Java来实现文本转图片需求示例

@Slf4j
public class TextUtils {

    /**
     * 文本=》图片
     * 目前不支持彩色图片
     */
    private static final int FONT_SIZE = 24;
    private static final int PADDING = 20;
    private static final Color BACKGROUND_COLOR = Color.WHITE;
    private static final Color TEXT_COLOR = Color.BLACK;
    private static final String TEMP_FILE_PREFIX = "tmp_";
    private static final String IMAGE_SUFFIX = "png";
    private static final String[] PREFERRED_FONTS = {
            "DejaVu Sans Mono",      // 优先使用等宽字体
			"Monospaced",             // Java默认等宽字体
            "Symbola",                // Unicode符号专用字体
            "Segoe UI Symbol",        // Windows符号字体
            "Apple Symbols",         // macOS符号字体
            "Noto Sans Symbols"      // Google符号字体
    };

    public static String convertImage(String text) {
        Path tempFile = null;
        try {
            tempFile = Files.createTempFile(TEMP_FILE_PREFIX, "." + IMAGE_SUFFIX);
            String filePath = tempFile.toAbsolutePath().toString();
            // 分割文本行（\R支持所有不同操作系统换行符格式）
            List<String> lines = Arrays.asList(text.split("\\R"));
            // 获取最佳可用字体
            Font font = getBestAvailableFont();
            // 创建临时图像用于计算尺寸
            BufferedImage tempImage = new BufferedImage(1, 1, BufferedImage.TYPE_INT_RGB);
            Graphics2D tempG = tempImage.createGraphics();
            try {
                tempG.setFont(font);
                FontMetrics metrics = tempG.getFontMetrics();
                // 计算最大行宽和总高度
                int maxWidth = 0;
                for (String line : lines) {
                    int width = metrics.stringWidth(line);
                    if (width > maxWidth) maxWidth = width;
                }
                int totalHeight = metrics.getHeight() * lines.size();
                // 创建实际图像
                int imageWidth = maxWidth + 2 * PADDING;
                int imageHeight = totalHeight + 2 * PADDING;
                BufferedImage image = new BufferedImage(
                        imageWidth, imageHeight, BufferedImage.TYPE_INT_RGB);
                Graphics2D g = image.createGraphics();
                try {
                    // 设置渲染参数
                    g.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING,
                            RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
                    g.setFont(font);
                    g.setColor(BACKGROUND_COLOR);
                    g.fillRect(0, 0, imageWidth, imageHeight);
                    g.setColor(TEXT_COLOR);
                    // 绘制文本行
                    int y = PADDING + metrics.getAscent();
                    for (String line : lines) {
                        g.drawString(line, PADDING, y);
                        y += metrics.getHeight();
                    }
                }finally {
                    g.dispose();
                }
                //写入文件
                ImageIO.write(image, IMAGE_SUFFIX, new File(filePath));
            }finally {
                tempG.dispose();
            }
            return filePath;
        }catch (Exception e) {
            log.error("text convert image error: ", e);
            deleteTempFile(tempFile);
            return null;
        }
    }

    private static Font getBestAvailableFont() {
        GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
        List<String> availableFonts = Arrays.asList(ge.getAvailableFontFamilyNames());
        // 查找首选字体
        for (String fontName : PREFERRED_FONTS) {
            if (availableFonts.contains(fontName)) {
                return new Font(fontName, Font.PLAIN, FONT_SIZE);
            }
        }
        // 回退到支持更广的字体
        if (availableFonts.contains("Symbola")) {
            return new Font("Symbola", Font.PLAIN, FONT_SIZE);
        }
        // 最终回退到等宽字体
        return new Font(Font.MONOSPACED, Font.PLAIN, FONT_SIZE);
    }

    public static void deleteTempFile(Path tempFile) {
        if (tempFile != null) {
            try {
                Files.deleteIfExists(tempFile);
            } catch (Exception e) {
                log.error("Failed to delete temp file: {}", tempFile, e);
            }
        }
    }
}