Go to http://dev.mysql.com/downloads/connector/j and with in the dropdown select &quot;Platform Independent&quot; then it will show you the options to download tar.gz file or zip file.

Download zip file and extract it, with in that you will find `mysql-connector-XXX.jar` file

If you are using maven then you can add the dependency from the link http://mvnrepository.com/artifact/mysql/mysql-connector-java

Select the version you want to use and add the dependency in your `pom.xml` file

If you have WL server installed, pick it up from under  
\Oracle\Middleware\wlserver_10.3\server\lib\mysql-connector-java-commercial-5.1.17-bin.jar

Otherwise, download it from:  
http://www.java2s.com/Code/JarDownload/mysql/mysql-connector-java-5.1.17-bin.jar.zip

Here&#39;s a one-liner using Maven:

    mvn dependency:get -Dartifact=mysql:mysql-connector-java:5.1.38

Then, with default settings, it&#39;s available in:

    $HOME/.m2/repository/mysql/mysql-connector-java/5.1.38/mysql-connector-java-5.1.38.jar

Just replace the version number if you need a different one.

I am working on some javascript UI, and using a lot of touch events like &#39;touchend&#39; for improved response on touch devices. However, there are some logical issues which are bugging me ...

I have seen that many developers mingle &#39;touchend&#39; and &#39;click&#39; in the same event. In many cases it will not hurt, but essentially the function would fire twice on touch devices:

    button.on(&#39;click touchend&#39;, function(event) {
      // this fires twice on touch devices
    });

It has been suggested that one could detect touch capability, and set the event appropriately for example:

    var myEvent = (&#39;ontouchstart&#39; in document.documentElement) ? &#39;touchend&#39; : &#39;click&#39;;
    button.on(myEvent, function(event) {
      // this fires only once regardless of device
    });

The problem with the above, is that it will break on devices that support both touch and mouse. If the user is currently using mouse on a dual-input device, the &#39;click&#39; will not fire because only &#39;touchend&#39; is assigned to the button.

Another solution is to detect the device (e.g. &quot;iOS&quot;) and assign an event based on that:
https://stackoverflow.com/questions/8503453/click-event-called-twice-on-touchend-in-ipad.
Of course, the solution in the link above is only for iOS (not Android or other devices), and seems more like a &quot;hack&quot; to solve something quite elementary.

Another solution would be to detect mouse-motion, and combine it with touch-capability to figure out if the user is on mouse or touch. Problem of course being that the user might not be moving the mouse from when you want to detect it ...

The most reliable solution I can think of, is to use a simple [debounce][1] function to simply make sure the function only triggers once within a short interval (for example 100ms):

    button.on(&#39;click touchend&#39;, $.debounce(100, function(event) {
      // this fires only once on all devices
    }));

Am I missing something, or does anyone have any better suggestions?

*Edit:* I found this link after my post, which suggests a similar solution as the above:
https://stackoverflow.com/questions/7018919/how-to-bind-touchstart-and-click-events-but-not-respond-to-both

  [1]: http://benalman.com/projects/jquery-throttle-debounce-plugin/

JavaScript touchend versus click dilemma

I have inherited some Python code which is used to create huge tables (of up to 19 columns wide by 5000 rows). It took **nine seconds** for the table to be drawn on the screen. I noticed that each row was added using this code:

    sTable = sTable + &#39;\n&#39; + GetRow()

where `sTable` is a string.

I changed that to:

    sTable += &#39;\n&#39; + GetRow()

and I noticed that the table now appeared in **six seconds**.

And then I changed it to:

    sTable += &#39;\n%s&#39; % GetRow()

based on [these Python performance tips](https://wiki.python.org/moin/PythonSpeed/PerformanceTips#String_Concatenation) (still six seconds).

Since this was called about 5000 times, it highlighted the performance issue. But why was there such a large difference? And why didn&#39;t the compiler spot the problem in the first version and optimise it?

Why is variable1 += variable2 much faster than variable1 = variable1 + variable2?

I installed and tried to use jasper report studio. The first brick wall you hit when you try to create a datasource for your reports is 

    java.lang.ClassNotFoundException: com.mysql.jdbc.Driver

The forums say I need to install a jar on the classpath. I have no idea how to do this, so the first hurdle is how to get the jar. The only place I can find is this:  

http://dev.mysql.com/downloads/connector/j/ 

but this unfortunately gives you an msi installer, not a jar. I don&#39;t want to install stuff, just get the jar.

I have mysql DB installed, had have trawled through the install dir in program files, but can&#39;t find the jar.

Anyone know the official (not malware site) way to get hold of the mysql jar?  It seems bizarre that its so hard to find.

I have windows 8 64 bit and mysql 5.6.


Where can I download mysql jdbc jar from?

I installed and tried to use jasper report studio. The first brick wall you hit when you try to create a datasource for your reports is
<pre><code class="hljs language-makefile">java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
</code></pre>
The forums say I need to install a jar on the classpath. I have no idea how to do this, so the first hurdle is how to get the jar. The only place I can find is this:
<a href="http://dev.mysql.com/downloads/connector/j/" target="_blank" rel="noopener noreferrer">http://dev.mysql.com/downloads/connector/j/</a>
but this unfortunately gives you an msi installer, not a jar. I don't want to install stuff, just get the jar.
I have mysql DB installed, had have trawled through the install dir in program files, but can't find the jar.
Anyone know the official (not malware site) way to get hold of the mysql jar? It seems bizarre that its so hard to find.
I have windows 8 64 bit and mysql 5.6.

I&#39;m having trouble getting a very-nested relationship to work correctly in laravel.

The wanted behaviour is as follows, 

**I select an event by ID and i want to see which persons are subscribed to it.**
Now the problem is there are some tables between the event and the person..

This is the query that works!

    SELECT persons.id, 
           persons.firstname, 
           persons.lastname, 
           event_scores.score 
    FROM   events 
           JOIN cities 
             ON cities.id = events.city_id 
           JOIN companies 
             ON cities.id = companies.city_id 
           JOIN persons 
             ON companies.id = persons.company_id 
           JOIN event_scores 
             ON event_scores.person_id = persons.id 
    WHERE  event_scores.event_id = 1 
    GROUP  BY persons.id 

# These are my relations #
### Event Model ###

    class Event extends Eloquent
    {
	    protected $table = &#39;events&#39;;

	    public function city()
	    {
		    return $this-&gt;belongsTo(&#39;City&#39;);
	    }
    }
### City Model ###
    class City extends Eloquent
    {
	    protected $table = &#39;cities&#39;;

	    public function companies()
	    {
		    return $this-&gt;hasMany(&#39;Company&#39;);
	    }

	    public function event()
	    {
		    return $this-&gt;hasMany(&#39;Event&#39;);
	    }
    }

### Company Model ###
    class Company extends Eloquent {

	    protected $table = &#39;companies&#39;;

	    public function persons()
	    {
		    return $this-&gt;hasMany(&#39;Person&#39;);
	    }

	    public function city()
	    {
		    return $this-&gt;belongsTo(&#39;City&#39;);
	    }
    }

### Person Model ###
    class Person extends Eloquent
    {
	    protected $table = &#39;persons&#39;;

	    public function company()
	    {
		    return $this-&gt;belongsTo(&#39;Company&#39;);
	    }

	    public function eventscore()
	    {
		    return $this-&gt;belongsToMany(&#39;Event&#39;, &#39;event_scores&#39;, &#39;person_id&#39;, &#39;event_id&#39;)
			    -&gt;withPivot(&#39;score&#39;)
			    -&gt;withTimestamps();
	    }
    }

# What I have tried #

    return Event::with(&#39;city&#39;)-&gt;with(&#39;company&#39;)-&gt;get();

and

	return Event::with(&#39;city&#39;)
		-&gt;whereHas(&#39;companies&#39;, function($query) use ($company_id){
			$query-&gt;where(&#39;company_id&#39;, $company_id);
		})-&gt;get();

And many other possibilities, I&#39;m really stuck on this. Is it so difficult in laravel to achieve this kind of nested relationship linking?

Thanks!

Laravel nested relationships

So about a year ago I started a project and like all new developers I didn&#39;t really focus too much on the structure, however now I am further along with Django it has started to appear that my project layout mainly my models are horrible in structure.

I have models mainly held in a single app and really most of these models should be in their own individual apps, I did try and resolve this and move them with south however I found it tricky and really difficult due to foreign keys ect.

However due to Django 1.7 and built in support for migrations is there a better way to do this now?

How to move a model between two Django apps (Django 1.7)

I am trying to understand how to UPDATE multiple rows with different values and I just don&#39;t get it. The solution is everywhere but to me it looks difficult to understand.

For instance, three updates into 1 query:

	UPDATE table_users
    SET cod_user = &#39;622057&#39;
        , date = &#39;12082014&#39;
    WHERE user_rol = &#39;student&#39;
        AND cod_office = &#39;17389551&#39;; 

	UPDATE table_users
    SET cod_user = &#39;2913659&#39;
        , date = &#39;12082014&#39;
    WHERE user_rol = &#39;assistant&#39;
        AND cod_office = &#39;17389551&#39;; 

	UPDATE table_users
    SET cod_user = &#39;6160230&#39;
        , date = &#39;12082014&#39;
    WHERE user_rol = &#39;admin&#39;
        AND cod_office = &#39;17389551&#39;; 

I [read][1] an example, but I really don&#39;t understand how to make the query. i.e:

    UPDATE table_to_update
    SET cod_user= IF(cod_office = &#39;17389551&#39;,&#39;622057&#39;,&#39;2913659&#39;,&#39;6160230&#39;)
        ,date = IF(cod_office = &#39;17389551&#39;,&#39;12082014&#39;)
    WHERE ?? IN (??) ;

I&#39;m not entirely clear how to do the query if there are multiple condition in the WHERE and in the IF condition..any ideas?

  [1]: http://www.karlrixon.co.uk/writing/update-multiple-rows-with-different-values-and-a-single-sql-query/

MySQL - UPDATE multiple rows with different values in one query

I am not sure how to fix this:

    dyn-72-33-214-45:python mona$ sudo /usr/local/mysql/bin/mysqld stop
    2014-09-06 09:49:04 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
    2014-09-06 09:49:04 22992 [Warning] Setting lower_case_table_names=2 because file system for /usr/local/mysql-5.6.15-osx10.7-x86_64/data/ is case insensitive
    2014-09-06 09:49:04 22992 [ERROR] Fatal error: Please read &quot;Security&quot; section of the manual to find out how to run mysqld as root!
    
    2014-09-06 09:49:04 22992 [ERROR] Aborting
    
    2014-09-06 09:49:04 22992 [Note] Binlog end
    2014-09-06 09:49:04 22992 [Note] /usr/local/mysql/bin/mysqld: Shutdown complete



Fatal error: Please read &quot;Security&quot; section of the manual to find out how to run mysqld as root

I&#39;ve been trying to create a new database connection on workbench. However, every time I test a connection there is an error message that says

&gt; Failed to connect to mysql at 127.0.0.1:3306 with user root access denied for user &#39;root&#39;@&#39;localhost&#39;(using password:YES) 

I don&#39;t know what&#39;s the cause of this error. I have tried uninstalling and re-installing my workbench 6.1 and mysql server 5.6 but the error is still unsolved.

Failed to connect to mysql at 127.0.0.1:3306 with user root access denied for user &#39;root&#39;@&#39;localhost&#39;(using password:YES)

Spring-Boot is a pretty awesome tool, but the documentation is a bit sparse when it comes to more advanced configuration. How can I set properties like the maximum size for my database connection pool?

Spring-Boot supports `tomcat-jdbc`, `HikariCP` and `Commons DBCP` natively are they all configured the same way?

Spring-Boot: How do I set JDBC pool properties like maximum number of connections?

I&#39;ve been reading around, [here][1], [here][2] and [here][3] about the advantages of using `rewriteBatchedStatements=true`

If I understood it right, with `rewriteBatchedStatements=true` the JDBC will *pack* as many queries as possible into a single network packet, lowering this way the network overhead. Am I right?

Then it comes into my attention that the value defined in the MySQL server for the `max_allowed_packet` may cause problems with the queries (queries not being executed on the server).

So my second question is, does JDBC knows the value assigned to `max_allowed_packet` and therefore make the packet smaller than the defined value for `max_allowed_packet` or that is something that the developer has to take in consideration?

If I understood something wrong, please let me know as well.


  [1]: http://java-persistence-performance.blogspot.ch/2013/05/batch-writing-and-dynamic-vs.html
  [2]: http://anonymousbi.wordpress.com/2014/02/11/increase-mysql-output-to-80k-rowssecond-in-pentaho-data-integration/
  [3]: http://blog.javabien.net/2014/05/14/mysql-and-jdbc-batch-inserts/

MySQL and JDBC with rewriteBatchedStatements=true

When I try to read data from the database, at least using

`((Session)em.getDelegate()).createCriteria()` 

an exception is throws saying that a transaction is not present. 

When I add the annotation: 

    @Transactional(
        value = SomeClass.TRANSACTIONAL_MANAGER, 
        propagation = Propagation.SUPPORTS, 
        readOnly = true
    )

it works fine.

However, since reading will happen million of times per second to access and read data, I want to make sure that our environment is not clogged up unnecessarily. 

**If not, what is the cost of creating a read-only `Propagation.Supports` transaction?** 

Can I not create a Hibernate Criteria Query without a transaction, in combination with Spring? 





Do you need a database transaction for reading data?

Some background:

I have a Java 1.6 webapp running on Tomcat 7. The database is MySQL 5.5. Previously, I was using Mysql JDBC driver 5.1.23 to connect to the DB. Everything worked. I recently upgraded to Mysql JDBC driver 5.1.33. After the upgrade, Tomcat would throw this error when starting the app.

&lt;!-- language: lang-none --&gt;

    WARNING: Unexpected exception resolving reference
    java.sql.SQLException: The server timezone value &#39;UTC&#39; is unrecognized or represents
      more than one timezone. You must configure either the server or JDBC driver (via
      the serverTimezone configuration property) to use a more specifc timezone value if
      you want to utilize timezone support.

Why is this happening?

MySQL JDBC Driver 5.1.33 - Time Zone Issue

Edit: Well, apparently it was too opinion based, so let me try to reword it more precisely - 

Are there any clear caveats or drawbacks of using LocalDate, LocalTime etc. in a Java code that does not need any backwards compatibility, and if so - what are they?

I&#39;m looking for things like &quot;Current EE libraries X and Y don&#39;t work correctly with LocalDate&quot; or &quot;This very useful pattern is broken with LocalTime&quot; et cetera.


----------
(here is the original question for reference)

With Java 8, a new time API is introduced, namely the java.time.LocalDate etc., but java.util.Date is not marked as deprecated.

I am writing a new project, which does not need to be backwards compatible. Should I only use LocalDate, LocalDateTime etc.? Are there any drawbacks to using this new API as opposed to the good old java.util.Date?

In particular - I am going to be working mainly with JDBC. From what I have seen JDBC handles java.util.Date well. Is it as well suited for LocalDate?


Searching yielded lots of sites telling how to convert from one format to the other, but no definitive answer as to should new code use the old API.

Thanks.

Should I use java.util.Date or switch to java.time.LocalDate

I am new to Android Studio.  
How can I add a few jar files in the `External Libraries` below the &lt; JDK &gt; folder?


![enter image description here][1]


  [1]: http://i.stack.imgur.com/5PXLJ.png

How to add a jar in External Libraries in Android Studio?

I have a file that I&#39;ve been reading into a List&lt;String&gt; via the following method:

    List&lt;String&gt; doc = java.nio.file.Files.readAllLines(new File(&quot;/path/to/src/resources/citylist.csv&quot;).toPath(), StandardCharsets.UTF_8);


Is there any nice (single-line) Java 7/8/nio2 way to pull off the same feat with a file that&#39;s inside an executable Jar (and presumably, has to be read with an InputStream)? Perhaps a way to open an InputStream via the classloader, then somehow coerce/transform/wrap it into a Path object? Or some new subclass of InputStream or Reader that contains an equivalent to File.readAllLines(...)?

I know I *could* do it the traditional way in a half page of code, or via some external library... but before I do, I want to make sure that recent releases of Java can&#39;t already do it &quot;out of the box&quot;.

equivalent to Files.readAllLines() for InputStream or Reader?

When running commands such as 

    mvn dependency:build-classpath
or

    mvn exec:java

Maven is unable to resolve a dependency of one of my modules on another. 

&gt; [ERROR] Failed to execute goal on project parser-app: Could not resolve dependencies for project project_group:A:jar:0.1-SNAPSHOT: Could not find artifact project_group:B:jar:0.1-SNAPSHOT

The project structure is as follows:

    /pom.xml
    /A/pom.xml
    /B/pom.xml

The parent pom is as follows:

    &lt;project xmlns=&quot;http://maven.apache.org/POM/4.0.0&quot; xmlns:xsi=&quot;http://www.w3.org/2001/XMLSchema-instance&quot;
      xsi:schemaLocation=&quot;http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd&quot;&gt;
      &lt;modelVersion&gt;4.0.0&lt;/modelVersion&gt;
      &lt;groupId&gt;project_group&lt;/groupId&gt;
      &lt;artifactId&gt;parent&lt;/artifactId&gt;
      &lt;packaging&gt;pom&lt;/packaging&gt;
      &lt;version&gt;0.1-SNAPSHOT&lt;/version&gt;
      &lt;name&gt;parent&lt;/name&gt;
    
      &lt;modules&gt;
        &lt;module&gt;A&lt;/module&gt;
        &lt;module&gt;B&lt;/module&gt;
      &lt;/modules&gt;

The first child module (the one failing to resolve the dependency):

        &lt;project xmlns=&quot;http://maven.apache.org/POM/4.0.0&quot; xmlns:xsi=&quot;http://www.w3.org/2001/XMLSchema-instance&quot;
      xsi:schemaLocation=&quot;http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd&quot;&gt;
      &lt;modelVersion&gt;4.0.0&lt;/modelVersion&gt;
      &lt;parent&gt;
        &lt;groupId&gt;parent_group&lt;/groupId&gt;
        &lt;artifactId&gt;parent&lt;/artifactId&gt;
        &lt;version&gt;0.1-SNAPSHOT&lt;/version&gt;
      &lt;/parent&gt;
      &lt;artifactId&gt;A&lt;/artifactId&gt;
      &lt;packaging&gt;jar&lt;/packaging&gt;
      &lt;name&gt;A&lt;/name&gt;
    
      &lt;dependencies&gt;
        &lt;dependency&gt;
          &lt;groupId&gt;parent_group&lt;/groupId&gt;
          &lt;artifactId&gt;B&lt;/artifactId&gt;
          &lt;version&gt;0.1-SNAPSHOT&lt;/version&gt;
        &lt;/dependency&gt;

The second child module (the dependency):

  

      &lt;project xmlns=&quot;http://maven.apache.org/POM/4.0.0&quot; xmlns:xsi=&quot;http://www.w3.org/2001/XMLSchema-instance&quot;
      xsi:schemaLocation=&quot;http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd&quot;&gt;
      &lt;modelVersion&gt;4.0.0&lt;/modelVersion&gt;
      &lt;parent&gt;
        &lt;groupId&gt;parent_group&lt;/groupId&gt;
        &lt;artifactId&gt;parent&lt;/artifactId&gt;
        &lt;version&gt;0.1-SNAPSHOT&lt;/version&gt;
      &lt;/parent&gt;
      &lt;artifactId&gt;B&lt;/artifactId&gt;
      &lt;packaging&gt;jar&lt;/packaging&gt;
      &lt;name&gt;B&lt;/name&gt;




Maven cannot resolve dependency for module in same multi-module project

I have a main class that expects certain properties that I pass using the -D option. I can access this in my IDE by sending them as VM options.

I package this application into a jar file using Maven and when I try the following:

`java -jar myjar.jar -Denviroment=dev`

or

`java -jar myjar.jar &quot;-Denvironment=dev&quot;`

The enviroment system property is not getting picked up.

Any pointers on what is going on?

How to pass system properties to a jar file

I am working on `YouTube broadcast` sample examples. I have created a sample `Java Project` &amp; added required jars. But, when I try to run the project it throws exception.

Exception :

    Throwable: com/fasterxml/jackson/core/JsonFactory
    java.lang.NoClassDefFoundError: com/fasterxml/jackson/core/JsonFactory
    	at com.google.api.client.json.jackson2.JacksonFactory.&lt;init&gt;(JacksonFactory.java:44)
    	at com.google.api.services.samples.youtube.cmdline.live.Auth.&lt;clinit&gt;(Auth.java:35)
    	at com.google.api.services.samples.youtube.cmdline.live.CreateBroadcast.main(CreateBroadcast.java:55)
    Caused by: java.lang.ClassNotFoundException: com.fasterxml.jackson.core.JsonFactory
    	at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
    	at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
    	at java.security.AccessController.doPrivileged(Native Method)
    	at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
    	at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
    	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
    	at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
    	... 3 more

I downloaded the project from [this GitHub repository][1]. 


  [1]: https://github.com/youtube/api-samples/tree/master/java

Content Type	Original Author	Original Content on Stackoverflow
Question	John Little	View Question on Stackoverflow
Solution 1 - Mysql	Prasad Khode	View Answer on Stackoverflow
Solution 2 - Mysql	Roshith	View Answer on Stackoverflow
Solution 3 - Mysql	ryenus	View Answer on Stackoverflow

Where can I download mysql jdbc jar from?

Mysql Problem Overview

Mysql Solutions

Solution 1 - Mysql

Solution 2 - Mysql

Solution 3 - Mysql

Why is variable1 += variable2 much faster than variable1 = variable1 + variable2?

JavaScript touchend versus click dilemma

Attributions