关于网友提出的“ javalangIllegalArgumentException”问题疑问,本网通过在网上对“ javalangIllegalArgumentException”有关的相关答案进行了整理,供用户进行参考,详细问题解答如下:
问题: javalangIllegalArgumentException
描述: 我测试了下commons-beanUtil,结果出现如下错误:21 Exception in thread "main" java.lang.IllegalArgumentException: bm_URL
at org.apache.commons.beanutils.ResultSetIterator.get(ResultSetIterator.java:116)
at com.ljj.commons.dbutil.BeanUtilsExample3.main(BeanUtilsExample3.java:24)
ljh
感觉到很奇怪,我的数据库mysql:表中字段username,bm_URL都为varchar类型,注释掉System.out.println(bean.get("bm_URL")+"\t");能正常输出结果,类型一致为什么出现这种错误了,请高手指教。
package com.ljj.commons.dbutil;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Iterator;
import org.apache.commons.beanutils.DynaBean;
import org.apache.commons.beanutils.ResultSetDynaClass;
public class BeanUtilsExample3 {
public static void main(String args[]) throws Exception {
Connection conn = getConnection();
PreparedStatement ps = conn
.prepareStatement("select id,username,bm_URL from bookmark order by id desc");
ResultSet rs = ps.executeQuery();
ResultSetDynaClass rsdc = new ResultSetDynaClass(rs);//重点,二次封装,对连接对象有依赖
Iterator itr = rsdc.iterator();
while (itr.hasNext()) {
DynaBean bean = (DynaBean) itr.next();
System.out.print(bean.get("id") + "\t");
System.out.print(bean.get("username") + "\t");
System.out.println(bean.get("bm_URL")+"\t");
System.out.println();
}
conn.close();
}
private static Connection getConnection() {
String url = "jdbc:mysql://localhost:3306/bookmarks";
String username = "root";
String password = "123456";
Connection conn = null;
try {
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection(url, username, password);
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
return conn;
}
}
解决方案1: LZ:请加个try{}cache(Exception e){ e.printStatckTrace();}
看看具体的异常类型,这样很快你就会发现问题!
以上介绍了“ javalangIllegalArgumentException”的问题解答,希望对有需要的网友有所帮助。
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