Java Tutorial/Servlet/XML Word PDF Mp3
Содержание
Display PDF based on Request Parameter
<source lang="java">
import java.io.*; import javax.servlet.*; import javax.servlet.http.*; import java.util.*; import java.net.*; public class MyServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String fileName = (String) request.getParameter("file");
if (fileName == null || fileName.equals(""))
throw new ServletException(
"Invalid or non-existent file parameter in UrlServlet servlet.");
if (fileName.indexOf(".pdf") == -1)
fileName = fileName + ".pdf";
URL pdfDir = null;
URLConnection urlConn = null;
ServletOutputStream stream = null;
BufferedInputStream buf = null;
try{
pdfDir = new URL(getServletContext().getInitParameter("remote-pdf-dir") + fileName);
} catch (MalformedURLException mue){
throw new ServletException(mue.getMessage());
}
try{
stream = response.getOutputStream();
response.setContentType("application/pdf");
response.addHeader(
"Content-Disposition","attachment; filename="+fileName );
urlConn = pdfDir.openConnection();
response.setContentLength( (int) urlConn.getContentLength() );
buf = new BufferedInputStream(urlConn.getInputStream());
int readBytes = 0;
while((readBytes = buf.read()) != -1)
stream.write(readBytes);
} catch (IOException ioe){
throw new ServletException(ioe.getMessage());
} finally {
if(stream != null)
stream.close();
if(buf != null)
buf.close();
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request,response);
}
}</source>
Send MP3 file back to client with Servlet
<source lang="java">
import java.io.*; import javax.servlet.*; import javax.servlet.http.*; import java.util.*; import java.text.DateFormat; public class MyServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String fileName = (String) request.getParameter("file");
if (fileName == null || fileName.equals(""))
throw new ServletException(
"Invalid or non-existent file parameter in SendMp3 servlet.");
if (fileName.indexOf(".mp3") == -1)
fileName = fileName + ".mp3";
String mp3Dir = getServletContext().getInitParameter("mp3-dir");
if (mp3Dir == null || mp3Dir.equals(""))
throw new ServletException(
"Invalid or non-existent mp3Dir context-param.");
ServletOutputStream stream = null;
BufferedInputStream buf = null;
try{
stream = response.getOutputStream();
File mp3 = new File(mp3Dir + "/" + fileName);
response.setContentType("audio/mpeg");
response.addHeader("Content-Disposition","attachment; filename="+fileName );
response.setContentLength( (int) mp3.length() );
FileInputStream input = new FileInputStream(mp3);
buf = new BufferedInputStream(input);
int readBytes = 0;
while((readBytes = buf.read()) != -1)
stream.write(readBytes);
} catch (IOException ioe){
throw new ServletException(ioe.getMessage());
} finally {
if(stream != null)
stream.close();
if(buf != null)
buf.close();
}
} //end doGet
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request,response);
}
}</source>
Send Pdf to client using Servlet
<source lang="java">
import java.io.*; import javax.servlet.*; import javax.servlet.http.*; import java.util.*; import java.text.DateFormat; public class MyServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String fileName = (String) request.getParameter("file");
if (fileName == null || fileName.equals(""))
throw new ServletException(
"Invalid or non-existent file parameter in SendPdf servlet.");
if (fileName.indexOf(".pdf") == -1)
fileName = fileName + ".pdf";
String pdfDir = getServletContext().getInitParameter("pdf-dir");
if (pdfDir == null || pdfDir.equals(""))
throw new ServletException(
"Invalid or non-existent "pdf-Dir" context-param.");
ServletOutputStream stream = null;
BufferedInputStream buf = null;
try{
stream = response.getOutputStream();
File pdf = new File(pdfDir + "/" + fileName);
response.setContentType("application/pdf");
response.addHeader(
"Content-Disposition","attachment; filename="+fileName );
response.setContentLength( (int) pdf.length() );
FileInputStream input = new FileInputStream(pdf);
buf = new BufferedInputStream(input);
int readBytes = 0;
while((readBytes = buf.read()) != -1)
stream.write(readBytes);
} catch (IOException ioe){
throw new ServletException(ioe.getMessage());
} finally {
if(stream != null)
stream.close();
if(buf != null)
buf.close();
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request,response);
}
}</source>
Send Word file to client in a Servlet
<source lang="java">
import java.io.*; import javax.servlet.*; import javax.servlet.http.*; import java.util.*; import java.text.DateFormat; public class MyServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String fileName = (String) request.getParameter("file");
if (fileName == null || fileName.equals(""))
throw new ServletException(
"Invalid or non-existent file parameter in SendWord servlet.");
if (fileName.indexOf(".doc") == -1)
fileName = fileName + ".doc";
String wordDir = getServletContext().getInitParameter("word-dir");
if (wordDir == null || wordDir.equals(""))
throw new ServletException(
"Invalid or non-existent wordDir context-param.");
ServletOutputStream stream = null;
BufferedInputStream buf = null;
try{
stream = response.getOutputStream();
File doc = new File(wordDir + "/" + fileName);
//set response headers
response.setContentType("application/msword");
response.addHeader(
"Content-Disposition","attachment; filename="+fileName );
response.setContentLength( (int) doc.length() );
FileInputStream input = new FileInputStream(doc);
buf = new BufferedInputStream(input);
int readBytes = 0;
while((readBytes = buf.read()) != -1)
stream.write(readBytes);
} catch (IOException ioe){
throw new ServletException(ioe.getMessage());
} finally {
if(stream != null)
stream.close();
if(buf != null)
buf.close();
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request,response);
}
}</source>
Send XML data to client
<source lang="java">
import java.io.*; import javax.servlet.*; import javax.servlet.http.*; import java.util.*; import java.net.*; public class MyServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String file = "/WEB-INF/web.xml";
URL url = null;
URLConnection urlConn = null;
PrintWriter out = null;
BufferedInputStream buf = null;
try{
out = response.getWriter();
url = getServletContext().getResource(file);
response.setContentType("text/xml");
urlConn = url.openConnection();
urlConn.connect();
buf = new BufferedInputStream(urlConn.getInputStream());
int readBytes = 0;
//read from the file; write to the PrintWriter
while((readBytes = buf.read()) != -1)
out.write(readBytes);
} catch (MalformedURLException mue){
throw new ServletException(mue.getMessage());
} catch (IOException ioe){
throw new ServletException(ioe.getMessage());
} finally {
if(out != null)
out.close();
if(buf != null)
buf.close();
}
} //end doGet
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request,response);
}
}</source>
Send XML to client using Servlet
<source lang="java">
import java.io.*; import javax.servlet.*; import javax.servlet.http.*; import java.util.*; import java.text.DateFormat; public class MyServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String fileName = (String) request.getParameter("file");
if (fileName == null || fileName.equals(""))
throw new ServletException(
"Invalid or non-existent file parameter in SendXml servlet.");
if (fileName.indexOf(".xml") == -1)
fileName = fileName + ".xml";
String xmlDir = getServletContext().getInitParameter("xml-dir");
if (xmlDir == null || xmlDir.equals(""))
throw new ServletException(
"Invalid or non-existent xmlDir context-param.");
ServletOutputStream stream = null;
BufferedInputStream buf = null;
try{
stream = response.getOutputStream();
File xml = new File(xmlDir + "/" + fileName);
response.setContentType("text/xml");
response.addHeader(
"Content-Disposition","attachment; filename="+fileName );
response.setContentLength( (int) xml.length() );
FileInputStream input = new FileInputStream(xml);
buf = new BufferedInputStream(input);
int readBytes = 0;
//read from the file; write to the ServletOutputStream
while((readBytes = buf.read()) != -1)
stream.write(readBytes);
} catch (IOException ioe){
throw new ServletException(ioe.getMessage());
} finally {
if(stream != null)
stream.close();
if(buf != null)
buf.close();
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request,response);
}
}</source>
Use XPath in servlet
<source lang="java">
import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.jdom.Document; import org.jdom.JDOMException; import org.jdom.input.SAXBuilder; import org.jdom.xpath.XPath; public class PostServlet extends HttpServlet {
private SAXBuilder builder = new SAXBuilder();
private XPath nameXPath;
private XPath yearXPath;
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
if (!"text/xml".equals(request.getContentType())) {
response.getWriter().println("Please post as text/xml.");
} else {
try {
Document doc = builder.build(request.getReader());
StringBuffer buff = new StringBuffer();
buff.append("You searched for name "" + nameXPath.valueOf(doc)
+ """);
String year = yearXPath.valueOf(doc);
if (!"notselected".equals(year)) {
buff.append(" and year "" + year + """);
}
buff.append(".");
response.getWriter().print(buff.toString());
} catch (JDOMException e) {
response.getWriter().print(
"Error getting search terms: " + e.getMessage());
}
}
}
public void init() throws ServletException {
try {
nameXPath = XPath.newInstance("/search/name/text()");
yearXPath = XPath.newInstance("/search/year/text()");
} catch (JDOMException e) {
throw new ServletException("Unable to create XPaths", e);
}
super.init();
}
}</source>
