Spring mvc的表单验证

首先web.xml中的配置

<servlet>
    <servlet-name>servletmvc</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    //这里是拦截到src下的配置文件，不用复制到web-inf中
    <init-param>
            <param-name>contextConfigLocation</param-name>
            //这里拦截的配置文件命名为的命名+servlet.xml
            <param-value>classpath:servletmvc-servlet.xml</param-value>
     </init-param>
  </servlet>
  <servlet-mapping>
    <servlet-name>servletmvc</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>

servletmvc-servlet.xml配置文件

    <mvc:annotation-driven>mvc:annotation-driven>
    <context:component-scan base-package="com.hopu">

    context:component-scan>
    //视图解析
    <bean id="internalResourceViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp/">property>
        <property name="suffix" value=".jsp">property>
    bean>

创建一个测试用的javabean

private Integer uid;
    private String name;
    private String pwd;

    public Integer getUid() {
        return uid;
    }
    public void setUid(Integer uid) {
        this.uid = uid;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getPwd() {
        return pwd;
    }
    public void setPwd(String pwd) {
        this.pwd = pwd;
    }

接下来写你要用到的表单验证

//创建一个类实现Validator 接口重写里面的方法
public class MyValidtor implements Validator {

    //验证与实体类是否关联
    @Override
    public boolean supports(Class clas) {
        // TODO Auto-generated method stub
        return User.class.equals(clas);
    }

    //在这里写验证
    @Override
    public void validate(Object obj, Errors errors) {
        // TODO Auto-generated method stub
        ValidationUtils.rejectIfEmpty(errors,"name","", "用户名不能为空");
        ValidationUtils.rejectIfEmpty(errors,"pwd", "" , "密码不能为空");

        //这种方式是自定义
        /*User user = (User) obj;
        if(user.getName().length() > 6) {
            errors.rejectValue("name", "用户名不能大于6位");
        }*/
    }

}

在@Controller中

    //先绑定Validtor
    @InitBinder
    public void initBinder(WebDataBinder binder) {
        binder.addValidators(new MyValidtor());
    }



    @RequestMapping("/login")
    public String login(@Validated User user,Errors errors) {
        if(errors.getErrorCount()>0) {
            return "index";
        }
        return "index";

    }

创建jsp页面

//使用form标签
<%@taglib prefix="form" uri="http://www.springframework.org/tags/form" %>

<form:form action="login1" modelAttribute="user" method="post">
        <table>
            <tr>
                <td><form:input path="name"/><form:errors path="name"/>td>
            tr>
            <tr>
                <td><input type="text" name="pwd"/><form:errors path="pwd"/>td>
            tr>
            <tr>
                <td><input type="submit" value="login"/>td>
            tr>
        table>
    form:form>

完事