Android - Java parsing HL7 Message with HAPI v 2.2

I get this error when trying to parsing a HL7 message. I dont know why and how to fix it. I'm using hapi v2.2 . SO please help me. Thanks in advance!. Here is catlog!!!

08-28 15:03:28.552: E/dalvikvm(642): Could not find class 'ca.uhn.hl7v2.DefaultHapiContext', referenced from method com.example.hl7demo.MainActivity.onCreate


08-28 15:03:28.673: E/AndroidRuntime(642): java.lang.NoClassDefFoundError: ca.uhn.hl7v2.DefaultHapiContext

08-28 15:03:28.673: E/AndroidRuntime(642):  at com.example.hl7demo.MainActivity.onCreate(MainActivity.java:38)

bases on this tutorial http://hl7api.sourceforge.net/xref/ca/uhn/hl7v2/examples/ExampleParseMessages.html

It seems you forgot to add Hapi library to your build. If you using maven you just need to add appropriate maven dependencies as described here http://hl7api.sourceforge.net/using_maven.html

<!-- This is the core HAPI library -->
<dependency>
        <groupId>ca.uhn.hapi</groupId>
        <artifactId>hapi-base</artifactId>
        <version>${hapi.version.stable}</version>
</dependency>       

<!-- This is the structure JAR for HL7 v2.1 -->
<dependency>
        <groupId>ca.uhn.hapi</groupId>
        <artifactId>hapi-structures-v21</artifactId>
        <version>${hapi.version.stable}</version>
</dependency>

<!-- 
        If you want to use log4j for logging (recommended), you should include
        it, as well as the slf4j adaptor
-->
<dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-log4j12</artifactId>
        <version>${slf4j.version}</version>
</dependency>
<dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>${log4j.version}</version>
</dependency>

<!-- 
        Also add hapi-structures-v22, v23, etc. depending on which versions 
        of HL7 you need to create or parse 
-->     
<dependency>
        <groupId>ca.uhn.hapi</groupId>
        <artifactId>hapi-structures-v22</artifactId>
        <version>${hapi.version.stable}</version>
</dependency>
<dependency>
        <groupId>ca.uhn.hapi</groupId>
        <artifactId>hapi-structures-v23</artifactId>
        <version>${hapi.version.stable}</version>
</dependency>
<dependency>
        <groupId>ca.uhn.hapi</groupId>
        <artifactId>hapi-structures-v231</artifactId>
        <version>${hapi.version.stable}</version>
</dependency>
<dependency>
        <groupId>ca.uhn.hapi</groupId>
        <artifactId>hapi-structures-v24</artifactId>
        <version>${hapi.version.stable}</version>
</dependency>
<dependency>
        <groupId>ca.uhn.hapi</groupId>
        <artifactId>hapi-structures-v25</artifactId>
        <version>${hapi.version.stable}</version>
</dependency>
<dependency>
        <groupId>ca.uhn.hapi</groupId>
        <artifactId>hapi-structures-v251</artifactId>
        <version>${hapi.version.stable}</version>
</dependency>
<dependency>
        <groupId>ca.uhn.hapi</groupId>
        <artifactId>hapi-structures-v26</artifactId>
        <version>${hapi.version.stable}</version>
</dependency>