Java获取http和https网址对应html数据实例

2018-10-11 10:01:25来源：博客园阅读 ()

　　由于之前在公司一直用的C#做的软件开发，近些天有同学需要用Java做一个从指定网址获取信息的Java程序。正好不是很难，顺便复习了一下Java的知识。

　　要求如下，在https://www.marinetraffic.com/en/ais/details/ships/shipid:650235/mmsi:414726000/vessel:YU%20MING网址中得到如下图框中标记的数据。

　　程序如下：GetWebPosition类是主要程序类

package yinhang.wang;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSocketFactory;
import javax.net.ssl.TrustManager;
public class GetWebPosition {

   /**
   * @param args
   */
   public static void main(String[] args) {
       // TODO Auto-generated method stub
       String info = GetDataByTwo();
       System.out.println(info);
   }

   // 从指定的url中获取数据
   //https://www.marinetraffic.com/en/ais/details/ships/shipid:650235/mmsi:414726000/vessel:YU%20MING
       private static String HttpRequest(String requestUrl) {

           StringBuffer buffer = null;
           BufferedReader bufferedReader = null;
           InputStreamReader inputStreamReader = null;
           InputStream inputStream = null;
           HttpsURLConnection httpUrlConn = null;
           // 建立并向网页发送请求
           try {
               TrustManager[] tm = { new MyX509TrustManager() };
                SSLContext sslContext = SSLContext.getInstance("SSL", "SunJSSE");
                sslContext.init(null, tm, new java.security.SecureRandom());
                // 从上述SSLContext对象中得到SSLSocketFactory对象
                SSLSocketFactory ssf = sslContext.getSocketFactory();

               URL url = new URL(requestUrl);
               // 描述状态
               httpUrlConn = (HttpsURLConnection) url.openConnection();
               httpUrlConn.setSSLSocketFactory(ssf);
               httpUrlConn
               .setRequestProperty("User-Agent", "Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.100 Safari/537.36)");
               //防止报403错误。
                httpUrlConn.setDoOutput(true);
                httpUrlConn.setDoInput(true);
                httpUrlConn.setUseCaches(false);
               // 请求的类型
               httpUrlConn.setRequestMethod("GET");
               // 获取输入流
               inputStream = httpUrlConn.getInputStream();
               inputStreamReader = new InputStreamReader(inputStream, "utf-8");
               bufferedReader = new BufferedReader(inputStreamReader);
               // 从输入流读取结果
               buffer = new StringBuffer();
               String str = null;
               while ((str = bufferedReader.readLine()) != null) {
                   buffer.append(str);
               }
           } catch (Exception e) {
               e.printStackTrace();
           } finally {
               // 释放资源
               if (bufferedReader != null) {
                   try {
                       bufferedReader.close();
                   } catch (IOException e) {
                       e.printStackTrace();
                   }
               }
               if (inputStreamReader != null) {
                   try {
                       inputStreamReader.close();
                   } catch (IOException e) {
                       e.printStackTrace();
                   }
               }
               if (inputStream != null) {
                   try {
                       inputStream.close();
                   } catch (IOException e) {
                       e.printStackTrace();
                   }
               }
               if (httpUrlConn != null) {
                   httpUrlConn.disconnect();
               }
           }
           return buffer.toString();
       }　
    private static String HtmlFiter(String html) {

        StringBuffer buffer = new StringBuffer();
        String str1 = "";
        String str2 = "";
        //取出所用的范围,
        //Pattern p = Pattern.compile("(.*)(<div class=\"panel panel-primary no-border vertical-offset-20\">)(.*)(</div>)(.*)");
        Pattern p = Pattern.compile("(.*)(</script>)(.*)(<div class=\"wind_icon wind_low\")(.*)");
        Matcher m = p.matcher(html);
        if (m.matches()) {
            str1 = m.group(3);
            //取得时间：Vessel's Local Time:
            p = Pattern.compile("(.*)(time datetime=\")(.*)(\">)(.*)(</time>)(.*)(</span></strong>)(.*)");
            m = p.matcher(str1);
            if (m.matches()) {
                str2 = m.group(5);
                String str3 = m.group(7);
                buffer.append("\nVessel's Local Time: ");
                buffer.append(str2);
                buffer.append(str3);
                }
            // <a href="/en/ais/home/centerx:120.3903/centery:32.02979/zoom:10/mmsi:414726000/shipid:650235"
            // class="details_data_link">32.02979° / 120.3903°</a>
            //取得当前经纬度：Latitude / Longitude:
            p = Pattern.compile("(.*)(class=\"details_data_link\">)(.*)(</a></strong></span>)(.*)");
            m = p.matcher(str1);
            if (m.matches()) {
                str2 = m.group(3);
                buffer.append("\nLatitude / Longitude: ");
                buffer.append(str2);
            }
            //取得当前速度航线Speed/Course:
            p = Pattern.compile("(.*)(<span><strong>)(.*)(</strong></span>)(.*)");
            m = p.matcher(str1);
            if (m.matches()) {
                str2 = m.group(3);
                buffer.append("\nSpeed/Course: ");
                buffer.append(str2);
            }
            }
        return buffer.toString();
    }

        //封裝上述两个方法
       public static String GetDataByTwo(){
           //调用第一个方法,获得html字符串
           String html = HttpRequest("https://www.marinetraffic.com/en/ais/details/ships/shipid:650235/mmsi:414726000/vessel:YU%20MING");
           //调用第二个方法,过滤掉无用的信息
           String result = HtmlFiter(html);
           return result;
       }
}

MyX509TrustManager这个类的作用是提供安全证书去访问https类型的网站

package yinhang.wang;

import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;

import javax.net.ssl.X509TrustManager;

public class MyX509TrustManager implements X509TrustManager {
   public void checkClientTrusted(X509Certificate[] chain, String authType)
            throws CertificateException
          {
          }

          public void checkServerTrusted(X509Certificate[] chain, String authType)
            throws CertificateException
          {
          }

          public X509Certificate[] getAcceptedIssuers()
          {
            return null;
          }
}