クライアントがサーバーから2つの文字列を受け取り、独自の文字列で応答する必要がある2プレーヤーゲームを作成しています。ここでは、内部処理は関係ありません。重要なのは、サーバーからデータを送信するたびに、クライアントの1つがsetText（）関数に対してNullPointerExceptionを表示することです。私の大学の他の誰もその理由を知らないので、私は困惑しています。この問題の解決にご協力ください。コードは次のとおりです（IDEはNetBeans 7.3.1です）。
サーバ
public class TCPServer {
public static void main(String argv[]) throws Exception {
String childWord, childWord2;
Trie1 obj = new Trie1();
obj.loadTrie();
ServerSocket welcomeSocket = new ServerSocket(6759);
ServerSocket welcomeSocket2 = new ServerSocket(6559);
//BufferedReader dd = new BufferedReader(new InputStreamReader(System.in));
String parentWord;
while (true) {
Socket connectionSocket = welcomeSocket.accept();
Socket connectionSocket2 = welcomeSocket2.accept();
//parentWord = dd.readLine();
parentWord = GlobalStuff.word;
System.out.println("word: "+parentWord);
BufferedReader inFromClient =
new BufferedReader(new InputStreamReader(connectionSocket.getInputStream()));
DataOutputStream outToClient =
new DataOutputStream(connectionSocket.getOutputStream());
BufferedReader inFromClient2 =
new BufferedReader(new InputStreamReader(connectionSocket2.getInputStream()));
DataOutputStream outToClient2 =
new DataOutputStream(connectionSocket2.getOutputStream());
outToClient.writeBytes(parentWord + "\n");
outToClient2.writeBytes(parentWord + "\n");
outToClient.writeBytes(GlobalStuff.sentence + "\n");
outToClient2.writeBytes(GlobalStuff.sentence + "\n");
childWord = inFromClient.readLine();
childWord2 = inFromClient2.readLine();
/*System.out.println(childWord);
System.out.println(childWord2);*/
//System.out.println(clientSentence);
if (childWord.equals(childWord2)) {
System.out.println("The suggestions match!!");
obj.Trie1Main(parentWord, childWord);
} else {
System.out.println("The suggestions DO NOT match...the users entered:");
System.out.println(childWord+" and "+childWord2);
}
}
}
}
クライアント：
package clientserver;
import markI.*;
import sessionmanager.*;
import java.io.*;
import java.net.*;
public class Player1 extends javax.swing.JFrame {
private static Socket clientSocket;
private static BufferedReader inFromUser;
private static DataOutputStream outToServer;
private static BufferedReader inFromServer;
private static String modifiedSentence;
private static String modifiedWord;
/**
* Creates new form TestFrameOne
*/
public Player1() {
initComponents();
}
//user defined
private void initComponents() {
tlabel = new javax.swing.JLabel();
ilabel = new javax.swing.JLabel();
totalScore = new javax.swing.JLabel();
wordtf = new javax.swing.JTextField();
submit = new javax.swing.JButton();
close = new javax.swing.JButton();
round = new javax.swing.JLabel();
opponent = new javax.swing.JLabel();
hword = new javax.swing.JLabel();
timeLeft = new javax.swing.JLabel();
points = new javax.swing.JLabel();
jButton1 = new javax.swing.JButton();
jScrollPane1 = new javax.swing.JScrollPane();
sentenceArea = new javax.swing.JTextArea();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
tlabel.setFont(new java.awt.Font("Trebuchet MS", 1, 24)); // NOI18N
tlabel.setForeground(new java.awt.Color(51, 0, 255));
tlabel.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
tlabel.setText("WORD KING");
ilabel.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
ilabel.setIcon(new javax.swing.ImageIcon(getClass().getResource("/markI/crown_low.png"))); // NOI18N
totalScore.setFont(new java.awt.Font("Trebuchet MS", 1, 16)); // NOI18N
totalScore.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
totalScore.setText("0");
totalScore.setBorder(javax.swing.BorderFactory.createTitledBorder("Net Score"));
wordtf.setFont(new java.awt.Font("Trebuchet MS", 0, 14)); // NOI18N
wordtf.setBorder(javax.swing.BorderFactory.createTitledBorder("Alternate Word"));
submit.setBackground(new java.awt.Color(102, 0, 255));
submit.setFont(new java.awt.Font("Tahoma", 1, 14)); // NOI18N
submit.setText("Submit");
submit.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
submitActionPerformed(evt);
}
});
close.setText("X");
close.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
closeActionPerformed(evt);
}
});
round.setFont(new java.awt.Font("Trebuchet MS", 1, 16)); // NOI18N
round.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
round.setText("0");
round.setBorder(javax.swing.BorderFactory.createTitledBorder("Round"));
opponent.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
opponent.setIcon(new javax.swing.ImageIcon(getClass().getResource("/markI/face_low.jpg"))); // NOI18N
opponent.setBorder(javax.swing.BorderFactory.createTitledBorder("OPPONENT"));
hword.setFont(new java.awt.Font("Trebuchet MS", 1, 18)); // NOI18N
hword.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
hword.setBorder(javax.swing.BorderFactory.createTitledBorder("Highlighted Word"));
timeLeft.setFont(new java.awt.Font("Trebuchet MS", 1, 16)); // NOI18N
timeLeft.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
timeLeft.setText("30");
timeLeft.setBorder(javax.swing.BorderFactory.createTitledBorder("Time"));
points.setFont(new java.awt.Font("Trebuchet MS", 1, 16)); // NOI18N
points.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
points.setText("0");
points.setBorder(javax.swing.BorderFactory.createTitledBorder("Points"));
jButton1.setBackground(new java.awt.Color(102, 0, 255));
jButton1.setFont(new java.awt.Font("Tahoma", 1, 14)); // NOI18N
jButton1.setText("Leave Game");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
sentenceArea.setColumns(20);
sentenceArea.setRows(5);
sentenceArea.setText("The quick brown fox jumps over a lazy dog.");
sentenceArea.setBorder(javax.swing.BorderFactory.createTitledBorder("Sentence"));
jScrollPane1.setViewportView(sentenceArea);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
.addComponent(jScrollPane1, javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.LEADING, layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
.addComponent(hword, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(wordtf, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, 230, Short.MAX_VALUE))
.addGroup(layout.createSequentialGroup()
.addGap(55, 55, 55)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(ilabel)
.addComponent(tlabel))))
.addGap(18, 18, 18)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addGroup(layout.createSequentialGroup()
.addComponent(points, javax.swing.GroupLayout.PREFERRED_SIZE, 70, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addComponent(timeLeft, javax.swing.GroupLayout.PREFERRED_SIZE, 70, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createSequentialGroup()
.addComponent(round, javax.swing.GroupLayout.PREFERRED_SIZE, 70, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addComponent(totalScore, javax.swing.GroupLayout.PREFERRED_SIZE, 70, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addGroup(layout.createSequentialGroup()
.addComponent(opponent)
.addGap(18, 18, 18)
.addComponent(close)))))
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
.addGroup(layout.createSequentialGroup()
.addGap(21, 21, 21)
.addComponent(submit, javax.swing.GroupLayout.PREFERRED_SIZE, 113, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 115, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(35, 35, 35))))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addGap(29, 29, 29)
.addComponent(opponent))
.addGroup(layout.createSequentialGroup()
.addGap(18, 18, 18)
.addComponent(close)))
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addComponent(ilabel)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(tlabel)))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 32, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(hword, javax.swing.GroupLayout.PREFERRED_SIZE, 48, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(round)
.addComponent(totalScore))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(points)
.addComponent(timeLeft)
.addComponent(wordtf, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(submit, javax.swing.GroupLayout.PREFERRED_SIZE, 38, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 38, javax.swing.GroupLayout.PREFERRED_SIZE))
.addContainerGap())
);
pack();
}// </editor-fold>
private void submitActionPerformed(java.awt.event.ActionEvent evt) {
//wordtf.setText(modifiedSentence);
try {
String sentence = wordtf.getText();
System.out.println(sentence);
outToServer.writeBytes(sentence + '\n');
clientSocket.close();
} catch (Exception e) {
System.out.println("Some error through submit button.\n" + e.getMessage());
}
}
private void closeActionPerformed(java.awt.event.ActionEvent evt) {
System.exit(WIDTH); // TODO add your handling code here:
}
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
this.setVisible(false);
sessionmanager.WelcomePage.main(null);
}
/**
* @param args the command line arguments
*/
public static void main(String args[]) throws Exception {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(TestFrameOne.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(TestFrameOne.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(TestFrameOne.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(TestFrameOne.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Player1().setVisible(true);
}
});
//Start clientserver
inFromUser = new BufferedReader(new InputStreamReader(System.in));
clientSocket = new Socket("172.16.30.183", 6759);
//clientSocket = new Socket("172.16.38.156", 6759);
outToServer = new DataOutputStream(clientSocket.getOutputStream());
inFromServer = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
modifiedWord = inFromServer.readLine();
System.out.println("FROM SERVER: word " + modifiedWord);
hword.setText(modifiedWord);
modifiedSentence = inFromServer.readLine();
System.out.println("FROM SERVER: sentence " + modifiedSentence);
sentenceArea.setText(modifiedSentence);
//End clientserver
}
// Variables declaration - do not modify
private javax.swing.JButton close;
public static javax.swing.JLabel hword;
private javax.swing.JLabel ilabel;
private javax.swing.JButton jButton1;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JLabel opponent;
private javax.swing.JLabel points;
private javax.swing.JLabel round;
public static javax.swing.JTextArea sentenceArea;
private javax.swing.JButton submit;
private javax.swing.JLabel timeLeft;
private javax.swing.JLabel tlabel;
private javax.swing.JLabel totalScore;
public static javax.swing.JTextField wordtf;
// End of variables declaration
}
クライアントが正しく実行されている場合、これが出力になるはずです
エラーメッセージの272行目はhword.setText（modifiedWord）です。
つまり、このメソッドを呼び出す前に、それが初期化されていることを確認する必要hwordがnullあります。
GUIの更新は、いずれの場合もGUIスレッドで実行する必要があります。更新を実行するタスクを送信することをお勧めします。このようにして、使用するまでに初期化する必要があります。
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
hword.setText(modifiedWord);
}
});
ただし、静的フィールドを設定する代わりに、Player1インスタンスでこのメソッドを呼び出す必要があります。コンストラクターで静的フィールドを初期化するべきではありません。
Player1 player1 = new Player1();
EventQueue.invokeLater(() -> player1.setVisible(true));
EventQueue.invokeLater(() -> player1.setHwordText(modifiedWord));
このように、静的フィールドは必要ありません。
この記事はインターネットから収集されたものであり、転載の際にはソースを示してください。
侵害の場合は、連絡してください[email protected]
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