1)直接在服務器上生成PDF文件。
<%@ page import ="com.lowagie.text.*
,com.lowagie.text.pdf.*, java.io.*"%>
<%
String filename =
"PDF"+(new Random()).nextInt()+".pdf" ;
Document document =
new Document(PageSize.A4);
ServletOutputStream out1
= response.getOutputStream();
try{
PdfWriter writer =
PdfWriter.getInstance(document,
new FileOutputStream(filename) );
document.open();
document.add(new Paragraph("Hello World"));
document.close();
}
catch(Exception e){}
%>
上面的程序在服務器上生成了壹個靜態的PDF文件。顯然,每次運行所得的PDF文件的名稱應該是獨壹無二不能有重的。本程序通過隨機函數來命名生成的PDF文件。本程序的缺點就是,每次運行都會在服務器上產生壹個PDF文件,如果不及時刪除,數量會越來越大,這顯然是站點維護者所不願意看到的。
2)將PDF文件通過流的形式輸送到客戶端的緩存。這樣做的好處是不會在服務器上留下任何“遺跡”。
i)直接通過JSP頁面生成
<%@
page import="java.io.*,
java.awt.Color,com.lowagie.text.*,
com.lowagie.text.pdf.*"%>
<%
response.setContentType
( "application/pdf" );
Document document = new Document();
ByteArrayOutputStream buffer
= new ByteArrayOutputStream();
PdfWriter writer=
PdfWriter.getInstance( document, buffer );
document.open();
document.add(new Paragraph("Hello World"));
document.close();
DataOutput output =
new DataOutputStream
( response.getOutputStream() );
byte[] bytes = buffer.toByteArray();
response.setContentLength(bytes.length);
for( int i = 0;
i < bytes.length;
i++ )
{
output.writeByte( bytes[i] );
}
%>
ii)通過Servlet生成
import java.io.*;
import javax.servlet.*;
import javax.servlet..lowagie.text.*;
import com.lowagie.text.pdf.*;
public void doGet
(HttpServletRequest request,
HttpServletResponse response)
throws IOException,ServletException
{
Document document =
new Document(PageSize.A4, 36,36,36,36);
ByteArrayOutputStream ba
= new ByteArrayOutputStream();
try
{
PdfWriter writer =
PdfWriter.getInstance(document, ba);
document.open();
document.add(new
Paragraph("Hello World"));
}
catch(DocumentException de)
{
de.printStackTrace();
System.err.println
("A Document error:" +de.getMessage());
}
document.close();
response.setContentType
("application/pdf");
response.setContentLength(ba.size());
ServletOutputStream out
= response.getOutputStream();
ba.writeTo(out);
out.flush();
}