下面的代码获取 PDF 文件并将其显示在浏览器中。
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.lowagie.text.Document;
import com.lowagie.text.DocumentException;
import com.lowagie.text.pdf.PdfReader;
import com.lowagie.text.pdf.PdfStamper;
import com.lowagie.text.pdf.PdfStream;
import com.lowagie.text.pdf.PdfWriter;
public class WelcomeServlet extends HttpServlet {
private static final String DOCUMENT_LOCATION = "H:\\testPDF.pdf"; // a test pdf on my PC
@Override
public void init(ServletConfig config) throws ServletException {
super.init(config);
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
PdfReader reader = new PdfReader(DOCUMENT_LOCATION);
PdfStamper stamper = null;
try {
stamper = new PdfStamper(reader, baos);
} catch (DocumentException e) {
e.printStackTrace();
}
try {
stamper.close();
} catch (DocumentException e) {
System.out.println("Why is it making me do this?");
e.printStackTrace();
}
// set some response headers
response.setHeader("Expires", "0");
response.setHeader("Cache-Control", "must-revalidate, post-check=0, pre-check=0");
response.setHeader("Pragma", "public");
response.setContentType("application/pdf");
response.setContentLength(baos.size());
OutputStream os = response.getOutputStream();
baos.writeTo(os);
os.flush();
os.close();
}
}
如果我将其更改为此代码,它不会返回文件。唯一的区别是处理 PdfStamper 的行被删除。
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.lowagie.text.Document;
import com.lowagie.text.DocumentException;
import com.lowagie.text.pdf.PdfReader;
import com.lowagie.text.pdf.PdfStamper;
import com.lowagie.text.pdf.PdfStream;
import com.lowagie.text.pdf.PdfWriter;
public class WelcomeServlet extends HttpServlet {
private static final String DOCUMENT_LOCATION = "H:\\testPDF.pdf"; // a test pdf on my PC
@Override
public void init(ServletConfig config) throws ServletException {
super.init(config);
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
PdfReader reader = new PdfReader(DOCUMENT_LOCATION);
// set some response headers
response.setHeader("Expires", "0");
response.setHeader("Cache-Control", "must-revalidate, post-check=0, pre-check=0");
response.setHeader("Pragma", "public");
response.setContentType("application/pdf");
response.setContentLength(baos.size());
OutputStream os = response.getOutputStream();
baos.writeTo(os);
os.flush();
os.close();
}
}
为什么这只适用于 PdfStamper?我不想做任何盖章,我只想在浏览器中显示PDF。我是否遗漏了一些基本上可以代替 iText 中的 PdfStamper 的东西???