Question

这个错怎么解决,跪求大神

btnNewButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
int a=0;
String arrayStr;
arrayStr = textField.getText().trim();
for(int i=0;i<arrayStr.length();i++)
{
char charAt = arrayStr.charAt(i);
char charAt1 = arrayStr.charAt(i+1);
if(charAt==' '&&charAt1!=' ')
{
a++;
}
if(!Character.isDigit(charAt)&&charAt!=' ')
{
JOptionPane.showMessageDialog(null,"输入包含非法字符");
textField.setText("");
return;
}
}
String[] numStrs =new String[a];
numStrs = arrayStr.split("{1,}");
//textField1.setText(numStrs[0]);
//lblNewLabel.setText(numStrs[0]);
int[] numArray = new int[numStrs.length];
for(int i=0;i<numArray.length;i++)
{
numArray[i] = Integer.valueOf(numStrs[i]);
}
int min = numArray[0];
for(int j=0;j<numArray.length;j++)
{
if(min>numArray[j])
{
min=numArray[j];
}
}
textField1.setText(String.valueOf(min));
}
}

出现以下错误
Exception in thread "AWT-EventQueue-0" java.lang.StringIndexOutOfBoundsException: String index out of range: 5
at java.lang.String.charAt(Unknown Source)
at designer.ArrayMinValue$2.actionPerformed(ArrayMinValue.java:63)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
。。。。。

Answer 1

语法错误了，getElement(s)By后面无论是接Id还是class，亦或是tagname，前面都要加上document或者其他有效的element对象，即要写成document.getElementById("")这样的语法格式，这些方法都属于Element对象的方法，你前面不加上对象，而全局作用域又没有这些方法，自然就会报错了。