如何在AWS SDK版本2中获取进度详情并集成Swing自定义进度条

核心思路 #

• 自定义TransferListener替代默认的LoggingTransferListener，捕获上传进度事件
• 在进度回调中，使用Swing的EDT线程安全更新进度条组件，避免UI线程阻塞或异常

实现步骤与代码 #

1. 自定义TransferListener #

创建监听类，实现TransferListener接口，在transferProgressChanged方法中获取进度数据，并触发UI更新：

import software.amazon.awssdk.transfer.s3.progress.TransferProgress;
import software.amazon.awssdk.transfer.s3.progress.TransferListener;
import javax.swing.JProgressBar;
import java.awt.EventQueue;

public class SwingTransferListener implements TransferListener {
    private final JProgressBar progressBar;

    public SwingTransferListener(JProgressBar progressBar) {
        this.progressBar = progressBar;
    }

    @Override
    public void transferInitiated(Context context) {
        // 上传初始化时设置进度条最小值
        EventQueue.invokeLater(() -> progressBar.setMinimum(0));
    }

    @Override
    public void transferProgressChanged(Context context) {
        TransferProgress progress = context.progress();
        long bytesTransferred = progress.bytesTransferred();
        long totalBytes = progress.totalBytesToTransfer();
        
        // 计算百分比，避免除零
        int percentage = totalBytes > 0 ? (int) ((bytesTransferred * 100) / totalBytes) : 0;
        
        // 必须在EDT线程更新UI
        EventQueue.invokeLater(() -> {
            progressBar.setMaximum(100);
            progressBar.setValue(percentage);
            progressBar.setString(percentage + "%");
            progressBar.setStringPainted(true);
        });
    }

    @Override
    public void transferCompleted(Context context) {
        // 上传完成后设置进度为100%
        EventQueue.invokeLater(() -> {
            progressBar.setValue(100);
            progressBar.setString("上传完成");
        });
    }

    @Override
    public void transferFailed(Context context) {
        // 上传失败时更新提示
        EventQueue.invokeLater(() -> progressBar.setString("上传失败"));
    }
}

2. 整合Swing界面与S3上传逻辑 #

在Swing窗口中初始化进度条，并将自定义监听器传入S3TransferManager的上传配置：

import software.amazon.awssdk.auth.credentials.AwsCredentialsProvider;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.s3.S3ClientConfiguration;
import software.amazon.awssdk.transfer.s3.S3TransferManager;
import software.amazon.awssdk.transfer.s3.FileUpload;
import javax.swing.*;
import java.nio.file.Paths;

public class S3UploadUI extends JFrame {
    private JProgressBar uploadProgressBar;

    public S3UploadUI() {
        initUI();
    }

    private void initUI() {
        setTitle("S3文件上传");
        setSize(400, 150);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setLocationRelativeTo(null);

        uploadProgressBar = new JProgressBar();
        add(uploadProgressBar);

        // 启动上传线程，避免阻塞UI线程
        new Thread(this::startUpload).start();
    }

    private void startUpload() {
        String region = "your-region";
        AwsCredentialsProvider awsCredentialsProvider = // 初始化你的凭证提供者
                // 示例：DefaultCredentialsProvider.create();
                null;

        S3TransferManager s3TransferManager = S3TransferManager
                .builder()
                .s3ClientConfiguration(S3ClientConfiguration.builder()
                        .region(Region.of(region))
                        .credentialsProvider(awsCredentialsProvider)
                        .build())
                .build();

        FileUpload upload = s3TransferManager.uploadFile(u -> u
                .source(Paths.get("file1.txt"))
                .putObjectRequest(p -> p.bucket("bucket").key("file1.txt"))
                .overrideConfiguration(o -> o.addListener(new SwingTransferListener(uploadProgressBar))));

        try {
            upload.completionFuture().join();
        } catch (Exception e) {
            // 处理上传异常
            EventQueue.invokeLater(() -> JOptionPane.showMessageDialog(this, "上传出错: " + e.getMessage()));
        } finally {
            s3TransferManager.close();
        }
    }

    public static void main(String[] args) {
        // 在EDT线程启动Swing界面
        EventQueue.invokeLater(() -> {
            S3UploadUI ui = new S3UploadUI();
            ui.setVisible(true);
        });
    }
}

关键注意事项 #

• 线程安全：所有UI操作必须通过EventQueue.invokeLater（或SwingUtilities.invokeLater）在EDT线程执行，否则会导致Swing线程安全问题
• 进度计算：通过TransferProgress的bytesTransferred和totalBytesToTransfer计算百分比，注意处理totalBytes为0的边界情况（比如空文件）
• 资源释放：上传完成后务必关闭S3TransferManager，避免资源泄漏
• 异常处理：在completionFuture().join()处捕获异常，并用UI提示用户上传失败信息

内容的提问来源于stack exchange，提问作者santosh