java实现PDF报表生成通用工具类，可实现添加水印，提供前端下载方法。
首先在maven中引入需用到的jar包：
<!--引入PDF处理-->
<dependency>
<groupId>com.itextpdf</groupId>
<artifactId>itextpdf</artifactId>
<version>5.5.13</version>
</dependency>
<dependency>
<groupId>com.itextpdf</groupId>
<artifactId>itext-asian</artifactId>
<version>5.2.0</version>
</dependency>
PdfUtil工具类：
import com.itextpdf.text.*;
import com.itextpdf.text.Font;
import com.itextpdf.text.Rectangle;
import com.itextpdf.text.pdf.*;
import org.apache.commons.io.IOUtils;
import javax.servlet.http.HttpServletResponse;
import javax.swing.*;
import java.awt.*;
import java.io.*;
import java.lang.reflect.Field;
import java.util.List;
/**
* @author ：debruyne
* @date ：Created in 2019/12/10 15:18
* @description： PDF文件工具类
* @modified By：
* @version: $
*/
public class PdfUtil {
/**
* @param objectList 报表内容list
* @param copyPath 生成文件路径（至文件名）
* @param title 报表标题
* @param columnHeaders 报表 列标题数组
* @param <T> 内容类型
* @throws IllegalAccessException
*/
public static <T> void generatePdfFile(List<T> objectList, String copyPath, String title, String[] columnHeaders) throws IllegalAccessException {
try {
// 新建文件
Document document = new Document();
//建立一个书写器(Writer)与document对象关联，并把文档写入到磁盘中
PdfWriter.getInstance(document, new FileOutputStream(copyPath));
document.open();
// 中文字体
BaseFont bfChinese = BaseFont.createFont("STSong-Light", "UniGB-UCS2-H", BaseFont.EMBEDDED);
// 标题字体
Font titleChinese = new Font(bfChinese, 16, Font.BOLD);
// 内容小标题字体
Font contenttitleChinese = new Font(bfChinese, 11, Font.BOLD);
//设置标题
Paragraph par = new Paragraph(title, titleChinese);
par.setAlignment(Element.ALIGN_CENTER);
//文档中加入标题
document.add(par);
//文档中加入空行
Paragraph blankRow51 = new Paragraph(18f, " ", contenttitleChinese);
document.add(blankRow51);
//设置表格的列数
int col = columnHeaders.length;
//新建一个表格
PdfPTable table = new PdfPTable(col);
//设置表格占PDF文档100%宽度
table.setWidthPercentage(100);
//设置每列表格宽度
int[] widths=new int[columnHeaders.length];
int wight=100/columnHeaders.length;
for (int i = 0; i < widths.length; i++) {
widths[i]=wight;
}
table.setWidths(widths);
//设置表格标题样式
BaseColor lightGrey01 = new BaseColor(0xCC,0xCC,0xCC);
for (int i = 0; i < columnHeaders.length; i++) {
PdfPCell cell = toPdfPCell(columnHeaders[i],Element.ALIGN_CENTER);
cell.setBackgroundColor(lightGrey01);
table.addCell(cell);
}
//表格赋值啊，这里使用反射获取对象属性
if (objectList.size()>0){
for (T obj : objectList) {
Field[] fields= obj.getClass().getDeclaredFields();
for (Field field : fields) {
field.setAccessible(true);
table.addCell(toPdfPCell(field.get(obj).toString(),Element.ALIGN_CENTER));
}
}
}
//把表格加入到文档中
document.add(table);
//关闭文档
document.close();
} catch (DocumentException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public static PdfPCell toPdfPCell(String name, int align) throws DocumentException, IOException {
// 中文字体
BaseFont bfChinese = BaseFont.createFont("STSong-Light", "UniGB-UCS2-H", BaseFont.NOT_EMBEDDED);
// 内容字体
Font fontChinese = new Font(bfChinese, 11, Font.NORMAL);
PdfPCell cell=new PdfPCell(new Paragraph(name,fontChinese));
// 设置内容水平居中显示
cell.setHorizontalAlignment(align);
// 设置垂直居中
cell.setVerticalAlignment(Element.ALIGN_MIDDLE);
return cell;
}
/**
* 给PDF文件加水印
* @param inputFile 操作的文件位置
* @param outputFile 生成的文件位置
* @param date 水印内容
* @param user 水印内容
*/
public static void waterMark(String inputFile, String outputFile, String date,String user) {
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(date);
metrics = label.getFontMetrics(label.getFont());
textH = metrics.getHeight();
textW = metrics.stringWidth(label.getText());
PdfContentByte under;
for (int i = 1; i < total; i++) {
under = stamper.getOverContent(i);
under.saveState();
under.setGState(gs);
under.beginText();
under.setFontAndSize(base, 18);
//水印位置坐标
int dateHeight = 20;
int dateWidth = 520;
int userHeight = 40;
int userWidth = 560;
// 水印文字成0度角倾斜
under.showTextAligned(Element.ALIGN_LEFT, user, userWidth - textW,
userHeight - textH, 0);
under.showTextAligned(Element.ALIGN_LEFT, date, dateWidth - textW,
dateHeight - textH, 0);
under.endText();
}
//关闭流
stamper.close();
reader.close();
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 进行PDF文件下载
* @param filename 服务器文件
* @param exportFileName 下载到客户端的文件名
* @param response
*/
public void downloadPDF(String filename,String exportFileName, HttpServletResponse response){
InputStream input = null;
OutputStream out = null;
try {
input=new FileInputStream(filename);
response.reset();
response.setContentType("application/pdf");
response.addHeader("Content-Disposition", "attachment;filename=\""
+ new String(exportFileName.getBytes("utf-8"), "ISO_8859_1") + "\"");
response.addHeader("Content-Length", "" + input.available());
out = response.getOutputStream();
IOUtils.copy(input, out);
}catch (Exception e){
e.printStackTrace();
}
finally {
IOUtils.closeQuietly(input);
IOUtils.closeQuietly(out);
}
}
}
测试实体类Student:
public class Student {
private String name;
private String gender;
private String phone;
private String studentId;
private String math;
private String english;
public String getMath() {
return math;
}
public void setMath(String math) {
this.math = math;
}
public String getEnglish() {
return english;
}
public void setEnglish(String english) {
this.english = english;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
public String getStudentId() {
return studentId;
}
public void setStudentId(String studentId) {
this.studentId = studentId;
}
}
测试方法：
public class Test {
public static void main(String[] args) {
Test test=new Test();
test.test();
}
private void test(){
List<Student> list=new ArrayList();
for (int i=0;i<=5;i++){
Student student=new Student();
student.setGender("男");
student.setName("张三");
student.setPhone("1320818027"+i);
student.setStudentId("20153106059"+i);
student.setMath("9"+i);
student.setEnglish("8"+i);
list.add(student);
}
String title="成绩单";
//这里需要保持标题数组的顺序和Student中定义的顺序一致
String[] columnHeaders={"姓名","性别","电话","学号","数学","英语"};
try {
//生成PDF文件，不带水印
PdfUtil.generatePdfFile(list,"E:\\File\\student.pdf",title,columnHeaders);
//给刚才生成的PDF文件加水印（时间+用户）
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String date=sdf.format(new Date());
PdfUtil.waterMark("E:\\File\\student.pdf","E:\\File\\studentwater.pdf",date,"debruyne");
} catch (IllegalAccessException e) {
e.printStackTrace();
}
}
}
不带 水印的文件student.pdf：
带水印的文件studentwater.pdf：
附前端下载方法：
fileDownload: function(action) {
var formNode = document.createElement('form');
var formId = new Date().getTime();
formNode.id = formId;
formNode.method = 'post';
formNode.action = action;
$('body').append(formNode);
$('#' + formId).submit();
}
$(document).on('click', '.j-decisionfiledownload-btn', function() {
util.fileDownload('路径/'+ 参数);
});