NoSuchProviderException: smtp

Monday, December 29, 2008

If you get the error:
Caused by: javax.mail.NoSuchProviderException: smtp

You most likely having a conflicting jar file. This happened to me when moving from my local machine to a Fedora Linux server. I updated the java version to Java 6. Java 6 already has java mail functionality found in the mail.jar file. Remove any jar files having to do with mail and your exception will go away.

Labels: Bug Solutions, Technology

Linux MySQL Error

Saturday, December 27, 2008

if you try to use jdbc to connect to a MySQL database on a Linux distribution like Fedora or Redhat and get the error:

java.sql.SQLException: Unexpected exception encountered during query.
Caused by: java.io.CharConversionException

Solution:
modify /etc/my.cnf add the line:
default-character-set=utf8

You can also use a more recent version of java.

Labels: Technology

How to install and connect from a client to MySQL on Fedora

Wednesday, December 24, 2008

1. Install the rpm via yum with the following command: yum -y install mysql mysql-server
2. assign passwords to default accounts like this:
2a. switch to root account with: (usr/local/mysql/bin) mysql -u root
mysql> SET PASSWORD FOR ''@'localhost' = PASSWORD('newpwd');
mysql> SET PASSWORD FOR ''@'host_name' = PASSWORD('newpwd');
You can see the reference here.
3. Create a database with the command: CREATE DATABASE dbname;
4. If you would like to connect from a client you must enter a row in the "user" table like this:
insert into mysql.user(Host, User) values ('192.168.1.2','root');
4a. You can also check if your desired host already exists in the user table by first switching to the root account and then issuing the query: SELECT Host, User FROM mysql.user;
5. You now need to grant permissions with the command: GRANT ALL PRIVILEGES ON *.* TO 'user'@'host' IDENTIFIED BY 'password' WITH GRANT OPTION;
5a. restart mysql with the command (as root): service mysqld restart
6. Tadah!!!!! You're running MySQL on Fedora and connecting to your new database from a client!!!

Labels: Technology

MySQL Magic

Monday, December 22, 2008

How to login with the mysql user: sudo bin/mysqld_safe --user=mysql --log &
Shutdown mysql server: bin/mysqladmin -u root shutdown
switch to root user: bin/mysql -u root
initialize context for a database: USE databasename or mysql -h host -u user -p dbname

MySQL Commands

Create A Table
CREATE TABLE `joetest`.`User` (
`id` INT( 255 ) NOT NULL AUTO_INCREMENT,
`user_name` VARCHAR( 20 ) NOT NULL ,
`password` VARCHAR( 20 ) NOT NULL ,
PRIMARY KEY ( `id` )
) ENGINE = INNODB

Labels: Technology

Reading a file from a local directory into a byte array

Wednesday, December 17, 2008

This can be done with the following code:

public static byte[] getBytesFromFile(File file) throws IOException {
InputStream is = new FileInputStream(file);

// Get the size of the file
long length = file.length();

if (length > Integer.MAX_VALUE) {
// File is too large
}

// Create the byte array to hold the data
byte[] bytes = new byte[(int)length];

// Read in the bytes
int offset = 0;
int numRead = 0;
while (offset < bytes.length
&& (numRead=is.read(bytes, offset, bytes.length-offset)) >= 0) {
offset += numRead;
}

// Ensure all the bytes have been read in
if (offset < bytes.length) {
throw new IOException("Could not completely read file "+file.getName());
}

// Close the input stream and return bytes
is.close();
return bytes;
}

Labels: Technology