Java Reference
In-Depth Information
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<moreovernews>
<article id="_34226715">
<url>http://c.moreover.com/click/here.pl?x34226715</url>
<headline_text>
Assistant fire chief ascends to departments top role
</headline_text>
<source>Springfield News-Leader</source>
<media_type>text</media_type>
<cluster>moreover...</cluster>
<tagline></tagline>
<document_url>
http://www.springfieldnews-leader.com/news/
</document_url>
<harvest_time>Mar 20 2002 2:30AM</harvest_time>
<access_registration></access_registration>
<access_status></access_status>
</article>
...
</moreovernews>
The
SQLInsertBean
used to insert the content of an XML document into a database table is an
extension of the basic Xbean base class of
Listing 17-2
. The
processDocument()
method first calls
the
prepareStatement()
method, which creates a
PreparedStatement
to handle the
SQL
INSERT
command. The
PreparedStatement
is simply a SQL INSERT command with 11
placeholders, one for each data node in the article element (10 child elements, plus the id attribute).
Cross-
Reference
PreparedStatements
reduce the processing overhead of compiling a
SQL statement when it is to be used repetitivley. The advantages of using
the
PreparedStatement
object when performing multiple repetitions of a
SQL command is discussed in
Chapter 4
,
with a brief example in
Chapter
13
.
The
getValues()
method is passed an
<article>
element, which it parses to retrieve the id
attribute and the child elements. These are returned in a
String
array, which is passed to the
insertHeadline()
method. Note that a Java
null
is specifically inserted into the array for empty
child elements. These nulls are converted automatically to
SQL NULL
s on insertion.
The
insertHeadline()
method sets the parameters of the
PreparedStatement
from the
String
array and then calls the
PreparedStatement
's
executeUpdate()
method to insert the data from
the XML document.
After looping through all the <article> elements, the
Connection
object's
close()
method is called to
close the connection to the
DataSource
. If you fail to close the connection, the garbage collector will
close it for you.
Listing 17-11
illustrates the use of a
PreparedStatement
object to insert news
headlines into the database.
Listing 17-11: SQLInsertBean
