Coding Tricks

Hibernate optimistic locking

2009-03-23T08:01:00.000-07:00

@Column(name = "VERSION", nullable = false, columnDefinition = "bigint default 0")
@Version()
private Long version;

try {
    spaceShipManager.saveSpaceShip(ship);
} catch (HibernateOptimisticLockingFailureException e) {
    return mapping.findForward("error");
}

Hibernate annotation default column value

2009-03-23T07:59:00.000-07:00

@Column(name = "VERSION", nullable = false, columnDefinition = "bigint default 0")
private Long version;

Configure Interactive mode for QuickBooks Web Connector

2009-03-13T09:09:00.000-07:00

The name of my computer is "b04".

1) generate SSL certificate for Tomcat (see tomcat-docs/ssl-howto.html from your Tomcat for details).
During generating certificate the answer on question "What is your first and last name" must be the name of your host (b04 in my case).

2) specify CertURL in your .qwc file:

...
https://b04:8443/services/MySOAPService
...
https://b04:8443/somepage.htm
...

3) return "" from sendRequestXML()
return "Interactive mode" from getLastError()
return "https://b04:8443/somepage.htm" from getInteractiveURL()

Terminate Java process

2009-03-13T07:09:00.000-07:00

taskkill /IM java.exe /F
pause

Hibernate bytecode instrumentation (enhance persistent classes) with help of Maven

2009-03-12T14:52:00.000-07:00

Is used to enable Hibernate lazy property fetching. "**/model/*" are your persistent classes.

pom.xml:

<plugin>
    <artifactId>maven-antrun-plugin</artifactId>
    <executions>
        <execution>
            <id>Instrument domain classes</id>
            <configuration>
                <tasks>
                    <taskdef name="instrument"
                             classname="org.hibernate.tool.instrument.cglib.InstrumentTask">
                        <classpath>
                            <path refid="maven.dependency.classpath"/>
                            <path refid="maven.plugin.classpath"/>
                        </classpath>
                    </taskdef>
                    <instrument verbose="true">
                        <fileset dir="${project.build.outputDirectory}">
                            <include name="**/model/*.class"/>
                        </fileset>
                    </instrument>
                </tasks>
            </configuration>
            <phase>process-classes</phase>
            <goals>
                <goal>run</goal>
            </goals>
        </execution>
    </executions>
    <dependencies>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate</artifactId>
            <version>3.2.6.ga</version>
        </dependency>
    </dependencies>
</plugin>

Hibernate ddl (database schema) generation with help of Maven

2009-03-12T14:40:00.000-07:00

pom.xml:

<plugin>
    <!-- hibernate ddl generation -->
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>hibernate3-maven-plugin</artifactId>
    <version>2.0-alpha-2</version>
    <configuration>
        <components>
            <component>
                <name>hbm2ddl</name>
                <outputDirectory>.</outputDirectory>
            </component>
        </components>
        <componentProperties>
            <configurationfile>src/main/db/hibernate.cfg.xml</configurationfile>
            <drop>false</drop>
            <create>true</create>
            <export>false</export>
            <jdk5>true</jdk5>
            <format>true</format>
        </componentProperties>
    </configuration>
    <executions>
        <execution>
            <id>export-mysql</id>
            <phase>process-classes</phase>
            <goals>
                <goal>hbm2ddl</goal>
            </goals>
            <configuration>
                <componentProperties>
                    <propertyfile>src/main/db/hibernate-mysql.properties</propertyfile>
                    <outputfilename>target/mysql-ddl.sql</outputfilename>
                </componentProperties>
            </configuration>
        </execution>
    </executions>
</plugin>

hibernate.cfg.xml:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
  "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
  "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <!--Annotated classes-->
        <mapping class="com.etymgiko.lyricscollection.model.Artist" />
        <mapping class="com.etymgiko.lyricscollection.model.Song" />
    </session-factory>
</hibernate-configuration>

hibernate-mysql.properties:

# This properties file defines the dialect for the MYSQL database
hibernate.dialect=org.hibernate.dialect.MySQL5InnoDBDialect

Java System properties

2009-03-10T06:08:00.000-07:00

import java.util.Arrays;

public class SystemProperties {

    public static void main(String [] args) {
        String [] keys = System.getProperties().keySet()
            .toArray(new String [] {});
        Arrays.sort(keys);
        for (String key: keys) {
            String value = System.getProperty(key);
            System.out.println(key + ": " + value);
        }
    }

}

Maven compile sources version 1.5

2009-03-02T07:20:00.000-08:00

Add following to pom.xml:

<build>
  <plugins>
      <plugin>
          <groupId>org.apache.maven.plugins</groupId>
          <artifactId>maven-compiler-plugin</artifactId>
          <configuration>
              <source>1.5</source>
              <target>1.5</target>
          </configuration>
      </plugin>
  </plugins>
</build>

Maven artifact sources

2009-03-01T06:52:00.000-08:00

Download sources of artifacts (from pom.xml) to local repository.

set JAVA_HOME=C:\jdk1.6.0
set MAVEN_HOME=D:\java\apache-maven-2.0.9
%MAVEN_HOME%\bin\mvn dependency:sources

Hibernate Spring where clause

2009-02-26T04:57:00.001-08:00

public List getSongs(Long artistId) {
return getHibernateTemplate().find("from Song as song where song.artist.id = ?", new Object [] {artistId});
}

Use regexp in Digester

2009-02-25T07:52:00.000-08:00

How to configure Digester to use reg exp pattern like *
<pattern value="*AddRs">
...
<pattern>

URL rulesXml = getClass().getClassLoader().getResource(path);
RuleSet ruleSet = new FromXmlRuleSet(rulesXml);
Digester digester = new Digester();
digester.setRules(new RegexRules(new SimpleRegexMatcher()));
digester.addRuleSet(ruleSet);
return digester;

Maven dependency tree

2009-02-25T07:13:00.000-08:00

set JAVA_HOME=C:\jdk1.6.0
set MAVEN_HOME=D:\java\apache-maven-2.0.9
%MAVEN_HOME%\bin\mvn dependency:tree > dep.txt