【发布时间】：2019-04-21 22:41:43
【问题描述】：
我的应用程序的一部分无法按我的意愿正常工作，我有一个类似于日志的 java fx listview，我正在尝试用它创建一个简单的日志。看代码，
我尝试添加一个任务，该任务每秒钟使用“writeLog”函数写入一个日志并且它工作（列表视图使用新字符串正确刷新）。第二个代码是相同的，但没有任务，它不像我想要的那样工作，在这种情况下 writeLog 将被其他类调用。 当从其他类调用 writeLog("any string..") 时，Observable 列表将正确更改，文件 ( log ) 也会更改，但列表视图不想显示添加到日志的新字符串。
public class ControllerServer implements Initializable {
@FXML
public ListView myListView;
private ObservableList<String> logList = FXCollections.observableArrayList();
@Override
public void initialize(URL location, ResourceBundle resources) {
try {
fillLogList();
MyTask task = new MyTask();
Timer timer = new Timer(true);
timer.scheduleAtFixedRate(task,4000,4000);
} catch (IOException e) {
e.printStackTrace();
}
if (logList!= null) {
for (int i = 0; i < logList.size(); i++) {
System.out.println(logList.get(i));
}
logList.addListener((javafx.beans.Observable observable)->{
System.out.println("changed list");
});
}
myListView.setItems(logList);
}
//METHODS
public void fillLogList() throws IOException {
BufferedReader reader = new BufferedReader(new FileReader("samplefile1.txt"));
String line;
while((line = reader.readLine())!=null) {
logList.add(line);
}
}
public void writeLog(String log) throws IOException {
BufferedWriter writer = new BufferedWriter(new FileWriter("samplefile1.txt", true));
writer.write(log);
if(logList!=null){
logList.add(log);
System.out.println("i'm writing this log inside the file, log say : " + log);
}else
writer.newLine();
writer.close();
}
class MyTask extends TimerTask {
@Override
public void run(){
try {
writeLog("Hello, i'm working inside this task, why?");
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
public class ControllerServer implements Initializable {
@FXML
public ListView myListView;
private ObservableList<String> logList = FXCollections.observableArrayList();
@Override
public void initialize(URL location, ResourceBundle resources) {
try {
fillLogList();
} catch (IOException e) {
e.printStackTrace();
}
if (logList!= null) {
for (int i = 0; i < logList.size(); i++) {
System.out.println(logList.get(i));
}
logList.addListener((javafx.beans.Observable observable)->{
System.out.println("changed list");
});
}
myListView.setItems(logList);
}
//METHODS
public void fillLogList() throws IOException {
BufferedReader reader = new BufferedReader(new FileReader("samplefile1.txt"));
String line;
while((line = reader.readLine())!=null) {
logList.add(line);
}
}
public void writeLog(String log) throws IOException {
BufferedWriter writer = new BufferedWriter(new FileWriter("samplefile1.txt", true));
writer.write(log);
if(logList!=null){
logList.add(log);
System.out.println("i'm writing this log inside the file, log say : " + log);
}else
writer.newLine();
writer.close();
}
}
public class Server extends Application {
private static ServerLog serverLog = new ServerLog();
private static ControllerServer controllerServer = new ControllerServer();
public static void main(String[] args) throws IOException {
Runnable r = () -> {
new File("users").mkdir();
try {
ServerSocket socket = new ServerSocket(8189);
while(true) {
Socket s = socket.accept();
ServiceHandler client = new ServiceHandler(s);
}
}catch(IOException e){e.printStackTrace();}
};
new Thread(r).start();
controllerServer.writeLog("server starting..");
launch(args);
}
@Override
public void start(Stage primaryStage) throws Exception {
Parent root = FXMLLoader.load(getClass().getResource("View/server.fxml"));
primaryStage.setScene(new Scene(root, 800, 600));
primaryStage.setTitle("Server Log");
primaryStage.show();
}
}
package server;
import server.Controller.ControllerServer;
import server.Model.*;
import java.io.*;
import java.net.Socket;
import static common.ServiceID.*;
import static common.ServiceID.FAILURE_RESPONSE;
public class ServiceHandler extends Thread{
private static Object lock = new Object();
private static ServerLog serverLog = new ServerLog();
private static ControllerServer controllerServer = new ControllerServer();
private Socket s;
public ServiceHandler(Socket s){
this.s = s;
this.start();
}
public void run()
{
try
{
controllerServer.writeLog("client address "+s.getInetAddress());
InputStream inputStream = s.getInputStream();
int servId = inputStream.read();
OutputStream outputStream = s.getOutputStream();
Thread t;
switch(servId) {
case WRITE_EMAIL:
controllerServer.writeLog("Writing Email, id : " + WRITE_EMAIL);
outputStream.write(SUCCESS_RESPONSE);
t = new Thread(new EmailReceiver(s,lock, servId));
t.start();
break;
case READ_ALL_EMAILS:
controllerServer.writeLog("Loading users list, id : " + READ_ALL_EMAILS);
outputStream.write(SUCCESS_RESPONSE);
t = new Thread(new EmailReader(s));
t.start();
break;
case USER_LIST:
controllerServer.writeLog("Caricamento lista utenti, id : " + USER_LIST);
outputStream.write(SUCCESS_RESPONSE);
t = new Thread(new UserGetter(s));
t.start();
break;
case LOGIN:
controllerServer.writeLog("Login, id " + LOGIN);
outputStream.write(SUCCESS_RESPONSE);
t = new Thread(new UserLogin(s));
t.start();
break;
case DELETE_EMAIL:
controllerServer.writeLog("delete email, id " + DELETE_EMAIL);
outputStream.write(SUCCESS_RESPONSE);
t = new Thread(new EmailDelete(s));
t.start();
break;
default:
controllerServer.writeLog("Error");
outputStream.write(FAILURE_RESPONSE);
break;
}
}
catch(Exception e)
{
e.printStackTrace();
}
}
}
【问题讨论】：
-
您发布的代码无法编译。请附上一个minimal reproducible example，说明您遇到的问题。
-
要显示的类太多了，问题很容易理解，如果我调用controllerServer.writeLog("something...");从我放的最后一个类中，它不会实时刷新我的列表视图，但是如果我在 ServerController 中添加一个任务，在日志中写入自己的内容，列表视图将实时显示新字符串。
-
我不是要你展示你所有的课程。我要求您创建一个minimal reproducible example。该链接将解释它是什么，并提供有关如何创建一个的好技巧。创建 MCVE 的过程通常也会引导您发现问题。
标签： java listview javafx observable observablecollection