The technical principles and applications of the jQuery framework in the Java class library
The technical principles and applications of the jQuery framework in the Java class library
Introduction:
Jquery is a popular JavaScript framework, which is widely used in Web development.This article will explore the technical principles of the Jquery framework in the Java library and its application in Java development.We will introduce the working principles and core characteristics of jQuery, and provide some related Java code examples.
1. The working principle of the jQuery framework:
1. Selectors (Selectors): jquery can choose the DOM element through the CSS selector.It can choose DOM elements based on the attributes such as label name, class name, ID, so as to more conveniently operate the DOM.
Example code:
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;
public class JquerySelectorsExample {
public static void main(String[] args) {
String html = "<html><body><div id=\"myDiv\">Hello, World!</div></body></html>";
Document doc = Jsoup.parse(html);
Element element = doc.select("#myDiv").first();
System.out.println(element.text());
}
}
2. Event handling: JQuery provides a wealth of event processing methods, which can register and process various events through simple code, such as clicking and Hanging.
Example code:
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;
public class JqueryEventHandlingExample {
public static void main(String[] args) {
String html = "<html><body><button id=\"myButton\">Click Me!</button></body></html>";
Document doc = Jsoup.parse(html);
Element button = doc.select("#myButton").first();
button.attr("onclick", "myFunction()");
System.out.println(button);
}
}
3. Animation Effects: Jquery provides a rich animation effect, which can use its built -in animation functions to achieve the effects of fading, sliding, and zooming.
Example code:
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;
public class JqueryAnimationEffectsExample {
public static void main(String[] args) {
String html = "<html><body><div id=\"myDiv\">Hello, World!</div></body></html>";
Document doc = Jsoup.parse(html);
Element div = doc.select("#myDiv").first();
div.attr("style", "display:none;");
div.append("<script>$(\"#myDiv\").fadeIn(1000);</script>");
System.out.println(div);
}
}
2. Application of jquery in Java development:
1. Web Scraping: Using the jQuery framework in the Java class library, we can quickly locate and obtain information on the target webpage through the selector to achieve climbing and analysis of web pages.
Example code:
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;
public class WebCrawlerExample {
public static void main(String[] args) {
String url = "https://example.com/";
try {
Document doc = Jsoup.connect(url).get();
Elements titles = doc.select(".title");
for (Element title : titles) {
System.out.println(title.text());
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
2. Dynamic Web Development: In the Java back -end development, we can use the jQuery framework in the Java library to deal with the dynamic interaction of the front end and return the back -end data to the front end in JSON format.
Example code:
import org.json.JSONArray;
import org.json.JSONObject;
public class RestApiExample {
public static void main(String[] args) {
JSONObject jsonObject = new JSONObject();
jsonObject.put("name", "John");
jsonObject.put("age", 30);
JSONArray jsonArray = new JSONArray();
jsonArray.put("Java");
jsonArray.put("Python");
jsonArray.put("JavaScript");
jsonObject.put("skills", jsonArray);
System.out.println(jsonObject);
}
}
in conclusion:
This article introduces the technical principles of the Jquery framework in the Java class library and its application in Java development.Jquery framework provides convenient DOM operation, rich event processing and animation effects through core characteristics such as selector, event processing and animation effects.In Java development, we can use these features to achieve functions such as web crawlers and dynamic interaction.I hope this article will help you understand the application of the jQuery framework in the Java class library.
