关于https的问题


上面是我现在的服务器架构。
第一个服务器：A
第二个服务器：B
现在第B上配置了https服务器。
A可以看做是B的客户端。
那么A需要配置什么关于https的东西吗？比如证书啊什么的。
现在A这边发送https请求就报错。
com.ibm.jsse2.util.h: PKIX path building failed: java.security.cert.CertPathBuilderException: PKIXCertPathBuilderImpl could not build a valid CertPath.; internal cause is: 
java.security.cert.CertPathValidatorException: The certificate issued by CN=GeoTrust Global CA, O=GeoTrust Inc., C=US is not trusted; internal cause is: 
java.security.cert.CertPathValidatorException: Certificate chaining error
 EXCEPTION MESSAGE : com.ibm.jsse2.util.h: PKIX path building failed: java.security.cert.CertPathBuilderException: PKIXCertPathBuilderImpl could not build a valid CertPath.; internal cause is: 
java.security.cert.CertPathValidatorException: The certificate issued by CN=GeoTrust Global CA, O=GeoTrust Inc., C=US is not trusted; internal cause is: 
java.security.cert.CertPathValidatorException: Certificate chaining error










com.ibm.jsse2.o.a(o.java:25)
com.ibm.jsse2.SSLSocketImpl.a(SSLSocketImpl.java:499)
com.ibm.jsse2.kb.a(kb.java:483)
com.ibm.jsse2.kb.a(kb.java:48)
com.ibm.jsse2.lb.a(lb.java:426)
com.ibm.jsse2.lb.a(lb.java:194)
com.ibm.jsse2.kb.s(kb.java:93)
com.ibm.jsse2.kb.a(kb.java:128)
com.ibm.jsse2.SSLSocketImpl.a(SSLSocketImpl.java:516)
com.ibm.jsse2.SSLSocketImpl.h(SSLSocketImpl.java:400)
com.ibm.jsse2.SSLSocketImpl.a(SSLSocketImpl.java:592)
com.ibm.jsse2.k.write(k.java:18)
java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:76)
java.io.BufferedOutputStream.flush(BufferedOutputStream.java:134)
org.apache.commons.httpclient.methods.StringRequestEntity.writeRequest(StringRequestEntity.java:146)
org.apache.commons.httpclient.methods.EntityEnclosingMethod.writeRequestBody(EntityEnclosingMethod.java:499)
org.apache.commons.httpclient.HttpMethodBase.writeRequest(HttpMethodBase.java:2114)
org.apache.commons.httpclient.HttpMethodBase.execute(HttpMethodBase.java:1096)
org.apache.commons.httpclient.HttpMethodDirector.executeWithRetry(HttpMethodDirector.java:398)
org.apache.commons.httpclient.HttpMethodDirector.executeMethod(HttpMethodDirector.java:171)
org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:397)
org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:323)
com.skcc.cip.metlife.cn.common.ChannelConnector.process(ChannelConnector.java:156)