Java Security

I have written a java client to access an Https server using HttpClient.
I am using a self signed certificate at the server.
The certificate file(.cer) is copied to the client machine and imported to cacerts using keytool .
I am getting the following error on executing the Java program from the client machine.
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javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: No trusted certificate found
at com.sun.net.ssl.internal.ssl.BaseSSLSocketImpl.a(DashoA12275)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.a(DashoA12275)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.a(DashoA12275)
at com.sun.net.ssl.internal.ssl.SunJSSE_az.a(DashoA12275)
at com.sun.net.ssl.internal.ssl.SunJSSE_az.a(DashoA12275)
at com.sun.net.ssl.internal.ssl.SunJSSE_ax.a(DashoA12275)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.a(DashoA12275)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.j(DashoA12275)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.a(DashoA12275)
at com.sun.net.ssl.internal.ssl.AppOutputStream.write(DashoA12275)
at org.apache.commons.httpclient.HttpConnection$WrappedOutputStream.write(HttpConnection.java:1360)
at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:66)
at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:124)
at org.apache.commons.httpclient.HttpConnection.flushRequestOutputStream(HttpConnection.java:790)
at org.apache.commons.httpclient.HttpMethodBase.writeRequest(HttpMethodBase.java:2271)
at org.apache.commons.httpclient.HttpMethodBase.processRequest(HttpMethodBase.java:2651)
at org.apache.commons.httpclient.HttpMethodBase.execute(HttpMethodBase.java:1087)
at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:643)
at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:497)
at com.mypack.HttpClientTest.main(HttpClientTest.java:15)
Caused by: sun.security.validator.ValidatorException: No trusted certificate found
at sun.security.validator.SimpleValidator.buildTrustedChain(SimpleValidator.java:304)
at sun.security.validator.SimpleValidator.engineValidate(SimpleValidator.java:107)
at sun.security.validator.Validator.validate(Validator.java:202)
at com.sun.net.ssl.internal.ssl.X509TrustManagerImpl.checkServerTrusted(DashoA12275)
at com.sun.net.ssl.internal.ssl.JsseX509TrustManager.checkServerTrusted(DashoA12275)
... 17 more
Exception in thread "main"
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Java code:
HttpClient httpclient = new HttpClient();
GetMethod httpget = new GetMethod("https://myapp.com/");
httpclient.executeMethod(httpget);
System.out.println(httpget.getStatusLine().toString());

PLEASE HELP!!!