Поиск метода по запросу

233

10 февраля 2019, 05:20

попробую изложить суть задачи

class Log
{
    String ip;
    String user;
    Date date;
    Event event;
    String number;
    Status status;}

Имеется соответствующий класс Log, все поля класса имеют геттеры. Необходимо реализовать метод который Получает запрос String с параметром:

get field1 for field2 = "value1"

Где: field1 - одно из полей: ip, user, date, event или status; field2 - одно из полей: ip, user, date, event или status; value1 - значение поля field2. Алгоритм обработки запроса следующий: просматриваем записи в логе, если поле field2 имеет значение value1, то добавляем поле field1 в множество, которое затем будет возвращено методом execute. Так вот я реализовал метод используя switch-case

public Set<Object> execute(String query) {
if (Log.testhelper(query))
                if (Log.testhelper(query))
            {
                String[]values=query.split(" = ");
                String value1=values[1].replace("\"","");
                String[]fields=values[0].split(" ");
                String field1=fields[1];
                String field2=fields[3];
                switch (field1)
                {
                    case "ip":
                    {
                        if (field2.equals("ip"))
                        {return logList.stream()
                                .filter(log -> log.getIp().equals(value1))
                                .map(log -> log.getIp())
                                .collect(Collectors.toSet());}
                        if (field2.equals("user"))
                        {return logList.stream()
                        .filter(log -> log.getUser().equals(value1))
                        .map(log -> log.getIp())
                        .collect(Collectors.toSet());}
                        if (field2.equals("date"))
                        {Date vdate=null;
                            try {
                                vdate=new SimpleDateFormat("dd.MM.yyyy HH:mm:ss").parse(value1);
                            } catch (ParseException e) {
                                e.printStackTrace();
                            }
                            Date finalVdate = vdate;
                            return logList.stream()
                                .filter(log -> log.getDate().equals(finalVdate))
                                .map(log -> log.getIp())
                                .collect(Collectors.toSet());}
                        if (field2.equals("event"))
                        {Event event=null;
                            if (value1.equals("LOGIN"))event=Event.LOGIN;
                            if (value1.equals("DOWNLOAD_PLUGIN"))event=Event.DOWNLOAD_PLUGIN;
                            if (value1.equals("WRITE_MESSAGE"))event=Event.WRITE_MESSAGE;
                            if (value1.equals("SOLVE_TASK"))event=Event.SOLVE_TASK;
                            if (value1.equals("DONE_TASK"))event=Event.DONE_TASK;
                            Event finalEvent = event;
                            return logList.stream()
                                .filter(log -> log.getEvent().equals(finalEvent))
                                .map(log -> log.getIp())
                                .collect(Collectors.toSet());}
                        if (field2.equals("status"))
                        {Status status=null;
                            if (value1.equals("OK"))status=Status.OK;
                            if (value1.equals("FAILED"))status=Status.FAILED;
                            if (value1.equals("ERROR"))status=Status.ERROR;
                            Status finalStatus = status;
                            return logList.stream()
                                .filter(log -> log.getStatus().equals(finalStatus))
                                .map(log -> log.getIp())
                                .collect(Collectors.toSet());}
                    }
                    case "user":
                    {
                        if (field2.equals("ip"))
                        {return logList.stream()
                                .filter(log -> log.getIp().equals(value1))
                                .map(log -> log.getUser())
                                .collect(Collectors.toSet());}
                        if (field2.equals("user"))
                        {return logList.stream()
                                .filter(log -> log.getUser().equals(value1))
                                .map(log -> log.getUser())
                                .collect(Collectors.toSet());}
                        if (field2.equals("date"))
                        {Date vdate=null;
                            try {
                                vdate=new SimpleDateFormat("dd.MM.yyyy HH:mm:ss").parse(value1);
                            } catch (ParseException e) {
                                e.printStackTrace();
                            }
                            Date finalVdate = vdate;
                            return logList.stream()
                                    .filter(log -> log.getDate().equals(finalVdate))
                                    .map(log -> log.getUser())
                                    .collect(Collectors.toSet());}
                        if (field2.equals("event"))
                        {Event event=null;
                            if (value1.equals("LOGIN"))event=Event.LOGIN;
                            if (value1.equals("DOWNLOAD_PLUGIN"))event=Event.DOWNLOAD_PLUGIN;
                            if (value1.equals("WRITE_MESSAGE"))event=Event.WRITE_MESSAGE;
                            if (value1.equals("SOLVE_TASK"))event=Event.SOLVE_TASK;
                            if (value1.equals("DONE_TASK"))event=Event.DONE_TASK;
                            Event finalEvent = event;
                            return logList.stream()
                                    .filter(log -> log.getEvent().equals(finalEvent))
                                    .map(log -> log.getUser())
                                    .collect(Collectors.toSet());}
                        if (field2.equals("status"))
                        {Status status=null;
                            if (value1.equals("OK"))status=Status.OK;
                            if (value1.equals("FAILED"))status=Status.FAILED;
                            if (value1.equals("ERROR"))status=Status.ERROR;
                            Status finalStatus = status;
                            return logList.stream()
                                    .filter(log -> log.getStatus().equals(finalStatus))
                                    .map(log -> log.getUser())
                                    .collect(Collectors.toSet());}
                    }
                    case "date":
                    {
                        if (field2.equals("ip"))
                        {return logList.stream()
                                .filter(log -> log.getIp().equals(value1))
                                .map(log -> log.getDate())
                                .collect(Collectors.toSet());}
                        if (field2.equals("user"))
                        {return logList.stream()
                                .filter(log -> log.getUser().equals(value1))
                                .map(log -> log.getDate())
                                .collect(Collectors.toSet());}
                        if (field2.equals("date"))
                        {Date vdate=null;
                            try {
                                vdate=new SimpleDateFormat("dd.MM.yyyy HH:mm:ss").parse(value1);
                            } catch (ParseException e) {
                                e.printStackTrace();
                            }
                            Date finalVdate = vdate;
                            return logList.stream()
                                    .filter(log -> log.getDate().equals(finalVdate))
                                    .map(log -> log.getDate())
                                    .collect(Collectors.toSet());}
                        if (field2.equals("event"))
                        {Event event=null;
                            if (value1.equals("LOGIN"))event=Event.LOGIN;
                            if (value1.equals("DOWNLOAD_PLUGIN"))event=Event.DOWNLOAD_PLUGIN;
                            if (value1.equals("WRITE_MESSAGE"))event=Event.WRITE_MESSAGE;
                            if (value1.equals("SOLVE_TASK"))event=Event.SOLVE_TASK;
                            if (value1.equals("DONE_TASK"))event=Event.DONE_TASK;
                            Event finalEvent = event;
                            return logList.stream()
                                    .filter(log -> log.getEvent().equals(finalEvent))
                                    .map(log -> log.getDate())
                                    .collect(Collectors.toSet());}
                        if (field2.equals("status"))
                        {Status status=null;
                            if (value1.equals("OK"))status=Status.OK;
                            if (value1.equals("FAILED"))status=Status.FAILED;
                            if (value1.equals("ERROR"))status=Status.ERROR;
                            Status finalStatus = status;
                            return logList.stream()
                                    .filter(log -> log.getStatus().equals(finalStatus))
                                    .map(log -> log.getDate())
                                    .collect(Collectors.toSet());}
                    }
                    case "event":
                    {
                        if (field2.equals("ip"))
                        {return logList.stream()
                                .filter(log -> log.getIp().equals(value1))
                                .map(log -> log.getEvent())
                                .collect(Collectors.toSet());}
                        if (field2.equals("user"))
                        {return logList.stream()
                                .filter(log -> log.getUser().equals(value1))
                                .map(log -> log.getEvent())
                                .collect(Collectors.toSet());}
                        if (field2.equals("date"))
                        {Date vdate=null;
                            try {
                                vdate=new SimpleDateFormat("dd.MM.yyyy HH:mm:ss").parse(value1);
                            } catch (ParseException e) {
                                e.printStackTrace();
                            }
                            Date finalVdate = vdate;
                            return logList.stream()
                                    .filter(log -> log.getDate().equals(finalVdate))
                                    .map(log -> log.getEvent())
                                    .collect(Collectors.toSet());}
                        if (field2.equals("event"))
                        {Event event=null;
                            if (value1.equals("LOGIN"))event=Event.LOGIN;
                            if (value1.equals("DOWNLOAD_PLUGIN"))event=Event.DOWNLOAD_PLUGIN;
                            if (value1.equals("WRITE_MESSAGE"))event=Event.WRITE_MESSAGE;
                            if (value1.equals("SOLVE_TASK"))event=Event.SOLVE_TASK;
                            if (value1.equals("DONE_TASK"))event=Event.DONE_TASK;
                            Event finalEvent = event;
                            return logList.stream()
                                    .filter(log -> log.getEvent().equals(finalEvent))
                                    .map(log -> log.getEvent())
                                    .collect(Collectors.toSet());}
                        if (field2.equals("status"))
                        {Status status=null;
                            if (value1.equals("OK"))status=Status.OK;
                            if (value1.equals("FAILED"))status=Status.FAILED;
                            if (value1.equals("ERROR"))status=Status.ERROR;
                            Status finalStatus = status;
                            return logList.stream()
                                    .filter(log -> log.getStatus().equals(finalStatus))
                                    .map(log -> log.getEvent())
                                    .collect(Collectors.toSet());}
                    }
                    case "status":
                    {
                        if (field2.equals("ip"))
                        {return logList.stream()
                                .filter(log -> log.getIp().equals(value1))
                                .map(log -> log.getStatus())
                                .collect(Collectors.toSet());}
                        if (field2.equals("user"))
                        {return logList.stream()
                                .filter(log -> log.getUser().equals(value1))
                                .map(log -> log.getStatus())
                                .collect(Collectors.toSet());}
                        if (field2.equals("date"))
                        {Date vdate=null;
                            try {
                                vdate=new SimpleDateFormat("dd.MM.yyyy HH:mm:ss").parse(value1);
                            } catch (ParseException e) {
                                e.printStackTrace();
                            }
                            Date finalVdate = vdate;
                            return logList.stream()
                                    .filter(log -> log.getDate().equals(finalVdate))
                                    .map(log -> log.getStatus())
                                    .collect(Collectors.toSet());}
                        if (field2.equals("event"))
                        {Event event=null;
                            if (value1.equals("LOGIN"))event=Event.LOGIN;
                            if (value1.equals("DOWNLOAD_PLUGIN"))event=Event.DOWNLOAD_PLUGIN;
                            if (value1.equals("WRITE_MESSAGE"))event=Event.WRITE_MESSAGE;
                            if (value1.equals("SOLVE_TASK"))event=Event.SOLVE_TASK;
                            if (value1.equals("DONE_TASK"))event=Event.DONE_TASK;
                            Event finalEvent = event;
                            return logList.stream()
                                    .filter(log -> log.getEvent().equals(finalEvent))
                                    .map(log -> log.getStatus())
                                    .collect(Collectors.toSet());}
                        if (field2.equals("status"))
                        {Status status=null;
                            if (value1.equals("OK"))status=Status.OK;
                            if (value1.equals("FAILED"))status=Status.FAILED;
                            if (value1.equals("ERROR"))status=Status.ERROR;
                            Status finalStatus = status;
                            return logList.stream()
                                    .filter(log -> log.getStatus().equals(finalStatus))
                                    .map(log -> log.getStatus())
                                    .collect(Collectors.toSet());}
                    }
                }
            }

Но по сути от значения field1 зависит строка .map(log -> log.getStatus()) так же как от field2 только параметр фильтра. Можно ли как то упростить данный код?

Answer 1

Упростить используя рефлекшн можно, например, так:

import java.lang.reflect.Field;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
public class So {
  public static void main(String[] args) throws ParseException, IllegalAccessException {
    String field1 = "ip";
    String field2 = "name";
    String value2 = "username";
    Log log = new Log("127.0.0.1", "username", "#1", Event.LOGIN);
    Object o = filterAndGetValue(log, "ip", "user", "username");
    System.out.println(o);

  }
  static final SimpleDateFormat simpleDateFormat = new SimpleDateFormat("dd.MM.yyyy HH:mm:ss");

  static Object filterAndGetValue(Log log, String field1String, String field2String, String value2) throws IllegalAccessException, ParseException {
    Field field1 = null;
    Field field2 = null;
    for (Field field : Log.class.getDeclaredFields()) {
      field.setAccessible(true);
      if (field.getName().equals(field1String)) {
        field1 = field;
      }
      if (field.getName().equals(field2String)) {
        field2 = field;
      }
    }
    if (field1 == null || field2 == null) {
      throw new IllegalArgumentException("No such fields");
    }
    Object actualValue = null;
    Class<?> type = field2.getType();
    if (type.equals(String.class)) {
      actualValue = value2;
    } else if (type.equals(Date.class)) {
      actualValue = simpleDateFormat.parse(value2);
    } else if (type.equals(Event.class)) {
      actualValue = Event.valueOf(value2);
    }

    if (actualValue == null) {
      throw new UnsupportedOperationException(String.format("Search through fields of type %s is not supported", type.getSimpleName()));
    }
    if (field2.get(log).equals(actualValue)) {
      return field1.get(log);
    } else {
      return null;
    }
  }
  enum Event {
    LOGIN;
  }
  static class Log {
    private String ip;
    private String user;
    private String number;
    private Event event;
    public Log(String ip, String user, String number, Event event) {
      this.ip = ip;
      this.user = user;
      this.number = number;
      this.event = event;
    }
  }
}