JTable 如何后台加载图片

问题：

JTable 如何后台加载图片

解决：

package yvhk.t3dcool.admin.appclient.model;

import javax.swing.*;
import javax.swing.table.DefaultTableCellRenderer;
import java.awt.*;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.util.HashMap;
import java.util.Map;

class ImgCellRender extends DefaultTableCellRenderer {
    Map<String, byte[]> imgCache = new HashMap<>(100);

    public void clearCache() {
        imgCache.clear();
    }

    @Override
    public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
        var url = UrlHelper.getDisplayImageUrl((String) value, "s150");
        //not work var ret = new JLabel("hello");
        var imgData = imgCache.get(url);
        ImageIcon icon;
        if (imgData == null) {
            var worker = new ImgLoaderWorker(url, () -> {
                var rect = table.getCellRect(row, column, true);
                table.repaint(rect);
            });
            worker.execute();
            icon = null;
        } else {
            icon = new ImageIcon(Toolkit.getDefaultToolkit().createImage(imgData));
        }
        setIcon(icon);
        return this;
    }


    class ImgLoaderWorker extends SwingWorker<byte[], Void> {
        final String url;
        private final Runnable doneHandle;

        ImgLoaderWorker(String url, Runnable doneHandle) {
            this.url = url;
            this.doneHandle = doneHandle;
        }

        @Override
        protected byte[] doInBackground() throws Exception {
            var ret = img(url);
            return ret;
        }

        @Override
        protected void done() {
            try {
                imgCache.put(url, get());
            } catch (Exception e) {
                System.err.println("加载图片出错");
            }
            if (doneHandle != null) {
                doneHandle.run();
            }
        }


        byte[] img(String url) throws IOException, InterruptedException, URISyntaxException {
            HttpRequest req = HttpRequest.newBuilder(new URI(url))
                    .GET().build();
            var resp = HttpClient.newHttpClient()
                    .send(req, HttpResponse.BodyHandlers.ofByteArray());
            var ret = resp.body();
            return ret;
        }

    }
}

package yvhk.t3dcool.admin.appclient.model;

import javax.swing.*;

import javax.swing.table.DefaultTableCellRenderer;

import java.awt.*;

import java.io.IOException;

import java.net.URI;

import java.net.URISyntaxException;

import java.net.http.HttpClient;

import java.net.http.HttpRequest;

import java.net.http.HttpResponse;

import java.util.HashMap;

import java.util.Map;

class ImgCellRender extends DefaultTableCellRenderer {

Map<String, byte[]> imgCache = new HashMap<>(100);

public void clearCache() {

imgCache.clear();

}

@Override

public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {

var url = UrlHelper.getDisplayImageUrl((String) value, "s150");

//not work var ret = new JLabel("hello");

var imgData = imgCache.get(url);

ImageIcon icon;

if (imgData == null) {

var worker = new ImgLoaderWorker(url, () -> {

var rect = table.getCellRect(row, column, true);

table.repaint(rect);

});

worker.execute();

icon = null;

} else {

icon = new ImageIcon(Toolkit.getDefaultToolkit().createImage(imgData));

}

setIcon(icon);

return this;

}

class ImgLoaderWorker extends SwingWorker<byte[], Void> {

final String url;

private final Runnable doneHandle;

ImgLoaderWorker(String url, Runnable doneHandle) {

this.url = url;

this.doneHandle = doneHandle;

}

@Override

protected byte[] doInBackground() throws Exception {

var ret = img(url);

return ret;

}

@Override

protected void done() {

try {

imgCache.put(url, get());

} catch (Exception e) {

System.err.println("加载图片出错");

}

if (doneHandle != null) {

doneHandle.run();

}

byte[] img(String url) throws IOException, InterruptedException, URISyntaxException {

HttpRequest req = HttpRequest.newBuilder(new URI(url))

.GET().build();

var resp = HttpClient.newHttpClient()

.send(req, HttpResponse.BodyHandlers.ofByteArray());

var ret = resp.body();

return ret;

}

IT问题

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JTable 如何后台加载图片

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