最近工作上写了点好久没使用了的java绘图代码，都快忘干净了，所以记录一下，最终实现的效果是下图这个样子，红色周边是美工设计的背景图，白色区域是要动态添加内容。
上代码：
1 package com.yueyongyueyou.common.service.impl;
2
3 import cn.hutool.core.img.ImgUtil;
4 import com.yueyongyueyou.common.service.IUploadFileDubboService;
5 import com.yueyongyueyou.common.service.ImageService;
6 import com.yueyongyueyou.config.service.IConfigParamService;
7 import org.springframework.stereotype.Service;
8
9 import javax.annotation.Resource;
10 import java.awt.*;
11 import java.awt.font.TextAttribute;
12 import java.awt.image.BufferedImage;
13 import java.math.BigDecimal;
14 import java.net.URL;
15 import java.text.AttributedString;
16 import java.text.DecimalFormat;
17
18 /**
19 * 图片绘制实现类
20 */
21 @Service
22 public class ImageServiceImpl implements ImageService {
23 /**
24 * 业务参数获取实现类
25 */
26 @Resource
27 private IConfigParamService configParamService;
28 /**
29 * 上传oss功能实现类
30 */
31 @Resource
32 private IUploadFileDubboService uploadService;
33
34 /**
35 * 将商品图、价格绘制到指定得背景图上，并上传到oss服务器
36 *
37 * @param goodsImg 商品图
38 * @param groupPrice 商品拼团价
39 * @param productPrice 商品零售价
40 * @return 上传后得图片访问地址
41 * @throws Exception
42 */
43 @Override
44 public String generateAppletShareImg(String goodsImg, BigDecimal groupPrice, BigDecimal productPrice) throws Exception {
45 //获取配置好的背景图
46 String imgPrefix = configParamService.getParamValue("yyyy.img.prefix");
47 String bgImg = configParamService.getParamValue("group:booking:share:bgimg");
48
49 //背景图
50 BufferedImage bgImage = ImgUtil.read(new URL(imgPrefix + bgImg));
51
52 //商品图
53 BufferedImage goodsImage = ImgUtil.read(new URL(imgPrefix + goodsImg));
54 int w = goodsImage.getWidth();
55 int h = goodsImage.getHeight();
56 int min = Math.min(w, h);
57 //切成尺寸最大得正方形
58 Image cut = ImgUtil.cut(goodsImage, new Rectangle((w - min) / 2, (h - min) / 2, min, min));
59
60 //定义颜色和字体
61 Color color_B3BCC9 = ImgUtil.getColor("#B3BCC9");
62 Color color_FF1355 = ImgUtil.getColor("#FF1355");
63 Color color_F43011 = ImgUtil.getColor("#F43011");
64 Font font_ht_33 = new Font("SimHei", Font.PLAIN, 33);
65 Font font_ht_36 = new Font("SimHei", Font.PLAIN, 36);
66 Font font_serif_33 = new Font("Microsoft Sans Serif", Font.PLAIN, 33);
67 Font font_serif_42 = new Font("Microsoft Sans Serif", Font.PLAIN, 42);
68
69 //定义文字变量
70 final String labelText1 = "幸运价:", labelText2 = "立即参与", labelSymbol = "¥", labelDot = ".";
71
72 DecimalFormat decimalFormat = new DecimalFormat("0.00#");
73 String groupPriceStr = decimalFormat.format(groupPrice == null ? BigDecimal.ZERO : groupPrice);
74 String[] split = groupPriceStr.split("\\.");
75 String integerPart = split[0];
76 String decimalPart = split[1];
77 String productPriceStr = decimalFormat.format(productPrice == null ? BigDecimal.ZERO : productPrice);
78
79 //开始绘画
80 Graphics2D graphics = bgImage.createGraphics();
81 //抗锯齿
82 graphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
83 //画白底
84 graphics.setColor(Color.WHITE);
85 graphics.fillRoundRect(30, 144, 570, 327, 18, 18);
86 //画商品
87 graphics.drawImage(cut, 54, 171, 279, 279, null);
88 //写右侧文字
89 graphics.setColor(color_B3BCC9);
90 graphics.setFont(font_ht_33);
91 graphics.drawString(labelText1, 363, 189 + 27);
92 //写团购价人民币符号
93 graphics.setColor(color_FF1355);
94 graphics.setFont(font_serif_33);
95 graphics.drawString(labelSymbol, 363, 246 + 37);
96 //写团购价整数部分
97 FontMetrics symbolMetrics = graphics.getFontMetrics(font_serif_33);
98 int symbolTextLength = symbolMetrics.stringWidth(labelSymbol);
99 symbolTextLength += 3;
100 graphics.setColor(color_FF1355);
101 graphics.setFont(font_serif_42);
102 graphics.drawString(integerPart + labelDot, 363 + symbolTextLength, 246 + 37);
103 //写团购价小数部分
104 FontMetrics numericMetrics = graphics.getFontMetrics(font_serif_33);
105 int numericTextLength = numericMetrics.stringWidth(integerPart + labelDot);
106 int adjust = (integerPart.length() + 1) * 5; //横坐标微调优化
107 graphics.setColor(color_FF1355);
108 graphics.setFont(font_serif_33);
109 graphics.drawString(decimalPart, 363 + symbolTextLength + numericTextLength + adjust, 246 + 37);
110 //写零售价
111 graphics.setColor(color_B3BCC9);
112 AttributedString attrString = new AttributedString(labelSymbol + productPriceStr);
113 attrString.addAttribute(TextAttribute.STRIKETHROUGH, TextAttribute.STRIKETHROUGH_ON);
114 attrString.addAttribute(TextAttribute.FONT, font_serif_33);
115 graphics.drawString(attrString.getIterator(), 363, 306 + 29);
116 //画红色按钮
117 graphics.setColor(color_F43011);
118 graphics.fillRoundRect(351, 378, 225, 72, 72, 72);
119 //写按钮文字
120 graphics.setColor(Color.WHITE);
121 graphics.setFont(font_ht_36);
122 graphics.drawString(labelText2, 393, 384 + 42);
123
124 //上传到oss服务器
125 String url = uploadService.uploadManagerFile(ImgUtil.toBytes(bgImage, ImgUtil.IMAGE_TYPE_PNG), ImgUtil.IMAGE_TYPE_PNG, 1, 0);
126
127 return url;
128 }
129 }