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Posted to java-dev@axis.apache.org by th...@apache.org on 2005/08/19 14:46:33 UTC
svn commit: r233475 - /webservices/axis/trunk/java/xdocs/mtom-guide.html
Author: thilina
Date: Fri Aug 19 05:46:22 2005
New Revision: 233475
URL: http://svn.apache.org/viewcvs?rev=233475&view=rev
Log:
Correcting few typos
Modified:
webservices/axis/trunk/java/xdocs/mtom-guide.html
Modified: webservices/axis/trunk/java/xdocs/mtom-guide.html
URL: http://svn.apache.org/viewcvs/webservices/axis/trunk/java/xdocs/mtom-guide.html?rev=233475&r1=233474&r2=233475&view=diff
==============================================================================
--- webservices/axis/trunk/java/xdocs/mtom-guide.html (original)
+++ webservices/axis/trunk/java/xdocs/mtom-guide.html Fri Aug 19 05:46:22 2005
@@ -1,4 +1,7 @@
-<html><title>Sending Binary data with SOAP</title><body><h1>Sending Binary Data With SOAP</h1><ul>
+<html><title>Sending Binary data with SOAP</title>
+<body>
+<h1>Sending Binary Data with SOAP</h1>
+<ul>
<li><a href="#1">Introduction</a></li>
<li><a href="#2">MTOM with Axis2 </a>
<ul>
@@ -23,9 +26,9 @@
Traditionally, two techniques for dealing with opaque data in XML have been used;</p><ol>
<li><strong> "By value"</strong> </li>
<blockquote>
- <p>Sending binary data by value is achieved by embedding opaque data(of course after some form of encoding) as element or attribute content of the XML component of data.
- The main advantage of this technique is that it give applications the ability to process and describe data based and looking only on XML component of the data. </p>
- <p>XML supports opaque data as content through the use of either base64 or hexadecimal text encoding.
+ <p>Sending binary data by value is achieved by embedding opaque data (of course after some form of encoding) as element or attribute content of the XML component of data.
+ The main advantage of this technique is that it gives applications the ability to process and describe data based and looking only on XML component of the data. </p>
+ <p>XML supports opaque data as content through the use of either base64 or hexadecimal text encoding.
Both these techniques bloat the size of the data. For UTF-8 underlying text encoding, base64 encoding increases the size of the binary data by a factor of 1.33x of the original size, while hexadecimal encoding expands data by a factor of 2x. Above factors will be doubled if UTF-16 text encoding is used. Also of concern is the overhead in processing costs (both real and perceived) for these formats, especially when decoding back into raw binary.</p>
</blockquote>
<li><strong>"By reference"</strong>
@@ -35,37 +38,47 @@
as external unparsed general entities
-outside of the XML document and then embedding reference URI's to those entities as elements or attribute values. This prevents the uneccesary bloating of data and wasting of processing power.
+outside of the XML document and then embedding reference URI's to those entities as elements or attribute values. This prevents the
+
+
+ unnecessary
+
+ bloating of data and wasting of processing power.
The primary obstacle for using these unparsed entities is their heavy reliance on DTDs, which impedes modularity as well as use of XML namespaces. </p>
- <p>There were several specifications introduced in the web services world to deal with this binary attachment problem using the "by reference" technique. <a href="http://www.w3.org/TR/SOAP-attachments">SOAP with Attachments</a> is one such example. Since SOAP prohibits document type declarations (DTD) in messages, this leads to the problem of not representing data as part of the message infoset, creating two data models. This scenerio is like sending attachments with an e-mail message. Even though those attachments are related to the message content they are not inside the message. This causes the technologies
+ <p>There were several specifications introduced in the web services world to deal with this binary attachment problem using the "by reference" technique. <a href="http://www.w3.org/TR/SOAP-attachments">SOAP with Attachments</a> is one such example. Since SOAP prohibits document type declarations (DTD) in messages, this leads to the problem of not representing data as part of the message infoset, creating two data models. This scenario is like sending attachments with an e-mail message. Even though those attachments are related to the message content they are not inside the message. This causes the technologies
for processing and description of data based on XML component of the data, to malfunction. One example is WS-Security. </p>
</blockquote>
</li>
-</ol><p><a href="http://www.w3.org/TR/2004/PR-soap12-mtom-20041116/">MTOM
+</ol>
+<p><a href="http://www.w3.org/TR/2004/PR-soap12-mtom-20041116/">MTOM
-(SOAP Message Transmission Optimization Mechanism)</a> is another specification which focuses on solving the "Attachments" problem. MTOM tries to leverage the advantages of above two techniques by trying to merge the above two techniques. MTOM is actually a "by reference" method. Wire format of a MTOM optimised message is same as the Soap with Attachments message , which also makes it backward compatible with SwA endpoints. The most notable feature of MTOM is the use of XOP:Include element, which is defined in <a href="http://www.w3.org/TR/2004/PR-xop10-20041116/">XML Binary Optimized Packaging (XOP)</a> specification to reference the binary attachments (external unparsed general entities) of the message.With the use of this exclusive element the attached binary content logically become inline(by value) with the SOAP document even though actually it is attached seperately. This merges the two realms by making it possible to work only with one data model. This allows the apllications to process and describe by only looking at XML part making reliance on DTDs obsolute. On a lighter note MTOM has standarized the referencing mechanism of SwA. Following is an extract from the <a href="http://www.w3.org/TR/2004/PR-xop10-20041116/">XOP</a> specification.</p><p><em> At the conceptual level, this binary data can be thought of as being base64-encoded in the XML Document. As this conceptual form might be needed during some processing of the XML Document (e.g., for signing the XML document), it is necessary to have a one to one correspondence between XML Infosets and XOP Packages. Therefore, the conceptual representation of such binary data is as if it were base64-encoded, using the canonical lexical form of XML Schema base64Binary datatype (see <a href="#XMLSchemaP2">[XML Schema Part 2: Datatypes Second Edition] </a><a href="http://www.w3.org/TR/2004/REC-xmlschema-2-20041028/#base64Binary">3.2.16 base64Binary </a>). In the reverse direction, XOP is capable of optimizing only base64-encoded Infoset data that is in the canonical lexical form. </em></p><p>Apache Axis2 supports <strong>Base64 encoding</strong>, <strong>SOAP with Attachments</strong> & <strong>MTOM (SOAP Message Transmission Optimization Mechanism).</strong></p><p><a name="2"></a></p><h1>MTOM with Axis2</h1><p><a name="21"></a></p><h2>Programming Model</h2><p>AXIOM is an (may be the first) Object Model which has the ability to hold binary data. It has been given this ability by allowing OMText to hold raw binary content in the form of javax.activation.DataHandler. OMText has been chosen for this purpose with two reasons. One is that XOP (MTOM) is capable of optimizing only base64-encoded Infoset data that is in the canonical lexical form of XML Schema base64Binary datatype. Other one is to preserve the infoset in both sender and receiver (To store the binary content in the same kind of object regardless of whether it is optimized or not). </p><p>MTOM allows to
+(SOAP Message Transmission Optimization Mechanism)</a> is another specification which focuses on solving the "Attachments" problem. MTOM tries to leverage the advantages of above two techniques by trying to merge the above two techniques. MTOM is actually a "by reference" method. Wire format of a MTOM optimized message is same as the Soap with Attachments message, which also makes it backward compatible with SwA endpoints. The most notable feature of MTOM is the use of XOP:Include element, which is defined in <a href="http://www.w3.org/TR/2004/PR-xop10-20041116/">XML Binary Optimized Packaging (XOP)</a> specification to reference the binary attachments (external unparsed general entities) of the message. With the use of this exclusive element the attached binary content logically become inline (by value) with the SOAP document even though actually it is attached separately. This merges the two realms by making it possible to work only with one data model. This allows the applications to process and describe by only looking at XML part making reliance on DTDs obsolete. On a lighter note MTOM has standardized the referencing mechanism of SwA. Following is an extract from the <a href="http://www.w3.org/TR/2004/PR-xop10-20041116/">XOP</a> specification.</p>
+<p><em> At the conceptual level, this binary data can be thought of as being base64-encoded in the XML Document. As this conceptual form might be needed during some processing of the XML Document (e.g., for signing the XML document), it is necessary to have a one to one correspondence between XML Infosets and XOP Packages. Therefore, the conceptual representation of such binary data is as if it were base64-encoded, using the canonical lexical form of XML Schema base64Binary datatype (see <a href="#XMLSchemaP2">[XML Schema Part 2: Datatypes Second Edition] </a><a href="http://www.w3.org/TR/2004/REC-xmlschema-2-20041028/#base64Binary">3.2.16 base64Binary</a>). In the reverse direction, XOP is capable of optimizing only base64-encoded Infoset data that is in the canonical lexical form. </em></p>
+<p>Apache Axis2 supports <strong>Base64 encoding</strong>, <strong>SOAP with Attachments</strong> & <strong>MTOM (SOAP Message Transmission Optimization Mechanism).</strong></p><p><a name="2"></a></p><h1>MTOM with Axis2</h1><p><a name="21"></a></p><h2>Programming Model</h2><p>AXIOM is an (may be the first) Object Model which has the ability to hold binary data. It has been given this ability by allowing OMText to hold raw binary content in the form of javax.activation.DataHandler. OMText has been chosen for this purpose with two reasons. One is that XOP (MTOM) is capable of optimizing only base64-encoded Infoset data that is in the canonical lexical form of XML Schema base64Binary datatype. Other one is to preserve the infoset in both sender and receiver (To store the binary content in the same kind of object regardless of whether it is optimized or not). </p>
+<p>MTOM allows to
- selectively encode portions of the message, which allows us to send base64encoded data as well as externally attached raw binary data referenced by "XOP" element (Optimised content) to be send in a SOAP message.
+ selectively encode portions of the message, which allows us to send base64encoded data as well as externally attached raw binary data referenced by "XOP" element (optimized content) to be send in a SOAP message.
-User can specify whether a OMText node which contains raw binary data or base64encoded binary data is qualified to be optimized or not at the contruction time of that node or later. To take the optimum efficiency of MTOM a user is advised to send smaller binary attachments using base64encoding (Non optimised) and larger attachments as optimised content.</p><source>
+User can specify whether an OMText node which contains raw binary data or base64encoded binary data is qualified to be optimized or not at the construction time of that node or later. To take the optimum efficiency of MTOM a user is advised to send smaller binary attachments using base64encoding (None optimized) and larger attachments as optimized content.</p>
+<source>
<pre> OMElement imageElement = fac.createOMElement("image", omNs);
// Creating the Data Handler for the image.
// User has the option to use a FileDataSource or a ImageDataSource
- // in this scenerio...
+ // in this scenario...
Image image;
image = new JDK13IO()
.loadImage(new FileInputStream(inputImageFileName));
ImageDataSource dataSource = new ImageDataSource("test.jpg",image);
DataHandler dataHandler = new DataHandler(dataSource);
- //create a OMText node with the above DataHandler and set optimised to true
+ //create an OMText node with the above DataHandler and set optimized to true
OMText textData = fac.createText(dataHandler, true);
imageElement.addChild(textData);
@@ -74,8 +87,10 @@
</source><p>Also a user can create an optimizable binary content node using a base64 encoded string, which contains encoded binary content, given with the mime type of the actual binary representation.</p><source>
<pre> String base64String = "xxxxxxxx";
OMText binaryNode = fac.createText(base64String,"image/jpg",true);</pre>
-</source><p>Axis2 uses javax.activation.DataHandler to handle the binary data. All optimised binary content nodes will be serialised as Base64 Strings if "MTOM is not enabled". One can also create binary content nodes which will not be optimised at any case. They will be serialised and send as Base64 Strings. </p><source>
-<pre> //create a OMText node with the above DataHandler and set optimised to false
+</source>
+<p>Axis2 uses javax.activation.DataHandler to handle the binary data. All optimized binary content nodes will be serialized as Base64 Strings if "MTOM is not enabled". One can also create binary content nodes which will not be optimized at any case. They will be serialized and send as Base64 Strings. </p>
+<source>
+<pre> //create an OMText node with the above DataHandler and set "optimized" to false
//This data will be send as Base64 encoded string regardless of MTOM is enabled or not
OMText textData = fac.createText(dataHandler, false);
image.addChild(textData);</pre>
@@ -83,16 +98,21 @@
<pre> Call call = new Call();
call.setTo(targetEPR);
call.set(Constants.Configuration.ENABLE_MTOM, Constants.VALUE_TRUE);</pre>
-</source><p> When this property is set to true any SOAP envelope which contains optimizable content (OMText nodes containing binary content with optimizable flag "true") will be serialised as a MTOM optimized message. Messages will not be packaged as MTOM if they did not contain any optimizable content even though MTOM is enabled. </p><p>Axis2 serializes all binary content nodes as Base64 encoded strings regardless of they are qualified to be optimize or not, if, </p><ul>
+</source>
+<p> When this property is set to true any SOAP envelope which contains optimizable content (OMText nodes containing binary content with optimizable flag "true") will be serialized as a MTOM optimized message. Messages will not be packaged as MTOM if they did not contain any optimizable content even though MTOM is enabled. </p>
+<p>Axis2 serializes all binary content nodes as Base64 encoded strings regardless of they are qualified to be optimize or not, if, </p><ul>
<li>"enableMTOM" property is set to false.</li>
<li>If envelope contains any element information items of name xop:Include (see <a href="#XOP">[XML-binary Optimized Packaging] </a><a href="http://www.w3.org/TR/2005/REC-xop10-20050125/#xop_infosets">3. XOP Infosets Constructs </a>). </li>
-</ul><p>MTOM is *always enabled* in Axis2 when it comes to receiving messages. Axis2 will automatically identify and de-serilize any MTOM messge it receives. </p><p></p><p><a name="23"></a></p>
+</ul>
+<p>MTOM is *always enabled* in Axis2 when it comes to receiving messages. Axis2 will automatically identify and de-serialize any MTOM message it receives. </p>
+<p></p><p><a name="23"></a></p>
<h2>Enabling MTOM optimization in the Server side</h2>
-<p>Axis 2 server automatically identifies incoming MTOM optimized messages based on the content-type and de-serializes accordingly. One can enableMTOM in the server side for outgoing messages,</p><ul>
+<p>Axis 2 server automatically identifies incoming MTOM optimized messages based on the content-type and de-serializes accordingly. User can enableMTOM in the server side for outgoing messages,</p>
+<ul>
<li> Globally for all services
<blockquote>
- <p>by adding and setting the "enableMTOM" parameter to true in the Axis2.xml.
- When it is set, *outgoing* messages *which contains optimizable content* will be serialized and send as a MTOM optimized messages. If it is not set all the binary content nodes will be serialized as Base64 encoded strings. </p>
+ <p> add and set the "enableMTOM" parameter to true in the Axis2.xml.
+ When it is set, *outgoing* messages *which contains optimizable content* will be serialized and send as a MTOM optimized messages. If it is not set all the binary data in binary content nodes will be serialized as Base64 encoded strings. </p>
</blockquote>
</li>
</ul><p><source><pre><parameter name="enableMTOM" locked="xsd:false">true</parameter></pre>
@@ -128,7 +148,8 @@
}
</pre></source><ul>
<li><strong><a name="242"></a>Client </strong></li>
-</ul><source><pre>
+</ul><source>
+<pre>
call.setTo(targetEPR);
// enabling MTOM
call.set(Constants.Configuration.ENABLE_MTOM, Constants.VALUE_TRUE);
@@ -141,16 +162,20 @@
OMElement ele = (OMElement) result.getFirstChild();
OMText binaryNode = (OMText) ele.getFirstChild();
- // Retreiving the DataHandler & then do whatever the processing to the data
+ // Retrieving the DataHandler & then do whatever the processing to the data
DataHandler actualDH;
actualDH = binaryNode.getDataHandler();
Image actualObject = new JDK13IO().loadImage(actualDH.getDataSource()
.getInputStream());
-</pre></source><p><a name="3"></a></p>
+</pre>
+</source><p><a name="3"></a></p>
<h1>SOAP with Attachments (SwA) with Axis2</h1>
-<p>Axis2 Handles SwA messages at the inflow only. When Axis2 receives a SwA message it extracts the binary attachment parts and put a reference to those parts in the Message Context. Users can access binary attachements using the content-id. Care should be taken to rip off the "cid" prefix when content-id is taken from the "Href" attributes. When accessing the message context from a service users need to use the message context injection mechanism by introducing a "init" methode to the service class.(see the folloowing service example) </p><p>Note: Axis2 supports content-id referencing only. Does not support Content Location referencing.</p><ul>
+<p>Axis2 Handles SwA messages at the inflow only. When Axis2 receives a SwA message it extracts the binary attachment parts and put a reference to those parts in the Message Context. Users can access binary attachments using the content-id. Care should be taken to rip off the "cid" prefix when content-id is taken from the "Href" attributes. When accessing the message context from a service users need to use the message context injection mechanism by introducing an "init" method to the service class.(see the following service example) </p>
+<p>Note: Axis2 supports content-id referencing only. Axis2 does not support Content Location referencing of MIME parts. </p>
+<ul>
<li><strong>Sample service which accepts a SwA message</strong></li>
-</ul><source><pre>
+</ul><source>
+<pre>
public class EchoSwA {
private MessageContext msgcts;
@@ -169,7 +194,7 @@
contentID = contentID.substring(4);
}
- // Retreiving the MIMEHelper instance (which contains reference to attachments)
+ // Retrieving the MIMEHelper instance (which contains reference to attachments)
// from the Message Context
MIMEHelper attachments = (MIMEHelper)msgcts.getProperty(MIMEHelper.ATTACHMENTS);
// Retrieving the respective DataHandler referenced by the content-id
@@ -184,7 +209,10 @@
}
}
-</pre></source><p>MTOM specification is designed to be backward compatible with the SOAP with Attachments specification. Even though the representation is different, both technologies have the same wire format. We can safely assume that any SOAP with Attachments endpoint can accept a MTOM optimized messages and treat them as SOAP with Attachment messages - Any MTOM optimised message is a valid SwA message. Because of that Axis2 does not define a seperate programming model or serialization for SwA. Users can use the MTOM programming model and serialization to send messages to SwA endpoints. </p><p>Note : Above is tested with Axis 1.x</p><ul>
+</pre>
+</source>
+<p>MTOM specification is designed to be backward compatible with the SOAP with Attachments specification. Even though the representation is different, both technologies have the same wire format. We can safely assume that any SOAP with Attachments endpoint can accept a MTOM optimized messages and treat them as SOAP with Attachment messages - Any MTOM optimized message is a valid SwA message. Because of that Axis2 does not define a separate programming model or serialization for SwA. Users can use the MTOM programming model and serialization to send messages to SwA endpoints. </p>
+<p>Note : Above is tested with Axis 1.x</p><ul>
<li><strong>A sample SwA message from Axis 1.x </strong></li>
</ul><source>
<pre>
@@ -213,23 +241,24 @@
</pre>
</source><ul>
<li><strong>Corresponding MTOM message from Axis2</strong></li>
-</ul>
+</ul>
<source>
-<pre>
Content-Type: multipart/related; boundary=MIMEBoundary4A7AE55984E7438034;
- type="application/xop+xml"; start="<0....@apache.org>";
- start-info="text/xml; charset=utf-8"
-
+<pre>
+Content-Type: multipart/related; boundary=MIMEBoundary4A7AE55984E7438034;
+ type="application/xop+xml"; start="<0....@apache.org>";
+ start-info="text/xml; charset=utf-8"
+
--MIMEBoundary4A7AE55984E7438034
content-type: application/xop+xml; charset=utf-8; type="application/soap+xml;"
content-transfer-encoding: binary
content-id: <0.09BC7F4BE2E4D3EF1B@apache.org>
-<?xml version='1.0' encoding='utf-8'?>
+<?xml version='1.0' encoding='utf-8'?>
<soapenv:Envelope xmlns:soapenv="...."....>
- ........
- <xop:Include href="cid:1.A91D6D2E3D7AC4D580@apache.org"
- xmlns:xop="http://www.w3.org/2004/08/xop/include">
- </xop:Include>
+ ........
+ <xop:Include href="cid:1.A91D6D2E3D7AC4D580@apache.org"
+ xmlns:xop="http://www.w3.org/2004/08/xop/include">
+ </xop:Include>
........
</soapenv:Envelope>
--MIMEBoundary4A7AE55984E7438034
@@ -240,24 +269,25 @@
<em>Binary Data.....</em>
--MIMEBoundary4A7AE55984E7438034--
</pre>
-</source>
-<p><a name="4"></a></p><h1>Advanced Topics</h1><p><a name="41"></a></p><h2>File Caching For Attachments</h2>
-<p>Axis2 comes handy with a file caching mechanism for incoming attachments, which gives Axis2 the
-ability to handle very large attachments without buffering them in memory at any time. Axis2 file
-caching streams the incoming MIME parts directly in to files, after reading the MIME part headers.</p>
-<P>Also a user can specify a size threshold for the File caching.When this threshold value is specified, only the attachments whose size is bigget than the threshold value will get
-cached in files. Smaller attachmments will remain in Memory. </p>
-<p>NOTE : It is a must to specify a directory to temporary store the attachments. Also care should be taken to *clean that directory* time to time.</p>
-<p>The following parameters needs to be set in Axis2.xml in order to enable file caching.</p><source><pre>
-<em><axisconfig name="AxisJava2.0">
- <!-- ================================================= -->
- <!-- Parameters -->
- <!-- ================================================= --></em>
+</source>
+<p><a name="4"></a></p><h1>Advanced Topics</h1><p><a name="41"></a></p><h2>File Caching For Attachments</h2>
+<p>Axis2 comes handy with a file caching mechanism for incoming attachments, which gives Axis2 the
+ability to handle very large attachments without buffering them in memory at any time. Axis2 file
+caching streams the incoming MIME parts directly in to files, after reading the MIME part headers.</p>
+<P>Also a user can specify a size threshold for the File caching. When this threshold value is specified, only the attachments whose size is bigger than the threshold value will get
+cached in files. Smaller attachments will remain in Memory. </p>
+<p>NOTE : It is a must to specify a directory to temporary store the attachments. Also care should be taken to *clean that directory* time to time.</p>
+<p>The following parameters need to be set in Axis2.xml in order to enable file caching.</p>
+<source><pre>
+<em><axisconfig name="AxisJava2.0">
+ <!-- ================================================= -->
+ <!-- Parameters -->
+ <!-- ================================================= --></em>
<parameter name="cacheAttachments" locked="xsd:false">true</parameter>
- <parameter name="attachmentDIR" locked="xsd:false"><em>temp directory</em></parameter>
- <parameter name="sizeThreshold" locked="xsd:false">4000</parameter>
- .........
- .........
+ <parameter name="attachmentDIR" locked="xsd:false"><em>temp directory</em></parameter>
+ <parameter name="sizeThreshold" locked="xsd:false">4000</parameter>
+ .........
+ .........
</axisconfig>
</pre></source></body></html>