public class Switch4
{
//获取指定品种的主力合约和交易合约
private void getCorrectContract(Map contractMap)
{
Map correctContractMap = contractMap; //原主力交易合约用来判断是否换月
correctContractMap.put("main_contract","15451"); //我在这里改变了MAP的值
correctContractMap.put("trade_contract","15122");
}
private void updataDataBase()
{
Map corMap = new HashMap();
corMap.put("main_contract","dfdfdfdf");
corMap.put("trade_contract","ttggg");
getCorrectContract(corMap); //结果contractList中MAP的值也改变了
System.out.println("完成"+corMap.get("main_contract"));
}
public static void main(String[] args)
{
Switch4 sw = new Switch4();
sw.updataDataBase();
}
}
打印结果
完成15451
map都什么特别的