| java.lang.Object
 net.sourceforge.jtds.jdbc.Support
| Support | | public class Support (Code) | | This class contains static utility methods designed to support the
main driver classes.
Implementation notes:
- The methods in this class incorporate some code from previous versions
of jTDS to handle dates, BLobs etc.
- This class contains routines to generate runtime messages from the resource file.
- The key data conversion logic used in Statements and result sets is implemented here.
- There is nothing here which is TDS specific.
author:
Mike Hutchinson
author:
jTDS project
version:
$Id: Support.java,v 1.56 2007/07/08 18:42:14 bheineman Exp $ |
| Method Summary | |
| static int | calculateNamedPipeBufferSize(int tdsVersion, int packetSize)
Calculate the buffer size to use when buffering the InputStream
for named pipes.
The buffer size is tied directly to the packet size because each request
to the SmbNamedPipe will send a request for a particular
size of packet. | | static Object | convert(Object callerReference, Object x, int jdbcType, String charSet)
Convert an existing data object to the specified JDBC type. | | public static Object | convertLOB(Object value)
Converts a LOB to the equivalent Java type, i.e. | | public static int | convertLOBType(int type)
Converts a LOB type constant to the equivalent Java type constant, i.e.
Types.CLOB to Types.LONGVARCHAR and
Types.BLOB to Types.LONGVARBINARY. | | static void | embedData(StringBuffer buf, Object value, boolean isUnicode, ConnectionJDBC2 connection)
Embed the data object as a string literal in the buffer supplied. | | static byte[] | encodeString(String cs, String value)
Encode a string into a byte array using the specified character set.
Parameters:
cs - The Charset name.
Parameters:
value - The value to encode. | | static String | getClassName(int jdbcType)
Retrieve the fully qualified java class name for the
supplied JDBC Types constant.
Parameters:
jdbcType - The JDBC Types constant. | | static int | getJdbcType(Object value)
Get the JDBC type constant which matches the supplied Object type.
Parameters:
value - The object to analyse. | | static int | getJdbcType(Class typeClass)
Get the JDBC type constant which matches the supplied Class. | | static String | getJdbcTypeName(int jdbcType)
Get a String describing the supplied JDBC type constant.
Parameters:
jdbcType - The constant to be decoded. | | static String | getParameterDefinitions(ParamInfo[] parameters)
Constructs a parameter definition string for use with
sp_executesql, sp_prepare, sp_prepexec, sp_cursoropen,
sp_cursorprepare and sp_cursorprepexec. | | static String | getStatementKey(String sql, ParamInfo[] params, int serverType, String catalog, boolean autoCommit, boolean cursor)
Generates a unique statement key for a given SQL statement. | | public static boolean | isWindowsOS()
Checks the os.name system property to see if it starts
with "windows". | | public static SQLWarning | linkException(SQLWarning sqle, Throwable cause)
Link the original cause to an SQLWarning.
This convenience method calls
Support.linkException(Exception,Throwable) and casts the result for cleaner code elsewhere.
Parameters:
sqle - The SQLWarning to enhance.
Parameters:
cause - The Throwable to link. | | public static SQLException | linkException(SQLException sqle, Throwable cause)
Link the original cause to an SQLException.
This convenience method calls
Support.linkException(Exception,Throwable) and casts the result for cleaner code elsewhere.
Parameters:
sqle - The SQLException to enhance.
Parameters:
cause - The Throwable to link. | | public static Throwable | linkException(Exception exception, Throwable cause)
Link the original cause to an Exception.
If running under JVM 1.4+ the Throwable.initCause(Throwable)
method will be invoked to chain the exception, else the exception is
logged via the
Logger class.
Modeled after the code written by Brian Heineman.
Parameters:
exception - The Exception to enhance.
Parameters:
cause - The Throwable to link. | | static BigDecimal | normalizeBigDecimal(BigDecimal value, int maxPrecision)
Normalize a BigDecimal value so that it fits within the
available precision.
Parameters:
value - The decimal value to normalize.
Parameters:
maxPrecision - The decimal precision supported by the server(assumed to be a value of either 28 or 38). | | static String | substituteParamMarkers(String sql, ParamInfo[] list)
Update the SQL string and replace the ? markers with parameter names
eg @P0, @P1 etc. | | static String | substituteParameters(String sql, ParamInfo[] list, ConnectionJDBC2 connection)
Substitute actual data for the parameter markers to simulate
parameter substitution in a PreparedStatement.
Parameters:
sql - The SQL containing parameter markers to substitute.
Parameters:
list - The parameter descriptors.
Parameters:
connection - The current connection. | | public static long | timeFromZone(java.util.Date value, Calendar target)
Convert a timestamp from a different Timezone.
Parameters:
value - the timestamp value.
Parameters:
target - the Calendar containing the TimeZone. | | public static long | timeToZone(java.util.Date value, Calendar target)
Convert a timestamp to a different Timezone. | | public static String | toHex(byte[] bytes)
Convert a byte[] object to a hex string.
Parameters:
bytes - The byte array to convert. |
| calculateNamedPipeBufferSize | | static int calculateNamedPipeBufferSize(int tdsVersion, int packetSize)(Code) | | Calculate the buffer size to use when buffering the InputStream
for named pipes.
The buffer size is tied directly to the packet size because each request
to the SmbNamedPipe will send a request for a particular
size of packet. In other words, if you only request 1 byte, the
SmbNamedPipe will send a request out and only ask for 1 byte
back. Buffering the expected packet size ensures that all of the data
will be returned in the buffer without wasting any space.
Parameters:
tdsVersion - the TDS version for the connection
Parameters:
packetSize - requested packet size for the connection minimum default packet size if packetSize == 0,else packetSize |
| convert | | static Object convert(Object callerReference, Object x, int jdbcType, String charSet) throws SQLException(Code) | | Convert an existing data object to the specified JDBC type.
Parameters:
callerReference - an object reference to the caller of this method;must be a Connection,Statement or ResultSet
Parameters:
x - the data object to convert
Parameters:
jdbcType - the required type constant fromjava.sql.Types the converted data object
throws:
SQLException - if the conversion is not supported or fails |
| convertLOB | | public static Object convertLOB(Object value) throws SQLException(Code) | | Converts a LOB to the equivalent Java type, i.e. Clob to
String and Blob to byte[]. If the
value passed is not a LOB object, it is left unchanged and no exception
is thrown; the idea is to transparently convert only LOBs.
Parameters:
value - an object that may be a LOB if the value was a LOB, the equivalent Java object, otherwisethe original value
throws:
SQLException - if an error occurs while reading the LOB contents |
| convertLOBType | | public static int convertLOBType(int type)(Code) | | Converts a LOB type constant to the equivalent Java type constant, i.e.
Types.CLOB to Types.LONGVARCHAR and
Types.BLOB to Types.LONGVARBINARY. If the
type passed is not that of a LOB, it is left unchanged and no exception
is thrown; the idea is to transparently convert only LOB types.
Parameters:
type - a Types constant defining a JDBC type, possibly aLOB if the type was that of a LOB, the equivalent Java object type,otherwise the original type |
| embedData | | static void embedData(StringBuffer buf, Object value, boolean isUnicode, ConnectionJDBC2 connection) throws SQLException(Code) | | Embed the data object as a string literal in the buffer supplied.
Parameters:
buf - The buffer in which the data will be embeded.
Parameters:
value - The data object.
Parameters:
isUnicode - Set to true if Unicode strings should be used, else false.
Parameters:
connection - The ConnectionJDBC2 object. |
| encodeString | | static byte[] encodeString(String cs, String value)(Code) | | Encode a string into a byte array using the specified character set.
Parameters:
cs - The Charset name.
Parameters:
value - The value to encode. The value of the String as a byte[]. |
| getClassName | | static String getClassName(int jdbcType)(Code) | | Retrieve the fully qualified java class name for the
supplied JDBC Types constant.
Parameters:
jdbcType - The JDBC Types constant. The fully qualified java class name as a String. |
| getJdbcType | | static int getJdbcType(Object value)(Code) | | Get the JDBC type constant which matches the supplied Object type.
Parameters:
value - The object to analyse. The JDBC type constant as an int. |
| getJdbcType | | static int getJdbcType(Class typeClass)(Code) | | Get the JDBC type constant which matches the supplied Class.
Parameters:
typeClass - the Class to analyse the JDBC type constant as an int |
| getJdbcTypeName | | static String getJdbcTypeName(int jdbcType)(Code) | | Get a String describing the supplied JDBC type constant.
Parameters:
jdbcType - The constant to be decoded. The text decode of the type constant as a String. |
| getParameterDefinitions | | static String getParameterDefinitions(ParamInfo[] parameters)(Code) | | Constructs a parameter definition string for use with
sp_executesql, sp_prepare, sp_prepexec, sp_cursoropen,
sp_cursorprepare and sp_cursorprepexec.
Parameters:
parameters - Parameters to construct the definition for a parameter definition string |
| getStatementKey | | static String getStatementKey(String sql, ParamInfo[] params, int serverType, String catalog, boolean autoCommit, boolean cursor)(Code) | | Generates a unique statement key for a given SQL statement.
Parameters:
sql - the sql statment to generate the key for
Parameters:
params - the statement parameters
Parameters:
serverType - the type of server to generate the key for
Parameters:
catalog - the catalog is required for uniqueness on MicrosoftSQL Server
Parameters:
autoCommit - true if in auto commit mode
Parameters:
cursor - true if this is a prepared cursor the unique statement key |
| isWindowsOS | | public static boolean isWindowsOS()(Code) | | Checks the os.name system property to see if it starts
with "windows".
true if os.name starts with "windows",else false. |
| linkException | | public static Throwable linkException(Exception exception, Throwable cause)(Code) | | Link the original cause to an Exception.
If running under JVM 1.4+ the Throwable.initCause(Throwable)
method will be invoked to chain the exception, else the exception is
logged via the
Logger class.
Modeled after the code written by Brian Heineman.
Parameters:
exception - The Exception to enhance.
Parameters:
cause - The Throwable to link. The original Exception object. |
| normalizeBigDecimal | | static BigDecimal normalizeBigDecimal(BigDecimal value, int maxPrecision) throws SQLException(Code) | | Normalize a BigDecimal value so that it fits within the
available precision.
Parameters:
value - The decimal value to normalize.
Parameters:
maxPrecision - The decimal precision supported by the server(assumed to be a value of either 28 or 38). The possibly normalized decimal value as a BigDecimal.
throws:
SQLException - If the number is too big. |
| substituteParamMarkers | | static String substituteParamMarkers(String sql, ParamInfo[] list)(Code) | | Update the SQL string and replace the ? markers with parameter names
eg @P0, @P1 etc.
Parameters:
sql - the SQL containing markers to substitute
Parameters:
list - the parameter list the modified SQL as a String |
| substituteParameters | | static String substituteParameters(String sql, ParamInfo[] list, ConnectionJDBC2 connection) throws SQLException(Code) | | Substitute actual data for the parameter markers to simulate
parameter substitution in a PreparedStatement.
Parameters:
sql - The SQL containing parameter markers to substitute.
Parameters:
list - The parameter descriptors.
Parameters:
connection - The current connection. The modified SQL statement. |
| timeFromZone | | public static long timeFromZone(java.util.Date value, Calendar target)(Code) | | Convert a timestamp from a different Timezone.
Parameters:
value - the timestamp value.
Parameters:
target - the Calendar containing the TimeZone. The new timestamp value as a long. |
| timeToZone | | public static long timeToZone(java.util.Date value, Calendar target)(Code) | | Convert a timestamp to a different Timezone.
Parameters:
value - the timestamp value
Parameters:
target - the Calendar containing the TimeZone the new timestamp value as a long |
| toHex | | public static String toHex(byte[] bytes)(Code) | | Convert a byte[] object to a hex string.
Parameters:
bytes - The byte array to convert. The hex equivalent as a String. |
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