如何改變DrJava

Question

我試圖在我的靜態方法運行切換功能，我不斷收到此錯誤源級別：

File: C:\Users\Darien Springer\Documents\Java\DaysInMonth.java [line: 6] 

Error: Cannot switch on a value of type String for source level below 1.7. 

Only convertible int values or enum variables are permitted 

我已經看過了一些指南，但他們都不似乎表明如何將來源級別改爲1.7以上。當我看着DrJava運行在Java 1.8版上的設置時，我對這個問題感到困惑。這是我的班級文件：

import java.util.Scanner; 
public class DaysInMonth { 

    public static void daysInaMonth (int year_number, String month_name) { 
     if(year_number % 4 != 0 || month_name != "February") { 
     switch(month_name) { 
      case "January": 
      case "March": 
      case "May": 
      case "July": 
      case "August": 
      case "October": 
      case "December": 
       System.out.print("31"); 
       break; 
      case "April": 
      case "June": 
      case "September": 
      case "November": 
       System.out.print("30"); 
       break; 
      case "February": 
       System.out.print("28"); 
       break; 
      default: 
       System.out.print("Please input "); 
       break; 
     } 
     } 
     else { 
      System.out.print("29"); 
     } 


    } 

Answer 1

您必須從Oracle網頁下載並安裝新的jdk版本。