占位符替换

1. PropertyPlaceholderHelper

Springframework 提供的一个工具类，用于占位符的替换。

public class PlaceholderUtil {

    public static String replace(String source, HashMap<String, String> dataMap) {
        PropertyPlaceholderHelper propertyPlaceholderHelper = new PropertyPlaceholderHelper("{", "}");
        return propertyPlaceholderHelper.replacePlaceholders(source, dataMap::get);
    }

    public static void main(String[] args) {
        String str = "The IP is {ip_address}, and the host name is [{hostName}]";

        HashMap<String, String> dataMap = new HashMap<>();
        dataMap.put("ip_address", "127.0.0.1");
        dataMap.put("hostName", "gw");

        System.out.println(replace(str, dataMap));
    }

}

2. FreeMarkerTemplateUtils Springframework 提供的一个使用给定模型处理邮件模版的工具类，可将模版中的占位符进行替换。

public String processTemplate() throws TemplateException, IOException {
    Template template = freemarkerConfigurer.createConfiguration().getTemplate("email.ftl");
    Map<String, String> dataMap = ImmutableMap.of(
            "username", "username",
            "message", "It's a Fine Day."
    );
    return FreeMarkerTemplateUtils.processTemplateIntoString(template, dataMap);
}