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社区首页 >问答首页 >Java模式匹配找不到具有正则表达式[A-Z0-9._%+-]+@[A-Z0-9.-]{3,65}\.[A-Z]{2,4}的电子邮件

问Java模式匹配找不到具有正则表达式[A-Z0-9._%+-]+@[A-Z0-9.-]{3,65}\.[A-Z]{2,4}的电子邮件
EN

Stack Overflow用户
提问于 2018-08-04 02:43:54
回答 4查看 911关注 0票数 1

我试图从网页中提取电子邮件；我有60个随机的网站url，并尝试从其中提取电子邮件用于测试目的，正在使用此A-Z0-9._%+-+@A-Z0-9.-{3,65}.A-Z{2,4}正则表达式在页面中查找电子邮件，并使用JSoup解析网站。

在一个可用的源中使用编辑的代码

代码语言：javascript
复制
import java.io.IOException;
import java.net.MalformedURLException;
import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.net.ssl.HostnameVerifier;
import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSession;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;

import org.jsoup.Connection;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;

public class TestingMail {
    // HERE WE CONSTRUCT CLASS
    public TestingMail(){}


    /****************** SETTING MAIN METHOD TO TEST CLASS *************************/
    public static void main(String[] args){
        // Setting initiator
        String Terms="Trending Bitcoin Investment Chat in NETHERLANDS";
        TestingMail extractor=new TestingMail();
        extractor.extract(Terms, extractor);
    }


    /****************** HERE WE CONSTRUCT THE EXTRACT METHOD **********************/
    public void extract(String terms, TestingMail extractor){
        // HERE WE START CONSTRUCTING THE EXTRACT PROCESSES
        int NUM_THREADS=10;
        int limit=10;
        String[] parseURL={};
        String[] crawedURL={};
        int istype=0;
        int start=0;
        // HERE WE START PROCESSING
        if(terms!=null && terms.length()>0){
            SSLContext sc = null;

            // LETS DISABLE SSL CERTIFICATE
            // Create a trust manager that does not validate certificate chains
            TrustManager[] trustAllCerts = new TrustManager[] {new X509TrustManager() {
                    public java.security.cert.X509Certificate[] getAcceptedIssuers() {
                        return null;
                    }
                    public void checkClientTrusted(X509Certificate[] certs, String authType) {
                    }
                    public void checkServerTrusted(X509Certificate[] certs, String authType) {
                    }
                }
            };

            try {
                sc = SSLContext.getInstance("SSL");
            } catch (NoSuchAlgorithmException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            try {
                sc.init(null, trustAllCerts, new java.security.SecureRandom());
            } catch (KeyManagementException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());

            // Create all-trusting host name verifier
            HostnameVerifier allHostsValid = new HostnameVerifier() {
                public boolean verify(String hostname, SSLSession session) {
                    return true;
                }
            };

            // Install the all-trusting host verifier
            HttpsURLConnection.setDefaultHostnameVerifier(allHostsValid);

            // HERE LETS CRAW DATA FROM GOOGLE
            crawedURL=new String[]{"https://www.globfinances.com", "https://napoleoninvestment.net", "https://www.meetup.com/BitcoinWednesday/?_cookie-check=PXZ_aLyoOMcdpbrs"};
            if(crawedURL!=null && crawedURL.length>0){
                // Here we loop mails to store send mails
                if(crawedURL.length<limit){
                    limit=crawedURL.length;
                    istype=1;
                }

                // Here we set the mails length
                parseURL=new String[limit];
                // HERE WE START THREAD POOL
                ExecutorService es = Executors.newFixedThreadPool(NUM_THREADS);
                List<Future<Integer>> futures = new ArrayList<>(NUM_THREADS);

                // Submit task to every thread:
                for (int i = 0; i < NUM_THREADS; i++) {
                    // Here we loop to get mails
                    if(start<crawedURL.length){
                        for(int k=start, j=0; j<crawedURL.length; k++, j++){
                            if(k<(limit-1)){
                                System.out.println(i+"=="+j);
                                // System.out.println(mails[k]);
                                parseURL[j]=crawedURL[k];
                            }
                            else{
                                start+=limit+1;
                                break;
                            }
                        }
                        // Here we thread task
                        futures.add(i, es.submit((Callable<Integer>) new Extractor(parseURL, extractor)));
                    }
                    else{
                        istype=1;
                        break;
                    }

                    // Checking thread type to prevent multiple run
                    if(istype==1){
                        break;
                    }
                } // end of loop

                // Shutdown thread pool
                es.shutdown();
                System.out.println("Thread: "+futures.size());
            }
        }
    }


    /******************* HERE WE CONSTRUCT THE EXTRACT METHOD *******************/
    private Integer mailExtract(String[] urls) throws MalformedURLException{
        // HERE WE START CONSTRUCTING THE MAIL EXTRACTED PROCESS
        String pattern = "\\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b";
        Set<String> emails = new HashSet<>();
        String[][] extracted={};
        int totalMails=0;
        // HERE WE START PROCESSING
        if(urls!=null && urls.length>0){
            extracted=new String[urls.length][];
            // Now lets extract mails
            Pattern pat = Pattern.compile(pattern);
            // Now lets loop
            for(int i=0; i<urls.length; i++){
                emails=parse(urls[i], pat);
                int key=0;
                if(emails.size()>0){
                    for(String email:emails){
                        extracted[i][key]=email;
                        key++;
                    } // end of loop
                }
            } // end of loop

            // HERE WE CHECK EXTRACTED LENGTH
            for(int j=0; j<extracted.length; j++){
                totalMails=totalMails+extracted[j].length;
            } // end of loop

            System.out.println(totalMails);
        }

        // Here we return
        return Integer.valueOf(totalMails);
    }


    /********* HERE WE START CONSTRUCTING THE PARSE FUNCTIONS **********/
    public Set<String> parse(String url, Pattern pat){
        // HERE WE CONSTRUCT THE EMAIL PARSER PROCESS
        Set<String> emailAddresses = new HashSet<>();
        boolean found=false;
        String contents="";
        // HERE WE START PROCESSING
        if(url!=null){
            contents=urlContent(url);
            if(contents.length()>0 && contents.indexOf("body")>=0){
                // Pattern pat = Pattern.compile(pattern);
                //Matches contents against the given Email Address Pattern
                Matcher match = pat.matcher(contents);
                found=match.find();
                //If match found, append to emailAddresses
                System.out.println("I found this: "+found);
                while(found) {
                    emailAddresses.add(match.group());
                } // end of while loop
            }
        }

        // Here we return
        return emailAddresses;
    }


    // HERE WE READ URL CONTENT TO STRING
        private String urlContent(String url){
            // HERE WE CONSTRUCT THE URL CONTENT RETURNER
            String content="";
            Document doc=null;
            String sUrl="";
            // HERE WE START PROCESSING
            try {
                SSLContext sc = null;

                // LETS DISABLE SSL CERTIFICATE
                // Create a trust manager that does not validate certificate chains
                TrustManager[] trustAllCerts = new TrustManager[] {new X509TrustManager() {
                        public java.security.cert.X509Certificate[] getAcceptedIssuers() {
                            return null;
                        }
                        public void checkClientTrusted(X509Certificate[] certs, String authType) {
                        }
                        public void checkServerTrusted(X509Certificate[] certs, String authType) {
                        }
                    }
                };

                try {
                    sc = SSLContext.getInstance("SSL");
                } catch (NoSuchAlgorithmException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                try {
                    sc.init(null, trustAllCerts, new java.security.SecureRandom());
                } catch (KeyManagementException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());

                // Create all-trusting host name verifier
                HostnameVerifier allHostsValid = new HostnameVerifier() {
                    public boolean verify(String hostname, SSLSession session) {
                        return true;
                    }
                };

                // Install the all-trusting host verifier
                HttpsURLConnection.setDefaultHostnameVerifier(allHostsValid);

                // HERE WE START CRAWLING
                if(url.startsWith("http")){
                    Connection con=Jsoup.connect(url).timeout(100000).ignoreHttpErrors(true).followRedirects(true).userAgent("Mozilla/5.0(compactible;Googlebot/2.1;+http://www.google.com/bot.html)");
                    Connection.Response resp = con.execute();
                    // HERE WE CHECK RESPONSE CODE
                    if (resp.statusCode() == 200) {
                        doc = con.get();
                        // Now lets get the text document
                        content=doc.html();
                    } // End of status check
                    else if(resp.statusCode() == 307){
                        String sNewUrl = resp.header("Location");
                        if (sNewUrl != null && sNewUrl.length() > 7)
                            sUrl = sNewUrl;
                        resp = Jsoup.connect(sUrl).timeout(100000).ignoreHttpErrors(true).userAgent("Mozilla/5.0(compactible;Googlebot/2.1;+http://www.google.com/bot.html)").execute();
                        doc =resp.parse();
                        // Now lets get the text document
                        content=doc.html();
                    } // End of status 307 check
                } // end of start with check
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            // Here we return
            return content;
        }



        /************* HERE WE CONSTRUCT INNER CLASS TO HANDLE THREAD *****************/
        public static final class Extractor implements Callable<Integer>{
            // HERE WE CONSTRUCT CLASS
            String[] Urls;
            TestingMail Extract;
            public Extractor(String[] urls, TestingMail extract){
                Urls=urls;
                Extract=extract;
            }

            /*********** HERE WE CALL THE CALLABLE ***********/
            @Override
            public Integer call() throws Exception {
                try {
                    return Extract.mailExtract(Urls);
                } catch (Throwable t) {
                    t.printStackTrace();
                    throw new RuntimeException(t);
                }
            }

            // END OF CLASS
        }

    // END OF CLASS
}

我添加了一些print语句来监视这个过程，但我一直得到的java模式匹配结果都是false。

这是我的控制台中的

代码语言：javascript
复制
52
0==0
0==1
0==2
0==3
0==4
0==5
0==6
0==7
0==8
Thread: 5 Extracted Mails: 0
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
java.lang.NullPointerException
    at system.soft.processor.MailExtractor.mailExtract(MailExtractor.java:202)
    at system.soft.processor.MailExtractor.access$0(MailExtractor.java:172)
    at system.soft.processor.MailExtractor$Extractor.call(MailExtractor.java:239)
    at system.soft.processor.MailExtractor$Extractor.call(MailExtractor.java:1)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
java.lang.NullPointerException
    at system.soft.processor.MailExtractor.mailExtract(MailExtractor.java:202)
    at system.soft.processor.MailExtractor.access$0(MailExtractor.java:172)
    at system.soft.processor.MailExtractor$Extractor.call(MailExtractor.java:239)
    at system.soft.processor.MailExtractor$Extractor.call(MailExtractor.java:1)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
java.lang.NullPointerException
    at system.soft.processor.MailExtractor.mailExtract(MailExtractor.java:202)
    at system.soft.processor.MailExtractor.access$0(MailExtractor.java:172)
    at system.soft.processor.MailExtractor$Extractor.call(MailExtractor.java:239)
    at system.soft.processor.MailExtractor$Extractor.call(MailExtractor.java:1)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
java.lang.NullPointerException
    at system.soft.processor.MailExtractor.mailExtract(MailExtractor.java:202)
    at system.soft.processor.MailExtractor.access$0(MailExtractor.java:172)
    at system.soft.processor.MailExtractor$Extractor.call(MailExtractor.java:239)
    at system.soft.processor.MailExtractor$Extractor.call(MailExtractor.java:1)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b
java.lang.NullPointerException
    at system.soft.processor.MailExtractor.mailExtract(MailExtractor.java:202)
    at system.soft.processor.MailExtractor.access$0(MailExtractor.java:172)
    at system.soft.processor.MailExtractor$Extractor.call(MailExtractor.java:239)
    at system.soft.processor.MailExtractor$Extractor.call(MailExtractor.java:1)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

我似乎不能理解为什么我没有收到电子邮件，至少有一个以上的网站在页脚包含一个支持电子邮件，但我的代码似乎无法获得它。我甚至将我的表达式更改为：\ba-zA-Z0-9.-+@a-zA-Z0-9.-+.a-zA-Z0-9.-+\b，但结果相同。我不知道丢失了什么，也不知道为什么表达式不起作用。

我们将非常感谢您的帮助。

java
regex
pattern-matching
jsoup
EN

回答 4

Stack Overflow用户

回答已采纳

发布于 2018-08-04 03:31:04

对于任何编程问题来说，最有用的一个特性就是Minimal, Complete, and Verifiable example。这里有一个解决你的问题的方法：

代码语言：javascript
复制
import java.util.regex.*;
class Test {
  public static void main(String[] args) {
    Pattern pat = Pattern.compile("\\\\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\\\.[a-zA-Z0-9.-]+\\\\b");
    Matcher match = pat.matcher("<li>email@example.com</li>");
    System.out.println("I found this: "+ match.find() + " with expression: " + pat);
  }
}

它要短得多，但输出结果与您的代码相同：

代码语言：javascript
复制
I found this: false with expression: \\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b

它的问题是反斜杠是双重转义的。下面是没有额外转义的版本：

代码语言：javascript
复制
import java.util.regex.*;
class Test {
  public static void main(String[] args) {
    Pattern pat = Pattern.compile("\\b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z0-9.-]+\\b");
    Matcher match = pat.matcher("<li>info@napoleoninvestment.net</li>");
    System.out.println("I found this: "+ match.find() + " with expression: " + pat);
  }
}

下面是输出，现在显示了一个匹配：

代码语言：javascript
复制
I found this: true with expression: \b[a-zA-Z0-9.-]+@[a-zA-Z0-9.-]+\.[a-zA-Z0-9.-]+\b

不幸的是，我不知道如何将其应用到您的代码中，因为您没有包含定义pattern的部分。最有可能的是，这是由于混淆了代码的哪一层需要什么样的转义。例如，将Java字符串文字复制粘贴到文件中将不会在回读时产生相同的字符串文字，因为一个是Java语法，一个是原始数据，而后者不需要或不允许转义。

票数 2
EN

Stack Overflow用户

发布于 2018-08-04 03:38:06

您的正则表达式“很好”，一般来说，您的代码适合我。它下载一个页面，并在几处更正后找到电子邮件。您下载的页面内容中一定有某些内容。尝试显示您下载的页面的HTML，以确保您得到正确的响应。

无论如何，这里有几个错误：

  • 不要为每个网页编译电子邮件正则表达式模式。只编译一次并重用它。
  • 不要调用matcher.find()两次。每次你调用它时，它都会移动到下一个匹配，所以你会跳过每隔一次的电子邮件。调用它一次，然后赋值给变量。然后，根据需要多次使用此变量。
  • 您的模式没有任何匹配组"()"，但您正在调用matcher.group(1)。这将导致异常。请改用matcher.group()。
票数 1
EN

Stack Overflow用户

发布于 2018-08-04 02:51:15

听起来您的正则表达式并没有像您想象的那样工作。

我想你要找的正则表达式是这样的

代码语言：javascript
复制
"\A[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@
(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\z"

来源：email regex

票数 0
EN
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：

https://stackoverflow.com/questions/51678442

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