2014-09-25 133 views
-1

編輯:沒有錯誤,但我的輸出不符合預期。顯示沒有數據:Java無法找到符號錯誤

----jGRASP exec: java Driver 

[CONDITION TEMPERATURE  DATE, CONDITION  TEMPERATURE  DATE, CONDITION  TEMPERATURE  DATE] 

The average of Temperatures is :0 
The average of Temperatures is :0 
The average of Temperatures is :0 
Searching for the condition Foggy 
Sorting the data by temperatures: 

----jGRASP: operation complete. 

我有三個類。

天氣

import java.util.*; 

public class Weather implements Comparable<Weather> 

{ 

    public String condition; 

    public int temperature; 

    public Calendar date; 



    public Weather() 

    { 

      condition=null; 

      temperature=0; 

      date=new GregorianCalendar(); 

    } 

    public Weather(String cond, int temp, Calendar d) 

    { 

      condition=cond; 

      temperature=temp; 

      date=d; 

    } 



    public String getCondition() 

    { 

      return condition; 

    } 

    public int getTemperature() 

    { 

      return temperature; 

    } 

    public Calendar getDate() 

    { 

      return date; 

    } 

    public int compareTo(Weather compareTemp) 

    { 

      int compareQuantity = ((Weather) compareTemp).getTemperature(); 

      //ascending order 

      return this.temperature - compareQuantity; 

    } 

    public String toString() 

    { 

      return getCondition()+"\t"+ getTemperature()+"\t"+getDate(); 

    } 

    public int compare(Weather w1, Weather w2) { 

     if(w1.getTemperature() == w2.getTemperature()){ 

      return 0; 

     } else { 

      return -1; 

     } 

    } 

} 

WeatherList

import java.util.*; 

public class WeatherList 

{ 

    public String cond; 

    public int temp; 

    public Calendar d; 

    //public int month, year,day; 

    public ArrayList<Weather> weather; 

    public int size; 



    public WeatherList() 

    {} 

    public WeatherList(String cond, int temp, Calendar date) 

    { 

      this.cond=cond; 

      this.temp=temp; 

      this.d=date; 

      weather=new ArrayList<Weather>(); 

    } 

    //add method 

    public void addMethod(String cond, int temp, Calendar d) 

    { 

      Weather w=new Weather(cond, temp,d); 

      weather.add(w); 

    } 

    // size increase method 

    public void setsize() 

    { 

      if(weather.size()==0) 

      { 

       size=weather.size()*2; 

      } 

    } 

    //averageTemp method that returns average of temperatures 

    public int averageTemp() 

    { 

      int avg; 

      int total=0; 

      List<Weather> list= weather; 

      for(Weather ls: list) 

        total=+ls.getTemperature(); 

      avg=total/weather.size(); 



    return avg; 

    } 



    public String toString() 

    { 

      return "CONDITION \t TEMPERATURE \t DATE"; 

    } 

    public void display() 

    { 

      for(int i=0; i<weather.size(); i++) 

       System.out.println(weather.get(i)); 

    } 



    public void searchCondition(String s) 

    { 

      boolean f=false; 

      for (int i = 0; i<weather.size(); i++) 

      { 

       if (weather.get(i).equals(s)) 

       { 

        System.out.println("The date when it is Foggy is: " +weather.get(i).getDate()); 

        System.out.println("The difference in the temperature is: " + (averageTemp()- weather.get(i).getTemperature())); 

        f = true; 

       } 

      }  

      if (!f) 

       System.out.println("Key not found"); 

    } 





    public void sortTemperature() 

    { 

      List<Weather> l= weather; 

      Collections.sort(l); 

     for(Weather str: weather){ 



      System.out.println(toString()); 

       System.out.println(str.getCondition()+"\t"+ str.getTemperature()+"\t"+str.getDate()); 

     } 

    } 



    /*public void findTemp() 

    { 

      //int searchkey=75; 



      int index = Collections.binarySearch(weather, "75"); 

       System.out.println("Element found at : " + index); 

    } 

    */ 

} 

驅動

import java.util.*; 

public class Driver 

{ 
    public static void main(String args[]) 

    { 

      Calendar gc=new GregorianCalendar(); 

      String con; 

      int tem; 

      int day, month, year; 

      Calendar d; 

      ArrayList<WeatherList> w1=new ArrayList<WeatherList>(); 

      Scanner scan=new Scanner(System.in); 

       gc.set(45, 9+1, 12); 

       WeatherList w2=new WeatherList("Foggy", 67, gc); 

       gc.set(20, 10+1, 2); 

       WeatherList w3=new WeatherList("Rainy", 30, gc); 

       gc.set(29, 0+1, 22); 

       WeatherList w4=new WeatherList("Cold", 45, gc); 

       w1.add(w2); 

       w1.add(w3); 

       w1.add(w4); 

      System.out.println(w1.toString()); 

      for(int i=0; i<w1.size();i++) 

      { 

       w1.get(i).display(); 

      } 

      System.out.println(); 

      for(int i=0;i<w1.size();i++) 

      System.out.println("The average of Temperatures is :"+ w1.get(i).averageTemp()); 

      System.out.println("Searching for the condition Foggy"); 

      for(int i=0; i<w1.size();i++) 

      { 

       w1.get(i).display(); 

      } 

      System.out.println("Sorting the data by temperatures: "); 

      w1.sortTemperature(); 

    } 
} 

我得到的錯誤是:

 ----jGRASP exec: javac -g Driver.java 

Driver.java:70: error: cannot find symbol 
      w1.sortTemperature(); 
      ^
    symbol: method sortTemperature() 
    location: variable w1 of type ArrayList<WeatherList> 
1 error 

----jGRASP wedge2: exit code for process is 1. 
----jGRASP: operation complete. 

我不確定問題是什麼,如果有人有任何想法,請讓我知道我做錯了什麼。謝謝。

+1

請只提供相關的代碼。 – 2014-09-25 06:20:32

+0

'w1'是一個'ArrayList',java中的arraylist沒有'sortTemperature'方法 – 2014-09-25 06:22:24

回答

2
cannot find symbol w1.sortTemperature(); 
^ symbol: method sortTemperature() 
location: variable w1 of type ArrayList 1 error 

您正試圖在ArrayList上調用sortTemperature()

您需要在您自己的類實例上調用它。

也許,因爲w1是這些實例的列表(但不知道你正在嘗試做的)

for (WeatherList w: w1){ 
    w.sortTemperature(); 
} 
+0

這樣做可以修復我的錯誤,但是我的輸出不顯示任何數據。請參閱編輯。 – BasedRebel 2014-09-25 06:50:34

0

w1是一個ArrayList和沒有方法sortTemperature()

方法sortTemperature()在對象WetherList中定義。

因此,您必須從列表w1.get(0)中讀取一個對象,然後才能撥打sortTemperature()

w1.get(0).sortTemperature()

0

sortTemperatureWeatherList類的方法,而你試圖調用它ArrayList

您應該迭代列表,然後在該對象上調用sortTemperature

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