Question

我试图将所有搜索结果显示在网页中，但无法这样做。

TwitterCrawlServlet.java

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        ConfigurationBuilder cb = new ConfigurationBuilder();
        cb.setDebugEnabled(true)
              .setOAuthConsumerKey("xxx")
              .setOAuthConsumerSecret("xxx")
              .setOAuthAccessToken("xxx")
              .setOAuthAccessTokenSecret("xxx");
        TwitterFactory tf = new TwitterFactory(cb.build());
        Twitter twitter = tf.getInstance();
            try {
                Query query = new Query("Cocaine");
                QueryResult result;
                result = twitter.search(query);
                List<Status> tweets = result.getTweets();
                for (Status tweet : tweets) {
                    System.out.println("@" + tweet.getUser().getScreenName() + " - " + tweet.getText());
                }

                System.exit(0);
            } catch (TwitterException te) {
                te.printStackTrace();
                System.out.println("Failed to search tweets: " + te.getMessage());
                System.exit(-1);
            }

我的index.html

<!DOCTYPE html>
<html>
  <head>
    <meta http-equiv="Content-type" content="text/html; charset=utf-8">
    <title>Stock Analysis Using Hadoop Framework</title>
  </head>
  <body>
    <form action ="TwitterCrawlServlet">
        <input type="submit" value="send"/>
    </form>
  </body>
</html>

我的web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>FinalYearProject</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
  </welcome-file-list>
  <servlet>
    <description></description>
    <display-name>TwitterCrawlServlet</display-name>
    <servlet-name>TwitterCrawlServlet</servlet-name>
    <servlet-class>com.fyp.pkg.TwitterCrawlServlet</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>TwitterCrawlServlet</servlet-name>
    <url-pattern>/TwitterCrawlServlet</url-pattern>
  </servlet-mapping>
</web-app>

我能够成功运行TwitterCrawlServlet的代码作为单独的Java应用程序。当我试图在Tomcat上运行它时。它显示HTTP Status 500

Logs on my browser

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: Error instantiating servlet class com.fyp.pkg.TwitterCrawlServlet
    org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:562)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:395)
    org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:250)
    org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:188)
    org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302)
    java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    java.lang.Thread.run(Thread.java:745)
root cause

java.lang.NoClassDefFoundError: twitter4j/TwitterException
    java.lang.Class.getDeclaredConstructors0(Native Method)
    java.lang.Class.privateGetDeclaredConstructors(Class.java:2595)
    java.lang.Class.getConstructor0(Class.java:2895)
    java.lang.Class.newInstance(Class.java:354)
    org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:562)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:395)
    org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:250)
    org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:188)
    org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302)
    java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    java.lang.Thread.run(Thread.java:745)
root cause

java.lang.ClassNotFoundException: twitter4j.TwitterException
    org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1676)
    org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1521)
    java.lang.Class.getDeclaredConstructors0(Native Method)
    java.lang.Class.privateGetDeclaredConstructors(Class.java:2595)
    java.lang.Class.getConstructor0(Class.java:2895)
    java.lang.Class.newInstance(Class.java:354)
    org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:562)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:395)
    org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:250)
    org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:188)
    org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302)
    java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    java.lang.Thread.run(Thread.java:745)

My twitter4j classpath

Answer 1

删除

System.exit（0）;

从

更改for循环

for (Status tweet : tweets) {
                System.out.println("@" + tweet.getUser().getScreenName() + " - " + tweet.getText());
            }

要

PrintWriter writer = response.getWriter();
for (Status tweet : tweets) {
                System.out.println("@" + tweet.getUser().getScreenName() + " - " + tweet.getText());
                writer.write("@" + tweet.getUser().getScreenName() + " - " + tweet.getText());  

writer.flush();
                }
writer.close();

无法使用Twitter4j运行搜索推文

1 个答案: