package cn.iocoder.yudao.module.mes.framework.qrcode;
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import cn.hutool.core.util.StrUtil;
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import cn.hutool.extra.qrcode.QrCodeUtil;
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import cn.hutool.extra.qrcode.QrConfig;
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import cn.iocoder.yudao.framework.common.util.http.HttpUtils;
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import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
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import jakarta.servlet.http.HttpServletResponse;
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import lombok.extern.slf4j.Slf4j;
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import javax.imageio.ImageIO;
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import java.awt.Color;
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import java.awt.Font;
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import java.awt.FontMetrics;
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import java.awt.Graphics2D;
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import java.awt.GraphicsEnvironment;
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import java.awt.RenderingHints;
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import java.awt.image.BufferedImage;
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import java.io.IOException;
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import java.util.ArrayList;
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import java.util.LinkedHashMap;
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import java.util.List;
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import java.util.Map;
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import java.util.Set;
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import java.util.zip.ZipEntry;
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import java.util.zip.ZipOutputStream;
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/**
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* 二维码标签图片工具类
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* <p>
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* 生成"二维码 + 右侧可读文本"的合成图片：二维码只编码纯码值，文本叠加关键信息，
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* 即使数据库丢失也能从打印图片还原关键信息。
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*/
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@Slf4j
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public final class QrCodeImageUtils {
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private QrCodeImageUtils() {
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}
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/** 批量导出二维码数量上限（防止一次性生成过多导致内存/响应过大） */
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public static final int MAX_QR_EXPORT = 2000;
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/** 二维码边长 */
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private static final int QR_SIZE = 260;
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/** 图片四周留白 */
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private static final int PADDING = 16;
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/** 二维码与文本间距 */
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private static final int GAP = 24;
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/** 文本区域宽度 */
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private static final int TEXT_WIDTH = 380;
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/** 字体大小 */
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private static final int FONT_SIZE = 15;
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/** 行高 */
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private static final int LINE_HEIGHT = 24;
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/** 字段间距 */
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private static final int FIELD_GAP = 6;
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/** 中文字体候选（按优先级），避免 Linux headless 下文字变方框 */
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private static final String[] FONT_CANDIDATES = {
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"Noto Sans CJK SC", "WenQuanYi Zen Hei", "Microsoft YaHei", "SimSun", "Arial"
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};
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private static final String FONT_NAME = resolveFontName();
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/**
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* 生成二维码标签图片
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*
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* @param code 二维码内容（纯码值）
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* @param keyValues 叠加的可读文本（顺序即绘制顺序）
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* @return 合成图片
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*/
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public static BufferedImage createQrLabel(String code, LinkedHashMap<String, String> keyValues) {
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QrConfig config = new QrConfig();
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config.setErrorCorrection(ErrorCorrectionLevel.H); // 打印标签易磨损，用高容错
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config.setMargin(1); // 保证静区，扫码率
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config.setWidth(QR_SIZE);
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config.setHeight(QR_SIZE);
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BufferedImage qrImage = QrCodeUtil.generate(code, config);
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Font labelFont = new Font(FONT_NAME, Font.BOLD, FONT_SIZE);
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Font valueFont = new Font(FONT_NAME, Font.PLAIN, FONT_SIZE);
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// 第一遍：测量文本块总高度，用于确定图片高度
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int textHeight = measureTextHeight(keyValues, labelFont, valueFont);
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int height = PADDING * 2 + Math.max(QR_SIZE, textHeight);
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int width = PADDING * 2 + QR_SIZE + GAP + TEXT_WIDTH;
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BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
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Graphics2D g = image.createGraphics();
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try {
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g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
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g.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
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g.setColor(Color.WHITE);
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g.fillRect(0, 0, width, height);
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// 二维码（垂直居中）
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int qrY = (height - QR_SIZE) / 2;
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g.drawImage(qrImage, PADDING, qrY, null);
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// 可读文本
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int textX = PADDING + QR_SIZE + GAP;
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int textY = (height - textHeight) / 2;
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drawKeyValues(g, keyValues, labelFont, valueFont, textX, textY);
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} finally {
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g.dispose();
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}
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return image;
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}
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/**
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* 将多张二维码标签图片写入 ZIP 响应（流式，逐张生成，内存只占一张）
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*
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* @param response 响应
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* @param zipName ZIP 文件名（不含后缀）
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* @param labels 标签列表
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*/
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public static void writeZip(HttpServletResponse response, String zipName, List<QrLabelInfo> labels) throws IOException {
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response.setContentType("application/zip");
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response.setHeader("Content-Disposition",
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"attachment;filename=" + HttpUtils.encodeUtf8(zipName + ".zip"));
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ZipOutputStream zip = new ZipOutputStream(response.getOutputStream());
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try {
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for (QrLabelInfo label : labels) {
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BufferedImage image = createQrLabel(label.getCode(), label.getKeyValues());
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zip.putNextEntry(new ZipEntry(label.getFileName() + ".png"));
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ImageIO.write(image, "png", zip);
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zip.closeEntry();
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}
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zip.finish();
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zip.flush();
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} finally {
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// 不 close ZipOutputStream，避免关闭底层 ServletOutputStream（与 FileTypeUtils 同理）
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}
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}
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// ==================== 私有方法 ====================
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private static String resolveFontName() {
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Set<String> families = Set.of(GraphicsEnvironment.getLocalGraphicsEnvironment().getAvailableFontFamilyNames());
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for (String candidate : FONT_CANDIDATES) {
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if (families.contains(candidate)) {
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return candidate;
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}
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}
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return Font.SANS_SERIF;
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}
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private static int measureTextHeight(LinkedHashMap<String, String> keyValues, Font labelFont, Font valueFont) {
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BufferedImage scratch = new BufferedImage(1, 1, BufferedImage.TYPE_INT_RGB);
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Graphics2D g = scratch.createGraphics();
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try {
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return measureKeyValuesHeight(g, keyValues, labelFont, valueFont);
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} finally {
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g.dispose();
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}
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}
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private static int measureKeyValuesHeight(Graphics2D g, LinkedHashMap<String, String> keyValues,
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Font labelFont, Font valueFont) {
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int total = 0;
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for (Map.Entry<String, String> entry : keyValues.entrySet()) {
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String label = StrUtil.emptyToDefault(entry.getKey(), "") + "：";
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String value = StrUtil.emptyToDefault(entry.getValue(), "");
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g.setFont(labelFont);
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int labelWidth = g.getFontMetrics().stringWidth(label);
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g.setFont(valueFont);
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List<String> lines = wrapText(g, value, TEXT_WIDTH - labelWidth);
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total += Math.max(1, lines.size()) * LINE_HEIGHT + FIELD_GAP;
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}
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return total;
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}
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private static void drawKeyValues(Graphics2D g, LinkedHashMap<String, String> keyValues,
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Font labelFont, Font valueFont, int x, int y) {
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FontMetrics labelMetrics = g.getFontMetrics(labelFont);
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int baselineOffset = labelMetrics.getAscent(); // drawString 的 y 是基线，先下移一个 ascent
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int baseline = y + baselineOffset;
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for (Map.Entry<String, String> entry : keyValues.entrySet()) {
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String label = StrUtil.emptyToDefault(entry.getKey(), "") + "：";
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String value = StrUtil.emptyToDefault(entry.getValue(), "");
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g.setFont(labelFont);
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int labelWidth = g.getFontMetrics().stringWidth(label);
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g.setColor(Color.BLACK);
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g.drawString(label, x, baseline);
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g.setFont(valueFont);
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int remainingWidth = TEXT_WIDTH - labelWidth;
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List<String> lines = wrapText(g, value, remainingWidth);
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if (!lines.isEmpty()) {
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g.drawString(lines.get(0), x + labelWidth, baseline);
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baseline += LINE_HEIGHT;
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for (int i = 1; i < lines.size(); i++) {
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g.drawString(lines.get(i), x, baseline);
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baseline += LINE_HEIGHT;
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}
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} else {
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baseline += LINE_HEIGHT;
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}
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baseline += FIELD_GAP;
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}
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}
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/**
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* 文本按最大宽度换行（逐字测量，兼容中文）
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*/
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private static List<String> wrapText(Graphics2D g, String text, int maxWidth) {
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List<String> lines = new ArrayList<>();
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if (StrUtil.isEmpty(text)) {
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return lines;
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}
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if (maxWidth <= 0) {
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lines.add(text);
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return lines;
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}
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StringBuilder current = new StringBuilder();
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FontMetrics metrics = g.getFontMetrics();
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for (int i = 0; i < text.length(); i++) {
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char ch = text.charAt(i);
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String test = current.toString() + ch;
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if (metrics.stringWidth(test) > maxWidth && current.length() > 0) {
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lines.add(current.toString());
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current = new StringBuilder().append(ch);
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} else {
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current.append(ch);
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}
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}
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if (current.length() > 0) {
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lines.add(current.toString());
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}
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return lines;
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}
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}
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