package No2;
import java.util.*;
import java.io.*;
public class Test {
public static void main(String[] args)throws IOException
{
HashMap hm=new HashMap();
Child ch1=new Child("SN02312","谢谢");
Child ch2=new Child("SN0232314124122","小小");
hm.put("SN02312","谢谢");
hm.put("SN0232314124122","小小");
//遍历1
/*
if(hm.containsKey("SN02312"))
{
System.out.println("有");
Child temp=(Child)hm.get("SN02312");
System.out.println("name="temp.getName+" "+"num="+temp.getNum);
}else
{
System.out.println("没有");
}
}
}
class Child
{
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getNum() {
return num;
}
public void setNum(String num) {
this.num = num;
}
String name;
String num;
public Child(String num,String name)
{
this.name=name;
this.num=num;
}
}
程序报错:
Exception in thread "main" java.lang.ClassCastException: java.lang.String cannot be cast to No2.Child
at No2.Test.main(Test.java:28)
为什么这里不能转成String ?麻烦给个比较详细的解答,查了好久...