类变量中未处理的异常类型 IOException

Question

>我有一个类，我在其中填充变量值，如下所示

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) {

但是，Java 编译器给出错误"未处理的异常类型 IOException"My ReadPropertiesFile 抛出 IOException。

Answer 1

使用静态初始值设定项。

public class JSONDBWriter {
    public static String driver;
   static {
        try{
            driver = //...
        } catch (IOException e){
            //
        }
    }
    //other methods
}

如果您希望变量是最终变量，请尝试如下操作：

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
}