Question

public class TestBean {
    private String[] array;

    public String[] getArray() {
        return array;
    }

    public void setArray(String[] array) {
        this.array = array;
    }
}

import java.lang.reflect.InvocationTargetException;

import org.apache.commons.beanutils.BeanUtils;

public class BeanUtilTest {
    public static void main(String[] args) {
        TestBean bean = new TestBean();
        try {
            BeanUtils.setProperty(bean, "array[0]", "zero");
        } catch (IllegalAccessException | InvocationTargetException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

运行代码时，会出现以下异常

java.lang.NullPointerException
at org.apache.commons.beanutils.PropertyUtilsBean.setIndexedProperty(PropertyUtilsBean.java:1414)
at org.apache.commons.beanutils.BeanUtilsBean.setProperty(BeanUtilsBean.java:1016)
at org.apache.commons.beanutils.BeanUtils.setProperty(BeanUtils.java:313)
at BeanUtilTest.main(BeanUtilTest.java:10)

运行时数组大小会增加。所以我不想要一个固定大小的数组。应在运行时定义数组大小。

Answer 1

您需要初始化数组或使用

设置数组

BeanUtils.setProperty(bean, "array", array);

然后使用以下操作设置值

BeanUtils.setProperty(bean, "array[0]", "zero");

运行期间数组大小不会增加

Java - 异常PropertyUtilsBean.setIndexedProperty

1 个答案: