目录
Freemarker 是一种流行的模板引擎，它可以使用 Java、C#、PHP 等语言编写模板，并从模板中生成 HTML、XML、文本等各种文件格式。Freemarker 模板由一个或多个包含变量和指令的文本文件组成，这些变量和指令可以在运行时被替换或执行。
依赖包
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-freemarker</artifactId>
</dependency>
配置模板文件目录
- 文件存放在项目resources/templates
freemarker:
template-loader-path: classpath:/templates
Java代码
html转png图片需要用到wkhtmltopdf
@Autowired
private FreeMarkerConfigurer freeMarkerConfigurer;
public void test() {
Configuration configuration = freeMarkerConfigurer.getConfiguration();
Template template = configuration.getTemplate("indexHTKWECHAT_PAY.html");
// 数据
Map<String, Object> data = new HashMap<>();
File htmlFile = writeHtml(template, data);
File pngFile = createAgreementPicture(htmlFile);
}
// html 替换占位符
private File writeHtml(Template template, Map<String, Object> data) throws IOException, TemplateException {
String fileName = UUID.randomUUID().toString();
File htmlFile = new File(FileUtil.getTmpDir(), fileName + ".html");
FileWriter sw = new FileWriter(htmlFile);
log.info("生成协议html, 地址:{}, 参数:{} ", htmlFile.getAbsolutePath(), data);
template.process(data, sw);
return htmlFile;
}
// html 转png 示例代码
private File createAgreementPicture(File htmlFile) throws IOException {
File outputFile = new File(FileUtil.getTmpDir(), htmlFile.getName() + ".png");
log.info("生成图片开始, HTML地址 {}, 图片地址:{}", htmlFile.getAbsolutePath(), outputFile.getAbsolutePath());
String commandProcess = "wkhtmltoimage --width 400 --quality 94 " + htmlFile.getPath() + " " + outputFile.getPath();
log.info("协议执行procommand:{}", commandProcess);
long startTime = System.currentTimeMillis(); //获取开始时间
Process process = Runtime.getRuntime().exec(commandProcess);
try {
int exitVal = process.waitFor();
log.info("协议html转换png结果:{}", exitVal);
} catch (InterruptedException e) {
e.printStackTrace();
log.info("协议html转换png错误:{}", e.getMessage());
throw new IOException(e);
}
long endTime = System.currentTimeMillis(); //获取结束时间
log.info("程序运行时间： " + (endTime - startTime) + "ms");
log.info("生成图片结束,地址: {}", outputFile.getPath());
Thumbnails.of(outputFile).scale(1).outputQuality(0.9).toFile(outputFile);
return outputFile;
}