BeanUtils.setProperty出错

BeanUtils.setProperty报错
今天使用BeanUtils.setProperty的时候不知怎么报错
我后来重新写了一个很简单的测试demo结果仍然报一样的错，以下是代码
student.java

public class Student {
	private String studentName;
	private String sex;
	public String getStudentName() {
		return studentName;
	}
	public void setStudentName(String studentName) {
		this.studentName = studentName;
	}
	public String getSex() {
		return sex;
	}
	public void setSex(String sex) {
		this.sex = sex;
	}
}

test类

public class TestUtil {
	public static void main(String args[]) throws Exception{
		Object obj = Class.forName("com.xiaohao.entity.Student").newInstance();
		Student stu = (Student) obj;
		BeanUtils.setProperty(stu, "sex", "man");
		System.out.println(stu.getSex());
	}
}

BeanUtils.setProperty(stu, "sex", "man");这一句报错

具体错误信息
Exception in thread "main" java.lang.ExceptionInInitializerError
at test.TestUtil.main(TestUtil.java:10)
Caused by: com.sun.org.apache.commons.logging.LogConfigurationException: com.sun.org.apache.commons.logging.LogConfigurationException: java.lang.NullPointerException (Caused by java.lang.NullPointerException) (Caused by com.sun.org.apache.commons.logging.LogConfigurationException: java.lang.NullPointerException (Caused by java.lang.NullPointerException))
at com.sun.org.apache.commons.logging.impl.LogFactoryImpl.newInstance(LogFactoryImpl.java:543)
at com.sun.org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:235)
at com.sun.org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:209)
at com.sun.org.apache.commons.logging.LogFactory.getLog(LogFactory.java:351)
at com.sun.org.apache.commons.beanutils.BeanUtils.<clinit>(BeanUtils.java:111)
... 1 more
Caused by: com.sun.org.apache.commons.logging.LogConfigurationException: java.lang.NullPointerException (Caused by java.lang.NullPointerException)
at com.sun.org.apache.commons.logging.impl.LogFactoryImpl.getLogConstructor(LogFactoryImpl.java:397)
at com.sun.org.apache.commons.logging.impl.LogFactoryImpl.newInstance(LogFactoryImpl.java:529)
... 5 more
Caused by: java.lang.NullPointerException
at com.sun.org.apache.commons.logging.impl.LogFactoryImpl.getLogConstructor(LogFactoryImpl.java:374)
... 6 more

求分析下原因

------解决思路----------------------
包用错了。应该是  import org.apache.commons.beanutils.BeanUtils;  下面的。

------解决思路----------------------
3L正解，删掉 import com.sun.org.apache.commons.beanutils.BeanUtils;
添加 import org.apache.commons.beanutils.BeanUtils;