Question

我使用BlueJ

该程序编译正确，但当我尝试执行它时，它说

java.lang.NumberFormatException: empty string (in sun.misc.FLoating Decimal)
at java.lang.Double.parseDouble(Double.java:538)
at Employee.accept(Employee.java:12)
at Employee.main(Employee.java:26)

import java.io.*;
class Employee {
  String name;
  double gross;
  double basic;
  char grade;
  int age;
  public void accept() throws IOException {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    System.out.println("Enter name,age,grade and basic");
    name = br.readLine();
    age = Integer.parseInt(br.readLine());
    grade = (char) br.read();
    basic = Double.parseDouble(br.readLine());
    double da = 0.25 * basic;
    double hra = 0.15 * basic;
    double pf = 0.0833 * basic;
    double gross = basic + da + hra;
    double net = gross - pf;
  }
  public void display() throws IOException {
    System.out.println("Age : " + age + "Grade : " + grade + "Basic : " + basic + "Gross pay : " + gross);
  }
  public static void main(String args[]) throws IOException {
    Employee obj = new Employee();
    obj.accept();
    obj.display();
  }
}

Answer 1

正如我上面提到的那样，在你的代码中，你要解析它的字符串是不可解析的，因为字符串格式不正确或字符串为空。正如我在你的代码示例和上面的例外中看到的，你已经明确地提到你的字符串是空的，所以在这里你必须检查你的字符串是空的还是在转换之前为null然后只执行类型转换。我给你代码示例请检查它可能对你有所帮助：

import java.io.*;
class Employee {
  String name;
  double gross;
  double basic;
  char grade;
  int age;
  public void accept() throws IOException {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    System.out.println("Enter name,age,grade and basic");
    name = br.readLine();
    String ageStr = br.readLine();
    if(ageStr != null || ageStr != 0)
     age = Integer.parseInt();
    else
    // do your else logic
    grade = (char) br.read();
    String basicStr = br.readLine();
    if(basicStr != null || basicStr != "")
        basic = Double.parseDouble(basicStr);
    else
        // do your else logic
    double da = 0.25 * basic;
    double hra = 0.15 * basic;
    double pf = 0.0833 * basic;
    double gross = basic + da + hra;
    double net = gross - pf;
  }
  public void display() throws IOException {
    System.out.println("Age : " + age + "Grade : " + grade + "Basic : " + basic + "Gross pay : " + gross);
  }
  public static void main(String args[]) throws IOException {
    Employee obj = new Employee();
    obj.accept();
    obj.display();
  }
}

我希望你能找到解决方案。

double.parseDouble中的java.lang.NumberFormatException

1 个答案: