动态jsp页面转PDF输出到页面的实现方法

最近工作中遇到不少问题。总结一下。这段代码主要功能是将一个生成jsp页面转发成pdf输出到页面

需要利用itext

string html = servletutils.forward(request,response,"/web-inf/jsp/depot/print/jhd.jsp"); //转发请求到jsp，返回解析之后的内容而不是输出到浏览器
//system.out.println(html);
byte[] pdf = pdfutils.html2pdf(html);
response.setcontenttype("application/pdf");
response.setheader("content-length",string.valueof(pdf.length));
response.setheader("connection","keep-alive");
response.setheader("accept-ranges","none");
response.setheader("x-frame-options","deny");
outputstream out = response.getoutputstream();
out.write(pdf);
out.flush();
public class servletutils {
/**
* 此forward方法执行完毕之后不会输出内容到浏览器，而是把输出到字节流，最后以字符串的形式返回
* @param request
* @param response
* @param src
* @return
*/
public static string forward(httpservletrequest request, httpservletresponse response, string src) {
try{
/* ↓↓↓↓↓重新构造response，修改response中的输出流对象，使其输出到字节数组↓↓↓↓↓ */
final bytearrayoutputstream bytearrayoutputstream = new bytearrayoutputstream();
final servletoutputstream servletouputstream = new servletoutputstream() {
@override
public void write(int b) throws ioexception {
bytearrayoutputstream.write(b);
}
@override
public boolean isready() {
return false;
}
@override
public void setwritelistener(writelistener writelistener) {
}
};
final printwriter printwriter = new printwriter(new outputstreamwriter(bytearrayoutputstream, "utf-8"));
response = new httpservletresponsewrapper(response) {
public servletoutputstream getoutputstream() {
return servletouputstream;
}
public printwriter getwriter() {
return printwriter;
}
};
/* ↑↑↑↑↑↑重新构造response，修改response中的输出流对象，使其输出到字节数组↑↑↑↑↑↑ */
//执行forward操作
request.getrequestdispatcher(src).forward(request,response);
//把字节流中的内容太转为字符串
return new string(bytearrayoutputstream.tobytearray(),"utf-8");
}
catch (exception e){
throw new runtimeexception(e);
}
}
}
import com.itextpdf.text.*;
import com.itextpdf.text.pdf.pdfwriter;
import com.itextpdf.tool.xml.pipeline;
import com.itextpdf.tool.xml.xmlworker;
import com.itextpdf.tool.xml.xmlworkerfontprovider;
import com.itextpdf.tool.xml.xmlworkerhelper;
import com.itextpdf.tool.xml.exceptions.cssresolverexception;
import com.itextpdf.tool.xml.html.cssappliers;
import com.itextpdf.tool.xml.html.cssappliersimpl;
import com.itextpdf.tool.xml.html.tags;
import com.itextpdf.tool.xml.parser.xmlparser;
import com.itextpdf.tool.xml.pipeline.css.cssresolver;
import com.itextpdf.tool.xml.pipeline.css.cssresolverpipeline;
import com.itextpdf.tool.xml.pipeline.end.pdfwriterpipeline;
import com.itextpdf.tool.xml.pipeline.html.htmlpipeline;
import com.itextpdf.tool.xml.pipeline.html.htmlpipelinecontext;
import java.io.*;
/**
* pdf工具类
*/
public class pdfutils {
/**
* 把html转换成pdf，以字节数组的形式返回pdf文件
* @param html
* @return pdf字节数组
* @throws ioexception
* @throws documentexception
* @throws cssresolverexception
*/
public static byte[] html2pdf(string html) throws ioexception, documentexception,cssresolverexception {
document document = new document(pagesize.a4);
bytearrayoutputstream os = new bytearrayoutputstream();
pdfwriter writer = pdfwriter.getinstance(document,os);
document.open();
xmlworkerfontprovider fontprovider = new xmlworkerfontprovider(){
@override
public font getfont(string fontname, string encoding, float size, int style) {
return super.getfont(fontname == null ? "宋体" : fontname, encoding, size, style);
}
};
fontprovider.addfontsubstitute("lowagie", "garamond");
fontprovider.setuseunicode(true);
//使用我们的字体提供器，并将其设置为unicode字体样式
cssappliers cssappliers = new cssappliersimpl(fontprovider);
htmlpipelinecontext htmlcontext = new htmlpipelinecontext(cssappliers);
htmlcontext.settagfactory(tags.gethtmltagprocessorfactory());
cssresolver cssresolver = xmlworkerhelper.getinstance().getdefaultcssresolver(true);
pipeline<?> pipeline = new cssresolverpipeline(cssresolver,new htmlpipeline(htmlcontext, new pdfwriterpipeline(document,writer)));
xmlworker worker = new xmlworker(pipeline, true);
xmlparser p = new xmlparser(worker);
p.parse(new inputstreamreader(new bytearrayinputstream(html.getbytes("gbk"))));
document.close();
return os.tobytearray();
}
}

以上所述是小编给大家介绍的动态jsp页面转pdf输出到页面的实现方法，希望对大家有所帮助