JavaFX 2 - ObservableList <message>到TableView </message>

时间：2012-11-01 20:50:09

标签： tableview javafx

希望我能尽可能清楚地回答我的问题。我正在使用JavaFX库为gui开发一个小型Java应用程序。我正在进行POP连接并将消息存储为ObservableList。为此，我使用javax.mail。我将这个observablelist传递给tableview，并且我将以下值传递给TableColumns：

        fromColumn.setCellValueFactory(
            new PropertyValueFactory<Message,String>("from")
        );
        subjectColumn.setCellValueFactory(
            new PropertyValueFactory<Message,String>("subject")
        );
        dateColumn.setCellValueFactory(
            new PropertyValueFactory<Message,String>("sentDate")
        );

主题和sentDate正在完美地读入。但遗憾的是“from”正在向TableColumn添加对象引用，因为Message-Class中的From-Attribute是一个InternetAdress-Object，而它的toString（）方法不会返回一个字符串，但可能是一个引用。结果是从下面显示了以下内容：

[Ljavax.mail.internet.InternetAddress;@3596cd38

有人知道如何在上述专栏中显示InternetAdress的字符串值吗？

先谢谢

3 个答案:

答案 0 :(得分：1)

我认为你需要定义一个自定义单元格值工厂来获取所需格式的地址信息，而不是使用PropertyValueFactory。

以下示例适用于只读表 - 如果表中的消息数据需要可编辑，则解决方案将更加复杂。 

fromColumn.setCellValueFactory(new Callback<CellDataFeatures<Message, String>, ObservableValue<String>>() {
    @Override public ObservableValue<String> call(CellDataFeatures<Message, String> m) {
        // m.getValue() returns the Message instance for a particular TableView row
        return new ReadOnlyObjectWrapper<String>(Arrays.toString(m.getValue().getFrom()));
    }
});

这是一个可执行示例（加上示例数据文件），演示了如何使用自定义单元格值工厂。将示例数据文件放在与应用程序java程序相同的目录中，并确保构建系统将示例文件复制到构建输出目录，该目录包含应用程序的已编译类文件。您将需要路径上的javamail jar文件来编译和运行应用程序。

import java.io.*;
import java.util.Arrays;
import java.util.logging.*;
import javafx.application.Application;
import javafx.beans.property.ReadOnlyObjectWrapper;
import javafx.beans.value.ObservableValue;
import javafx.collections.*;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.control.TableColumn.CellDataFeatures;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.layout.VBox;
import javafx.scene.text.Font;
import javafx.stage.Stage;
import javafx.util.Callback;
import javax.mail.*;
import javax.mail.internet.MimeMessage;

public class MailTableSample extends Application {
  private TableView<Message> table = new TableView<Message>();
  public static void main(String[] args) { launch(args);}

  @Override public void start(Stage stage) {
    stage.setTitle("Table View Sample");

    final Label label = new Label("Mail");
    label.setFont(new Font("Arial", 20));

    table.setEditable(false);

    TableColumn subjectColumn = new TableColumn("Subject");
    subjectColumn.setMinWidth(100);
    subjectColumn.setCellValueFactory(
      new PropertyValueFactory<Message, String>("subject")
    );

    TableColumn sentDate = new TableColumn("Sent");
    sentDate.setMinWidth(100);
    sentDate.setCellValueFactory(
      new PropertyValueFactory<Message, String>("sentDate")
    );

    TableColumn fromColumn = new TableColumn("From");
    fromColumn.setMinWidth(200);
    fromColumn.setCellValueFactory(new Callback<CellDataFeatures<Message, String>, ObservableValue<String>>() {
        @Override public ObservableValue<String> call(CellDataFeatures<Message, String> m) {
          try {
            // m.getValue() returns the Message instance for a particular TableView row
            return new ReadOnlyObjectWrapper<String>(Arrays.toString(m.getValue().getFrom()));
          } catch (MessagingException ex) {
            Logger.getLogger(MailTableSample.class.getName()).log(Level.SEVERE, null, ex);
            return null;
          }
        }
    });    

    table.setItems(fetchMessages());
    table.getColumns().addAll(fromColumn, subjectColumn, sentDate);
    table.setPrefSize(600, 200);

    final VBox vbox = new VBox();
    vbox.setSpacing(5);
    vbox.setPadding(new Insets(10));
    vbox.getChildren().addAll(label, table);

    stage.setScene(new Scene(vbox));
    stage.show();
  }

  private ObservableList<Message> fetchMessages() {
    ObservableList<Message> messages = FXCollections.observableArrayList();
    try {
      Session session = Session.getDefaultInstance(System.getProperties());
      for (int i = 0; i < 3; i++) {
        InputStream mboxStream = new BufferedInputStream(
          getClass().getResourceAsStream("msg_" + (i+1) + ".txt")
        );
        Message message = new MimeMessage(session, mboxStream);
        messages.add(message);
      }
    } catch (MessagingException ex) {
      Logger.getLogger(MailTableSample.class.getName()).log(Level.SEVERE, null, ex);
    }

    return messages;
  }
}

msg_1.txt 

From cras@irccrew.org  Tue Jul 23 19:39:23 2002
Received: with ECARTIS (v1.0.0; list dovecot); Tue, 23 Jul 2002 19:39:23 +0300 (EEST)
Return-Path: <cras@irccrew.org>
Delivered-To: dovecot@procontrol.fi
Received: from shodan.irccrew.org (shodan.irccrew.org [80.83.4.2])
    by danu.procontrol.fi (Postfix) with ESMTP id 434B423848
    for <dovecot@procontrol.fi>; Tue, 23 Jul 2002 19:39:23 +0300 (EEST)
Received: by shodan.irccrew.org (Postfix, from userid 6976)
    id 175FA4C0A0; Tue, 23 Jul 2002 19:39:23 +0300 (EEST)
Date: Tue, 23 Jul 2002 19:39:23 +0300
From: Timo Sirainen <tss@iki.fi>
To: dovecot@procontrol.fi
Subject: [dovecot] first test mail
Message-ID: <20020723193923.J22431@irccrew.org>
Mime-Version: 1.0
Content-Disposition: inline
User-Agent: Mutt/1.2.5i
Content-Type: text/plain; charset=us-ascii
X-archive-position: 1
X-ecartis-version: Ecartis v1.0.0
Sender: dovecot-bounce@procontrol.fi
Errors-to: dovecot-bounce@procontrol.fi
X-original-sender: tss@iki.fi
Precedence: bulk
X-list: dovecot
X-IMAPbase: 1096038620 0000010517
X-UID: 1                                                  
Status: O

lets see if it works

msg_2.txt 

From cras@irccrew.org  Mon Jul 29 02:17:12 2002
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    id 8BAD24C0A0; Mon, 29 Jul 2002 02:17:11 +0300 (EEST)
Date: Mon, 29 Jul 2002 02:17:11 +0300
From: John Smith <jsmithspam@yahoo.com>
To: dovecot@procontrol.fi
Subject: [dovecot] Dovecot 0.93 released
Message-ID: <20020729021711.W22431@irccrew.org>
Mime-Version: 1.0
Content-Disposition: inline
User-Agent: Mutt/1.2.5i
Content-Type: text/plain; charset=us-ascii
X-archive-position: 2
X-ecartis-version: Ecartis v1.0.0
Sender: dovecot-bounce@procontrol.fi
Errors-to: dovecot-bounce@procontrol.fi
X-original-sender: tss@iki.fi
Precedence: bulk
X-list: dovecot
X-UID: 2                                                  
Status: O

First alpha quality release, everything critical is now implemented. From
now on it's mostly stabilization and optimization. Features that can't break
existing code could still be added, especially SSL and authentication stuff.

msg_3.txt 

From cras@irccrew.org  Wed Jul 31 22:48:41 2002
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Date: Wed, 31 Jul 2002 22:48:39 +0300
From: Timo Sirainen <tss@iki.fi>
To: dovecot@procontrol.fi
Subject: [dovecot] v0.95 released
Message-ID: <20020731224839.H22431@irccrew.org>
Mime-Version: 1.0
Content-Disposition: inline
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Content-Type: text/plain; charset=us-ascii
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X-UID: 3                                                  
Status: O

v0.95 2002-07-31  Timo Sirainen <tss@iki.fi>

    + Initial SSL support using GNU TLS, tested with v0.5.1.
      TLS support is still missing.
    + Digest-MD5 authentication method
    + passwd-file authentication backend
    + Code cleanups
    - Found several bugs from mempool and ioloop code, now we should
      be stable? :)
    - A few corrections for long header field handling

示例程序输出： Sample TableView with Mail Message Info

答案 1 :(得分：0)

使用上面提到的解决方案，我按原样使用它，或者我接受Eclipse的建议我添加了一个try / catch和另一个返回值，最后看起来像这样：

        fromColumn.setCellValueFactory(new Callback<CellDataFeatures<Message, String>, ObservableValue<String>>() {
        public ObservableValue<String> call(CellDataFeatures<Message, String> m) {
            // m.getValue() returns the Message instance for a particular TableView row
            try {
                return new ReadOnlyObjectWrapper<String>(Arrays.toString(m.getValue().getFrom()));
            } catch (MessagingException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            return null;
        }
    });

结果是一样的，我得到一个（视觉）空的tableview。这意味着即使tablecolumns也是空的，使用这个setCellFactury（） - 解决方案。好吧，作为解决方法，我可以定义一个类，我可以将三个值存储为String，然后使用PropertyValueFactory将其传递给setCellValueFactory（），但我希望能够正确完成它。

还有什么建议吗？

最好的问候

答案 2 :(得分：0)

这是jewelsea解决方案的Java 8版本，但是在令人敬畏的lambdas中：

fromColumn.setCellValueFactory(m -> {
        // m.getValue() returns the Message instance for a particular TableView row
        return new ReadOnlyObjectWrapper<String>(Arrays.toString(m.getValue().getFrom()));
    }
});
大笑，得爱上lambdas

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