如何改变DrJava

Question

我试图在我的静态方法运行切换功能，我不断收到此错误源级别：

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 

我已经看过了一些指南，但他们都不似乎表明如何将来源级别改为1.7以上。当我看着DrJava运行在Java 1.8版上的设置时，我对这个问题感到困惑。这是我的班级文件：

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

您必须从Oracle网页下载并安装新的jdk版本。