使用Apache Velocity Api，我们可以将Java 对象（列表、POJO 等）与（HTML）template 组合并创建（HTML）输出。
是否有任何 Java API 可以帮助对此进行逆向工程？此 API 的输入可以是 HTML 输出和使用的模板，输出应该是用于生成输出的数据（Java/XML 格式）。
我知道HTTP Unit API，但这只是让我提取 HTML 元素（如表格）。我正在寻找基于某个模板提取数据的东西。
【问题讨论】：
标签： java html reverse-engineering templating
您可以使用 google protobuf 来转换不同类型的消息。定义模板也很容易。我使用 JSON.parse() 创建 JavaScript 对象，在 Java 中，您可以使用 protobuf 将 JSON 转换为 Java 对象。
【讨论】：
我的回答可能对这个问题的作者没有用（我迟到了 5 年，所以我猜这不是正确的时间）但因为这是我在输入 HTML to POJO 时在 Google 上找到的第一个结果，我想它可能对可能遇到此答案的许多其他开发人员有用。
今天，我刚刚（以我公司的名义）发布了一个 HTML 到 POJO 的完整框架，您可以使用它来将 HTML 映射到任何 POJO 类，只需一些注释。该库本身非常方便，并且具有许多其他功能，同时非常易于插入。你可以在这里看看：https://github.com/whimtrip/jwht-htmltopojo
假设我们需要解析以下 html 页面：
<html>
<head>
<title>A Simple HTML Document</title>
</head>
<body>
<div class="restaurant">
<h1>A la bonne Franquette</h1>
<p>French cuisine restaurant for gourmet of fellow french people</p>
<div class="location">
<p>in <span>London</span></p>
</div>
<p>Restaurant n*18,190. Ranked 113 out of 1,550 restaurants</p>
<div class="meals">
<div class="meal">
<p>Veal Cutlet</p>
<p rating-color="green">4.5/5 stars</p>
<p>Chef Mr. Frenchie</p>
</div>
<div class="meal">
<p>Ratatouille</p>
<p rating-color="orange">3.6/5 stars</p>
<p>Chef Mr. Frenchie and Mme. French-Cuisine</p>
</div>
</div>
</div>
</body>
</html>
让我们创建我们想要映射到的 POJO：
public class Restaurant {
@Selector( value = "div.restaurant > h1")
private String name;
@Selector( value = "div.restaurant > p:nth-child(2)")
private String description;
@Selector( value = "div.restaurant > div:nth-child(3) > p > span")
private String location;
@Selector(
value = "div.restaurant > p:nth-child(4)"
format = "^Restaurant n\*([0-9,]+). Ranked ([0-9,]+) out of ([0-9,]+) restaurants$",
indexForRegexPattern = 1,
useDeserializer = true,
deserializer = ReplacerDeserializer.class,
preConvert = true,
postConvert = false
)
// so that the number becomes a valid number as they are shown in this format : 18,190
@ReplaceWith(value = ",", with = "")
private Long id;
@Selector(
value = "div.restaurant > p:nth-child(4)"
format = "^Restaurant n\*([0-9,]+). Ranked ([0-9,]+) out of ([0-9,]+) restaurants$",
// This time, we want the second regex group and not the first one anymore
indexForRegexPattern = 2,
useDeserializer = true,
deserializer = ReplacerDeserializer.class,
preConvert = true,
postConvert = false
)
// so that the number becomes a valid number as they are shown in this format : 18,190
@ReplaceWith(value = ",", with = "")
private Integer rank;
@Selector(value = ".meal")
private List<Meal> meals;
// getters and setters
}
现在还有Meal 类：
public class Meal {
@Selector(value = "p:nth-child(1)")
private String name;
@Selector(
value = "p:nth-child(2)",
format = "^([0-9.]+)\/5 stars$",
indexForRegexPattern = 1
)
private Float stars;
@Selector(
value = "p:nth-child(2)",
// rating-color custom attribute can be used as well
attr = "rating-color"
)
private String ratingColor;
@Selector(
value = "p:nth-child(3)"
)
private String chefs;
// getters and setters.
}
我们在 github 页面上对上述代码提供了更多解释。
目前，让我们看看如何废弃它。
private static final String MY_HTML_FILE = "my-html-file.html";
public static void main(String[] args) {
HtmlToPojoEngine htmlToPojoEngine = HtmlToPojoEngine.create();
HtmlAdapter<Restaurant> adapter = htmlToPojoEngine.adapter(Restaurant.class);
// If they were several restaurants in the same page,
// you would need to create a parent POJO containing
// a list of Restaurants as shown with the meals here
Restaurant restaurant = adapter.fromHtml(getHtmlBody());
// That's it, do some magic now!
}
private static String getHtmlBody() throws IOException {
byte[] encoded = Files.readAllBytes(Paths.get(MY_HTML_FILE));
return new String(encoded, Charset.forName("UTF-8"));
}
另一个简短的例子可以找到here
希望这会对那里的人有所帮助！
【讨论】：