Java输出文字到图片

描述

java 的awt工具包里是有图像类(Image)，所以可以读取图像并利用Graphics2D进行操作。但是ImageIO.read()方法读取图片时可能存在不正确处理图片ICC（ICC为JPEG图片格式中的一种头部信息）信息的问题，导致渲染图片前景色时蒙上一层红色，因此需要用JDK提供的Toolkit.getDefaultToolkit()进行操作。

代码

import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.FileOutputStream;
import java.net.URL;

public class PrintImageUtil {
    
    public String printWordImage(String word,String imgUrl){
        String imgStr = "";
        try {
            URL url = new URL(imgUrl);
            Image src = Toolkit.getDefaultToolkit().createImage(url);
            BufferedImage bi = toBufferedImage(src);
            if(bi != null){
                g = bi.createGraphics();
                g.setBackground(Color.WHITE);
                g.setColor(Color.WHITE);
                g.setFont(new Font("黑体",Font.ITALIC,50));
                g.drawString(word,130,250);
                g.setFont(new Font("黑体",Font.BOLD,15));
                g.drawString("兔比",130+26*word.length(),250);
                g.dispose();
                ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
                ImageIO.write(bi,"png",outputStream);
                byte[] bytes = outputStream.toByteArray();
                //该bytes数组就可以输出到文件，或者云服务器
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "http://img.yiqx.com/"+imgStr;
    }
    
    public static BufferedImage toBufferedImage(Image image) {
        if (image instanceof BufferedImage) {
            return (BufferedImage) image;
        }
        // This code ensures that all the pixels in the image are loaded
        image = new ImageIcon(image).getImage();
        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;
    }
}

一些问题

当代码打包上传到Linux服务器的时候，某些字体就无法使用了，所以需要到Winsows下找到对应的字体，最笨的办法就是复制所有的字体，上传到Linux服务器。服务器路径为/usr/java/jdk1.8.0_161/jre/lib/fonts(添加jdk支持的字体)/或者/usr/share/fonts/（添加系统字体）。