Question

我在这里有这个长字符串，在文本文件中有类似1000这样的行。我希望计算该文本文件中每个日期出现的频率。我想怎么办呢？

{"interaction":{"author":{"id":"53914918","link":"http:\/\/twitter.com\/53914918","name":"ITTIA","username":"s8c"},"content":"RT @fubarista: After thousands of years of wars I am not an optimist about peace. The US economy is totally reliant on war. It is the on ...","created_at":"Sun, 10 Jul 2011 08:22:16 +0100","id":"1e0aac556a44a400e07497f48f024000","link":"http:\/\/twitter.com\/s8c\/statuses\/89957594197803008","schema":{"version":2},"source":"oauth:258901","type":"twitter","tags":["attretail"]},"language":{"confidence":100,"tag":"en"},"salience":{"content":{"sentiment":4}},"twitter":{"created_at":"Sun, 10 Jul 2011 08:22:16 +0100","id":"89957594197803008","mentions":["fubarista"],"source":"oauth:258901","text":"RT @fubarista: After thousands of years of wars I am not an optimist about peace. The US economy is totally reliant on war. It is the on ...","user":{"created_at":"Mon, 05 Jan 2009 14:01:11 +0000","geo_enabled":false,"id":53914918,"id_str":"53914918","lang":"en","location":"Mouth of the abyss","name":"ITTIA","screen_name":"s8c","time_zone":"London","url":"https:\/\/thepiratebay.se"}}}

Answer 1

使用RandomAccessFile和BufferedReader类来读取部分数据，你可以使用字符串解析来计算每个日期的频率......

Answer 2

每个日期都有一些稳定的模式，如\ d \ d（Jan | Feb | ...）20 \ d \ d 所以你可以使用正则表达式提取这些日期（Java中的Pattern类）然后你可以使用HashMap增加某个对的值，其中key是找到的日期。很抱歉没有代码，但我希望能帮助你：）

Answer 3

我认为它是一个JSON字符串你应该解析而不是匹配。请参阅此示例HERE

Answer 4

将所需的字符串复制到test.text并将其放在c盘中工作代码，我使用了Pattern和Matcher类

模式中的

我给出了你问的日期模式，你可以在这里查看模式

“（周日|周一|周二|周三|周四|周五|周六）[，] \ d \ d（1月| 2月| 3月| 4月| 5月| 6月| 7月| 8月| 9月| 10月| 11月| 12月）\ d \ d \ d \ d“

检查代码

import java.io.BufferedReader;
import java.io.FileReader;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

class Test{
public static void main(String[] args) throws Exception {

    FileReader fw=new FileReader("c:\\test.txt");
    BufferedReader br=new BufferedReader(fw);
    int i;
    String s="";
    do
    {

        i=br.read();
        if(i!=-1)
        s=s+(char)i;


    }while(i!=-1);

    System.out.println(s);

    Pattern p=Pattern.compile
            (
                    "(Sun|Mon|Tue|Wed|Thu|Fri|Sat)[,] \\d\\d (Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec) \\d\\d\\d\\d"
                );

    Matcher m=p.matcher(s);
    int count=0;
    while(m.find())
    {
        count++;
        System.out.println("Match number "+count);
        System.out.println(s.substring(m.start(), +m.end()));


    }
    }


}

这里的Link 1和Link 2

非常好

Answer 5

您的输入字符串是JSON格式，因此我建议您使用JSON解析器，这使解析很多更容易，更重要健壮！虽然可能需要几分钟才能进入JSON解析，但这是值得的。

之后，解析“created_at”标签。创建一个地图，其中您的日期为关键，您的计数为值，并写下如下内容：

int estimatedSize = 500; // best practice to avoid some HashMap resizing
Map<String, Integer> myMap = new HashMap<>(estimatedSize);
String[] dates = {}; // here comes your parsed data, draw it into the loop later
for (String nextDate : dates) {
    Integer oldCount = myMap.get(nextDate);
    if (oldCount == null) { // not in yet
        myMap.put(nextDate, Integer.valueOf(1));
    }
    else { // already in
        myMap.put(nextDate, Integer.valueOf(oldCount.intValue() + 1));
    }
}

与最大出现次数匹配的字符串

5 个答案: