DataCenter=dc1
    Total:2
    prime:{0=1, 1=2, 2=3, 3=4, 4=1, 5=2, 6=3}
    obvious:{0=6, 1=7, 2=8, 3=5, 4=6, 5=7}
    mapping:{3=machineP.dc1.com, 2=machineQ.dc1.com}
    Machine:[machineP.dc1.com, machineQ.dc1.com]
DataCenter=dc3
    Total:2
    prime:{0=1, 1=2, 2=3, 3=4, 4=1, 5=2}
    obvious:{0=6, 1=7, 2=8, 3=5, 4=6}
    mapping:{3=machineO.dc3.com, 2=machineR.dc3.com}
    Machine:[machineO.dc3.com, machineR.dc3.com]

我正在尝试解析上述数据并将其存储在三个不同的 Maps 中。

• 主要 map :Map<String, Map<Integer, Integer>> prime = new HashMap<String, Map<Integer, Integer>>();
• 明显 map :Map<String, Map<Integer, Integer>> obvious = new HashMap<String, Map<Integer, Integer>>();
• 映射 map :Map<String, Map<Integer, String>> mapping = new HashMap<String, Map<Integer, String>>();

下面是描述:

• 在 Prime map 中，键将是 dc2值将为 {0=1, 1=2, 2=3, 3=4, 4=1, 5=2} .
• 在 Obvious 映射中，key 将是 dc2值将为 {0=6, 1=7, 2=8, 3=5, 4=6} .
• 在 Mapping map 中，key 将为 dc2值将为 {3=machineA.dc2.com, 2=machineB.dc2.com} .

对于其他数据中心也是如此。

解析上述字符串响应的最佳方法是什么？我应该在这里使用正则表达式还是简单的字符串解析？

public class DataParser {
    public static void main(String[] args) {
        String response = getDataFromURL();
        // here response will contain above string
        parseResponse(response);            
    }

    private void parseResponse(final String response) {
        // what is the best way to parse the response?
    }   
}

任何示例都会有很大帮助。

Answer 1

您可以像 ShellFish 推荐的那样，将响应拆分为 '\n'，然后处理每一行。

一种正则表达式方法如下(它不完整，但足以让您入门):

public static void main(String[] args) throws Exception {
    String response = "process=true\n" +
        "version=2\n" +
        "DataCenter=dc2\n" +
        "    Total:2\n" +
        "    prime:{0=1, 1=2, 2=3, 3=4, 4=1, 5=2}\n" +
        "    obvious:{0=6, 1=7, 2=8, 3=5, 4=6}\n" +
        "    mapping:{3=machineA.dc2.com, 2=machineB.dc2.com}\n" +
        "    Machine:[machineA.dc2.com, machineB.dc2.com]\n" +
        "DataCenter=dc1\n" +
        "    Total:2\n" +
        "    prime:{0=1, 1=2, 2=3, 3=4, 4=1, 5=2, 6=3}\n" +
        "    obvious:{0=6, 1=7, 2=8, 3=5, 4=6, 5=7}\n" +
        "    mapping:{3=machineP.dc1.com, 2=machineQ.dc1.com}\n" +
        "    Machine:[machineP.dc1.com, machineQ.dc1.com]\n" +
        "DataCenter=dc3\n" +
        "    Total:2\n" +
        "    prime:{0=1, 1=2, 2=3, 3=4, 4=1, 5=2}\n" +
        "    obvious:{0=6, 1=7, 2=8, 3=5, 4=6}\n" +
        "    mapping:{3=machineO.dc3.com, 2=machineR.dc3.com}\n" +
        "    Machine:[machineO.dc3.com, machineR.dc3.com]";

    Map<String, Map<Integer, Integer>> prime = new HashMap();
    Map<String, Map<Integer, Integer>> obvious = new HashMap();
    Map<String, Map<Integer, String>> mapping = new HashMap();

    String outerMapKey = "";
    int findCount = 0;
    Matcher matcher = Pattern.compile("(?<=DataCenter=)(.*)|(?<=prime:)(.*)|(?<=obvious:)(.*)|(?<=mapping:)(.*)").matcher(response);
    while(matcher.find()) {
        switch (findCount) {
            case 0:
                outerMapKey = matcher.group();
                break;
            case 1:
                prime.put(outerMapKey, new HashMap());
                String group = matcher.group().replaceAll("[\\{\\}]", "").replaceAll(", ", ",");
                String[] groupPieces = group.split(",");
                for (String groupPiece : groupPieces) {
                    String[] keyValue = groupPiece.split("=");
                    prime.get(outerMapKey).put(Integer.parseInt(keyValue[0]), Integer.parseInt(keyValue[0]));
                }
                break;
            // Add additional cases for obvious and mapping
        }

        findCount++;
        if (findCount == 4) {
            findCount = 0;
        }
    }

    System.out.println("Primes:");
    prime.keySet().stream().forEach(k -> System.out.printf("Key: %s Value: %s\n", k, prime.get(k)));
    // Add additional outputs for obvious and mapping
}

结果:

Primes:
Key: dc2 Value: {0=0, 1=1, 2=2, 3=3, 4=4, 5=5}
Key: dc1 Value: {0=0, 1=1, 2=2, 3=3, 4=4, 5=5, 6=6}
Key: dc3 Value: {0=0, 1=1, 2=2, 3=3, 4=4, 5=5}

解释正则表达式模式的引用资料: http://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html

http://www.regular-expressions.info/lookaround.html