SpringBoot 那些事 Spring Boot 集成 FreeMarker 详解案例 | 泥瓦匠BYSocket

二、运行 springboot-freemarker 工程

git clone 下载工程 springboot-learning-example ，项目地址见 GitHub – https://github.com/JeffLi1993/springboot-learning-example。下面开始运行工程步骤（Quick Start）：

1.数据库准备

a.创建数据库 springbootdb：

CREATE DATABASE springbootdb;

b.创建表 city ：(因为我喜欢徒步)

DROP TABLE IF EXISTS  `city`;
CREATE TABLE `city` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT COMMENT'城市编号',
  `province_id` int(10) unsigned  NOT NULL COMMENT'省份编号',
  `city_name` varchar(25) DEFAULT NULL COMMENT'城市名称',
  `description` varchar(25) DEFAULT NULL COMMENT'描述',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;

c.插入数据

INSERT city VALUES (1 ,1,'温岭市','BYSocket 的家在温岭。');

2. 项目结构介绍

项目结构如下图所示：

org.spring.springboot.controller – Controller 层

org.spring.springboot.dao – 数据操作层 DAO

org.spring.springboot.domain – 实体类

org.spring.springboot.service – 业务逻辑层

Application – 应用启动类

resources/application.properties – 应用配置文件，应用启动会自动读取配置

resources/web – *.ftl文件，是 FreeMarker 文件配置路径。在 application.properties 配置

resources/mapper – DAO Maper XML 文件

3.改数据库配置

打开 application.properties 文件， 修改相应的数据源配置，比如数据源地址、账号、密码等。（如果不是用 MySQL，pom 自行添加连接驱动依赖，然后修改驱动名配置。）

4.编译工程

在项目根目录 springboot-learning-example，运行 maven 指令：

mvn clean install

5.运行工程

右键运行 springboot-freemarker 工程 Application 应用启动类的 main 函数，然后在浏览器访问：

获取 ID 编号为 1 的城市信息页面：

获取城市列表页面：

6.补充

运行环境：JDK 7 或 8，Maven 3.0+

技术栈：SpringBoot、Mybatis、FreeMarker

三、 springboot-freemarker 工程配置详解

具体代码见 GitHub – https://github.com/JeffLi1993/springboot-learning-example

1.pom.xml 依赖

pom.xml 代码如下：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
   <modelVersion>4.0.0</modelVersion>
   <groupId>springboot</groupId>
   <artifactId>springboot-freemarker</artifactId>
   <version>0.0.1-SNAPSHOT</version>
   <name>springboot-freemarker :: Spring Boot 集成 FreeMarker 案例</name>
   <!-- Spring Boot 启动父依赖 -->
   <parent>
       <groupId>org.springframework.boot</groupId>
       <artifactId>spring-boot-starter-parent</artifactId>
       <version>1.5.1.RELEASE</version>
   </parent>
   <properties>
       <mybatis-spring-boot>1.2.0</mybatis-spring-boot>
       <mysql-connector>5.1.39</mysql-connector>
   </properties>
   <dependencies>
       <!-- Spring Boot Freemarker 依赖 -->
       <dependency>
           <groupId>org.springframework.boot</groupId>
           <artifactId>spring-boot-starter-freemarker</artifactId>
       </dependency>
       <!-- Spring Boot Web 依赖 -->
       <dependency>
           <groupId>org.springframework.boot</groupId>
           <artifactId>spring-boot-starter-web</artifactId>
       </dependency>
       <!-- Spring Boot Test 依赖 -->
       <dependency>
           <groupId>org.springframework.boot</groupId>
           <artifactId>spring-boot-starter-test</artifactId>
           <scope>test</scope>
       </dependency>
       <!-- Spring Boot Mybatis 依赖 -->
       <dependency>
           <groupId>org.mybatis.spring.boot</groupId>
           <artifactId>mybatis-spring-boot-starter</artifactId>
           <version>${mybatis-spring-boot}</version>
       </dependency>
       <!-- MySQL 连接驱动依赖 -->
       <dependency>
           <groupId>mysql</groupId>
           <artifactId>mysql-connector-java</artifactId>
           <version>${mysql-connector}</version>
       </dependency>
       <!-- Junit -->
       <dependency>
           <groupId>junit</groupId>
           <artifactId>junit</artifactId>
           <version>4.12</version>
       </dependency>
   </dependencies>
</project>

在 pom.xml 依赖中增加 Spring Boot FreeMarker 依赖。

2.配置 FreeMarker

然后在 application.properties 中加入 FreeMarker 相关的配置：

## Freemarker 配置
## 文件配置路径
spring.freemarker.template-loader-path=classpath:/web/
spring.freemarker.cache=false
spring.freemarker.charset=UTF-8
spring.freemarker.check-template-location=true
spring.freemarker.content-type=text/html
spring.freemarker.expose-request-attributes=true
spring.freemarker.expose-session-attributes=true
spring.freemarker.request-context-attribute=request
spring.freemarker.suffix=.ftl

这是我这块的配置，如果需要更多的 FreeMarker 配置，可以查看下面的详解：

spring.freemarker.allow-request-override=false # Set whether HttpServletRequest attributes are allowed to override (hide) controller generated model attributes of the same name.
spring.freemarker.allow-session-override=false # Set whether HttpSession attributes are allowed to override (hide) controller generated model attributes of the same name.
spring.freemarker.cache=false # Enable template caching.
spring.freemarker.charset=UTF-8# Template encoding.
spring.freemarker.check-template-location=true # Check that the templates location exists.
spring.freemarker.content-type=text/html # Content-Type value.
spring.freemarker.enabled=true # Enable MVC view resolution for this technology.
spring.freemarker.expose-request-attributes=false # Set whether all request attributes should be added to the model prior to merging with the template.
spring.freemarker.expose-session-attributes=false # Set whether all HttpSession attributes should be added to the model prior to merging with the template.
spring.freemarker.expose-spring-macro-helpers=true # Set whether to expose a RequestContext for use by Spring's macro library, under the name "springMacroRequestContext".
spring.freemarker.prefer-file-system-access=true # Prefer file system access for template loading. File system access enables hot detection of template changes.
spring.freemarker.prefix=# Prefix that gets prepended to view names when building a URL.
spring.freemarker.request-context-attribute=# Name of the RequestContext attribute for all views.
spring.freemarker.settings.*=# Well-known FreeMarker keys which will be passed to FreeMarker's Configuration.
spring.freemarker.suffix=# Suffix that gets appended to view names when building a URL.
spring.freemarker.template-loader-path=classpath:/templates/ # Comma-separated list of template paths.
spring.freemarker.view-names=# White list of view names that can be resolved.

3.展示层 Controller 详解

/**
 * 城市 Controller 实现 Restful HTTP 服务
 * <p>
 * Created by bysocket on 07/02/2017.
 */
@Controller
public class CityController {
   @Autowired
   private CityService cityService;
   @RequestMapping(value ="/api/city/{id}", method = RequestMethod.GET)
   public String findOneCity(Model model,@PathVariable("id") Long id) {
       model.addAttribute("city", cityService.findCityById(id));
       return "city";
   }
   @RequestMapping(value ="/api/city", method = RequestMethod.GET)
   public String findAllCity(Model model) {
       List<City> cityList = cityService.findAllCity();
       model.addAttribute("cityList",cityList);
       return "cityList";
   }
}

a.这里不是走 HTTP + JSON 模式，使用了 @Controller 而不是先前的 @RestController

b.方法返回值是 String 类型，和 application.properties 配置的 Freemarker 文件配置路径下的各个 *.ftl 文件名一致。这样才会准确地把数据渲染到 ftl 文件里面进行展示。

c.用 Model 类，向 Model 加入数据，并指定在该数据在 Freemarker 取值指定的名称。