Grails 实现简单登录

折腾了一上午，终于用Grails实现了一个最最简单，没有任何校验的登录功能。虽然慢，但也挺开心的，记录一下。
域类：

class User {

    static constraints = {
    }
    
    String username ;
    String password ;
    
}

控制器：

class UserController {

    static allowedMethods = [save: "POST", update: "POST", delete: "POST"]

    def index() {
        redirect(action: "login", params: params)
    }
    
    def login = {
       
    }
    
    def loginCheck = {
        def user = User.findByUsernameAndPassword(params.username, params.password)
        if(user){
            session.user = user
            flash.message = "Hello ${user.username}!"
            redirect(action:"success")      
        }else{
            flash.message = "Sorry, ${params.username}. Please try again."
            redirect(action:"login")
        }
    }
    
    def success ={

    }

    def list() {
        params.max = Math.min(params.max ? params.int('max') : 10, 100)
        [userInstanceList: User.list(params), userInstanceTotal: User.count()]
    }

    def create() {
        [userInstance: new User(params)]
    }

    def save() {
        def userInstance = new User(params)
        if (!userInstance.save(flush: true)) {
            render(view: "create", model: [userInstance: userInstance])
            return
        }

        flash.message = message(code: 'default.created.message', args: [message(code: 'user.label', default: 'User'), userInstance.id])
        redirect(action: "show", id: userInstance.id)
    }

    def show() {
        def userInstance = User.get(params.id)
        if (!userInstance) {
            flash.message = message(code: 'default.not.found.message', args: [message(code: 'user.label', default: 'User'), params.id])
            redirect(action: "list")
            return
        }

        [userInstance: userInstance]
    }

    def edit() {
        def userInstance = User.get(params.id)
        if (!userInstance) {
            flash.message = message(code: 'default.not.found.message', args: [message(code: 'user.label', default: 'User'), params.id])
            redirect(action: "list")
            return
        }

        [userInstance: userInstance]
    }

    def update() {
        def userInstance = User.get(params.id)
        if (!userInstance) {
            flash.message = message(code: 'default.not.found.message', args: [message(code: 'user.label', default: 'User'), params.id])
            redirect(action: "list")
            return
        }

        if (params.version) {
            def version = params.version.toLong()
            if (userInstance.version > version) {
                userInstance.errors.rejectValue("version", "default.optimistic.locking.failure",
                    [message(code: 'user.label', default: 'User')] as Object[],
                          "Another user has updated this User while you were editing")
                render(view: "edit", model: [userInstance: userInstance])
                return
            }
        }

        userInstance.properties = params

        if (!userInstance.save(flush: true)) {
            render(view: "edit", model: [userInstance: userInstance])
            return
        }

        flash.message = message(code: 'default.updated.message', args: [message(code: 'user.label', default: 'User'), userInstance.id])
        redirect(action: "show", id: userInstance.id)
    }

    def delete() {
        def userInstance = User.get(params.id)
        if (!userInstance) {
            flash.message = message(code: 'default.not.found.message', args: [message(code: 'user.label', default: 'User'), params.id])
            redirect(action: "list")
            return
        }

        try {
            userInstance.delete(flush: true)
            flash.message = message(code: 'default.deleted.message', args: [message(code: 'user.label', default: 'User'), params.id])
            redirect(action: "list")
        }
        catch (DataIntegrityViolationException e) {
            flash.message = message(code: 'default.not.deleted.message', args: [message(code: 'user.label', default: 'User'), params.id])
            redirect(action: "show", id: params.id)
        }
    }
}

登录页面：

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

<html>
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>用户登录</title>
  </head>
  <body>
  <g:if test="${flash.message}">
    <div class="message">${flash.message}</div>
  </g:if>
  <form action="loginCheck" method="post">
    <table>
      <tr>
        <td>用户名</td>
        <td>
          <input type="text" name="username"/>
        </td>
      </tr>
      <tr>
        <td>密码</td>
        <td>
          <input type="password" name="password"/>
        </td>
      </tr>
        <td>
          <input type="submit" value="提交"/>
        </td>
    </table>
  </form>
</body>
</html>

成功页面：

<html>
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>登录成功</title>
  </head>
  <body>
    <h1>
      <g:if test="${flash.message}">
      <div class="message">
        ${flash.message}
      </div>
    </g:if>
    </h1>
</body>
</html>

所有东西都是最简单的