未处理的异常类型为IOException

Question

我有一个类我在哪里填充变量值如下

public class JSONDBWriter{ 

    // JDBC driver name, database URL, Database credentials 
    private static final String JDBC_DRIVER = ReadPropertiesFile("JDBC_DRIVER"); 
    private static final String DB_URL = ReadPropertiesFile("DB_URL"); 
    private static final String USER = ReadPropertiesFile("USER"); 
    private static final String PASS = ReadPropertiesFile("PASS"); 



    public static void main(String[] args) { 

然而，Java编译器是给错误“未处理的异常类型为IOException” 我ReadPropertiesFile抛出IOException异常。

Answer 1

使用静态初始化器。

public class JSONDBWriter { 
    public static String driver; 

    static { 
     try{ 
      driver = //... 
     } catch (IOException e){ 
      // 
     } 
    } 
    //other methods 
} 

如果你希望你的变量是最终，你可以试试下面：

public class Test { 

    public static final String test = getDataNoException(); 

    private static String getData() throws IOException { 
     return "hello"; 
    } 

    private static String getDataNoException() { 
     try { 
      return getData(); 
     } catch (IOException e) { 
      e.printStackTrace(); 
      return "no data"; 
     } 
    } 
    //other methods 
}