1､引用Maven的pom.xml中引用配置
<dependency>
<groupId>com.itextpdf</groupId>
<artifactId>itextpdf</artifactId>
<version>5.5.9</version>
</dependency>
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>28.2-jre</version>
</dependency>2､使用URLConnection下载多个图片到本地
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
public class Utils {
public static String getParam(String url, String name) {
String params = url.substring(url.indexOf("?") + 1, url.length());
Map<String, String> split = Splitter.on("&").withKeyValueSeparator("=").split(params);
return split.get(name);
}
/**
* @Description: 下载多个图片
* @param picurls 多个图片地址 path 图片下载存放目录 fileNames 多个文件名称 ,不传fileNames=null则取url中参数值，此时ParamName必须传
* @return void
* @throws
*/
public static void downloadPicture(String[] picurls,String path,String[] fileNames,String ParamName) throws IOException {
try {
//多个图片下载地址
for(int i=0;i<picurls.length;i++) {
//根据图片地址构建URL
URL url= new URL(picurls[i]);
URLConnection conn = url.openConnection();
conn.setReadTimeout(10000);
conn.setConnectTimeout(10000);
conn.connect();
DataInputStream dataInputStream = new DataInputStream(conn.getInputStream());
//创建目录和图片
File pathFile=new File(path);
File file =null;
if(fileNames!=null){
file=new File(path+File.separator+fileNames[i]);
} else {
file=new File(path+File.separator+ getParam(picurls[i],ParamName));
}
if(!pathFile.exists()) {
pathFile.mkdirs();
file.createNewFile();
}
if(!file.exists()) {
file.createNewFile();
}
//通过流复制图片
FileOutputStream fileOutputStream = new FileOutputStream(file);
ByteArrayOutputStream output = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int length;
while ((length = dataInputStream.read(buffer)) > 0) {
output.write(buffer, 0, length);
}
fileOutputStream.write(output.toByteArray());
dataInputStream.close();
fileOutputStream.close();
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
3､使用IText合成多个图片到单个pdf
1) 使用IText将多个图片转成多个pdf文件
public static void imageToPDF(String path,String imagePath)
{
File file = new File(path);
Document document = new Document();
try {
PdfWriter.getInstance(document, new FileOutputStream(file));
} catch (FileNotFoundException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (DocumentException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
document.open();
document.newPage();
Image image = null;
try {
try {
image = Image.getInstance(imagePath);
} catch (BadElementException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
image.setAbsolutePosition(0, 0);
image.setBorderWidth(0);
image.scaleAbsolute(PageSize.A4);
try {
document.add(image);
} catch (DocumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
document.close();
}
2) 使用IText将多个pdf合成到一个pdf文件
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import com.lowagie.text.Document;
import com.lowagie.text.pdf.BaseFont;
import com.lowagie.text.pdf.PdfContentByte;
import com.lowagie.text.pdf.PdfImportedPage;
import com.lowagie.text.pdf.PdfReader;
import com.lowagie.text.pdf.PdfWriter;
public class MergePDF {
public static void main(String[] args) {
try {
List<InputStream> pdfs = new ArrayList<InputStream>();
pdfs.add(new FileInputStream("c:\\1.pdf"));
pdfs.add(new FileInputStream("c:\\2.pdf"));
OutputStream output = new FileOutputStream("c:\\merge.pdf");
MergePDF.concatPDFs(pdfs, output, true);
} catch (Exception e) {
e.printStackTrace();
}
}
public static void concatPDFs(List<InputStream> streamOfPDFFiles,
OutputStream outputStream, boolean paginate) {
Document document = new Document();
try {
List<InputStream> pdfs = streamOfPDFFiles;
List<PdfReader> readers = new ArrayList<PdfReader>();
int totalPages = 0;
Iterator<InputStream> iteratorPDFs = pdfs.iterator();
// Create Readers for the pdfs.
while (iteratorPDFs.hasNext()) {
InputStream pdf = iteratorPDFs.next();
PdfReader pdfReader = new PdfReader(pdf);
readers.add(pdfReader);
totalPages += pdfReader.getNumberOfPages();
}
// Create a writer for the outputstream
PdfWriter writer = PdfWriter.getInstance(document, outputStream);
document.open();
BaseFont bf = BaseFont.createFont(BaseFont.HELVETICA,
BaseFont.CP1252, BaseFont.NOT_EMBEDDED);
PdfContentByte cb = writer.getDirectContent(); // Holds the PDF
// data
PdfImportedPage page;
int currentPageNumber = 0;
int pageOfCurrentReaderPDF = 0;
Iterator<PdfReader> iteratorPDFReader = readers.iterator();
// Loop through the PDF files and add to the output.
while (iteratorPDFReader.hasNext()) {
PdfReader pdfReader = iteratorPDFReader.next();
// Create a new page in the target for each source page.
while (pageOfCurrentReaderPDF < pdfReader.getNumberOfPages()) {
document.newPage();
pageOfCurrentReaderPDF++;
currentPageNumber++;
page = writer.getImportedPage(pdfReader,
pageOfCurrentReaderPDF);
cb.addTemplate(page, 0, 0);
// Code for pagination.
if (paginate) {
cb.beginText();
cb.setFontAndSize(bf, 9);
cb.showTextAligned(PdfContentByte.ALIGN_CENTER, ""
+ currentPageNumber + " of " + totalPages, 520,
5, 0);
cb.endText();
}
}
pageOfCurrentReaderPDF = 0;
}
outputStream.flush();
document.close();
outputStream.close();
} catch (Exception e) {
e.printStackTrace();
} finally {
if (document.isOpen())
document.close();
try {
if (outputStream != null)
outputStream.close();
} catch (IOException ioe) {
ioe.printStackTrace();
}
}
}
}
相关文档：iText PDF Java API 入门介绍教程