BeanUtils-“描述”方法返回不正确的数组值

Question

I want to convert a bean class to a map (key=the name of the member,value=the value of the member).

I'm using the method BeanUtils.describe(beanClass);

( Edit :I'm using commons-beanutils 1.8.3, jdk 1.6.0_20, on commons-beanutils 1.5 it works)

The problem is that the return value is incorrect, (the map contain only the first item from the array),

the code:

public class Demo {

        private ArrayList<String> myList = new ArrayList<String>();

        public Demo() {
            myList.add("first_value");
            myList.add("second_value");
        }

        public ArrayList<String> getMyList() {
            return myList;
        }

        public void setMyList(ArrayList<String> myList) {
            this.myList = myList;
        }

        public static void main(String[] args) {
            Demo myBean = new Demo();
            try {
                Map describe = BeanUtils.describe(myBean);
                Iterator it = describe.entrySet().iterator();
                while (it.hasNext()) {
                    Map.Entry pairs = (Map.Entry) it.next();
                    System.out.println(String.format("key=%s,value=%s", (String) pairs.getKey(), (String) pairs.getValue()));

                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

• The expected output:

key=myList,value= [first_value,second_value]

key=class,value=class $Demo

• But the real output is:

key=myList,value= [first_value]

key=class,value=class $Demo

As you can see the array contains two values but the output(and the map) contains only one,why??

Thanks,

Benny

Answer 1

我在计算机上运行代码示例，输出为：key = myList，value = [first_value，second_value] key = class，value = class com.gpdi.infores.dao.test.Demo使用JDK5或更高版本即可。