freemarker获取html模板进行渲染输出 - 好文

文章目录

* freemarker获取html模板进行渲染输出
<https://blog.csdn.net/yunfeng482/article/details/80317344#freemarkerhtml_1>
* 应用场景 <https://blog.csdn.net/yunfeng482/article/details/80317344#_2>
* maven工程配置引入依赖
<https://blog.csdn.net/yunfeng482/article/details/80317344#maven_10>
* 创建获取模板测试类 <https://blog.csdn.net/yunfeng482/article/details/80317344#_20>
* Product类
<https://blog.csdn.net/yunfeng482/article/details/80317344#Product_87>
* 执行输出 <https://blog.csdn.net/yunfeng482/article/details/80317344#_127>
* Freemarker相应工具类FreemarkerUtil
<https://blog.csdn.net/yunfeng482/article/details/80317344#FreemarkerFreemarkerUtil_142>
* 总结 <https://blog.csdn.net/yunfeng482/article/details/80317344#_193>
* 注意事项 <https://blog.csdn.net/yunfeng482/article/details/80317344#_196>

<>freemarker获取html模板进行渲染输出

<>应用场景

1、获取html文件内容进行模板解析，返回到页面展示
2、获取html文件内容进行模板解析，进行邮件发送
3、获取xml文件内容进行模板接卸，生成office办公文件，达到apache poi的效果

一些class引用官方demo，当做测试。

<>maven工程配置引入依赖
<dependency> <groupId>org.freemarker</groupId> <artifactId>freemarker</
artifactId> <version>2.3.28</version> </dependency>
<>创建获取模板测试类
package test.freemarker; import freemarker.template.Configuration; import
freemarker.template.Template; import freemarker.template.TemplateException;
import freemarker.template.TemplateExceptionHandler; import org.junit.Test;
import java.io.File; import java.io.IOException; import java.io.
OutputStreamWriter; import java.io.Writer; import java.util.HashMap; import java
.util.Map; /** * @author yunfeng * @version V.1.0 * @title * @Desc * @create
2018-05-14 22:49 **/ public class TestFm { @Test public void test() throws
IOException{ /*
------------------------------------------------------------------------ */ /*
You should do this ONLY ONCE in the whole application life-cycle: */ /* Create
and adjust the configuration singleton */ Configuration cfg = new Configuration(
Configuration.VERSION_2_3_27); cfg.setDirectoryForTemplateLoading(new File(
"d:/freemarker/templates")); cfg.setDefaultEncoding("UTF-8"); cfg.
setTemplateExceptionHandler(TemplateExceptionHandler.RETHROW_HANDLER); cfg.
setLogTemplateExceptions(false); cfg.setWrapUncheckedExceptions(true); /*
------------------------------------------------------------------------ */ /*
You usually do these for MULTIPLE TIMES in the application life-cycle: */ /*
Create a data-model */ Map root = new HashMap(); root.put("user", "Big Joe");
Product latest= new Product(); latest.setUrl("products/greenmouse.html"); latest
.setName("green mouse"); root.put("latestProduct", latest); /* Get the template
(uses cache internally) */ Template temp = cfg.getTemplate("test.ftlh"); /*
Merge data-model with template */ Writer out = new OutputStreamWriter(System.out
); try { temp.process(root, out); } catch (TemplateException e) { e.
printStackTrace(); } // Note: Depending on what `out` is, you may need to call
`out.close()`. // This is usually the case for file output, but not for servlet
output. } }
<>Product类
package test.freemarker; /** * @author yunfeng * @version V.1.0 * @title *
@Desc * @create 2018-05-14 22:51 **/ public class Product { private String url;
private String name; // As per the JavaBeans spec., this defines the "url" bean
property // It must be public! public String getUrl() { return url; } public
void setUrl(String url) { this.url = url; } // As per the JavaBean spec., this
defines the "name" bean property // It must be public! public String getName() {
return name; } public void setName(String name) { this.name = name; } }
<>执行输出
<html> <head> <title>Welcome!</title> </head> <body> <h1>Welcome Big Joe!</h1>
<p>Our latest product: <a href="products/greenmouse.html">green mouse</a>! </
body> </html>
<>Freemarker相应工具类FreemarkerUtil
import freemarker.template.Configuration; import freemarker.template.Template;
import freemarker.template.TemplateException; import freemarker.template.
TemplateExceptionHandler; import org.slf4j.Logger; import org.slf4j.
LoggerFactory; import java.io.File; import java.io.IOException; import java.io.
StringWriter; import java.util.Map; /** * @author yunfeng * @version V1.0 *
@date 2018-05-24 22:55 */ public class FreemarkerUtil { private final static
Logger logger= LoggerFactory.getLogger(QuartzUtils.class); /** * 获取模板内容 * *
@param template 模板文件 * @param map 模板参数 * @return 渲染后的模板内容 * @throws IOException
IOException * @throws TemplateException TemplateException */ public static
StringgetTemplate(String template, Map map) throws IOException,
TemplateException{ Configuration cfg = new Configuration(Configuration.
VERSION_2_3_27); String templatePath = FreemarkerUtil.class.getResource("/").
getPath(); logger.info("FreemarkerUtil template = " + template); logger.debug(
"templatePath = " + templatePath); cfg.setDirectoryForTemplateLoading(new File(
templatePath)); cfg.setDefaultEncoding("UTF-8"); cfg.setTemplateExceptionHandler
(TemplateExceptionHandler.RETHROW_HANDLER); cfg.setLogTemplateExceptions(false);
cfg.setWrapUncheckedExceptions(true); Template temp = cfg.getTemplate(template)
; StringWriter stringWriter = new StringWriter(); temp.process(map, stringWriter
); return stringWriter.toString(); } }
<>总结

然后项目中通过调用FreemarkerUtil .getTemplate(String template, Map
map)即可返回对应渲染模板内容。也可以用其他模板框架去渲染页面jsonup

<>注意事项

* Configuration缓存 Template实例，所以当你cfg.getTemplate(“test.ftlh”)下次调用
时，它可能不会再读取和解析模板文件，只是Template第一次返回相同的实例。
* 不要不必要地重新创建Configuration 实例; 创建很消耗性能，而且会失去了模板缓存。Configuration实例应当作为应用程序级别的单例。

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