FreeMarker 2: How to download the jar package of FreeMarker and how to introduce it into the project; a small example of FreeMarker (the case is a Java project, not a web project);

The basic use of FreeMarker; the important thing is to use the three steps of using Freemarker!

The ftl file is a script! ! !

table of Contents

One: How to download and install FreeMarker:

Two: How to introduce freeMarker; FreeMarker Editor editor plug-in installation;

1. Introduce Freemarker:

2. FreeMarker Editor editor plug-in installation

Three: FreeMarker actual coding example

One: How to download and install FreeMarker:

Visit: https://freemarker.apache.org/ ; FreeMarker is an open source project provided by Apache;

There are two ways to install FreeMarker: (1) the first way to manually download the jar package; (2) the other way through Maven;

Two: How to introduce freeMarker; FreeMarker Editor editor plug-in installation;

1. Introduce Freemarker:

2. FreeMarker Editor editor plug-in installation

Recommended installation: FreeMarker IDE from JBoss Tools 1.5

So far, everything is ready;

Three: FreeMarker actual coding example

FreeMarkerSample1 content: use FreeMarker, combined with templates for output;

(1) The operation of Freemarker is divided into three steps: loading template; creating data; generating output ;

package com.imooc.freemarker;

import java.io.IOException;
import java.io.OutputStreamWriter;
import java.util.HashMap;
import java.util.Map;

import freemarker.core.ParseException;
import freemarker.template.Configuration;
import freemarker.template.MalformedTemplateNameException;
import freemarker.template.Template;
import freemarker.template.TemplateException;
import freemarker.template.TemplateNotFoundException;

public class FreeMarkerSample1 {

	public static void main(String[] args) throws TemplateNotFoundException, MalformedTemplateNameException, ParseException, IOException, TemplateException {
		// TODO Auto-generated method stub
		// 1.加载模板
		// Configuration对象是FreeMarker的核心配置对象
		// 1.1创建核心配置对象
		Configuration config = new Configuration(Configuration.VERSION_2_3_31);// 因为我们下载的freemarker版本为2.3.31；所以这儿构造参数为2_3_31;
		// 1.2设置加载的目录;    这儿的意思:在FreeMarkerSample1这个类所在包中去加载指定的ftl文件；第二个参数传递一个空字符串代表是当前包；
		config.setClassForTemplateLoading(FreeMarkerSample1.class, "");
		// 1.3得到模板对象;;;; 以为1.2中设置了，只去扫描FreeMarkerSample1这个类所在包中的ftl,所以1.3这一步getTemplate()参数只需要指定ftl文件名字就可以了；
		Template t = config.getTemplate("sample1.ftl");
		// 2.创建数据 ；；；；；对于Freemaker来说，其数据就是一个Map类型的对象；
		// Map用来包含需要向模板中传入的数据
		Map<String,Object> dataMap = new HashMap<String,Object>();
		dataMap.put("site", "百度");
		dataMap.put("url", "http://www.baidu.com/");
		// 3.产生输出；；；这个输出，可以向文件输入，可以向控制台输出，可以向网络流中输出；向什么地方输出，取决于使用哪种类型的输出对象；
		t.process(dataMap, new OutputStreamWriter(System.out)); 
		// System.out：是向控制台输出的核心对象；System.out这个对象本质是一个PrintStream类型的对象，而process()方法的第二个参数需要是Writer类型的对象，所以使用new OutputStreamWriter(System.out)，转换一下；
		
	}

}

Then, when the following content is written in sample1.ftl:

${site}-${url}

At this time, the output of running FreeMarkerSample1 is:

百度-http://www.baidu.com/

……………………………………………………

Then, when the following content is written in sample1.ftl:

${site}~~~${url}

At this time, the output of running FreeMarkerSample1 is:

百度~~~http://www.baidu.com/

Through the above example, we can find one thing: the background part only writes the code and prepares the data, and does not care about how the data is displayed in the foreground;

The ftl file is responsible for how the data is displayed;

This seems to reflect the separation of data and display; separation of work, separation of "front and back" work, naturally the overall efficiency of the project can be improved! ! !

So, what??? to be added

Need other examples, continue to deepen~~~