Java：模板引擎FreeMarker

FreeMarker Template Language (FTL)

文档：

• en: https://freemarker.apache.org/docs/index.html
• cn: http://freemarker.foofun.cn/index.html

依赖

    org.freemarker
    freemarker
    2.3.31

使用示例

package com.pengshiyu;

import freemarker.template.Configuration;
import freemarker.template.Template;

import java.io.*;
import java.util.HashMap;
import java.util.Map;

public class FreemarkerDemo {

    public static void main(String[] args) throws Exception {
        // 第一步：配置freemarker
        Configuration configuration = new Configuration(Configuration.DEFAULT_INCOMPATIBLE_IMPROVEMENTS);
        // 设置模板路径
        configuration.setDirectoryForTemplateLoading(new File("./"));

        // 第二步：加载模板
        Template template = configuration.getTemplate("template.ftl");

        // 第三步：模板数据
        Map data = new HashMap();
        data.put("name", "汤姆");
        data.put("age", 23);

        // 第四步：渲染输出
        // 输出到字符串
        Writer stringWriter = new StringWriter();
        template.process(data, stringWriter);
        stringWriter.close();
        System.out.println(stringWriter.toString());

        // 输出到文件
        Writer fileWriter = new FileWriter(new File("hello.html"));
        template.process(data, fileWriter);
        fileWriter.close();
    }
}

模板文件 template.ftl

    
        Demo
    
    
        ${name}
        ${age}
    

输出结果 hello.html

    
        Demo
    
    
        汤姆
        23
    

问题及解决

报错

严重: DefaultObjectWrapper.incompatibleImprovements was set to the object returned by Configuration.getVersion(). That defeats the purpose of incompatibleImprovements, and makes upgrading FreeMarker a potentially breaking change. Also, this probably won't be allowed starting from 2.4.0. Instead, set incompatibleImprovements to the highest concrete version that's known to be compatible with your application.

解决方式

// 不推荐使用
Configuration configuration = new Configuration(Configuration.getVersion());

// 修改为：
Configuration configuration = new Configuration(Configuration.DEFAULT_INCOMPATIBLE_IMPROVEMENTS);

模板语法

Hello ${name}



    is Tom

    is Jack

    not is Tom




    ${item.name} ${item.age}

参考 FreeMarker 快速入门 SpringBoot整合FreeMarker模板报错