java实现图片和pdf添加铺满文字水印

依赖jar包

<!-- pdf start -->

<dependency>

    <groupId>com.itextpdf</groupId>

    <artifactId>itextpdf</artifactId>
    <version>5.3.2</version>
</dependency>

<dependency>
    <groupId>com.itextpdf</groupId>
    <artifactId>itext-asian</artifactId>
    <version>5.2.0</version>
</dependency>

<!-- pdf end -->

一,图片添加铺满水印

====================================start========================================

package cn.*.*.*;

import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;

import javax.imageio.ImageIO;

/**
*
* @Title ImageWatermarkUtil
* @Description
* @author Zheng.Zeng
* @date 2018年8月29日 下午4:47:38
*/
public class ImgFilePWartermark {
// 水印透明度
private static float alpha = 0.6f;
// 水印文字大小
public static final int FONT_SIZE = 18;
// 水印文字字体
private static Font font = new Font ("宋体", Font.PLAIN, FONT_SIZE);
// 水印文字颜色
private static Color color = Color.white;
// 水印之间的间隔
private static final int XMOVE = 80;
// 水印之间的间隔
private static final int YMOVE = 80;

/**
* 给图片添加水印文字
* @param logoText 水印文字
* @param srcImgPath 源图片路径
* @param targerPath 目标图片路径
*/
public static void ImageByText (String logoText, String srcImgPath, String targerPath) {
ImageByText (logoText, srcImgPath, targerPath, null);
}


/**
* 获取文本长度。汉字为1:1,英文和数字为2:1
*/
private static int getTextLength (String text) {
int length = text.length ();
for (int i = 0; i < text.length (); i++) {
String s = String.valueOf (text.charAt (i));
if (s.getBytes ().length > 1) {
length++;
}
}
length = length % 2 == 0 ? length / 2 : length / 2 + 1;
return length;
}


/**
* 给图片添加水印文字、可设置水印文字的旋转角度
*
* @param logoText
* @param srcImgPath
* @param targerPath
* @param degree
*/
public static void ImageByText (String logoText, String srcImgPath, String targerPath, Integer degree) {

InputStream is = null;
OutputStream os = null;
try {
// 源图片
Image srcImg = ImageIO.read (new File (srcImgPath));
int width = srcImg.getWidth (null);// 原图宽度
int height = srcImg.getHeight (null);// 原图高度
BufferedImage buffImg = new BufferedImage (srcImg.getWidth (null), srcImg.getHeight (null),
BufferedImage.TYPE_INT_RGB);
// 得到画笔对象
Graphics2D g = buffImg.createGraphics ();
// 设置对线段的锯齿状边缘处理
g.setRenderingHint (RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g.drawImage (srcImg.getScaledInstance (srcImg.getWidth (null), srcImg.getHeight (null), Image.SCALE_SMOOTH),
0, 0, null);
// 设置水印旋转
if (null != degree) {
g.rotate (Math.toRadians (degree), (double) buffImg.getWidth () / 2, (double) buffImg.getHeight () / 2);
}
// 设置水印文字颜色
g.setColor (color);
// 设置水印文字Font
g.setFont (font);
// 设置水印文字透明度
g.setComposite (AlphaComposite.getInstance (AlphaComposite.SRC_ATOP, alpha));

int x = -width / 2;
int y = -height / 2;
int markWidth = FONT_SIZE * getTextLength (logoText);// 字体长度
int markHeight = FONT_SIZE;// 字体高度

// 循环添加水印
while (x < width * 1.5) {
y = -height / 2;
while (y < height * 1.5) {
g.drawString (logoText, x, y);

y += markHeight + YMOVE;
}
x += markWidth + XMOVE;
}
// 释放资源
g.dispose ();
// 生成图片
os = new FileOutputStream (targerPath);
ImageIO.write (buffImg, "JPG", os);
System.out.println ("添加水印文字成功!");
} catch (Exception e) {
e.printStackTrace ();
} finally {
try {
if (null != is)
is.close ();
} catch (Exception e) {
e.printStackTrace ();
}
try {
if (null != os)
os.close ();
} catch (Exception e) {
e.printStackTrace ();
}
}
}

public static void main (String[] args) {
String srcImgPath = "C:\Users\Administrator\Pictures\Saved Pictures\太阳系星体桌面壁纸-ZOL桌面壁纸_files\ChMkJlmhRcaIf3kwAAGdeRjj2I0AAf_UAJJWF4AAZ2R574.jpg";
// 水印文字
String logoText = "打印无效";
String targerTextPath2 = "C:\Users\Administrator\Pictures\Saved Pictures\123123.jpg";
System.out.println ("给图片添加水印文字开始...");
// 给图片添加正水印文字
//ImgFilePWartermark.ImageByText (logoText, srcImgPath, targerTextPath2, -40);
// 给图片添加斜水印文字
ImgFilePWartermark.ImageByText (logoText, srcImgPath, targerTextPath2, -40);
System.out.println ("给图片添加水印文字结束...");
}
}

====================================end========================================

二.pdf添加铺满文字水印

====================================start========================================

package cn.cnnho.wartmark.startegy;
import java.awt.FontMetrics;
import java.io.FileOutputStream;
import javax.swing.JLabel;
import com.itextpdf.text.Element;
import com.itextpdf.text.Rectangle;
import com.itextpdf.text.pdf.BaseFont;
import com.itextpdf.text.pdf.PdfContentByte;
import com.itextpdf.text.pdf.PdfGState;
import com.itextpdf.text.pdf.PdfReader;
import com.itextpdf.text.pdf.PdfStamper;

public class PdfFilePWartermark {

public static void main(String[] args) {
waterMark("F://公告内容//关于结合中国特殊消费习惯的星优选供应链上游、下游业务指导.pdf", "F://公告内容//111.pdf", "打印无效");
}


private static int interval = -5;
public static void waterMark(String inputFile,
String outputFile, String waterMarkName) {
try {
PdfReader reader = new PdfReader(inputFile);
PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(
outputFile));

BaseFont base = BaseFont.createFont("STSong-Light", "UniGB-UCS2-H", BaseFont.EMBEDDED);

Rectangle pageRect = null;
PdfGState gs = new PdfGState();
gs.setFillOpacity(0.3f);
gs.setStrokeOpacity(0.4f);
int total = reader.getNumberOfPages() + 1;

JLabel label = new JLabel();
FontMetrics metrics;
int textH = 0;
int textW = 0;
label.setText(waterMarkName);
metrics = label.getFontMetrics(label.getFont());
textH = metrics.getHeight();
textW = metrics.stringWidth(label.getText());

PdfContentByte under;
for (int i = 1; i < total; i++) {
pageRect = reader.getPageSizeWithRotation(i);
under = stamper.getOverContent(i);
under.saveState();
under.setGState(gs);
under.beginText();
under.setFontAndSize(base, 20);

//水印文字成30度角倾斜
//你可以随心所欲的改你自己想要的角度
for (int height = interval + textH; height < pageRect.getHeight();
height = height + textH*3) {
for (int width = interval + textW;
width < pageRect.getWidth() + textW;
width = width + textW*2)
{ under.showTextAligned(Element.ALIGN_LEFT,waterMarkName, width - textW,
height - textH, 30);
}
}
// 添加水印文字
under.endText();
}
//说三遍
//一定不要忘记关闭流
//一定不要忘记关闭流
//一定不要忘记关闭流
stamper.close();
reader.close();
} catch (Exception e) {
e.printStackTrace();
}
}


}

====================================end========================================

原文地址:https://www.cnblogs.com/guangxiang/p/10892530.html