Spring Boot 集成 FreeMarker 详解案例

客官°小女子只卖身不卖艺 2021-06-24 15:56 406阅读 0赞

[http://ifeve.com/spring-boot-%E9%9B%86%E6%88%90-freemarker-%E8%AF%A6%E8%A7%A3%E6%A1%88%E4%BE%8B/][http_ifeve.com_spring-boot-_E9_9B_86_E6_88_90-freemarker-_E8_AF_A6_E8_A7_A3_E6_A1_88_E4_BE_8B]

### 一、Springboot 那些事 ###

SpringBoot 很方便的集成 FreeMarker ，DAO 数据库操作层依旧用的是 Mybatis，本文将会一步一步到来如何集成 FreeMarker 以及配置的详解：

Springboot 那些事：

系类文章：

> [《Spring Boot 之 RESRful API 权限控制》][Spring Boot _ RESRful API]
> 
> [《Spring Boot 之 HelloWorld详解》][Spring Boot _ HelloWorld]
> 
> [《Springboot 整合 Mybatis 的完整 Web 案例》][Springboot _ Mybatis _ Web]
> 
> [《Springboot 实现 Restful 服务，基于 HTTP / JSON 传输》][Springboot _ Restful _ HTTP _ JSON]
> 
> [《Springboot 集成 FreeMarker》][Springboot _ FreeMarker]

### 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][GitHub]。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：

localhost:8080/api/city/1

获取城市列表页面：

localhost:8080/api/city

**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][GitHub]

**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>
    
        
        <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>
            
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-freemarker</artifactId>
            </dependency>
    
            
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
    
            
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
    
            
            <dependency>
                <groupId>org.mybatis.spring.boot</groupId>
                <artifactId>mybatis-spring-boot-starter</artifactId>
                <version>${mybatis-spring-boot}</version>
            </dependency>
    
            
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>${mysql-connector}</version>
            </dependency>
    
            
            <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。

### 四、小结 ###

FreeMarker 是常用的模板引擎，很多开发 Web 的必选。

推荐阅读《 [Springboot 那些事][Springboot]》

[http_ifeve.com_spring-boot-_E9_9B_86_E6_88_90-freemarker-_E8_AF_A6_E8_A7_A3_E6_A1_88_E4_BE_8B]: http://ifeve.com/spring-boot-%E9%9B%86%E6%88%90-freemarker-%E8%AF%A6%E8%A7%A3%E6%A1%88%E4%BE%8B/
[Spring Boot _ RESRful API]: http://www.bysocket.com/?p=1080
[Spring Boot _ HelloWorld]: http://www.bysocket.com/?p=1124
[Springboot _ Mybatis _ Web]: http://www.bysocket.com/?p=1610
[Springboot _ Restful _ HTTP _ JSON]: http://www.bysocket.com/?p=1627
[Springboot _ FreeMarker]: http://www.bysocket.com/?p=1666
[GitHub]: https://github.com/JeffLi1993/springboot-learning-example
[Springboot]: http://www.bysocket.com/?page_id=1639