Using Spring Declarative Transaction With Load Time Weaving

It is virtually imperative to use declarative transaction management in aspectj mode if you want to invoke a transactional method of an object from  another of its functions, which may be named as self invocation. In case of self invocation method invocations will not be intercepted by spring created Proxy objects thus a new transaction won’t be started.  For more information you may refer to related spring document.

To overcome this matter, aspectj mode is available. In aspectj mode binary code of the targed class is weaved to include desired code snippets. This can be accomplished in two different ways, load time weaving (LTW) or compile time weaving(CTW). In this article LTW will be at center of attention.

Required Configuration

Maven Configuration

Only dependencies matter, so remaining configuration is omitted.

     <dependencies>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-annotations</artifactId>
            <version>${hibernate.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjrt</artifactId>
            <version>1.6.9</version>
        </dependency>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.6.9</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aspects</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-agent</artifactId>
            <version>2.5.6</version>
        </dependency>
        <dependency>
            <groupId>c3p0</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.1.2</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate</artifactId>
            <version>${hibernate.version}</version>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.9</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate.javax.persistence</groupId>
            <artifactId>hibernate-jpa-2.0-api</artifactId>
            <version>1.0.0.Final</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.15</version>
        </dependency>
    </dependencies>

Spring Configuration

Only related sections are excerpted, nothing special with remaining configuration. Do not forget to add following definitions to spring application context file.

<!-- aspectj mode is required for successful transactional behaviour in case of invoking transactional method of the class from another method of the same class. -->

 <tx:annotation-driven transaction-manager="transactionManager" mode="aspectj"/>

<!--  activate load time weaving, namely modifying target class methods to include transaction specific code during load time -->

 <context:load-time-weaver/>

Launching the Application

First make sure that all required files are in classpath. You may create a UBER jar with all dependencies included or you may put all libraries in particular folders and manually specify them whilst launcing the application. My preference was over second approach due to shorter build time.

Knowing the absolute path of spring-agent.jar, launch the application as shown below:

Java –javaagent:C:/absolute-path-to-jar/spring-agent-2.5.6.jar Main

Project Files

You may download project files to play with complete code.