使用Redis计算大文件字数的java最佳解决方案
我想用java计算一个大文件的字数。由于只有一台机器,我不能使用map reduce。我想用Redis来存储单词的频率,而不是使用哈希映射。实际上,数据是源源不断的
我所想的是,我将推送redis排序集中每个词的字数。但我不知道这是不是最好的解决方案。请提供最佳解决方案来计算流媒体数据的字数
用于字数统计的Java代码-
public class WordCount {
public static void main(String args[]) {
Map<String, Integer> wordMap = wordMap("filename");
List<Entry<String, Integer>> list = sortByValue(wordMap);
for (Map.Entry<String, Integer> entry : list) {
System.out.println(entry.getKey() + " => " + entry.getValue());
}
}
public static Map<String, Integer> wordMap(String fileName) {
Map<String, Integer> wordMap = new HashMap<>();
try (FileInputStream fis = new FileInputStream(fileName);
DataInputStream dis = new DataInputStream(fis);
BufferedReader br = new BufferedReader(new InputStreamReader(dis))) {
// words are separated by whitespace
Pattern pattern = Pattern.compile("\\s+");
String line = null;
while ((line = br.readLine()) != null) {
line = line.toLowerCase();
String[] words = pattern.split(line);
for (String word : words) {
if (wordMap.containsKey(word)) {
wordMap.put(word, (wordMap.get(word) + 1));
} else {
wordMap.put(word, 1);
}
}
}
} catch (IOException ioex) {
ioex.printStackTrace();
}
return wordMap;
}
public static List<Entry<String, Integer>> sortByValue(Map<String, Integer> wordMap) {
Set<Entry<String, Integer>> entries = wordMap.entrySet();
List<Entry<String, Integer>> list = new ArrayList<>(entries);
Collections.sort(list, new Comparator<Map.Entry<String, Integer>>() {
@Override
public int compare(Map.Entry<String, Integer> o1, Map.Entry<String, Integer> o2)
{
return (o2.getValue()).compareTo(o1.getValue());
}
});
return list;
}
}
# 1 楼答案
关于如何使用{a2}在Java上的Redis数据上执行Map Reduce,有一个很好的{a1}