小编dra*_*226的帖子

下面的代码一直给出java.lang.NumberFormatException: empty String:

private void jButton4ActionPerformed(java.awt.event.ActionEvent evt) {
    double AText = Double.parseDouble(angleAField.getText());
    double BText = Double.parseDouble(angleBField.getText());
    double CText = Double.parseDouble(angleCField.getText());
    double aText = Double.parseDouble(sideaField.getText());
    double bText = Double.parseDouble(sidebField.getText());
    double cText = Double.parseDouble(sidecField.getText());

    if (getMissing(angleAField.getText()) == false && getMissing(angleCField.getText()) == false) { //doesnt have angle C ,find Angle A
        double angleA = Math.round(Math.asin((Math.sin(BText) / bText) * aText));
        angleAField.setText("" + angleA);
    }
}

public boolean getMissing(String Field) {
    try {
        if (Field.equals("")) {
            return false; // has number
        }
    } …