小编jNe*_*erd的帖子

我尝试使用netbeans开发一个java程序,其中GUI接受来自五个文本字段的主题标记,并在各自的文本字段中显示总标记,百分比和等级.问题是我在执行GUI时遇到错误.我尝试用double替换int来保存百分比的百分比,但这没有帮助.我无法找到任何错误,因为我是初学者,我无法理解我的netbeans在监视器中给出的错误.请帮忙.

ERRORS: Exception in thread "AWT-EventQueue-0" java.lang.NumberFormatException: For input string: "           34"
    at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
    at java.lang.Integer.parseInt(Integer.java:481)
    at java.lang.Integer.parseInt(Integer.java:527)
    at NewJFrame.submit_buttonActionPerformed(NewJFrame.java:173)
    at NewJFrame.access$000(NewJFrame.java:4)
    at NewJFrame$1.actionPerformed(NewJFrame.java:60)

这是我做过的编码.

        int sub1_ = Integer.parseInt(sub1.getText());
    int sub2_ = Integer.parseInt(sub2.getText());
    int sub3_ = Integer.parseInt(sub3.getText());
    int sub4_ = Integer.parseInt(sub4.getText());
    int sub5_ = Integer.parseInt(sub5.getText());

    // Here each subject holds a max. of 100 marks.

    int a = sub1_+sub2_+sub3_+sub4_+sub5_;
    total_marks.setText(""+a);

    // Since each subject holds a max. of 100 marks, the total marks of five subjects sums up to 500. …