Java如何读取和下载网页？

时间：2024-07-24 11:34:50

在Java编程中，如何读取和下载网页？

以下示例显示如何使用net.URL类的URL()构造函数来读取和下载网页。

package com.yiibai;

import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.FileWriter;

import java.io.InputStreamReader;

import java.net.URL;

public class DownloadingWebpage {

    public static void main(String[] args) throws Exception {

        URL url = new URL("http://www.yiibai.com");

        BufferedReader reader = new BufferedReader(new InputStreamReader(url.openStream()));

        BufferedWriter writer = new BufferedWriter(new FileWriter("save2yiibai-index.html"));

        String line;

        while ((line = reader.readLine()) != null) {

            System.out.println(line);

            writer.write(line);

            writer.newLine();

        }

        reader.close();

        writer.close();

    }

}
Java

上述代码示例将产生以下结果(输出易百教程的首页页面源代码，并保存到save2yiibai-index.html文件中) -

<!--

输出易百教程的首页页面源代码

-->

<!DOCTYPE HTML>

<html>

<head><!--

-->

<!DOCTYPE HTML>

<html>

<head>

... ... 省略
Shell

示例-2

Java读取和下载网页的另一个示例：

package com.yiibai;

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 DownloadingWebpage2 {

    public static void main(String[] args) {

        URL url;

        InputStream is = null;

        BufferedReader br;

        String line;

        try {

            url = new URL("http://www.yiibai.com/javaexamples/date_time_month.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) {

            }

        }

    }

}
Java

上述代码示例将产生以下结果(输出页面源代码) -

<!DOCTYPE HTML>

<html>

<head>

<meta charset="UTF-8">

<meta http-equiv="X-UA-Compatible" content="IE=edge">

...... 省略

相关文章