Eu sei, há muitas perguntas diferentes e muitas respostas sobre esse problema ... Mas eu não consigo entender ...

Eu tenho: ubuntu-9.10-desktop-amd64 + NetBeans6.7.1 instalado "como está" de fora. rep. Preciso me conectar a algum site pelo HTTPS. Para isso eu uso o HttpClient do Apache.

Do tutorial eu li:

"Uma vez que você tenha o JSSE instalado corretamente, a comunicação HTTP segura sobre SSL deve ser
simples como comunicação HTTP simples ". E algum exemplo:

HttpClient httpclient = new HttpClient();
GetMethod httpget = new GetMethod("https://www.verisign.com/"); 
try { 
  httpclient.executeMethod(httpget);
  System.out.println(httpget.getStatusLine());
} finally {
  httpget.releaseConnection();
}

Até agora, escrevo isto:

HttpClient client = new HttpClient();

HttpMethod get = new GetMethod("https://mms.nw.ru");
//get.setDoAuthentication(true);

try {
    int status = client.executeMethod(get);
    System.out.println(status);

    BufferedInputStream is = new BufferedInputStream(get.getResponseBodyAsStream());
    int r=0;byte[] buf = new byte[10];
    while((r = is.read(buf)) > 0) {
        System.out.write(buf,0,r);
    }

} catch(Exception ex) {
    ex.printStackTrace();
}

Como resultado, tenho um conjunto de erros:

javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
        at sun.security.ssl.Alerts.getSSLException(Alerts.java:192)
        at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1627)
        at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:204)
        at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:198)
        at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:994)
        at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:142)
        at sun.security.ssl.Handshaker.processLoop(Handshaker.java:533)
        at sun.security.ssl.Handshaker.process_record(Handshaker.java:471)
        at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:904)
        at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1132)
        at sun.security.ssl.SSLSocketImpl.writeRecord(SSLSocketImpl.java:643)
        at sun.security.ssl.AppOutputStream.write(AppOutputStream.java:78)
        at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82)
        at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140)
        at org.apache.commons.httpclient.HttpConnection.flushRequestOutputStream(HttpConnection.java:828)
        at org.apache.commons.httpclient.HttpMethodBase.writeRequest(HttpMethodBase.java:2116)
        at org.apache.commons.httpclient.HttpMethodBase.execute(HttpMethodBase.java:1096)
        at org.apache.commons.httpclient.HttpMethodDirector.executeWithRetry(HttpMethodDirector.java:398)
        at org.apache.commons.httpclient.HttpMethodDirector.executeMethod(HttpMethodDirector.java:171)
        at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:397)
        at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:323)
        at simpleapachehttp.Main.main(Main.java:41)
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
        at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:302)
        at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:205)
        at sun.security.validator.Validator.validate(Validator.java:235)
        at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:147)
        at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:230)
        at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:270)
        at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:973)
        ... 17 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
        at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:191)
        at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:255)
        at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:297)
        ... 23 more

O que devo fazer para criar a conexão SSL mais simples? (Provavelmente sem KeyManager e Gerenciador de confiança, etc.)