《Spring Boot in Action》【6. Grails】
6. Grails
6.1 使用GORM持久化数据
GORM（Grails object-relational mapping）Book实体：
package readinglist
import grails.persistence.*
@Entity
class Book {
Reader reader
String isbn
String title
String author
String description
}要在Spring Boot项目中使用GORM，加入依赖：
compile("org.grails:gorm-hibernate4-spring-boot:1.1.0.RELEASE")这是通过Hibernate，如果你使用MongoDB，也是可以的：
compile("org.grails:gorm-mongodb-spring-boot:1.1.0.RELEASE")GORM Reader实体：
package readinglist
import grails.persistence.*
import org.springframework.security.core.GrantedAuthority
import org.springframework.security.core.authority.SimpleGrantedAuthority
import org.springframework.security.core.userdetails.UserDetails
@Entity
class Reader implements UserDetails {
String username
String fullname
String password
Collection getAuthorities() {
Arrays.asList(new SimpleGrantedAuthority("READER"))
}
boolean isAccountNonExpired() {
true
}
boolean isAccountNonLocked() {
true
}
boolean isCredentialsNonExpired() {
true
}
boolean isEnabled() {
true
}
}ReadingListController
package readinglist
import org.springframework.beans.factory.annotation.Autowired
import org.springframework.boot.context.properties.ConfigurationProperties
import org.springframework.http.HttpStatus
import org.springframework.stereotype.Controller
import org.springframework.ui.Model
import org.springframework.web.bind.annotation.ExceptionHandler
import org.springframework.web.bind.annotation.RequestMapping
import org.springframework.web.bind.annotation.RequestMethod
import org.springframework.web.bind.annotation.ResponseStatus
@Controller
@RequestMapping("/")
@ConfigurationProperties("amazon")
class ReadingListController {
@Autowired
AmazonProperties amazonProperties
@ExceptionHandler(value=RuntimeException.class)
@ResponseStatus(value=HttpStatus.BANDWIDTH_LIMIT_EXCEEDED)
def error() {
"error"
}
@RequestMapping(method=RequestMethod.GET)
def readersBooks(Reader reader, Model model) {
List readingList = Book.findAllByReader(reader)
model.addAttribute("reader", reader)
if (readingList) {
model.addAttribute("books", readingList)
model.addAttribute("amazonID", amazonProperties.getAssociateId())
}
"readingList"
}
@RequestMapping(method=RequestMethod.POST)
def addToReadingList(Reader reader, Book book) {
Book.withTransaction {
book.setReader(reader)
book.save()
}
"redirect:/"
}
} Groovy SecurityConfig：
package readinglist
import org.springframework.context.annotation.Configuration
import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder
import org.springframework.security.config.annotation.web.builders.HttpSecurity
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter
import org.springframework.security.core.userdetails.UserDetailsService
@Configuration
class SecurityConfig extends WebSecurityConfigurerAdapter {
void configure(HttpSecurity http) throws Exception {
http
.authorizeRequests()
.antMatchers("/").access("hasRole('READER')")
.antMatchers("/**").permitAll()
.and()
.formLogin()
.loginPage("/login")
.failureUrl("/login?error=true")
}
void configure(AuthenticationManagerBuilder auth) throws Exception {
auth
.userDetailsService(
{ username -> Reader.findByUsername(username) }
as UserDetailsService)
}
}6.2 用GSP编写视图
目前为止我们都是使用Thymeleaf作为模板引擎，Grails项目同时提供了Groovy Server Pages（GSP）的自动配置，添加如下依赖：
compile("org.grails:grails-gsp-spring-boot:1.0.0")接下来，把Thymeleaf readingList.html改写成readingList.gsp，同样是放在src/main/resources/templates路径下：
<html>
<head>
<title>Reading Listtitle>
<link rel="stylesheet" href="/style.css">link>
head>
<body>
<h2>Your Reading Listh2>
<g:if test="${books}">
<g:each in="${books}" var="book">
<dl>
<dt class="bookHeadline">
${book.title} by ${book.author}
(ISBN: ${book.isbn}")
dt>
<dd class="bookDescription">
<g:if test="book.description">
${book.description}
g:if>
<g:else>
No description available
g:else>
dd>
dl>
g:each>
g:if>
<g:else>
<p>You have no books in your book listp>
g:else>
<hr/>
<h3>Add a bookh3>
<form method="POST">
<label for="title">Title:label>
<input type="text" name="title"
value="${book?.title}"/><br/>
<label for="author">Author:label>
<input type="text" name="author"
value="${book?.author}"/><br/>
<label for="isbn">ISBN:label>
<input type="text" name="isbn"
value="${book?.isbn}"/><br/>
<label for="description">Description:label><br/>
<textarea name="description" rows="5" cols="80">
${book?.description}
textarea>
<input type="hidden" name="${_csrf.parameterName}"
value="${_csrf.token}" />
<input type="submit" value="Add Book" />
form>
body>
html>需要注意的是，我们有一个隐藏域来放CSRF（Cross-Site Request Forgery）token，Spring Security要求在POST请求中有这个token，Thymeleaf会自动在渲染的HTML中加入这个token，但在GSP中，你得显式指定。
6.3 混合Spring Boot和Grails 3
Grails是一个建立在Spring，Groovy，Hibernate等之上的高层框架，目前，Grails 3建立在Spring Boot之上，所以对于Grails开发者和Spring Boot开发者来说，都有很好的开发体验。
在Mac OS X和大部分Unix系统上，安装Grails最方便的方法是使用SDKMAN：
$ sdk install grails在Windows或者不能使用SDKMAN的系统上，你只好下载，解压并把bin目录添加到环境变量里去，检查安装是否成功：
$ grails -version创建Grails项目
$ grails create-app readinglist运行：
$ grails run-app因为Grails 3的Gradle脚本使用了Spring Boot插件，所以也可以使用bootRun运行：
$ gradle bootRun当然也可以打包运行：
$ gradle build
...
$ java -jar build/lib/readingList-0.1.jar定义domain
$ grails create-domain-class Book它会创建两个文件：Book.groovy和BookSpec.groovy，后面一个文件是测试Book类的Spock specification，初始是空的，Book.groovy在grails-app/domain/readingList目录下，像这样：
package readinglist
class Book {
static constraints = {
}
}我们添加一些字段：
package readinglist
class Book {
static constraints = {
}
String reader
String isbn
String title
String author
String description
}静态变量constraints是用来定义验证约束的，这里我们不关心。
编写Grails控制器
有几种命令可以创建Controller：
- create-controller——创建一个空的Controller
- generate-controller——生成包含指定domain类型CRUD操作的骨架Controller
- generate-all——生成包含指定domain类型CRUD操作的骨架Controller以及视图
我们使用第一个：
$ grails create-controller ReadingList该命令会在grails-app/controllers/readingList目录下创建一个ReadingListController：
package readinglist
class ReadingListController {
def index() { }
}此时该控制器已经可以处理/readingList请求了，会返回grails-app/views/readingList/index.gsp视图（暂时还不存在）
package readinglist
import static org.springframework.http.HttpStatus.*
import grails.transaction.Transactional
class ReadingListController {
def index() {
respond Book.list(params), model:[book: new Book()]
}
@Transactional
def save(Book book) {
book.reader = 'Craig'
book.save flush:true
redirect(action: "index")
}
}接下来就是编写GSP页面，和6.2中的差不多：
<html>
<head>
<meta name="layout" content="main"/>
<title>Reading Listtitle>
<link rel="stylesheet"
href="/assets/main.css?compile=false" />
<link rel="stylesheet"
href="/assets/mobile.css?compile=false" />
<link rel="stylesheet"
href="/assets/application.css?compile=false" />
head>
<body>
<h2>Your Reading Listh2>
<g:if test="${bookList && !bookList.isEmpty()}">
<g:each in="${bookList}" var="book">
<dl>
<dt class="bookHeadline">
${book.title}span> by ${book.author}
(ISBN: ${book.isbn}")
dt>
<dd class="bookDescription">
<g:if test="${book.description}">
${book.description}
g:if>
<g:else>
No description available
g:else>
dd>
dl>
g:each>
g:if>
<g:else>
<p>You have no books in your book listp>
g:else>
<hr/>
<h3>Add a bookh3>
<g:form action="save">
<fieldset class="form">
<label for="title">Title:label>
<g:field type="text" name="title" value="${book?.title}"/><br/>
<label for="author">Author:label>
<g:field type="text" name="author" value="${book?.author}"/><br/>
<label for="isbn">ISBN:label>
<g:field type="text" name="isbn" value="${book?.isbn}"/><br/>
<label for="description">Description:label><br/>
<g:textArea name="description" value="${book?.description}" rows="5" cols="80"/>
fieldset>
<fieldset class="buttons">
<g:submitButton name="create" class="save"
value="${message(code: 'default.button.create.label', default: 'Create')}" />
fieldset>
g:form>
body>
html>