8 File Access and Mail Beans and Tags

File System Destination

If the destination is in a file system, you must provide a properties file that designates a base directory. The properties file must be named fileaccess.properties, must be located in the /WEB-INF directory of your application, and must have a fileaccess.basedir entry that indicates an absolute directory path. Here is an example:

fileaccess.basedir=/tmp

fileaccess.basedir=c:/tmp

There should be subdirectories as appropriate under the base directory, such as a subdirectory for each authorized user. Destination subdirectories under the base directory must be specified through an attribute of the upload bean or tag. All directories and subdirectories must already exist and be writable; they cannot be created or made writable through OC4J functionality.

Database Destination

If the destination is in a database, you can optionally use a default table, fileaccess, that you create through the supplied fileaccess.sql script, or you can use any other previously existing table containing the required column types. In either case, you must provide a connection to the database, as an instance of either oracle.jsp.dbutil.ConnBean or the standard java.sql.Connection. You can provide a ConnBean instance explicitly, or in a JSP page you also have the option of providing it implicitly as a result of nesting the httpUpload tag inside a dbOpen tag. (For information about the ConnBean JavaBean and dbOpen tag, see Chapter 4, "Data-Access JavaBeans and Tags".)

You are also required to specify a destination through an attribute of the upload bean or tag. The destination is simply a Java string value that will be placed in the prefix column of the database table. The prefix is equivalent to a file system path.

File data is written to a database as either a BLOB or a CLOB. You can specify which through an upload bean or tag attribute.

If you do not use the default fileaccess table, you must use attributes of the upload bean or tag to specify the database table name and the names of the columns that will contain the file data, the file prefix, and the file name. Any other table you use must adhere to the pattern of fileaccess, as follows:

• It must have a concatenated unique key consisting of the column that holds the file name and the column that holds the prefix.

• It must have a BLOB or CLOB column for the file data.

• Any column other than the file data column must allow null data.

Security Considerations for Uploading

For uploading to a database, the database table does not have a column to indicate a particular authorized user for any given file. Therefore, without precaution, each user can see files that were uploaded by other users, without having to know the file prefixes. To prevent this, you can prepend an appropriate user name to each prefix.

Security Considerations for Downloading

For downloading, consider limiting the users' ability to see what is in the source (server-side) file system or database. Without precaution, the following scenarios are possible:

• For file system downloading, a source value of "*" (perhaps specified through user input) would mean that all directories under the base directory would be available for downloading, with the names of all the files presumably being displayed for the user to choose from.

• For recursive downloading from a database, all files having a prefix beginning with the source string (perhaps specified through user input) would be available for downloading, with the names of all these files presumably being displayed. A source of "*" matches all prefixes.

If this is of concern, you can consider protective measures such as the following:

• Not accepting source values of "*" when downloading from file systems

• Not allowing recursive downloading from databases

• Automatically prepending the source value with a partial directory path or prefix string, such as a user name, to restrict the areas to which users have access

Summary of Required Attributes

The following list summarizes required attributes for HttpUploadBean:

• Always required: destination

• Also required for uploads to a database: destinationType, connection

• Also required for uploads to a database table other than the default fileaccess table: table, prefixColumn, fileNameColumn, dataColumn

• Also required for uploads to a database table using a CLOB column for file data: fileType

In addition, for an upload to a file system, you must call the setBaseDir() method to provide a servlet context and HTTP request object so that the bean can find the fileaccess.properties file that specifies the base directory.

Methods

Here are descriptions of the public methods of HttpUploadBean.

• void upload(javax.servlet.http.HttpServletRequest req) throws FileAccessException

  Once all required and appropriate bean attributes have been set, use this method for the upload. The req parameter is the HTTP request instance containing the multipart form-encoded files. For a JSP page, use the implicit request object.

• void setBaseDir(javax.servlet.ServletContext sc, javax.servlet.http.HttpServletRequest req) throws FileAccessException

  For an upload to a file system, use this method to determine what to use as a base directory. It gets this information from the fileaccess.properties file in your application /WEB-INF directory, which it finds through the servlet context input parameter. The baseDir setting, together with the destination setting, specifies the absolute path to the upload directory.

  The req parameter is the servlet request instance to use in requesting the base directory information. For JSP pages, use the implicit request object.

  This method is not relevant for database uploads.

• void setDestination(String destination)

  This method is always required.

  For an upload to a file system, destination and the base directory together specify the absolute path to the upload directory.

  For an upload to a database, destination is used as the file prefix. (There is no "base directory".) The prefix is equivalent to a file system path and can be used to group files into a hierarchy. It is permissible to include separator characters such as "." and "/" in the destination string.

  
  

  Note: Typically, the destination value will be based at least partially on user input.

  
  

• void setDestinationType(String destinationType) throws FileAccessException

• void setDestinationType(int destinationType) throws FileAccessException

  Use the overloaded setDestinationType() method to specify whether the upload is to a file system or a database.

  To upload to a database, set destinationType to one of the following: the string "database", the defined String constant FileAccessUtil.DATABASE, the int value 1, or the defined int constant FileAccessUtil.LOCATION_TYPE_DATABASE.

  Uploading to a file system is the default, but if you want to specify this explicitly, set destinationType to one of the following: the string "filesystem", the defined String constant FileAccessUtil.FILESYSTEM, the int value 0, or the defined int constant FileAccessUtil.LOCATION_TYPE_FILESYSTEM.

  FileAccessUtil is in the oracle.jsp.webutil.fileaccess package.

• String getDestinationType()

  Retrieve the destination information. Note there is a getter method for the string version only.

• void setOverwrite(String overwrite) throws FileAccessException

• void setOverwrite(boolean overwrite)

  Use the overloaded setOverwrite() method to overwrite existing files or update rows with the same file name and prefix. This is relevant for both file system and database uploads.

  Overwriting is enabled by default, but you can enable it explicitly with an overwrite setting of the string "true" or the boolean value true. Disable overwriting with a setting of the string "false" or the boolean value false. String settings are case-insensitive. No settings are accepted other than those listed here.

• void setFileType(String fileType) throws FileAccessException

• void setFileType(int fileType) throws FileAccessException

  For an upload to a database, use the overloaded setFileType() method to specify whether the data is to be stored in a BLOB for binary data (the default) or a CLOB for character data. For a CLOB, set fileType to one of the following: the string "character", the defined String constant FileAccessUtil.CHARACTER_FILE, or the int value 1. To explicitly specify a BLOB, set fileType to one of the following: the string "binary", the defined String constant FileAccessUtil.BINARY_FILE, or the int value 0. String settings are case-insensitive. No settings are accepted other than those listed here.

  FileAccessUtil is in the oracle.jsp.webutil.fileaccess package.

• String getFileType()

  Retrieve the file type information. Note there is a getter method for the string version only.

• void setTable(String tableName)

  For an upload to a database table other than the default fileaccess table, use this method to specify the table name.

• String getTable()

  Retrieve the table name.

• void setPrefixColumn(String prefixColumnName)

  For an upload to a database table other than the default fileaccess table, use this method to specify the name of the column containing the file prefix. (In fileaccess, this column name is fileprefix.) The destination value will be written into this column.

• String getPrefixColumn()

  Retrieve the name of the column containing the file prefix.

• void setFileNameColumn(String fileNameColumnName)

  For an upload to a database table other than the default fileaccess table, use this method to specify the name of the column containing the file name. (In fileaccess, this column name is filename.) File names will include any file name extensions.

• String getFileNameColumn()

  Retrieve the name of the column containing the file name.

• void setDataColumn(String dataColumnName)

  For an upload to a database table other than the default fileaccess table, use this method to specify the name of the BLOB or CLOB column containing the file contents. (In fileaccess, this column name is data.)

• String getDataColumn()

  Retrieve the name of the column containing the file contents.

• void setConnection(ConnBean conn)

• void setConnection(java.sql.Connection conn)

  For an upload to a database table (default table or otherwise), use this overloaded method to provide a database connection. You can provide an instance of either oracle.jsp.dbutil.ConnBean or the standard java.sql.Connection type. For information about the ConnBean JavaBean, see "ConnBean for a Database Connection".

  If you use a Connection instance, you must explicitly open and close it. For a ConnBean instance, this is handled automatically.

• java.util.Enumeration getFileNames()

  This method returns an Enumeration instance containing the names of the files that were uploaded. (This functionality is not available through the httpUpload tag.)

Example:

This example uses a plain HTML form to specify a file to upload to a file system, then uses a JSP page that employs HttpUploadBean for the upload.

Here is the HTML form, which specifies beanUploadExample.jsp for its action and will generate the multipart upload stream.

<html><body>
<form action="beanUploadExample.jsp" ENCTYPE="multipart/form-data" method=POST>
<br> File to upload: <INPUT TYPE="FILE" NAME="File" SIZE="50" MAXLENGTH="120" >
<br><INPUT TYPE="SUBMIT" NAME="Submit" VALUE="Send"> </form>
</body></html>

And here is the beanUploadExample.jsp page.

<%@ page language="java" 
         import="java.util.*, oracle.jsp.webutil.fileaccess.*" %>
<html><body>
<% String userdir = "fileaccess"; %>   // user's part of the upload directory
<jsp:useBean id="upbean" 
   class="oracle.jsp.webutil.fileaccess.HttpUploadBean" >
   <jsp:setProperty name="upbean" property="destination" 
                     value="<%= userdir %>" />
</jsp:useBean>
<%   upbean.setBaseDir(application, request);
         upbean.upload(request); 
         Enumeration fileNames = upbean.getFileNames();
         while (fileNames.hasMoreElements()) { %>
              <br><%= (String)fileNames.nextElement() %>
  <% } %>
<br>Done!
</body></html>

Summary of Required Attributes

The following list summarizes required attributes for HttpDownloadBean:

• Always required: source

• Also required for uploads to a database: sourceType, connection

• Also required for downloads from a database table other than the default fileaccess table: table, prefixColumn, fileNameColumn, dataColumn

• Also required for downloads from a database table using a CLOB column for file data: fileType

In addition, for a download from a file system, you must call the setBaseDir() method to provide a servlet context and HTTP request object so that the bean can find the fileaccess.properties file that specifies the base directory.

Methods

Here are descriptions of the public methods of HttpDownloadBean.

• void listFiles(javax.servlet.http.HttpServletRequest req) throws FileAccessException

  Once all required and appropriate bean attributes have been set, use this method to list the files available for download. These are files in the source directory or matching the source database prefix. The req parameter is the HTTP response instance. For a JSP page, use the implicit request object.

  For use from the file list, you can create HREF links to DownloadServlet, passing it each file and file prefix, allowing users to select the link for each file they want to download.

  
  

  Note: The listFiles() method writes the file names to memory and to the JSP page or servlet. If you later want to access the file names again, use the getFileNames() method to read them from memory.

  
  

• java.util.Enumeration getFileNames()

  This method returns an Enumeration instance containing the names of the files that are available for download. It requires that the listFiles() method was already called. The listFiles() method writes the file names to memory and to the JSP page or servlet. The getFileNames() method reads them from memory.

• void setBaseDir(javax.servlet.ServletContext sc, javax.servlet.http.HttpServletRequest req) throws FileAccessException

  For a download from a file system, use this method to determine what to use as the base directory. It gets this information from the fileaccess.properties file in your application /WEB-INF directory, which it finds through the servlet context input parameter. The baseDir setting, together with the source setting, specifies the absolute path to the directory from which files will be downloaded.

  The sc parameter is the servlet context instance for the application. For JSP pages, use the implicit application object.

  The req parameter is for the HTTP request instance to use in requesting the base directory information. For JSP pages, use the implicit request object.

  A base directory is not relevant for downloads from a database.

• void setSource(String source)

  This is always required.

  For a download from a file system, source and the base directory together specify the absolute path to the directory from which files will be downloaded. If source is set to "*", then all directories under the base directory will be available for downloading.

  For a download from a database, source is used as the file prefix. (The base directory is not relevant.) The prefix is equivalent to a file system path and can be used to group files into a hierarchy. If recursive downloading is enabled (through the setRecurse() method), "%" will be appended onto the source value, and the WHERE clause for the query will contain an appropriate LIKE clause. Therefore, all files with prefixes that are partially matched by the source value will be available for download. If you want to match all rows in the database table, set source to "*".

  
  

  Note: Typically, the source value will be based at least partially on user input.

  
  

• void setSourceType(String sourceType) throws FileAccessException

• void setSourceType(int sourceType) throws FileAccessException

  Use the overloaded setSourceType() method to specify whether the download is from a file system or a database.

  To download from a database, set sourceType to one of the following: the string "database", the defined String constant FileAccessUtil.DATABASE, the int value 1, or the defined int constant FileAccessUtil.LOCATION_TYPE_DATABASE.

  Downloading from a file system is the default, but if you want to specify this explicitly, set sourceType to one of the following: the string "filesystem", the defined String constant FileAccessUtil.FILESYSTEM, the int value 0, or the defined int constant FileAccessUtil.LOCATION_TYPE_FILESYSTEM.

  FileAccessUtil is in the oracle.jsp.webutil.fileaccess package.

• String getSourceType()

  Retrieve the source type information. Note there is a getter method for the string version only.

• void setRecurse(String recurse) throws FileAccessException

• void setRecurse(boolean recurse)

  Use the overloaded setRecurse() method to enable or disable recursive downloading functionality, where files in file system subdirectories or with additional database prefix information will also be listed as available for downloading. As an example of this functionality from a database, assume source is set to "/user". Recursiveness would also find matches for files with prefixes such as "/user/bill" and "/user/mary", and also such as "/user1", "/user2", "/user1/tom", and "/user2/susan".

  Recursiveness is enabled by default, but you can enable it explicitly with a recurse setting of the string "true" or the boolean true. Disable the recursive functionality with a setting of the string "false" or the boolean false. String settings are case-insensitive. No settings are accepted other than those listed here.

• void setFileType(String fileType) throws FileAccessException

• void setFileType(int fileType) throws FileAccessException

  For a download from a database, use the overloaded setFileType() method to specify whether the data is stored in a BLOB for binary data (the default) or a CLOB for character data. For a CLOB, set fileType to one of the following: the string "character", the defined String constant FileAccessUtil.CHARACTER_FILE, or the int value 1. To explicitly specify a BLOB, set fileType to one of the following: the string "binary", the defined String constant FileAccessUtil.BINARY_FILE, or the int value 0. String settings are case-insensitive. No settings are accepted other than those listed here.

  FileAccessUtil is in the oracle.jsp.webutil.fileaccess package.

• String getFileType()

  Retrieve the file type information. Note there is a getter method for the string version only.

• void setTable(String tableName)

  For a download from a database table other than the default fileaccess table, use this method to specify the table name.

• String getTable()

  Retrieve the table name.

• void setPrefixColumn(String prefixColumnName)

  For a download from a database table other than the default fileaccess table, use this method to specify the name of the column containing the file prefix. (In fileaccess, this column name is fileprefix.)

• String getPrefixColumn()

  Retrieve the name of the column containing the file prefix.

• void setFileNameColumn(String fileNameColumnName)

  For a download from a database table other than the default fileaccess table, use this method to specify the name of the column containing the file name. (In fileaccess, this column name is filename.) The file name includes any file name extension.

• String getFileNameColumn()

  Retrieve the name of the column containing the file name.

• void setDataColumn(String dataColumnName)

  For a download from a database table other than the default fileaccess table, use this method to specify the name of the BLOB or CLOB column that holds the file contents. (In fileaccess, this column name is data.)

• String getDataColumn()

  Retrieve the name of the column containing the file contents.

• void setConnection(ConnBean conn)

• void setConnection(java.sql.Connection conn)

  For a download from a database table (default table or otherwise), use this method to provide a database connection. You can provide an instance of either oracle.jsp.dbutil.ConnBean or the standard java.sql.Connection type. For information about the ConnBean JavaBean, see "ConnBean for a Database Connection".

  If you use a Connection instance, you must explicitly open and close it. For a ConnBean instance, this is handled automatically.

Example

This example is a JSP page that uses HttpDownloadBean for a download from a file system. Note that the page must construct the URL for the download servlet.

<%@ page language="java" import="java.util.*, oracle.jsp.webutil.fileaccess.*" %>
<html><body>
<% String servletPath = "/servlet/download/";  // path to the download servlet
   String userDir = "fileaccess/";   // user part of  download directory
%>
<jsp:useBean id="dbean" 
   class="oracle.jsp.webutil.access.HttpDownloadBean" >
   <jsp:setProperty name="dbean" property="source" value='<%=userDir %>' />
</jsp:useBean>
<%    dbean.setBaseDir(application, request);   
      dbean.listFiles(request); %>
The following files were found:
<%   Enumeration fileNames = dbean.getFileNames(); 
         while (fileNames.hasMoreElements()) { 
                String name = (String)fileNames.nextElement();  %>
               <br><a href="<%= servletPath + name %>" > <%= name %></a>
<%    } %>
<br>Done!
</body></html>

Syntax

<fileaccess:httpUploadForm formsAction = "action" 
                         [ maxFiles = "max_number" ]
                         [ fileNameSize = "file_input_box_num_chars" ]
                         [ maxFileNameSize = "max_file_name_num_chars" ]
                         [ includeNumbers = "true" | "false" ]
                         [ submitButtonText = "button_label_text" ] />

Attributes

• formsAction (required): This is to indicate the action that will be performed after the form is submitted. For example, formsAction could be the name of a JSP page that uses HttpUploadBean or the httpUpload tag.

• maxFiles: Use this if you want to specify the number of input lines you want to appear in the form. The default is 1.

• fileNameSize: Use this if you want to specify the character-width of the file name input box (or boxes). The default is 20 characters.

• maxFileNameSize: Use this if you want to specify the maximum number of characters allowed in a file name. The default is 80 characters.

• includeNumbers: Set this to "true" if you want the file name input boxes to be numbered. The default setting is "false".

• submitButtonText: Use this if you want to specify the text that appears on the "submit" button of the form. The default is "Send".

Syntax

<fileaccess:httpUpload destination = "dir_path_or_prefix"
                 [ destinationType = "filesystem" | "database" ]
                 [ connId = "id" ]
                 [ scope = "request" | "page" | "session" | "applicaton" ]
                 [ overwrite = "true" | "false" ]
                 [ fileType = "character" | "binary" ]
                 [ table = "table_name" ]
                 [ prefixColumn = "column_name" ]
                 [ fileNameColumn = "column_name" ]
                 [ dataColumn = "column_name" ] />

Attributes

• destination (required): For uploading to a file system, this indicates the path, beneath the base directory supplied in the /WEB-INF/fileaccess.properties file, of the directory into which files will be uploaded. For uploading to a database, destination indicates the file prefix, conceptually equivalent to a file system path.

  
  

  Note: Typically, the destination value will be based at least partially on user input.

  
  

• destinationType: Set this to "database" for uploading to a database. The default is to upload to a file system, but you can also explicitly set it to "filesystem". These values are case-insensitive.

• connId: For uploading to a database, use this attribute to provide a ConnBean connection ID for the database connection to be used. Or, alternatively, use the httpUpload tag inside a dbOpen tag to implicitly use the dbOpen connection. For information about the ConnBean JavaBean and dbOpen tag provided with OC4J, see Chapter 4, "Data-Access JavaBeans and Tags".

• scope: For uploading to a database, use this attribute to specify the scope of the ConnBean instance for the connection. The scope setting here must match the scope setting when the ConnBean instance was created, such as in a dbOpen tag. If the httpUpload tag is nested inside a dbOpen tag, then there is no need to specify connId or scope. In this case, information will be taken from the dbOpen tag. Otherwise, the default scope setting is "page".

• overwrite: Set this to "false" if you do not want to overwrite existing files that have the same paths and names as the files you are uploading, or if you do not want to update rows with the same file name and prefix for database uploading. In this case, an error will be generated if a file already exists. By default, overwrite is set to "true" and httpUpload overwrites files.

• fileType: For uploading to a database, set this attribute to "character" for character data, which will be written into a CLOB. The default setting is "binary" for binary data, which will be written into a BLOB.

• table: For uploading to a database table other than the default fileaccess table, use this attribute to specify the table name.

• prefixColumn: For uploading to a database table other than the default fileaccess table, use this attribute to specify the name of the column containing file prefixes. This column is where the destination values will be written.

• fileNameColumn: For uploading to a database table other than the default fileaccess table, use this attribute to specify the name of the column containing file names.

• dataColumn: For uploading to a database table other than the default fileaccess table, use this attribute to specify the name of the column containing file contents.

Example

This example has a page that uses the httpUploadForm tag to create the HTML form for specifying files to upload. The httpUploadForm tag specifies httpUploadExample.jsp as its forms action. The httpUploadExample.jsp page uses the httpUpload tag to upload to the default fileaccess table in a database.

Here is the page for the HTML form:

<%@ page language="java" import="java.io.*"  %>
<%@ taglib uri="http://xmlns.oracle.com/j2ee/jsp/tld/ojsp/fileaccess.tld"
           prefix="upload" %>
<html> <body>
<fileaccess:httpUploadForm 
      formsAction="httpUploadExample.jsp"
      maxFiles='<%= request.getParameter("MaxFiles") %>'
      includeNumbers="true"  fileNameSize="50"  maxFileNameSize="120" >
          <br> File:
</fileaccess:httpUploadForm>
</body> </html> 

And following is the httpUploadExample.jsp page. Note that the httpUpload tag gets its database connection as a result of being inside a dbOpen tag. Also note that useDataSource.jsp is used to obtain the connection, if necessary. See "useDataSource.jsp".

<%@ page language="java" %>
<%@ taglib uri="http://xmlns.oracle.com/j2ee/jsp/tld/ojsp/fileaccess.tld"
           prefix="upload" %>
<%@ taglib uri="http://xmlns.oracle.com/j2ee/jsp/tld/ojsp/sqltaglib.tld"
           prefix="sql" %>
<% String dataSrcStr=request.getParameter("dataSrcStr"); // get conn string
   if (dataSrcStr==null) {  dataSrcStr=(String)session.getValue("dataSrcStr"); }
   else {  session.putValue("dataSrcStr",dataSrcStr); }
   if (dataSrcStr==null) { %>
       <jsp:forward page="useDataSource.jsp" />
<% } %>
<html><body>
<sql:dbOpen dataSource="<%= dataSrcStr %>" >
   <fileaccess:httpUpload  destinationType = "database"
                           destination="tagexample" />
</sql:dbOpen>
Done! </body></html>

Syntax

<fileaccess:httpDownload servletPath = "path"
                   source = "dir_path_or_prefix"
                 [ sourceType = "filesystem" | "database" ]
                 [ connId = "id" ]
                 [ scope = "request" | "page" | "session" | "applicaton" ]
                 [ recurse = "true" | "false" ]
                 [ fileType = "character" | "binary" ]
                 [ table = "table_name" ]
                 [ prefixColumn = "column_name" ]
                 [ fileNameColumn = "column_name" ]
                 [ dataColumn = "column_name" ] />

Attributes

• servletPath (required): This is the path to the Oracle DownloadServlet, which executes the actual download of each file. For example, if DownloadServlet has been installed in the application app and mapped to the name download, then use "/app/download/", with leading and trailing slashes, as the servletPath setting. The httpDownload tag handler uses this path in constructing the URL to DownloadServlet.

  See "The Download Servlet" for more information about this servlet.

• source (required): For downloading from a file system, this attribute indicates the path, beneath the base directory supplied in the file /WEB-INF/fileaccess.properties, of the directory from which files are retrieved. A value of "*" results in all directories under the base directory being available.

  For downloading from a database, this attribute indicates the file prefix, conceptually equivalent to a file system path. If recursive downloading is enabled (through the recurse attribute), "%" will be appended onto the source value, and the WHERE clause for the query will contain an appropriate LIKE clause. Therefore, all files with prefixes that are partially matched by the source value will be available for download. If you want to match all rows in the database table, set source to "*".

  
  

  Note: Typically, the source value is based at least partially on user input.

  
  

• sourceType: Set this to "database" for downloading from a database. The default is to download from a file system, or you can explicitly set this to "filesystem".

• connId: For downloading from a database, use this attribute to provide a ConnBean connection ID for the database connection to be used. Or, alternatively, you can use the httpDownload tag inside a dbOpen tag to implicitly use the dbOpen connection. For information about the ConnBean JavaBean and dbOpen tag provided with OC4J, see Chapter 4, "Data-Access JavaBeans and Tags".

• scope: For downloading from a database, use this attribute to specify the scope of the ConnBean instance for the connection. The scope setting here must match the scope setting when the ConnBean instance was created, such as in a dbOpen tag. If the httpDownload tag is nested inside a dbOpen tag, then there is no need to specify connId or scope. In this case, information will be taken from the dbOpen tag. Otherwise, the default scope setting is "page".

• recurse: Set this to "false" if you do not want recursive downloading functionality, where files in file system subdirectories or with additional database prefix information will also be listed as available for download. As an example of this functionality from a database, assume you have set source to "/user". Recursiveness would also find matches for files with prefixes such as "/user/bill" and "/user/mary", and also such as "/user1", "/user2", "/user1/tom", and "/user2/susan". The default mode is recursiveness, or you can enable it explicitly with a setting of "true".

• fileType: For downloading from a database, set this attribute to "character" for character data, which will be retrieved from a CLOB. The default setting is "binary" for binary data, which will be retrieved from a BLOB.

• table: For downloading from a database table other than the default fileaccess table, use this attribute to specify the table name.

• prefixColumn: For downloading from a database table other than the default fileaccess table, use this attribute to specify the name of the column containing file prefixes, which is where source values are stored.

• fileNameColumn: For downloading from a database table other than the default fileaccess table, use this attribute to specify the name of the column containing file names. File names include any file name extensions.

• dataColumn: For downloading from a database table other than the default fileaccess table, use this attribute to specify the name of the column that stores the file contents.

Example

This example is a JSP page that uses the httpDownload tag to download from the default fileaccess table of a database. The tag body content ("<br>:") will be output before each file name in the list of files available for download. Note that you must specify the DownloadServlet servlet path in the httpDownload tag. The tag handler will use it in constructing the URL to DownloadServlet, which performs the actual downloading.

<%@ page language="java" %>
<%@ taglib uri="http://xmlns.oracle.com/j2ee/jsp/tld/ojsp/fileaccess.tld"
           prefix="download" %>
<%@ taglib uri="http://xmlns.oracle.com/j2ee/jsp/tld/ojsp/sqltaglib.tld"
           prefix="sql" %>
<% String dataSrcStr=request.getParameter("dataSrcStr");
   if (dataSrcStr==null) { dataSrcStr=(String)session.getValue("dataSrcStr");}
   else { session.putValue("dataSrcStr",dataSrcStr);}
   if (dataSrcStr==null) { %>
      <jsp:forward page="useDataSource.jsp" />
<% } %>
<html> <body>
<% String servletPath = "/servlet/download/"; %>
<sql:dbOpen dataSource="<%= dataSrcStr %>" >
<fileaccess:httpDownload sourceType = "database" 
            source="tagexample" servletPath = '<%= servletPath %>' >
   <br>:
</fileaccess:httpDownload>
</sql:dbOpen>
<br>Done!
</body> </html>

sendMail Tag Usage Notes

Be aware of the following when using the sendMail tag:

• The sender and recipient attributes are required, and either the host or session attribute is required.

• Multiple recipients, cc targets, or bcc targets are space-delimited or comma-delimited.

• Use of serverAttachment assumes server-side attachments are enabled in the sendmail.properties file. Similarly, use of clientAttachment assumes client-side attachments are enabled in sendmail.properties. Only one mode can be enabled for a single application. See "Enabling Attachments".

• File names in the serverAttachment setting can be comma-delimited or semicolon-delimited, but not space-delimited.

• The e-mail body can contain JSP syntax, which will be processed by the JSP translator.

• Attributes used by the tag are typically input by the user in form fields. All attributes accept request-time expressions.

• The prefix "mail:" is used in the tag syntax here. This is by convention but is not required. You can specify any desired prefix in your taglib directive.

• See "Tag Syntax Symbology and Notes" for general information about tag syntax conventions in this manual.