NullpointerException异常产生的原因:对null成员进行操作。
package cn.tcm;
public class Test_Nullpointer {
//private static final String NULL = null;
private String a=null;
public void run(){
try{
System.out.println(a.length());
}
catch( NullPointerException e){
System.out.print("不能对NULL成员进行任何操作");
}
}
public static void main(String arg[]){
(new Test_Nullpointer()).run();
}
}