run Groovy’s groovyConsole.bat, got SecurityException: Prohibited package name: java.lang

java groovy

Solution:
My system’s CLASSPATH variable contains this entry: C:\midp2.0fcs\classes
Delete it then groovyConsole.bat will work.
Other entries in the CLASSPATH don’t matter.

use Mail Server Pro to send email to myself, on localhost

email, java, server, app

1. Install Mail Server Pro (one month trial). A windows service (SMTP Server Service) will be installed.
    Change settings: Authentication is not required.
                               IP Range Lists, add “1×2.1x.6.x9″ local ip address.
                               Local Domains add chao.com
                               Domain Users add “richie” and “xing”
2. Outlook add account: richie@zhao.com; POP3 incoming server “1×2.1x.6.x9″; SMTP localhost; user name “richie@zhao.com”
3. In java code (-context.xml): sender (JavaMailSenderImpl)’s host property: localhost

Failed to load or instantiate TagLibraryValidator class

running the springMVC-petclinic-hibernate sample app,
got this:
SEVERE: Exception Processing ErrorPage[exceptionType=java.lang.Exception, location=/WEB-INF/jsp/uncaughtException.jsp]
org.apache.jasper.JasperException: /WEB-INF/jsp/uncaughtException.jsp(1,1) Failed to load or instantiate TagLibraryValidator class: org.apache.taglibs.standard.tlv.JstlCoreTLV
        at org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:40)

solution: create a folder springMVC-petclinic-hibernate\web\WEB-INF\lib, then put jstl.jar and standard.jar inside it.
reason: even though the jstl.jar is already in classpath, it’s ignored by the servlet container; have to put the jar along with jsp pages manually.

hibernate-validator-3.1.0.GA not compatible with Core_hibernate-distribution-3.3.1.GA

Use hibernate-validator-3.1.0.GA with Core_hibernate-distribution-3.3.1.GA,
got this error:
java.lang.NoSuchMethodError: org.hibernate.event.PreUpdateEvent.getSource()Lorg/hibernate/engine/SessionImplementor;
at org.hibernate.validator.event.ValidateEventListener.onPreUpdate(ValidateEventListener.java:177)
at org.hibernate.action.EntityUpdateAction.preUpdate(EntityUpdateAction.java:237)

solution: download hibernate-distribution-3.3.0.SP1, use the old hibernate3.jar to replace the new one in distribution-3.3.1.GA.

http://opensource.atlassian.com/projects/hibernate/browse/HV-66

java.lang.NoSuchFieldError: name org.slf4j.impl.Log4jLoggerAdapter.(Log4jLoggerAdapter.java

problem: AnnotationConfiguration cfg = new AnnotationConfiguration(); fails
and javax.servlet.ServletException: Servlet.init() for servlet PersistentController threw exception
java.lang.NoSuchFieldError: name
    org.slf4j.impl.Log4jLoggerAdapter.<init>(Log4jLoggerAdapter.java:75)
   
solution: download a new http://www.slf4j.org/dist/slf4j-1.5.2.tar.gz
(having multiple javassist.jar doesn’t matter)
http://groups.google.com/group/comp.lang.java.programmer/browse_thread/thread/c6d647699b02fb5e/becc5c738902506b?tvc=2#becc5c738902506b

servlet problem: hibernate-validator (requestValidator.getInvalidValues(data) fails)

This section of code fails (data is the bean object):

InvalidValue[] validationMessages;
ClassValidator requestValidator = new ClassValidator(data.getClass());
validationMessages = requestValidator.getInvalidValues(data); //fails here!

Don’t know why but this works (“hobby” is one of the fields of the data bean):
requestValidator.getInvalidValues(data, “hobby”)

So, I modified the whole section to use request’s getParameterMap to traverse each bean property:
    InvalidValue[] validationMessages;
    List<InvalidValue[]> validationMsgList = new ArrayList<InvalidValue[]>();
    ClassValidator requestValidator = new ClassValidator(data.getClass());
    Map pMap = request.getParameterMap();
    Iterator ParIt = pMap.entrySet().iterator();
    while (ParIt.hasNext()) {
            Map.Entry pairs = (Map.Entry) ParIt.next();
            String key = “” + pairs.getKey();
            validationMessages = requestValidator.getInvalidValues(data, key);
            validationMsgList.add(validationMessages);
    }

App finally runs.

Java regex (Regular expression)

regex java

US Zip Code: \d{5}(?:-\d{4})?
A zip code has two formats: five digits OR five digits, a hyphen and four more digits.
\d{5}: the pattern starts with five digits. The 5 within the braces indicates that the previous pattern should match five times.
(?:-\d{4})?: It’s a non-capturing parenthesis, starts with (?:. Question mark at the end means optional.
-\d{4}: a hyphen followed by four digits

US SSN(social security number): \d{3}([-]?)\d{2}\1\d{4}
the digits are written in two different ways: as nine digits or as three digits, a hyphen, two digits, another hyphen and four more digits.
\d{3}: The pattern starts with three digits
([-]?): is a capturing group. Inside the group is an optional hyphen. Whatever matches inside the parentheses will be remembered and can be recalled later in the pattern as \1.
\d{2}: two more digits.
\1: the symbol for the grouped pattern from earlier in the regular expression. If a hyphen was used earlier in the expression, then a hyphen must be used here. If a hyphen was not matched earlier, then a hyphen cannot be entered here.
\d{4}: four more digits.

User ID: [a-zA-Z]{3,5}[a-zA-Z0-9]?\d{2}
might be from three to five letters followed by three digits or three to six letters followed by two digits.

Note: When writing regular expressions in Java, each \ character must be written as double backslashes, \\.

1. Square brackets define a character class. [xyz] will match x, y or z, but only one of them.
2. If the class starts with ^, then it will match all characters that are not listed inside the brackets: [^abc] any character except a, b or c (negation)
3. A hyphen can be used to include a range of characters: [a-z] will match any lowercase letter. [a-zA-Z] a through z or A through Z, inclusive (range)

Character Class	Meaning
.	Any character, except line terminators
\d	A digit: [0-9]
\D	A non-digit: [^0-9]
\s	A whitespace character: [ \t\n\x0B\f\r]
\S	A non-whitespace character: [^\s]
\w	A word character: [a-zA-Z_0-9]
\W	A non-word character: [^\w]

access Google Data APIs, behind proxy

google, java

(libraries needed: gdata, JavaMail, servlet2.4)
In Eclipse, under application’s context menu “run as, run configurations”:
program arguments: xxzhao@gmail.com xxzhaospsw
VM arguments: -Dhttp.proxyHost=proxysrv007-zhengxian -Dhttp.proxyPort=8080 -Dhttps.proxyHost=proxysrv007-zhengxian -Dhttps.proxyPort=8080 -Dhttp.proxyUser=liezi.info\xxing -Dhttp.proxyPassword=e*********

DWR(direct-web-remoting) starts here……

dwr, java, jsp, spring

1. Download the dwr.jar (also need commons-logging)
2. Add “<servlet>” and “<servlet-mapping>” into web.xml
3. Create a dwr.xml file. This file defines what classes DWR can create and remote for use by Javascript.
4. Testing url: http://localhost:8080/[YOUR-WEBAPP]/dwr/
-----------------------------------------------------------
OK. Environment is setup. Do a simple example:
1. Inside my “hello.jsp” file’s header, insert
<script type=”text/javascript” src=”javascript/validator.js”></script>
<script type=”text/javascript” src=”/springapp/dwr/interface/DemoPercIncre.js”> </script>
<script type=”text/javascript” src=”/springapp/dwr/interface/PercentageIncre.js”> </script>
<script type=”text/javascript” src=’/springapp/dwr/engine.js’></script>
<script type=”text/javascript” src=’/springapp/dwr/util.js’></script>
<SCRIPT LANGUAGE=”JavaScript”>
function update() {
      var percent = dwr.util.getValue(“percToIncre”);
      PercentageIncre.increPrice(percent, function(data) {
        dwr.util.setValue(“IncreProcessed”, data);
      });
    }
</SCRIPT>
2. Inside “Body”, create input box:
<p>Increase Price by Percent:
<input type=”text” id=”percToIncre” onChange=”digitvalidation(this, 1, 2,’You MUST enter 1 or 2 Integer Digits’,'Integer’);” />
<input value=”Excute” type=”button” onclick=”update()” />
<br />Response: <span id=”IncreProcessed“></span>
</p>
3. Create dwr.xml under WEB-INF, to link the javascript and the java-class.
<dwr>
    <allow>
        <create creator=”new” javascript=”PercentageIncre“>
            <param name=”class” value=”springapp.web.PercentageIncre” />
        </create>
    </allow>
</dwr>
4. Then create the java-class: PercentageIncre.java
package springapp.web;
public class PercentageIncre {
    public String increPrice(String perc) {
        return “Hello, I pretend to increase the price by ” + perc + “% percent.”;
    }
}

note: WEB-INF seems to be a special folder, my hello.jsp can’t find any js files fall into that folder by using “src=…”. I have to create a “javascript” folder parallel with WEB-INF, put js files in it, and in hello.jsp use “<script type=”text/javascript” src=”javascript/validator.js”></script>” to include that validator.js file.

 


Spring…… with database (hsqldb)

1. Create server.bat which contains:

java -classpath ..\war\WEB-INF\lib\hsqldb.jar org.hsqldb.Server -database test

2. Use Ant to do some targets: “ant createTables loadData printData“, sql files are stored in a folder.
3. Create JdbcProductDao.java (extends SimpleJdbcDaoSupport implements ProductDao), which includes: public List<Product> getProductList() and public void saveProduct(Product prod).
4. Modify “SimpleProductManager.java” to use “ProductDao“.
5. Modify “springapp-servlet.xml“, hard-coded product list is removed.
6. Create a new ‘applicationContext.xml’, to separate the service and persistence layer configuration from the web layer configuration.