Introduction to Twitter4J – Twitter4J简介

最后修改: 2017年 3月 11日

1. Overview

1.概述。

In this article, we will have a look at using Twitter4J in a Java application to communicate with Twitter.

在这篇文章中，我们将看看如何在Java应用程序中使用Twitter4J来与Twitter通信。

2. Twitter4J

2.Twitter4J

Twitter4J is an open source Java library, which provides a convenient API for accessing the Twitter API.

Twitter4J是一个开源的Java库，它为访问Twitter API提供了方便的API。

Simply put, here’s how we can interact with the Twitter API; we can:

简单地说，这里我们可以与Twitter的API进行互动；我们可以。

  • Post a tweet
  • Get timeline of a user, with a list of latest tweets
  • Send and receive direct messages
  • Search for tweets and much more

This library ensures that we can easily do these operations, and it also ensures the security and privacy of a user – for which we naturally need to have OAuth credentials configured in our app.

这个库确保我们可以很容易地进行这些操作，它也确保了用户的安全和隐私–为此我们自然需要在我们的应用程序中配置OAuth凭证。

3. Maven Dependencies

3.Maven的依赖性。

We need to start by defining the dependency for Twitter4J in our pom.xml:

我们需要先在pom.xml中定义Twitter4J的依赖关系。

<dependency>
    <groupId>org.twitter4j</groupId>
    <artifactId>twitter4j-stream</artifactId>
    <version>4.0.6</version>
</dependency>

To check if any new version of the library has been released – track the releases here.

要检查库的任何新版本是否已经发布–跟踪这里的发布情况。

4. Configuration

4.配置。

Configuring Twitter4J is easy and can be done in various ways – for example in a plain text file or a Java class or even using environment variables.

配置Twitter4J很简单，可以通过各种方式进行–例如在一个纯文本文件或一个Java类中，甚至使用环境变量。

Let’s look at each of these ways, one at a time.

让我们逐一看一下这些方式。

4.1. Plain Text File

4.1.纯文本文件。

We can use a plain text file – named twitter4j.properties – to hold our configuration details. Let’s look at the properties which need to be provided:

我们可以使用一个纯文本文件–名为twitter4j.properties–来保存我们的配置细节。让我们来看看需要提供的属性。

oauth.consumerKey =       // your key
oauth.consumerSecret =    // your secret
oauth.accessToken =       // your token
oauth.accessTokenSecret = // your token secret

All these attributes can be obtained from Twitter Developer console after you make a new app.

所有这些属性都可以在你制作一个新的应用程序之后从Twitter开发者控制台获得。

4.2. Java Class

4.2. Java类

We can also use a ConfigurationBuilder class to configure Twitter4J programmatically in Java:

我们还可以使用ConfigurationBuilder类来在Java中以编程方式配置Twitter4J。

ConfigurationBuilder cb = new ConfigurationBuilder();
cb.setDebugEnabled(true)
  .setOAuthConsumerKey("your consumer key")
  .setOAuthConsumerSecret("your consumer secret")
  .setOAuthAccessToken("your access token")
  .setOAuthAccessTokenSecret("your access token secret");
TwitterFactory tf = new TwitterFactory(cb.build());
Twitter twitter = tf.getInstance();

Note that we’ll be using the Twitter instance in next section – when we start to fetch data.

注意，我们将在下一节使用Twitter实例–当我们开始获取数据时。

4.3. Environment Variables

4.3.环境变量。

Configuring through environment variables is another choice we have. If we do that, note that we’ll need a twitter4j prefix in our variables:

通过环境变量进行配置是我们的另一个选择。如果我们这样做，请注意我们的变量中需要有twitter4j前缀。

$ export twitter4j.oauth.consumerKey =       // your key
$ export twitter4j.oauth.consumerSecret =    // your secret
$ export twitter4j.oauth.accessToken =       // your access token
$ export twitter4j.oauth.accessTokenSecret = // your access token secret

5. Adding / Retrieving Real-Time Tweet Data

5.添加/检索实时推特数据。

With a fully configured application, we can finally interact with Twitter.

有了一个完全配置好的应用程序，我们终于可以与Twitter互动了。

Let’s look at few examples.

让我们看看几个例子。

5.1. Post a Tweet

5.1.发布推文。

We’ll start by updating a tweet on Twitter:

我们先在推特上更新一条推文。

public String createTweet(String tweet) throws TwitterException {
    Twitter twitter = getTwitterinstance();
    Status status = twitter.updateStatus("creating baeldung API");
    return status.getText();
}

By using status.getText(), we can retrieve the tweet just posted.

通过使用status.getText()，我们可以检索到刚刚发布的tweet。

5.2. Get the Timeline

5.2.获取时间线。

We can also fetch a list of tweets from the user’s timeline:

我们还可以从用户的时间轴上获取推文列表。

public List<String> getTimeLine() throws TwitterException {
    Twitter twitter = getTwitterinstance();
    
    return twitter.getHomeTimeline().stream()
      .map(item -> item.getText())
      .collect(Collectors.toList());
}

By using twitter.getHomeTimeline(), we get all tweets posted by the current account ID.

通过使用twitter.getHomeTimeline()，我们得到了当前账户ID发布的所有推文。

5.3. Send a Direct Message

5.3.发送直接信息。

Sending and receiving a direct message to followers is also possible using the Twitter4j:

使用Twitter4j也可以向追随者发送和接收直接信息。

public static String sendDirectMessage(String recipientName, String msg) 
  throws TwitterException {
 
    Twitter twitter = getTwitterinstance();
    DirectMessage message = twitter.sendDirectMessage(recipientName, msg);
    return message.getText();
}

The sendDirectMessage method takes two parameters:

sendDirectMessage方法需要两个参数。

  • RecipientName: the twitter username of a message recipient
  • msg: message content

If recipient will not be found, the sendDirectMessage will throw an exception with exception code 150.

如果找不到收件人，sendDirectMessage将抛出一个异常代码150。

5.4. Search for Tweets

5.4.搜索推文</strong

We can also search for tweets containing some text. By doing this, we’ll get a list of tweets with the username of users.

我们还可以搜索包含一些文字的推文。通过这样做，我们会得到一个带有用户用户名的推文列表。

Let’s see how such a search can be performed:

让我们看看如何进行这样的搜索。

public static List<String> searchtweets() throws TwitterException {
 
    Twitter twitter = getTwitterinstance();
    Query query = new Query("source:twitter4j baeldung");
    QueryResult result = twitter.search(query);
    
    return result.getTweets().stream()
      .map(item -> item.getText())
      .collect(Collectors.toList());
}

Clearly, we can iterate over each tweet received in a QueryResult and fetch relative data.

显然，我们可以在QueryResult中迭代收到的每条tweet，并获取相对数据。

5.5. The Streaming API

5.5.流媒体API</strong

Twitter Streaming API is useful when updates are required in real-time; it handles thread creation and listens to events.

Twitter Streaming API在需要实时更新时非常有用；它可以处理线程创建和监听事件。

Let’s create a listener which listens to tweet updates from a user:

让我们创建一个监听器，监听来自用户的推特更新。

public static void streamFeed() {

    StatusListener listener = new StatusListener() {

        @Override
        public void onException(Exception e) {
            e.printStackTrace();
        }
        @Override
        public void onDeletionNotice(StatusDeletionNotice arg) {
        }
        @Override
        public void onScrubGeo(long userId, long upToStatusId) {
        }
        @Override
        public void onStallWarning(StallWarning warning) {
        }
        @Override
        public void onStatus(Status status) {
        }
        @Override
        public void onTrackLimitationNotice(int numberOfLimitedStatuses) {
        }
    };

    TwitterStream twitterStream = new TwitterStreamFactory().getInstance();

    twitterStream.addListener(listener);

    twitterStream.sample();
}

We can put some println() statement to check the output tweet stream in all of the methods. All tweets have location metadata associated with it.

我们可以在所有的方法中放入一些println()语句来检查输出的tweet流。所有推文都有与之相关的位置元数据。

Please note that all the tweets data fetched by the API are in the UTF-8 format and since Twitter is a multi-language platform, some data format may be unrecognizable based upon its origin.

请注意，由API获取的所有推文数据都是UTF-8格式，由于Twitter是一个多语言平台，一些数据格式可能根据其来源而无法识别。

6. Conclusion

6.结论。

This article was a quick but comprehensive introduction to using Twitter4J with Java.

这篇文章是对用Java使用Twitter4J的快速但全面的介绍。

The implementation of shown examples can be found on GitHub – this is a Maven based project, so it should be easy to import and run as it is. The only change we need to do is to insert our own OAuth credentials.

所示示例的实现可以在GitHub上找到 – 这是一个基于Maven的项目，所以应该很容易导入并按原样运行。我们需要做的唯一改变是插入我们自己的OAuth凭证。