Java实现PDF在线预览功能(四种方式)

@RequestMapping ( "/preview1" )

public void er(HttpServletResponse response){

     File file = new File( "G:\\桌面\\Thymeleaf3.0中文翻译文档@HdhCmsTestjava1234测试数据.pdf" );

     if (file.exists()){

         byte [] data = null ;

         try {

             FileInputStream input = new FileInputStream(file);

             data = new byte [input.available()];

             input.read(data);

             response.getOutputStream().write(data);

             input.close();

         } catch (Exception e) {

             System.out.println(e);

         }

     } else {

         return ;

     }

}

@ResponseBody

@RequestMapping ( "/preview2" )

public void findPdf( HttpServletResponse response) throws IOException{

     response.setContentType( "application/pdf" );

     FileInputStream in = new FileInputStream( new File( "G:\\桌面\\Thymeleaf3.0中文翻译文档@HdhCmsTestjava1234测试数据.pdf" ));

     OutputStream out = response.getOutputStream();

     byte [] b = new byte [ 512 ];

     while ((in.read(b))!=- 1 ) {

         out.write(b);

     }

     out.flush();

     in.close();

     out.close();

}

@ResponseBody

@RequestMapping ( "/preview3" )

public void devDoc(HttpServletRequest request, HttpServletResponse response, String storeName) throws Exception {

     request.setCharacterEncoding( "UTF-8" );

     String ctxPath = request.getSession().getServletContext().getRealPath( "" );

     String downLoadPath = "G:\\桌面\\Thymeleaf3.0中文翻译文档@HdhCmsTestjava1234测试数据.pdf" ;

     response.setContentType( "application/pdf" );

     FileInputStream in = new FileInputStream( new File(downLoadPath));

     OutputStream out = response.getOutputStream();

     byte [] b = new byte [ 1024 ];

     while ((in.read(b))!=- 1 ) {

         out.write(b);

     }

     out.flush();

     in.close();

     out.close();

}

@ResponseBody

@RequestMapping ( "/preview" )

public void download( HttpServletResponse response

                     ) throws IOException {

     String filePath = "G:\\桌面\\Thymeleaf3.0中文翻译文档@HdhCmsTestjava1234测试数据.pdf" ;

     System.out.println( "filePath:" + filePath);

     File f = new File(filePath);

     if (!f.exists()) {

         response.sendError( 404 , "File not found!" );

         return ;

     }

     BufferedInputStream br = new BufferedInputStream( new FileInputStream(f));

     byte [] bs = new byte [ 1024 ];

     int len = 0 ;

     response.reset(); // 非常重要

     if ( true ) { // 在线打开方式

         URL u = new URL( "file:///" + filePath);

         String contentType = u.openConnection().getContentType();

         response.setContentType(contentType);

         response.setHeader( "Content-Disposition" , "inline;filename="

                 + "2019年上半年英语四级笔试准考证(戴林峰).pdf" );

         // 文件名应该编码成utf-8，注意：使用时，我们可忽略这句

     } else {

         // 纯下载方式

         response.setContentType( "application/x-msdownload" );

         response.setHeader( "Content-Disposition" , "attachment;filename="

                 + "2019年上半年英语四级笔试准考证(戴林峰).pdf" );

     }

     OutputStream out = response.getOutputStream();

     while ((len = br.read(bs)) > 0 ) {

         out.write(bs, 0 , len);

     }

     out.flush();

     out.close();

     br.close();

}

import java.io.File;

import java.io.FileInputStream;

import java.io.OutputStream;

import org.apache测试数据mons.io.IOUtils;

@RequestMapping (value = "/showpdf" )

     public void showpdf(HttpServletRequest request, HttpServletResponse response, Model model) {

         try {

             File file = new File( "D:/xyptFile/java.pdf" );

             FileInputStream fileInputStream = new FileInputStream(file);

             response.setHeader( "Content-Type" , "application/pdf" );

             OutputStream outputStream = response.getOutputStream();

             IOUtils.write(IOUtils.toByteArray(fileInputStream), outputStream);

         } catch (Exception e) {

             e.printStackTrace();

         }

     }