如何使用 Java 读取和下载网页
问题描述
如何读取和下载网页?
解决方案
以下示例显示如何读取和下载网页 net.URL 类的 URL() 构造函数。
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.InputStreamReader;
import java.net.URL;
public class Main {
public static void main(String[] args) throws Exception {
URL url = new URL("http://www.google.com");
BufferedReader reader = new BufferedReader(new InputStreamReader(url.openStream()));
BufferedWriter writer = new BufferedWriter(new FileWriter("data.html"));
String line;
while ((line = reader.readLine()) != null) {
System.out.println(line);
writer.write(line);
writer.newLine();
}
reader.close();
writer.close();
}
}
结果
上述代码示例将产生以下结果。
Welcome to Java Tutorial Here we have plenty of examples for you! Come and Explore Java!
以下是另一个读取和下载网页的示例。
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
public class NewClass {
public static void main(String[] args) {
URL url;
InputStream is = null;
BufferedReader br;
String line;
try {
url = new URL("https://www.tutorialspoint.com/javaexamples/net_singleuser.html");
is = url.openStream(); // throws an IOException
br = new BufferedReader(new InputStreamReader(is));
while ((line = br.readLine()) != null) {
System.out.println(line);
}
} catch (MalformedURLException mue) {
mue.printStackTrace();
} catch (IOException ioe) {
ioe.printStackTrace();
}
finally {
try {
if (is != null) is.close();
} catch (IOException ioe) {}
}
}
}
结果
上述代码示例将产生以下结果。
<!DOCTYPE html> <!--[if IE 8]><html class="ie ie8"> <![endif]--> <!--[if IE 9]><html class="ie ie9"> <![endif]--> <!--[if gt IE 9]><!--> <html> <!--<![endif]--> <head> <!-- Basic --> <meta charset="utf-8"> <title>Java Examples - Socket to a single client</title> <meta name="description" content="Java Examples Socket to a single client : A beginner's tutorial containing complete knowledge of Java Syntax Object Oriented Language, Methods, Overriding, Inheritance, Polymorphism, Interfaces, Packages, Collections, Networking, Multithreading, Generics, Multimedia, Serialization, GUI." /> <meta name="keywords" content="Java, Tutorials, Learning, Beginners, Basics, Object Oriented Language, Methods, Overriding, Inheritance, Polymorphism, Interfaces, Packages, Collections, Networking, Multithreading, Generics, Multimedia, Serialization, GUI." /> <base href="https://www.tutorialspoint.com/" /> <link rel="shortcut icon" href="/favicon.ico" type="image/x-icon" /> <meta name="viewport" content="width=device-width,initial-scale=1.0,user-scalable=yes"> <meta property="og:locale" content="en_US" /> <meta property="og:type" content="website" /> <meta property="fb:app_id" content="471319149685276" /> <meta property="og:site_name" content="www.tutorialspoint.com" /> <meta name="robots" content="index, follow"/> <meta name="apple-mobile-web-app-capable" content="yes"> <meta name="apple-mobile-web-app-status-bar-style" content="black"> <meta name="author" content="tutorialspoint.com"> <script type="text/javascript" src="/theme/js/script-min-v4.js"></script>
java_networking.html
