sending and receiving xml in java application

8/14/2019 Sending and receiving xml in java application

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Sending and receiving XML

in a Java application

Sean C. Sullivansean seansullivan comSeptember 2003


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Agenda

XML

XML via HTTP

XML via JMS XML via JavaMail

XML via FTP


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Agenda

XML

XML via HTTP


XML via FTP


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XML

Sun Microsystems

SUNW

XML is a syntax for describing and structuring data


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Application integration

[If you look at] where XML is really, trulybeing used right now, it's [for] lightweight,quick and dirty enterprise application

integration. [] you could achieveremarkably acceptable results in enterpriseapplication integration simply by binding aset of XML messages to ship back and

forth.

Tim Bray, 9/23/2003, news.com interview


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Data exchange

Application BApplication A


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XML request

97210

12208

35

OVERNIGHT


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XML response

68.00


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Agenda

XML

XML via HTTP


XML via FTP


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HTTP protocol

HTTP

server

HTTP

client

request


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HTTP protocol

HTTP

server

HTTP

client

request

response


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HTTP protocol methods

GET

POST

HEAD


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HTTP headers

Content-Type

Accept


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MIME types for XML

text/xml

application/xml

text/xml-external-parsed-entity application/xml-external-parsed-entity

application/xml-dtd

application/soap+xml


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Jakarta Commons HTTPClient


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Example: HTTP POST

import org.apache.commons.httpclient.*;

importorg.apache.commons.httpclient.methods*;

PostMethod post = new PostMethod(

http://www.foo.com/bar);

post.setRequestBody(strXML);

post.setRequestHeader(

Content-type,

application/xml);


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Example: HTTP POST

post.setRequestHeader(

Accept,

application/xml);

HttpClient client = new HttpClient();

int result = client.executeMethod(post);

//

String strXMLResponse =post.getResponseBodyAsString();

post.releaseConnection();


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Receiving XML using a Servlet

public class XMLServlet extends

javax.servlet.http.HttpServlet

{

protected void doPost(

HttpServletRequest req,

HttpServletResponse resp)

{// method implementation

}

}


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doPost method

//

String type = req.getContentType();

int contentLength =

req.getContentLength();

char[] xmlData = newchar[contentLength];

BufferedReader reader =

httpRequest.getReader();

//


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doPost (continued)

do

{

n = reader.read(xmlData, bytesRead,

xmlData.length - bytesRead);if (n > 0)

{

bytesRead += n;

}

} while ( (n != -1)

&& (bytesRead < contentLength) )


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Agenda

XML

XML via HTTP


XML via FTP


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Java Message Service

messaging API for J2EE platform

Point-to-point

JMS Queue

Publish-Subscribe

JMS Topic

at most once delivery mode

transactional


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JMS message queue

Message

Producer

Message Queue

123Message

Consumer


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Sending XML using JMS

import javax.jms.*;

import javax.naming.*;

Queue queue;

ConnectionFactory cf;

queue = /* lookup via JNDI */;

cf = /* lookup via JNDI */;

Connection conn = cf.createConnection();

Session session = conn.createSession();


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Receiving XML via JMS

Choose one:

javax.jms.MessageConsumer

Message Driven Bean (MDB)


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Example: Message Driven Bean

public void onMessage(Message msg)

{

//

if (msg instanceof TextMessage)

{

TextMessage tm = (Message) msg;

String strXML = tm.getText();}

//

}


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Example: XML via JavaMail

import javax.mail.*;

import javax.mail.internet.*;

Session sess = /* JNDI lookup */;MimeMessage msg = newMimeMessage(sess);

msg.setFrom(from);//


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//

msg.setRecipients(

Message.RecipientType.TO,recipients);

msg.setSubject(Hello XML);

//


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//

MimeBodyPart mbp = new MimeBodyPart();

mbp.setContent(strXML,

application/xml);

Multipart mp = new MimeMultipart();

mp.addBodyPart(mbp);

msg.setContent(mp);

Transport.send(msg);

//


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Agenda

XML

XML via HTTP


XML via FTP


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FTP with Jakarta Commons Net


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Example: XML via FTP

import org.apache.commons.net.ftp.*;

FTPClient ftp = new FTPClient();

ftp.connect(ftp.example.com);

ftp.login(username, password);


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Example: XML via FTP

ftp.setFileType(FTP.BINARY_FILE_TYPE);

ftp.enterLocalPassiveMode();

ftp.storeFile(foo.xml,

xmlInputStream);

ftp.logout();

ftp.disconnect();


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Additional topics

Sockets

SOAP

XML-RPC Binary encodings for XML


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Additional resources

http://www.w3.org/XML/

http://www.xml.com/

http://java.sun.com/xml/ http://xml.apache.org/

http://ws.apache.org/axis/

http://jakarta.apache.org/


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sending and receiving xml in java application

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