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Publish Maven site with Amazon S3 and CloudFront

Amazon S3 now supports static website hosting . As a 10 years Maven user, I wonder how easy it is to deploy Maven generated site to Amazon S3 and let the rock-solid storage provider to host my project websites. There are several existing s3 wagon providers , which all seem to have the same problem, not supporting directory copy. This is understandable since before S3 new website hosting feature, I guess people mostly expect to deploy artifacts rather than website to S3. So my first task is to write an AWS S3 wagon that supports directory copy. With AWS Java SDK , task becomes as simple as one single class . I made my S3 wagon available in Maven central repository at org.cyclopsgroup:awss3-maven-wagon:0.1 . The source code is hosted in github:jiaqi/cym2/awss3 . The next thing is to create an S3 bucket in console . To avoid trouble, bucket name is set to the future website domain name according to this discussion . Website feature needs to be explicitly enabled. I also created an...
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Customize IdGenerator in JPA, gap between Hibernate and JPA annotations

JPA annotation is like a subset of Hibernate annotation, this means people will find something available in Hibernate missing in JPA. One of the important missing features in JPA is customized ID generator. JPA doesn't provide an approach for developer to plug in their own IdGenerator. For example, if you want the primary key of a table to be BigInteger coming from sequence, JPA will be out of solution. Assume you don't mind the mixture of Hibernate and JPA Annotation and your JPA provider is Hibernate, which is mostly the case, a solution before JPA starts introducing new Annotation is, to replace JPA @SequenceGenerator with Hibernate @GenericGenerator. Now, let the code talk. /** * Ordinary JPA sequence. * If the Long is changed into BigInteger, * there will be runtime error complaining about the type of primary key */ @Id @Column(name = "id", precision = 12) @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "XyzIdGenerator") @SequenceGe...
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1300ms to 160ms, tune Spring/Hibernate on slow MySQL

I write this article to remember the different behaviour various JDBC connection pool displays when they work with slow JDBC connection(to MySQL database, in this case). It starts with a typical Java application on Spring, Hibernate, Jetty, ApacheCXF and MySQL like following code. Version 1: without correct pooling //... service code @Transactional(isolation=Isolation.READ_COMMITTED) public void foo() { //... do something with database } //... connection pool configuration ... class = "com.mysql.jdbc.jdbc2.optional.MysqlConnectionPoolDataSource"; url = "jdbc:mysql://mysql.far-far-away.com/mysystem"; user = ... //... transaction management configuration in spring ... <tx:annotation-driven transaction-manager="transactionManager" order="100" /> <bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager"> <property name="sessionFactory" ref="mySessionFact...
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