Spring Boot 集成 FreeMarker 详解案例

作者:泥瓦匠

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:

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:
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

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。

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

 

原创文章,作者:kepupublish,如若转载,请注明出处:https://blog.ytso.com/113730.html

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