ssm遇到的问题

1.

Caused by: java.lang.IllegalArgumentException
    at org.springframework.asm.ClassReader.<init>(Unknown Source)
    at org.springframework.asm.ClassReader.<init>(Unknown Source)
    at org.springframework.asm.ClassReader.<init>(Unknown Source)
    at 

原因：版本低，所有版本都必须是4.0以上，

2.乱码问题：
(①)web.xml添加(解决前端传过来数据乱码的问题)：
　　<!-- 解决post乱码问题的过滤器 -->

<filter>
  <filter-name>CharacterEncodingFilter</filter-name>
  <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
  <init-param>
    <param-name>encoding</param-name>
    <param-value>utf-8</param-value>
  </init-param>
</filter>
<filter-mapping>
  <filter-name>CharacterEncodingFilter</filter-name>
  <url-pattern>/*</url-pattern>
</filter-mapping>

(②)页面添加:

<%@ page contentType="text/html;charset=UTF-8" %>

<meta  http-equiv="Content-Type" content="text/html; charset=utf-8">