Object org.apache.commons.beanutils.ConvertUtilsBean.convert(String value, Class clazz) nullPointException

在工程做如下类似使用时，系统会报null指针异常。

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01.import org.apache.commons.beanutils.ConvertUtils;
02.
03.public class T {
04.
05. /**
06. * @param args
07. * @author Ken_xu
08. */
09. public static void main(String[] args)

{ 10. // TODO Auto-generated method stub 11. Object obj = ConvertUtils.convert("1", null); 12. System.out.println(obj); 13. }

14.
15.}
import org.apache.commons.beanutils.ConvertUtils;

public class T {

/**

• @param args
• @author Ken_xu
  */
  public static void main(String[] args) { // TODO Auto-generated method stub Object obj = ConvertUtils.convert("1", null); System.out.println(obj); }

}

Exception in thread "main" java.lang.NullPointerException
at org.apache.commons.beanutils.ConvertUtilsBean.convert(ConvertUtilsBean.java:418)
at org.apache.commons.beanutils.ConvertUtils.convert(ConvertUtils.java:217)
at T.main(T.java:11)

经过分析源代码发现

Object org.apache.commons.beanutils.ConvertUtilsBean.convert(String value, Class clazz)
这个类的这个方法的源代码如下

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01.public Object convert(String value, Class clazz) {
02.
03. if (log.isDebugEnabled())

{ 04. log.debug("Convert string '" + value + "' to class '" + 05. clazz.getName() + "'"); 06. }

07. Converter converter = lookup(clazz);
08. if (converter == null)

{ 09. converter = lookup(String.class); 10. }

11. if (log.isTraceEnabled())

{ 12. log.trace(" Using converter " + converter); 13. }

14. return (converter.convert(clazz, value));
15.
16.}
public Object convert(String value, Class clazz) {

if (log.isDebugEnabled())

{ log.debug("Convert string '" + value + "' to class '" + clazz.getName() + "'"); }

Converter converter = lookup(clazz);
if (converter == null)

{ converter = lookup(String.class); }

if (log.isTraceEnabled())

{ log.trace(" Using converter " + converter); }

return (converter.convert(clazz, value));

}

分析后认为是由于当前工程使用了log4j实现，并且设置了全局debug级别，最终导致报异常。

解决方法如下：
在log4j.properties配置文件中增加如下代码

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01.#屏蔽BUG org.apache.commons.beanutils.ConvertUtilsBean.convert(String value, Class clazz)
02.log4j.logger.org.apache.commons.beanutils=INFO