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Displaying notes 21 - 30
Created by zhidao on January 26, 2012 20:37:45
Last update: January 26, 2012 20:37:45
There are 4 positioning styles in CSS: static : this is the default positioning style. Elements are positioned according to the normal flow of the page. fixed : the element position is fixed relative to the browser window, i.e., when you scroll, the element does not move with other contents in the page. relative : the element is positioned relative to its normal position (i.e., static position). You can use relative positioning to offset an element from its normal position. Other elements are positioned as if the relative positioned element were in its normal position. absolute : the element is positioned relative to the first ancestor element that is not static positioned. If all ancestor elements are static positioned, the element is positioned relative to...
Created by James on January 26, 2012 16:02:55
Last update: January 26, 2012 16:02:55
To append additional data to a form before Ajax form submit:
var data = $(form).serializeArray();
data.push(...
Created by James on January 26, 2012 14:26:23
Last update: January 26, 2012 14:26:23
To get the value:
$('#idOfTheSelectDropdown :selected').val();
To get the text:
$('#idOfTheSelectDropdown :selected').text()
Created by timo on January 25, 2012 20:13:13
Last update: January 25, 2012 20:13:13
The MIPS CPU is able to run both big-endian and little-endian. So a system built on MIPS can be either big-endian (mips) or little-endian (mipsel).
The file command shows the architecture:
$ file ls
ls: ELF 32-bit LSB executable, MIPS, ...
but readelf will tell the endianness:
$ readelf -h ls
ELF Header:
Magic: 7f 45...
Created by zhidao on January 25, 2012 19:27:53
Last update: January 25, 2012 19:28:47
The spring MVC annotation-driven declaration:
<?xml version="1.0" encoding="UTF-8"?> <beans x... does the following magic : Among others, registers: RequestMappingHandlerMapping RequestMappingHandlerAdapter ExceptionHandlerExceptionResolver in support of processing requests with annotated controller methods using annotations such as @RequestMapping , @ExceptionHandler , etc. Enables Spring 3 style type conversion through a ConversionService instance in addition to the JavaBeans PropertyEditors used for Data Binding. Enables support for formatting Number fields using the @NumberFormat annotation through the ConversionService . Enables support for formatting Date, Calendar, Long, and Joda Time fields using the @DateTimeFormat annotation, if Joda Time 1.3 or higher is present on the classpath. Enables support for validating @Controller inputs with @Valid , if a JSR-303 Provider is present on the classpath. Enables HttpMessageConverter support for @RequestBody method parameters and...
Created by zhidao on January 25, 2012 16:07:29
Last update: January 25, 2012 16:07:29
A JSON response is auto-magically returned when you add the @ResponseBody annotation to the return value of a @RequestMapping annotated method:
import org.springframework.stereotype.Controller;
...
For magic to happen, you must:
Add annotation-driven to the org.springframework.web.servlet.DispatcherServlet config xml:
<?xml version="1.0" encoding="UTF-8"?>
<beans x...
Put Jackson jar files on CLASSPATH (i.e., under WEB-INF/lib ), which includes jackson-core-asl-1.6.4.jar and jackson-mapper-asl-1.6.4.jar .
Created by zhidao on January 23, 2012 15:00:19
Last update: January 23, 2012 15:00:19
The domain object is annotated @Entity , but Java runtime complains that it's not an entity class.
Cause: : class not listed in persistence.xml , or persistence.xml misplaced, or multiple persistence.xml files existed.
Created by zhidao on January 23, 2012 14:58:58
Last update: January 23, 2012 14:58:58
This exception occurs when the Java object attribute is of type String, while the database column is of type CHAR(n), and hibernate.hbm2ddl.auto is validate in persistence.xml .
There are two solutions:
Add columnDefinition to the @Column annotation:
@Column(name = “STATE_CODE”, columnDefinition = “c...
Remove hibernate.hbm2ddl.auto from persistence.xml .
Created by zhidao on January 22, 2012 21:18:19
Last update: January 22, 2012 21:18:45
Once in a while, people want to set the context root of a web application in web.xml . Let me remind myself and others here: context root is not set in web.xml! .
The context root is specified by things outside of the webapp :
For web application packaged inside a EAR, context root can be specified in the context-root element of the web module:
<application xmlns="http://java.sun.com/xml/ns/j2e...
For web application deployed standalone, the configuration is container specific. For the JBoss container, it may be specified in jboss-web.xml :
<jboss-web>
<context-root>bank</context-roo...
Created by zhidao on January 20, 2012 15:12:49
Last update: January 20, 2012 15:13:17
Spring automatically binds request parameters to form bean properties, but there's one catch: the names must match. There seems to be no easy way to map a request parameter to a bean property with a different name!
I found this note in Stackoverflow: Understanding the concept of data binding in a Spring-MVC app . That was what I was about to do also. But then I decided just change the names to match.
