关于RESTful风格设计时候出现的一些问题405

今天在写测试的时候发现下面的方式会出现405错误

<form action="${pageContext.request.contextPath}/delete/${teacher.id}" method="post">
    <button class="btn btn-danger btn-sm delete_btn" type="submit">
        <input type="hidden" name="_method" value="DELETE"/>
        <span class="glyphicon glyphicon-trash">删除</span>
    </button>
</form>

@PutMapping(value = "/update")
public String edit(TeacherMap teacherMap){
    for (String key:teacherMap.getTeacherMap().keySet()) {
        teacherDao.update(teacherMap.getTeacherMap().get(key));
    }
    return "redirect:/getALL";
}

问题的原因在于没有设置过滤器

org.springframework.web.filter.HiddenHttpMethodFilter

在web.xml中设置

<filter>
  <filter-name>hiddenHttpMethodFilter</filter-name>
  <filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
</filter>

<filter-mapping>
  <filter-name>hiddenHttpMethodFilter</filter-name>
  <url-pattern>/*</url-pattern>
</filter-mapping>

然后问题就没有了