我想在做作业方面得到一点帮助。我的方法无法按照我的预期去做。我很确定问题出在nlpClassify（）中，但是我不确定。当前，clpClassify（）只会为变量输出0。欢迎任何建议。
public class TweetHandler implements TweetHandlerInterface {
private Scanner inFile = null;
private String tweet = null;
private String[] temp = null;
private int counter = 0;
List<AbstractTweet> tweetList = new ArrayList<AbstractTweet>();
List<AbstractTweet> dataList = new ArrayList<AbstractTweet>();
List<String[]> dataBaseList = new ArrayList<String[]>();
@Override
public List<AbstractTweet> loadTweetsFromText(String filePath) {
MainApp main = null;
try {
inFile = new Scanner ( new FileReader(filePath));
}
catch( FileNotFoundException er ){
System.err.println(er);
main.printMenu();
}
String line = null;
//String[] data = null;
//int counter = 0;
while ( inFile.hasNextLine() ) {
line = inFile.nextLine();
parseTweetLine(line);
counter++;
}
System.out.println("Reading tweets from file..."
+ "\n" + counter + " tweets read.");
inFile.close();
return tweetList;
}
@Override
public AbstractTweet parseTweetLine(String tweetLine) {
temp = tweetLine.split("\",\"");
tweet = temp[5];
if( temp.length > 6 ){
for( int i = 0; i < temp.length; i++ ){
tweet += " " + temp[i];
}
}
temp[0] = temp[0].replaceAll("\"","");
tweet = tweet.replaceAll("\\p{Punct}", "");
temp[5] = tweet;
int target = Integer.parseInt(temp[0]);
int id = Integer.parseInt(temp[1]);
SimpleDateFormat format = new SimpleDateFormat("EE MMM dd HH:mm:ss zzz yyyy");
Date date = new Date();
try{
date = format.parse(temp[2]);
}
catch( ParseException e ){
System.err.println("Error with date parsing. " + e);
}
String flag = temp[3];
String user = temp[4];
String text = temp[5];
Tweet tweets = new Tweet(target,id,date,flag,user,text);
return tweets;
}
/**
* calls classifyTweet
*/
public void nlpClassify(){ //prints out accuracy
System.out.println("Classifying tweets...");
counter = 0;
int correct = 0,
wrong = 0;
float accuracy = 0.0f;
AbstractTweet tweets;
for( int i = 0; i < tweetList.size(); i++ ){
tweets = tweetList.get(i);
tweets.setPredictedPolarity(classifyTweet(tweets));
int target = tweets.getTarget();
int polarity = tweets.getPredictedPolarity();
System.out.println("Target: " + target );
System.out.println("Prediction: " + polarity );
for( int j = 0; j < 75; j++ ){
System.out.print("=");
}
System.out.println();
if( target == polarity ){
correct++;
}
else{
wrong++;
}
counter++;
accuracy = ( correct / counter ) * 100.0f;
}
System.out.println( "Classified " + counter + " tweets." );
System.out.println( "Correct tweets: " + correct );
System.out.println( "Wrong tweets: " + wrong );
System.out.println( "Accuracy: " + accuracy );
}
@Override
public int classifyTweet(AbstractTweet tweet) {
int calcPolarity = SentimentAnalyzer.getParagraphSentiment( tweet.getText() );
tweet.setPredictedPolarity(calcPolarity);
return calcPolarity;
}
@Override
public void addTweetsToDB(List<AbstractTweet> tweets) {
System.out.println("Adding files to database... ");
int i = 0;
while( i < tweets.size()){
dataList.add(tweets.get(i));
i++;
}
}
@Override
public void deleteTweet(int id) {
int i = 0,
temp = 0;
Tweet obj = null;
while( i < dataList.size() ){
temp = obj.getId();
if( id == temp ){
dataList.remove(i);
--counter;
}
++i;
}
}
@Override
public void saveSerialDB() {
try{
FileOutputStream fileOut = new FileOutputStream("DB.ser");
ObjectOutputStream out = new ObjectOutputStream(fileOut);
out.writeObject(dataList);
out.close();
fileOut.close();
}
catch( IOException e ){
e.printStackTrace();
}
}
@Override
public void loadSerialDB() {
try{
FileInputStream fileIn = new FileInputStream("DB.ser");
ObjectInputStream in = new ObjectInputStream(fileIn);
dataList = (List<AbstractTweet>)in.readObject();
in.close();
fileIn.close();
}
catch( Exception e ){
e.printStackTrace();
}
}
@Override
public List<AbstractTweet> searchByUser(String user) {
int i = 0;
String temp = null;
Tweet obj = null;
while( i < dataList.size() ){
temp = obj.getUser();
if( user.equals(temp) )
dataList.add(obj);
++i;
}
return dataList;
}
忽略searchByUser（String user），我知道这是错误的，还没有解决它。如果您有建议，那也很酷。 这是界面。
public interface TweetHandlerInterface {
/**
* Loads tweets from a CSV text file.
* @param filePath The path to the CSV file.
* @return A list of tweets as objects.
*/
List<AbstractTweet> loadTweetsFromText(String filePath);
/**
* Parses a single line from the CSV file and returns a tweet as an object.
* @param tweetLine A string containing the contents of a single line in the CSV file.
* @return A tweet as an object.
*/
AbstractTweet parseTweetLine(String tweetLine);
/**
* Classifies a tweet as negative, neutral, or positive by using the text of the tweet.
* @param tweet A tweet object.
* @return 0 = negative, 2 = neutral, 4 = positive.
*/
int classifyTweet(AbstractTweet tweet);
/**
* Adds a list of new tweets to the existing database.
* @param tweets A list of tweet objects.
*/
void addTweetsToDB(List<AbstractTweet> tweets);
/**
* It deletes ad tweet from the database, given its id.
* @param id The id value of the tweet.
*/
void deleteTweet(int id);
/**
* Saves the database in the working directory as a serialized object.
*/
void saveSerialDB();
/**
* Loads tweet database.
*/
void loadSerialDB();
/**
* Searches the tweet database by user name. It returns a list of all tweets
* matching the given user name.
* @param user The user name to search for.
* @return A list of tweet objects.
*/
List<AbstractTweet> searchByUser(String user);
/**
* Searches the tweet database for tweets posted on a given date.
* @param date The date to search for.
* @return A list of tweet objects.
*/
List<AbstractTweet> searchByDate(Date date);
/**
* Searches the tweet database for tweets matching a given flag.
* @param flag The flag to search for.
* @return A list of tweet objects.
*/
List<AbstractTweet> searchByFlag(String flag);
/**
* Searches the tweet database for tweets matching a given substring.
* @param substring The substring to search for.
* @return A list of tweet objects.
*/
List<AbstractTweet> searchBySubstring(String substring);
}
这是我的Main（）。
public class MainApp {
public static void main (String[] args){
TweetHandler handler = new TweetHandler();
MainApp obj = new MainApp();
Tweet tweetObj = null;
String choice;
do{
obj.printMenu();
System.out.print("Enter a choice from above: ");
Scanner inputConsole = new Scanner( System.in );
choice = inputConsole.next();
String filePath = null;
switch( choice ){
case "0":
System.exit(0);
break;
case "1":
Scanner file = new Scanner ( System.in );
System.out.print("Enter the input file path: ");
filePath = file.nextLine();
handler.loadTweetsFromText(filePath);
break;
case "2":
handler.classifyTweet(handler.parseTweetLine(filePath));
handler.nlpClassify();
break;
case "3":
System.out.println("Enter ID of the tweet you wish to change: ");
break;
case "4":
System.out.println("Adding tweets to database...");
handler.addTweetsToDB(handler.loadTweetsFromText(filePath));
break;
case "5":
Scanner removeChoice = new Scanner( System.in );
System.out.println("Enter ID of tweet you wish to delete: ");
int remove = removeChoice.nextInt();
handler.deleteTweet(remove);
break;
case "6":
Scanner searching = new Scanner( System.in );
System.out.println("Search by: 1 User, 2 Date, 3 Flag, 4 Substring.");
int search = searching.nextInt();
switch(search){
case 1:
case 2:
case 3:
case 4:
}
break;
}
} while ( !"0".equals(choice) );
}
void printMenu(){
System.out.println("0. Exit program.\n"
+ "1. Load new tweet text file.\n"
+ "2. Classify tweets using NLP library and report accuracy.\n"
+ "3. Manually change tweet class label.\n"
+ "4. Add new tweets to database.\n"
+ "5. Delete tweet from database (given its id).\n"
+ "6. Search tweets by user, date, flag, or a matching substring.\n");
}
}
答案 0 :(得分：0)
您使用tweetList.size()进行循环。您可以打印出tweetList.size()以查看该值。我猜它是0。在您的代码中没有看到任何tweetList.add（obj）。因此tweetList一直都是空的。