From 0f2fc9f3ae314c8c50b4a63c83bedce0f38de106 Mon Sep 17 00:00:00 2001
From: hiqiuyi <178673693@qq.com>
Date: Mon, 25 Jul 2022 12:01:26 +0800
Subject: [PATCH] =?UTF-8?q?=E6=A0=B9=E6=8D=AE=E6=96=87=E5=AD=97=E5=88=9B?=
 =?UTF-8?q?=E5=BB=BA=E9=80=8F=E6=98=8E=E8=83=8C=E6=99=AF=E7=9A=84PNG?=
 =?UTF-8?q?=E5=9B=BE=E7=89=87?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../main/java/cn/hutool/core/img/ImgUtil.java | 36 +++++++++++--------
 .../java/cn/hutool/core/img/ImgUtilTest.java  | 22 ++++++++++++
 2 files changed, 44 insertions(+), 14 deletions(-)

diff --git a/hutool-core/src/main/java/cn/hutool/core/img/ImgUtil.java b/hutool-core/src/main/java/cn/hutool/core/img/ImgUtil.java
index a13290c26..c77e277c5 100755
--- a/hutool-core/src/main/java/cn/hutool/core/img/ImgUtil.java
+++ b/hutool-core/src/main/java/cn/hutool/core/img/ImgUtil.java
@@ -23,18 +23,7 @@ import javax.imageio.ImageWriter;
 import javax.imageio.stream.ImageInputStream;
 import javax.imageio.stream.ImageOutputStream;
 import javax.swing.ImageIcon;
-import java.awt.Color;
-import java.awt.Font;
-import java.awt.Graphics;
-import java.awt.Graphics2D;
-import java.awt.GraphicsConfiguration;
-import java.awt.GraphicsDevice;
-import java.awt.GraphicsEnvironment;
-import java.awt.HeadlessException;
-import java.awt.Image;
-import java.awt.Point;
-import java.awt.Rectangle;
-import java.awt.Toolkit;
+import java.awt.*;
 import java.awt.color.ColorSpace;
 import java.awt.font.FontRenderContext;
 import java.awt.geom.AffineTransform;
@@ -1370,6 +1359,19 @@ public class ImgUtil {
 		writePng(createImage(str, font, backgroundColor, fontColor, BufferedImage.TYPE_INT_ARGB), out);
 	}
 
+	/**
+	 * 根据文字创建透明背景的PNG图片
+	 *
+	 * @param str             文字
+	 * @param font            字体{@link Font}
+	 * @param fontColor       字体颜色，默认黑色
+	 * @param out             图片输出地
+	 * @throws IORuntimeException IO异常
+	 */
+	public static void createTransparentImage(String str, Font font, Color fontColor, ImageOutputStream out) throws IORuntimeException {
+		writePng(createImage(str, font, null, fontColor, BufferedImage.TYPE_INT_ARGB), out);
+	}
+
 	/**
 	 * 根据文字创建图片
 	 *
@@ -1392,13 +1394,19 @@ public class ImgUtil {
 		int height = unitHeight + 3;
 
 		// 创建图片
-		final BufferedImage image = new BufferedImage(width, height, imageType);
-		final Graphics g = image.getGraphics();
+		BufferedImage image = new BufferedImage(width, height, imageType);
+		Graphics g = image.getGraphics();
 		if (null != backgroundColor) {
 			// 先用背景色填充整张图片,也就是背景
 			g.setColor(backgroundColor);
 			g.fillRect(0, 0, width, height);
+		}else{
+			// 如果没有设置背景色，则设置为透明背景
+			g.dispose();
+			image = image.createGraphics().getDeviceConfiguration().createCompatibleImage(width, height, Transparency.TRANSLUCENT);
+			g = image.getGraphics();
 		}
+
 		g.setColor(ObjectUtil.defaultIfNull(fontColor, Color.BLACK));
 		g.setFont(font);// 设置画笔字体
 		g.drawString(str, 0, font.getSize());// 画出字符串
diff --git a/hutool-core/src/test/java/cn/hutool/core/img/ImgUtilTest.java b/hutool-core/src/test/java/cn/hutool/core/img/ImgUtilTest.java
index a91e3de6a..68794256a 100755
--- a/hutool-core/src/test/java/cn/hutool/core/img/ImgUtilTest.java
+++ b/hutool-core/src/test/java/cn/hutool/core/img/ImgUtilTest.java
@@ -1,6 +1,7 @@
 package cn.hutool.core.img;
 
 import cn.hutool.core.io.FileUtil;
+import cn.hutool.core.io.IORuntimeException;
 import org.junit.Assert;
 import org.junit.Ignore;
 import org.junit.Test;
@@ -146,4 +147,25 @@ public class ImgUtilTest {
 		System.out.println(mainColor);
 	}
 
+	@Test
+	public void createImageTest() throws IORuntimeException, IOException {
+		ImgUtil.createImage(
+				"版权所有",
+				new Font("黑体", Font.BOLD, 50),
+				Color.WHITE,
+				Color.BLACK,
+				ImageIO.createImageOutputStream(new File("d:/test/createImageTest.png"))
+		);
+	}
+
+	@Test
+	public void createTransparentImageTest() throws IORuntimeException, IOException {
+		ImgUtil.createTransparentImage(
+				"版权所有",
+				new Font("黑体", Font.BOLD, 50),
+				Color.BLACK,
+				ImageIO.createImageOutputStream(new File("d:/test/createTransparentImageTest.png"))
+		);
+	}
+
 }