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Created by magnum on October 22, 2012 20:03:05    Last update: October 22, 2012 20:03:05
First, the test command that sleeps random number of seconds ( sleeper.sh ): #!/bin/bash stime=$[$RANDOM % 20] sleep $sti... As comparison, synchronous pipe code: #include <sys/wait.h> #include <stdio.h> #in... Asynchronous pipe code: #include <sys/wait.h> #include <stdio.h> #in...
Created by Fang on August 16, 2010 21:44:41    Last update: August 16, 2010 22:01:46
The tags <sql:query> Queries a database. Syntax: <sql:query sql="sqlQuery" var="varName" [scope... or, put the query within the element body: <sql:query var="varName" [scope="{page|req... Attributes: Name Dynamic? Type Description sql true String SQL query statement. dataSource true javax.sql.DataSource or String Data source associated with the database to query. A String value represents a relative path to a JNDI resource or the JDBC parameters for the DriverManager class. maxRows true int The maximum number of rows to be included in the query result. If not specified, or set to -1, no limit on the maximum number of rows is enforced. startRow true int The returned Result object includes the rows starting at the specified index. The first row of the original query result set is at index...
Created by Dr. Xi on June 20, 2010 14:35:17    Last update: June 20, 2010 14:35:17
This XML signature validator comes from the Apache XML Security project. It validates the signature according to the core validation processing rules . It does not verify that the key used to generate the signature is a trusted key. You can override the KeySelector class to make sure that the signing key is from a trusted store. import javax.xml.crypto.*; import javax.xml.cry...
Created by Dr. Xi on February 24, 2010 21:13:05    Last update: February 24, 2010 21:19:54
This program demonstrates the use of the java.nio package to implement a single thread echo server. import java.io.IOException; import java.net.Ine...
Created by Dr. Xi on January 07, 2010 23:40:28    Last update: February 09, 2010 03:24:35
This is a utility to generate SQL insert statements for Oracle for one table, or a set of tables. It doesn't cover all possibilities but should be good enough for most cases. import java.io.*; import java.sql.*; import ... To generate insert statements for multiple tables, simply put the table names in a file, one per line, and use the -f switch.
Created by Dr. Xi on October 18, 2008 02:46:56    Last update: October 18, 2008 02:47:33
There are four pairs of methods in the java.sql.ResultSet class that deal with BLOBs/CLOBs: Reader getCharacterStream(int columnIndex) / Reader getCharacterStream(String columnName) InputStream getBinaryStream(int columnIndex) / InputStream getBinaryStream(String columnName) Blob getBlob(int i) / Blob getBlob(String colName) Clob getClob(int i) / Clob getClob(String colName) Example code: PreparedStatement pstmt = conn.prepareStatemen...
Created by Dr. Xi on August 11, 2007 23:19:26    Last update: August 12, 2007 01:39:33
For SQL Server 2000 and above, there are three functions: SELECT @@IDENTITY When a record is inserted into a table with a identity column, the function @@IDENTITY returns the last identity value that was inserted in the database on the same open connection. If a trigger adds a record into another table, which happens to have an identity column, @@IDENTITY will now return this value instead. SELECT IDENT_CURRENT('tablename') This will give you the most recent identity value for the given table regardless of who inserted it. SELECT SCOPE_IDENTITY() SCOPE_IDENTITY shows the most recently inserted IDENTITY in the current scope (which ignores any triggers that might fire). For SQL Server version prior to 2000, it is customary to use a stored procedure: CREATE PROCEDURE myProc @param1 INT AS......