java生成带表格的png图片,用于将表格数据转换为PNG图像文件的Java API或工具

你可以使用Java的开源库iText来实现生成带表格的PNG图片。以下是一个简单的示例代码：

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import com.itextpdf.awt.DefaultFontMapper;
import com.itextpdf.awt.FontMapper;
import com.itextpdf.awt.geom.Rectangle2D;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.pdf.BaseFont;
import com.itextpdf.text.pdf.PdfContentByte;
import com.itextpdf.text.pdf.PdfTemplate;
import com.itextpdf.text.pdf.PdfWriter;
import com.itextpdf.text.pdf.codec.PngEncoder;

public class TableToPNG {
    public static void main(String[] args) throws IOException, DocumentException {
        int width = 500;
        int height = 300;
        int marginLeft = 50;
        int marginTop = 50;
        int cellPadding = 5;
        int borderWidth = 1;
        int fontSize = 12;

        List<String[]> data = new ArrayList<String[]>();
        data.add(new String[] { "Name", "Age", "Gender" });
        data.add(new String[] { "John", "25", "Male" });
        data.add(new String[] { "Jane", "30", "Female" });
        data.add(new String[] { "Bob", "40", "Male" });

        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        Graphics2D g2d = image.createGraphics();
        g2d.setPaint(Color.WHITE);
        g2d.fillRect(0, 0, width, height);

        PdfWriter writer = PdfWriter.getInstance(null, new FileOutputStream("temp.pdf"));
        writer.setStrictImageSequence(true);
        writer.open();
        PdfContentByte cb = writer.getDirectContent();
        PdfTemplate tp = cb.createTemplate(width, height);

        FontMapper fontMapper = new DefaultFontMapper();
        BaseFont bf = BaseFont.createFont("Helvetica", BaseFont.WINANSI, BaseFont.EMBEDDED);
        fontMapper.putName("Helvetica", bf.getPostscriptFontName());
        cb.setFontAndSize(bf, fontSize);

        int numCols = data.get(0).length;
        float[] colWidths = new float[numCols];
        for (int i = 0; i < numCols; i++) {
            colWidths[i] = (width - 2 * marginLeft) / (float) numCols;
        }

        float yPos = height - marginTop - fontSize;
        for (String[] row : data) {
            float xPos = marginLeft;
            for (int i = 0; i < numCols; i++) {
                String cellText = row[i];
                Rectangle2D cellBounds = bf.getStringBounds(cellText, g2d.getFontRenderContext());

                float cellWidth = colWidths[i] - 2 * cellPadding - 2 * borderWidth;
                float cellHeight = (float) cellBounds.getHeight() + 2 * cellPadding + 2 * borderWidth;

                cb.roundRectangle(xPos, yPos - cellHeight, cellWidth, cellHeight, borderWidth);
                cb.stroke();

                cb.beginText();
                cb.showTextAligned(PdfContentByte.ALIGN_LEFT, cellText, xPos + cellPadding, yPos - cellPadding, 0);
                cb.endText();

                xPos += colWidths[i];
            }
            yPos -= fontSize + 2 * cellPadding + 2 * borderWidth;
        }

        tp.addImage(PngEncoder.encode(image));
        cb.addTemplate(tp, 0, 0);
        writer.flush();
        writer.close();

        File pngFile = new File("table.png");
        PngEncoder encoder = new PngEncoder();
        encoder.encode(tp.createGraphics(width, height), pngFile);
    }
}

这个示例代码将生成一个带有表格的PNG图片，并且保存为temp.pdf和table.png两个文件。你可以根据自己的需求进行修改。