Tao

When I try to use URLConnection to check if a url is accessible using the following code:

try {
    URL url = new URL("http://169.254.169.254/latest");

    URLConnection connection = url.openConnection();
    connection.setConnectTimeout(5000);
    connection.connect();
    System.out.println("Connected successfully using url");
} catch (IOException e) {
        e.printStackTrace();
}

I expected the behavior is: connect should be success if the host is reachable, else throw exception. It works fine without the anti-virus application, but always print “connected successfully” even the host is not reachable.

Then I tried to use Socket to connect:

Socket socket = new Socket();
socket.connect(new InetSocketAddress("169.254.169.254", 80));
if (socket.isConnected()) {
    System.out.println("Connected successfully using socket");
} else {
    System.out.println("Connected failed using socket");
}

But Still got the same problem.

The solution for it:

Disable http check in anti-virus, for example, in ESET NOD32, the settings is Web access protection -> Http, Https -> Http scanner

Preview support edit images, but the menu item is disabled by default when I open an image file. I thought it was because the Preview does not support this kind of file type. Recently, when I try to find a simple image editor only for add some text, oval or rectangle, I found that the Preview support it perfectly.

After customized the toolbar, the buttons enabled, and it’s very easy to add comments, but the menu item still disabled.

The following is what I found about how to customize the toolbar from the Preview Help.

Adding text to an image

You can add text to an image to describe what’s in it or when the image was created.

After you save the image, you can’t edit, move, or delete any text you added to it. If you think you’ll need to edit the text, convert the image to a PDF document, and then add notes to the PDF document. Notes added to a PDF document can be edited after they’re saved.

To add text to an image:

1. If the Annotate pop-up menu isn’t in the toolbar, choose View > Customize Toolbar and drag the Annotate pop-up menu to the toolbar.
2. Choose Note from the Annotate pop-up menu in the toolbar.
3. Drag over the area where you want the text to appear.
4. Enter your text.

Before you save the image, you can move, resize, edit, or delete the text. First choose Text Annotation from the Annotation pop-up menu in the toolbar. Then to edit the text, double-click it. To delete the text, click it so resize handles appear, and then press Delete.

diff -r -q -X exclude.list . testing

1. simple join two tables

purpose:
generate sql like:   

select * from photo p
    left join artist a on p.artist_id = a.artist_id
      where a.genre = 'something' and p.genre = 'something'

code:           

if(!CriteriaUtil::hasJoin($criteria, ArtistPeer::TABLE_NAME)){
    $criteria->addJoin(PhotoPeer::ARTIST_ID, ArtistPeer::ARTIST_ID, Criteria::LEFT_JOIN);
}
$criteria->add(ArtistPeer::GENRE, $genre);    
$criteria->add(PhotoPeer::GENRE, $genre);

2. join two tables, add AND OR between conditions
purpose:
generate sql like:    

select * from photo p
    left join artist a on p.artist_id = a.artist_id
      where (a.genre = 'some' or p.genre='something')
        and a.name = 'something'

code:   

if(!CriteriaUtil::hasJoin($criteria, ArtistPeer::TABLE_NAME)){
   $criteria->addJoin(PhotoPeer::ARTIST_ID, ArtistPeer::ARTIST_ID, Criteria::LEFT_JOIN);
}
$criteria->add(ArtistPeer::GENRE, $genre);
$c = $criteria->getCriterion(ArtistPeer::GENRE);
if($c != null){
   $c->addOr($criteria->getNewCriterion(PhotoPeer::GENRE, $genre));
}
$criteria->add(ArtistPeer::NAME, $name);

Note:
It's a good habit to check if we have joined the table already. to check this, you can use the following util class, it get all the joined tables, and check if the table exists in them.

class CriteriaUtil{
    public static function hasJoin($c, $table_name){
        $joins = $c->getJoins();
        if($joins != null){
            foreach($joins as $join){
                if($join->getRightTableName() == $table_name){
                    return true;
                }
                if($join->getLeftTableName() == $table_name){
                    return true;
                }
            }
        }
        return false;
    }
}

It maybe popup an error message to say that "QI for IEnumVARIANT failed on the unmanaged server" when open the Windows Live Writer.

After search on google, I found the resolution is import some settings into registry.

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{00020404-0000-0000-C000-000000000046}]
@="IEnumVARIANT"

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{00020404-0000-0000-C000-000000000046}\NumMethods]
@="7"

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{00020404-0000-0000-C000-000000000046}\ProxyStubClsid]
@="{00020421-0000-0000-C000-000000000046}"

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{00020404-0000-0000-C000-000000000046}\ProxyStubClsid32]
@="{00020421-0000-0000-C000-000000000046}"

You can also download the file here, unzip and import it to your registry.

Original article: http://www.symfony-project.com/book/1_0/18-Performance

Clearing Selective Parts of the Cache

During application development, you have to clear the cache in various situations:

• When you create a new class: Adding a class to an autoloading directory (one of the project's lib/ folders) is not enough to have symfony find it automatically. You must clear the autoloading configuration cache so that symfony browses again all the directories of the autoload.yml file and references the location of autoloadable classes--including the new ones.
• When you change the configuration in production: The configuration is parsed only during the first request in production. Further requests use the cached version instead. So a change in the configuration in the production environment (or any environment where SF_DEBUG is turned off) doesn't take effect until you clear the cached version of the file.
• When you modify a template in an environment where the template cache is enabled: The valid cached templates are always used instead of existing templates in production, so a template change is ignored until the template cache is cleared or outdated.
• When you update an application with the sync command: This case usually covers the three previous modifications.

The problem with clearing the whole cache is that the next request will take quite long to process, because the configuration cache needs to be regenerated. Besides, the templates that were not modified will be cleared from the cache as well, losing the benefit of previous requests.

That means it's a good idea to clear only the cache files that really need to be regenerated. Use the options of the clear-cache task to define a subset of cache files to clear, as demonstrated in Listing 18-14.

Listing 18-14 - Clearing Only Selective Parts of the Cache

// Clear only the cache of the myapp application

> symfony clear-cache myapp



// Clear only the HTML cache of the myapp application

> symfony clear-cache myapp template



// Clear only the configuration cache of the myapp application

> symfony clear-cache myapp config

You can also remove files by hand in the cache/ directory, or clear template cache files selectively from the action with the $cacheManager->remove() method, as described inChapter 12

Note:

1. We can use $cacheManager->remove() to clear cache after we deployed a new version product.

2. write code to generate models from database, and then call $cacheManager->remove() to clear cache.

#get the first parameter as the database name
DATABASE=$1
#if no database specified, then you can set the default one
if [ -z $DATABASE ]; then

DATABASE=default_database_name_here

fi



#mysql user and password to backup the database.
MYSQLUSER=mysql_user
MYSQLPWD=mysql_password
#path to backup
ARCHIVEPATH=~/backup/db_backup
DATE=`date +%Y%m%d`
YEAR=`date +%Y`
MONTH=`date +%m`
FOLDER_MONTH=$ARCHIVEPATH/$YEAR$MONTH
if [ ! -d $FOLDER_MONTH ]; then

echo "mkdir $FOLDER_MONTH"
mkdir $FOLDER_MONTH
fi
# Backup
echo "mysqldump -u$MYSQLUSER -p$MYSQLPWD $DATABASE | gzip > $FOLDER_MONTH/$DATABASE-$DATE.sql.gz"
mysqldump -u$MYSQLUSER -p$MYSQLPWD $DATABASE | gzip > $FOLDER_MONTH/$DATABASE-$DATE.sql.gz

and you can add the script to cron job under *nix and schedule under windows:

*nix:

Save the following text in file: db_backup.at

10 * * * * ~/backup/backup_db.sh databasename

and call

crontab db_backup.at

You need to change the period to run the script for your business, e.g. each day, each week etc.

edit file: /etc/network/interfaces

the original content should be something like:

# The primary network interface
auto eth0
iface eth0 inet static
address 192.168.0.5
netmask 255.255.255.0
network 192.168.0.0
broadcast 192.168.0.255
gateway 192.168.0.1
# dns-* options are implemented by the resolvconf package, if installed
dns-nameservers 192.168.0.1 

add the following settings in the file:

auto eth0:1

iface eth0:1 inet static

address 192.168.0.6

netmask 255.255.255.0

network 192.168.0.0

broadcast 192.168.0.255

gateway 192.168.0.1



# dns-* options are implemented by the resolvconf package, if installed
dns-nameservers 192.168.0.1 

run command in root mode:

/etc/init.d/networking restart

that's all. you can run ifconfig to check if it works.

I tested it in ubuntu 6.10.

Correct Implementation of #import
It is important to invoke ADO correctly in your program, or you can have compiler errors. The following code demonstrates the correct way to use #import with Msado10.dll the MSADO15.dll:

#import <msado15.dll>            \

no_namespace                     \

rename( "EOF", "adoEOF" )

error C2011: 'EditModeEnum' : 'enum' type redefinition
error C2011: 'LockTypeEnum' : 'enum' type redefinition
error C2011: 'FieldAttributeEnum' : 'enum' type redefinition
error C2011: 'DataTypeEnum' : 'enum' type redefinition
error C2011: 'ParameterDirectionEnum' : 'enum' type redefinition
error C2011: 'RecordStatusEnum' : 'enum' type redefinition

Here's the original solution in MSDN:
http://support.microsoft.com/kb/169496/EN-US/

Show how to add script to the client in aspx file.

/// <param name="rbl">RadioButtonList to apply script to</param>
/// <param name="page">The Page the script is going to be appended to</param>
/// <param name="script">The script to append</param>
public static void SetRadioButtonListItemScript(RadioButtonList rbl, Page page, string script)

{

for (int idx = 0; idx < rbl.Items.Count; idx++)

{

RegisterClientObjectFunction(page, rbl, idx, script);

}

}



/// <param name="page">The Page the script is going to be appended to</param>
/// <param name="rbl">RadioButtonList to apply script to</param>
/// <param name="idx">the index of the radio button</param>
/// <param name="script">The script to append</param>
static private void RegisterClientObjectFunction(Page page, RadioButtonList rbl, int idx, string script)

{

StringBuilder sw = new StringBuilder();

if (!page.IsStartupScriptRegistered(rbl.ClientID + "_" + idx.ToString() + "script"))

{

sw.Append(@"<SCRIPT>");

sw.Append(@"document.getElementById('" + rbl.ClientID + "_" + idx.ToString() + "').onclick=function() {" + script + "return true;}");

sw.Append(@"</SCRIPT>");

page.RegisterStartupScript(rbl.ClientID + "_" + idx.ToString() + "script", sw.ToString());

}

}



static private void RegisterClientObjectFunction(Page page, CheckBox chk, string script)

{

StringBuilder sw = new StringBuilder();

if (!page.IsStartupScriptRegistered(chk + "script"))

{

sw.Append(@"<SCRIPT>");

sw.Append(@"document.getElementById('"+chk.ClientID + "').onclick=function() {" + script + "return true;}");

sw.Append(@"</SCRIPT>");

page.RegisterStartupScript(chk.ClientID + "script", sw.ToString());

}

}

Add Command here to right button click in explore (Windows XP)

http://www.blogjava.net/Files/programmer/CMDHere.zip

1. Download the file and unzip the file CMDHere.reg.
2. Double click it to import into registry,
3. Right click on any folder, you'll see there's a menu which is "Command here",
4. Click it, you'll get into the cmd window with the current path is which you selected.

Or you can import the settings manually.

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Folder\shell\Command Prompt]
@="Command Prompt"

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Folder\shell\Command Prompt\command]
@="Cmd.exe /k pushd %L"

Set readonly for input text

document.getElementById("ctrl_id").readOnly  = true; //pay attention to the readOnly, it's case sensitive.

Set option to unable to select for select control:

<option value="Genre" disabled="disabled">Genre</option>

Set select control to disabled (it has no readonly property):

<select disabled="disabled"></select>

Add a new option to a select control, it works under firefox 2.x and IE 5.x:

function addOption(select_ctrl, option_value, option_text){

var ctrl = document.getElementById(selectctl);



if(ctrl == null)

return;



var doc = ctrl.ownerDocument;

if (!doc)

doc = ctrl.document;



var opt = doc.createElement('OPTION');

opt.value = option_value;

opt.text = option_text;



ctrl.options.add(opt, ctrl.options.length);

}

Delete an option from select control:

selectctl.options[selectctl.selectedIndex] = null;

Delete all options from select control:

selectctrl.options.length = 0;

Change the css for an object:

document.getElementById("ctrl_id").className="SHOWN";

Goal:

Use a ComboBox to select an item, and save the selected item's value to some textboxes. each control is using databinding.

Problems:

1. set control's value when comboBox changed, after the comboBox lost focus, the text was lost since the controls reload the data from binding source.

2. set binding source's value, the text will be set only when the comboBox lost focus. but we want to set the text immediately when the comboBox changed.

Solution:

set binding source's value, and call comboBox's writeValue for comboBox. this will write the comboBox's value to datasource, and reload all controls' value.

Test selectedTest = (Test)comboBox1.SelectedItem;



Test test = (Test)bindingSource1.DataSource;

if (selectedTest == null || test == null)

return;



//save the selected value to the binding source
test.Name = selectedTest.Name;
test.Value = selectedTest.Value;
//this will write the comboBox's value to datasource, and reload all controls' value
comboBox1.DataBindings["SelectedValue"].WriteValue();