Java實(shí)現(xiàn)根據(jù)圖片url下載圖片并動(dòng)態(tài)添加水印

更新時(shí)間：2026年01月08日 08:42:59 作者：專注寫bug

這篇文章主要為大家詳細(xì)介紹了如何使用Java實(shí)現(xiàn)根據(jù)圖片url下載圖片并動(dòng)態(tài)添加水印,文中的示例代碼講解詳細(xì),感興趣的小伙伴可以了解下

前言

為了一些數(shù)據(jù)安全性，需要將圖片打上自定義的水印。水印需要滿足下列設(shè)置。

支持橫向或縱向。
支持單挑或多條水印。
支持自定義顏色配置。
支持水印字體大小配置與透明度配置。

完整代碼

package img;

import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.StandardOpenOption;
import java.util.Objects;
import java.util.UUID;

/**
 * 變量控制水印
 */
public class WaterMarkExample {

    private static BufferedImage getBufferedImageByUrl(String imageUrl) throws IOException {
        // 從URL獲取圖片
        byte[] imageBytes = getImageBytesFromUrl(imageUrl);
        BufferedImage image = ImageIO.read(new java.io.ByteArrayInputStream(imageBytes));
        return image;
    }

    private static byte[] getImageBytesFromUrl(String imageUrl) throws IOException {
        OkHttpClient client = UnsafeOkHttpClient.getUnsafeClient();
        Request request = new Request.Builder()
                .url(imageUrl)
                .build();
        try (Response response = client.newCall(request).execute()) {
            return response.body().bytes();
        }
    }

    private static byte[] convertImageToBytes(BufferedImage image) throws IOException {
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        ImageIO.write(image, "png", bos);
        return bos.toByteArray();
    }

    /**
     * 圖片追加水印
     * @param image 原始圖片信息
     * @param watermarkText 水印文字
     * @param fontFilePath 字體文件
     * @param isItalic 是否字體為斜體
     * @param isSkew 水印是否傾斜
     * @param isMultiLine 水印行數(shù)是否為多行
     * @param waterMarkLineSize 水印行數(shù)
     * @param waterMarkFontSize 水印字體大小
     * @param alpha 透明度 [0,1]
     * @param waterMarkColor 水印顏色 取值來(lái)源 java.awt.Color
     * @return
     */
    private static BufferedImage addWatermark(BufferedImage image, String watermarkText, String fontFilePath,
                                              boolean isItalic, boolean isSkew, boolean isMultiLine,int waterMarkLineSize,float waterMarkFontSize,float alpha,Color waterMarkColor) {
        BufferedImage watermarkedImage = new BufferedImage(image.getWidth(), image.getHeight(), BufferedImage.TYPE_INT_RGB);
        Graphics2D g2d = watermarkedImage.createGraphics();
        g2d.drawImage(image, 0, 0, null);

        try {
            // 指定字體文件
            Font customFont = Font.createFont(Font.TRUETYPE_FONT, new File(fontFilePath));
            int fontStyle = isItalic? Font.ITALIC : Font.PLAIN;
            Font derivedFont = customFont.deriveFont(fontStyle, waterMarkFontSize);

            // 默認(rèn)演示使用，linux使用下面的代碼會(huì)加載失敗字體
            //g2d.setFont(new Font("微軟雅黑", isItalic? Font.ITALIC : Font.PLAIN, 30));

            g2d.setFont(derivedFont);
        } catch (FontFormatException | IOException e) {
            e.printStackTrace();
            g2d.setFont(new Font("Arial", isItalic? Font.ITALIC : Font.PLAIN, 30));
        }

        // 水印的顏色
        g2d.setColor(waterMarkColor);
        AlphaComposite alphaComposite = AlphaComposite.getInstance(AlphaComposite.SRC_OVER, alpha);
        g2d.setComposite(alphaComposite);

        // 圖片的尺寸
        int stringWidth = g2d.getFontMetrics().stringWidth(watermarkText);
        int stringHeight = g2d.getFontMetrics().getHeight();

        if (isMultiLine) {
            // 多行
            if (isSkew) {
                // 旋轉(zhuǎn)角度
                double rotationAngle = Math.toRadians(-45);
                int xStep = stringWidth + 50;
                int yStep = stringHeight + 50;
                for (int y = 0; y < image.getHeight(); y += yStep) {
                    for (int x = 0; x < image.getWidth(); x += xStep) {
                        AffineTransform oldTransform = g2d.getTransform();
                        g2d.rotate(rotationAngle, x + stringWidth / 2, y + stringHeight / 2);
                        g2d.drawString(watermarkText, x, y);
                        g2d.setTransform(oldTransform);
                    }
                }
            } else {
                waterMarkLineSize = Objects.isNull(waterMarkLineSize) ? 1:waterMarkLineSize;
                int x = (image.getWidth() - stringWidth) / 2;
                int y = (image.getHeight() - stringHeight) / 2;
                for (int i = 0; i < waterMarkLineSize; i++) {
                    g2d.drawString(watermarkText, x, y + i * (stringHeight + 20));
                }
            }
        } else {
            // 單行
            if (isSkew) {
                double rotationAngle = Math.toRadians(-45);
                int x = (image.getWidth() - stringWidth) / 2;
                int y = (image.getHeight() - stringHeight) / 2;
                AffineTransform oldTransform = g2d.getTransform();
                g2d.rotate(rotationAngle, x + stringWidth / 2, y + stringHeight / 2);
                g2d.drawString(watermarkText, x, y);
                g2d.setTransform(oldTransform);
            } else {
                int x = (image.getWidth() - stringWidth) / 2;
                int y = (image.getHeight() - stringHeight) / 2;
                g2d.drawString(watermarkText, x, y);
            }
        }

        g2d.dispose();
        return watermarkedImage;
    }

    public static void saveImage(byte[] imageBytes, String filePath) throws IOException {
        Path path = Path.of(filePath);
        Files.write(path, imageBytes, StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING);
    }
    public static void main(String[] args) throws IOException {
        String imageUrl = "https://i-blog.csdnimg.cn/direct/d102cabed76c4cd9b74b9469f42a4353.png";
        BufferedImage bufferedImageByUrl = getBufferedImageByUrl(imageUrl);

        String fontFilePath = System.getProperty("user.dir")+"/fill2word"+"/font/simfang.ttf";
        BufferedImage bufferedImage = addWatermark(bufferedImageByUrl,"香蕉集團(tuán)的香蕉不拿拿愛(ài)吃香蕉香蕉集團(tuán)的香蕉不拿拿愛(ài)吃香蕉香蕉集團(tuán)的香蕉不拿拿愛(ài)吃香蕉",fontFilePath,
                false,false,true,3,50,0.3f,Color.blue);
        byte[] watermarkedImageBytes = convertImageToBytes(bufferedImage);

        String out_file_base_path = "doc/"+ UUID.randomUUID();
        System.out.println(out_file_base_path);
        saveImage(watermarkedImageBytes,out_file_base_path+".png");
    }
}

一些補(bǔ)充

1、使用okhttp下載時(shí)提示ssl證書校驗(yàn)失敗

通常證書合法，直接使用下列代碼即可進(jìn)行http請(qǐng)求和下載。

OkHttpClient client = new OkHttpClient();

如果需要忽略ssl校驗(yàn)，可以自定義OkHttpClient，如下所示：

import okhttp3.OkHttpClient;
import javax.net.ssl.*;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;

public class UnsafeOkHttpClient {
    public static OkHttpClient getUnsafeClient() {
        try {
            // 創(chuàng)建一個(gè)信任所有證書的 TrustManager
            final X509TrustManager trustManager = new X509TrustManager() {
                @Override
                public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException {}
                @Override
                public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException {}
                @Override
                public X509Certificate[] getAcceptedIssuers() {
                    return new X509Certificate[0];
                }
            };

            // 獲取 SSLContext 并初始化
            SSLContext sslContext = SSLContext.getInstance("SSL");
            sslContext.init(null, new TrustManager[]{trustManager}, new java.security.SecureRandom());
            // 創(chuàng)建忽略證書的 SSLSocketFactory
            SSLSocketFactory sslSocketFactory = sslContext.getSocketFactory();

            // 構(gòu)建 OkHttpClient
            OkHttpClient.Builder builder = new OkHttpClient.Builder();
            builder.sslSocketFactory(sslSocketFactory, trustManager);
            builder.hostnameVerifier((hostname, session) -> true); // 忽略主機(jī)名驗(yàn)證

            return builder.build();
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
}

2、windows正常，但發(fā)布生產(chǎn)linux水印亂碼

一般出現(xiàn)此類問(wèn)題的根源在于linux環(huán)境不存在對(duì)應(yīng)的字體文件。

windows環(huán)境使用下列代碼進(jìn)行測(cè)試即可。

Graphics2D g2d = watermarkedImage.createGraphics();
g2d.drawImage(image, 0, 0, null);
// windows環(huán)境正常
g2d.setFont(new Font("微軟雅黑", isItalic? Font.ITALIC : Font.PLAIN, 30));
g2d.setFont(derivedFont);

但如果需要指定特定的字體文件，可以使用如下寫法。

Graphics2D g2d = watermarkedImage.createGraphics();
g2d.drawImage(image, 0, 0, null);

// linux 環(huán)境指定特定的字體文件
Font customFont = Font.createFont(Font.TRUETYPE_FONT, new File(fontFilePath));
int fontStyle = isItalic? Font.ITALIC : Font.PLAIN;
Font derivedFont = customFont.deriveFont(fontStyle, waterMarkFontSize);

g2d.setFont(derivedFont);

字體文件可以從windows系統(tǒng)的C:\Windows\Fonts中進(jìn)行拷貝。

到此這篇關(guān)于Java實(shí)現(xiàn)根據(jù)圖片url下載圖片并動(dòng)態(tài)添加水印的文章就介紹到這了,更多相關(guān)Java根據(jù)圖片url下載內(nèi)容請(qǐng)搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家！

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