原因:根据网上搜罗的一大堆文章以及自己的发现,是因为原始图片(jpeg)带有alpha通道才会变红,在mac上直接显示简介的看到。
image.png
然后发现使用下面这个方式可以解决变红的问题
// 把这行换成下面的方式
BufferedImage image = ImageIO.read(originFile);
// 这里是直接根据url读取图片
public static BufferedImage getBufferedImage(String imgUrl) throws MalformedURLException {
URL url = new URL(imgUrl);
ImageIcon icon = new ImageIcon(url);
Image image = icon.getImage();
// 如果是从本地加载,就用这种方式,没亲自测试过
// Image src=Toolkit.getDefaultToolkit().getImage(filePath);
// This code ensures that all the pixels in the image are loaded
BufferedImage bimage = null;
GraphicsEnvironment ge = GraphicsEnvironment
.getLocalGraphicsEnvironment();
try {
int transparency = Transparency.OPAQUE;
GraphicsDevice gs = ge.getDefaultScreenDevice();
GraphicsConfiguration gc = gs.getDefaultConfiguration();
bimage = gc.createCompatibleImage(image.getWidth(null),
image.getHeight(null), transparency);
} catch (HeadlessException e) {
// The system does not have a screen
}
if (bimage == null) {
// Create a buffered image using the default color model
int type = BufferedImage.TYPE_INT_RGB;
bimage = new BufferedImage(image.getWidth(null),
image.getHeight(null), type);
}
// Copy image to buffered image
Graphics g = bimage.createGraphics();
// Paint the image onto the buffered image
g.drawImage(image, 0, 0, null);
g.dispose();
return bimage;
}
原文链接:https://blog.csdn.net/Wu_Shang001/article/details/108227611
一个完整的例子:
package cn.com.xxx.web.controller;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.swing.*;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.MalformedURLException;
import java.net.URL;
@Controller
@RequestMapping("/image")
@Api(tags = "图片处理")
public class ImageController {
public static BufferedImage getBufferedImage(String imgUrl) throws MalformedURLException {
URL url = new URL(imgUrl);
ImageIcon icon = new ImageIcon(url);
Image image = icon.getImage();
// 如果是从本地加载,就用这种方式,没亲自测试过
// Image src=Toolkit.getDefaultToolkit().getImage(filePath);
// This code ensures that all the pixels in the image are loaded
BufferedImage bimage = null;
GraphicsEnvironment ge = GraphicsEnvironment
.getLocalGraphicsEnvironment();
try {
int transparency = Transparency.OPAQUE;
GraphicsDevice gs = ge.getDefaultScreenDevice();
GraphicsConfiguration gc = gs.getDefaultConfiguration();
bimage = gc.createCompatibleImage(image.getWidth(null),
image.getHeight(null), transparency);
} catch (HeadlessException e) {
// The system does not have a screen
}
if (bimage == null) {
// Create a buffered image using the default color model
int type = BufferedImage.TYPE_INT_RGB;
bimage = new BufferedImage(image.getWidth(null),
image.getHeight(null), type);
}
// Copy image to buffered image
Graphics g = bimage.createGraphics();
// Paint the image onto the buffered image
g.drawImage(image, 0, 0, null);
g.dispose();
return bimage;
}
/**
* 获取远程网络图片信息
* @param imageURL
* @return
*/
public BufferedImage getRemoteBufferedImage(String imageURL) {
URL url = null;
InputStream is = null;
BufferedImage bufferedImage = null;
try {
url = new URL(imageURL);
is = url.openStream();
bufferedImage = ImageIO.read(is);
} catch (MalformedURLException e) {
e.printStackTrace();
System.out.println("imageURL: " + imageURL + ",无效!");
return null;
} catch (IOException e) {
e.printStackTrace();
System.out.println("imageURL: " + imageURL + ",读取失败!");
return null;
} finally {
try {
if (is!=null) {
is.close();
}
} catch (IOException e) {
e.printStackTrace();
System.out.println("imageURL: " + imageURL + ",流关闭异常!");
return null;
}
}
return bufferedImage;
}
public BufferedImage mergeImage(String file1Url, String file2Url) throws MalformedURLException {
BufferedImage b = getBufferedImage(file1Url);
BufferedImage d = getBufferedImage(file2Url);
try {
int w = d.getWidth() / 4; //b.getWidth();
int h = d.getHeight() / 4; // b.getHeight();
int x = d.getWidth() / 2 - w / 2;
int y = d.getHeight() / 2 - h / 2;
Graphics2D g = d.createGraphics();
g.drawImage(b, x, y, w, h, null);
g.dispose();
} catch (Exception e) {
System.out.println(e.getMessage());
}
return d;
}
/**
* 根据url进行图片合并
*/
@ResponseBody
@RequestMapping(value = "mergeImage", method = RequestMethod.GET)
@ApiOperation(value = "根据url进行图片合并", httpMethod = "GET")
public void mergeImage(HttpServletRequest request, HttpServletResponse response) throws MalformedURLException {
BufferedImage bufferedImage = mergeImage("https://static-oss.cs.kemai.com.cn/vshop/0/c02582c1bba440ae89c216a8e9701daa.png", "https://work-cs.cloud.kemai.cn/img/qr_code.884b6411.png");
response.setContentType("image/png");
try (OutputStream out = response.getOutputStream()) {
//这里直接写入输出流
ImageIO.write(bufferedImage, "JPEG", response.getOutputStream());
} catch (Exception e) {
System.out.println(e.getLocalizedMessage());
}
}
}
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