java - 引起：java.net.UnknownHostException：www.btechldap.com

问题描述

我正在尝试通过 Java 代码访问 LDAP 服务器，因为我在 Internet 上建立了一个免费的托管服务器，并希望通过 LDAP 测试读取机制。但是当我访问它时，我得到了标题异常。

我在网上冲浪，发现 LDAP URL 格式应符合正确的做法和标准。我也解决了这个问题，但没有任何效果。

我不知道我在哪里做错了。

下面提供了完整的堆栈跟踪：

例外

Rdentry example failed.
javax.naming.CommunicationException: www.btechldap.com:1389 [Root exception is java.net.UnknownHostException: www.btechldap.com]
    at com.sun.jndi.ldap.Connection.<init>(Unknown Source)
    at com.sun.jndi.ldap.LdapClient.<init>(Unknown Source)
    at com.sun.jndi.ldap.LdapClient.getInstance(Unknown Source)
    at com.sun.jndi.ldap.LdapCtx.connect(Unknown Source)
    at com.sun.jndi.ldap.LdapCtx.<init>(Unknown Source)
    at com.sun.jndi.ldap.LdapCtxFactory.getUsingURL(Unknown Source)
    at com.sun.jndi.ldap.LdapCtxFactory.getUsingURLs(Unknown Source)
    at com.sun.jndi.ldap.LdapCtxFactory.getLdapCtxInstance(Unknown Source)
    at com.sun.jndi.ldap.LdapCtxFactory.getInitialContext(Unknown Source)
    at javax.naming.spi.NamingManager.getInitialContext(Unknown Source)
    at javax.naming.InitialContext.getDefaultInitCtx(Unknown Source)
    at javax.naming.InitialContext.init(Unknown Source)
    at javax.naming.InitialContext.<init>(Unknown Source)
    at javax.naming.directory.InitialDirContext.<init>(Unknown Source)
    at LDAPAccess.main(LDAPAccess.java:33)
Caused by: java.net.UnknownHostException: www.btechldap.com
    at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
    at java.net.PlainSocketImpl.connect(Unknown Source)
    at java.net.SocksSocketImpl.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at java.net.Socket.<init>(Unknown Source)
    at java.net.Socket.<init>(Unknown Source)
    at com.sun.jndi.ldap.Connection.createSocket(Unknown Source)
    ... 15 more

代码

import java.util.Hashtable;

import javax.naming.Context;
import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import javax.naming.directory.Attribute;
import javax.naming.directory.Attributes;
import javax.naming.directory.DirContext;
import javax.naming.directory.InitialDirContext;

public class LDAPAccess {

    public static void main(String[] args) {
        Hashtable env = new Hashtable(5, 0.75f);
        /*
         * Specify the initial context implementation to use.
         * This could also be set by using the -D option to the java program.
         * For example,
         *   java -Djava.naming.factory.initial=com.sun.jndi.ldap.LdapCtxFactory \
         *       Rdentry
         */
        env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.ldap.LdapCtxFactory");
        /* Specify host and port to use for directory service */
        env.put(Context.PROVIDER_URL, "ldap://www.btechldap.com:1389/dc=btechsample,dc=com");
        env.put(Context.SECURITY_AUTHENTICATION, "simple");
        env.put(Context.SECURITY_CREDENTIALS, "btechpass");
        try {
            /* get a handle to an Initial DirContext */
            DirContext ctx = new InitialDirContext(env);
            /* Read Babs' entry */
            Attributes attrs = ctx.getAttributes("uid");
            if (attrs == null) {
                System.out.println("uid" + "has no attributes");
            } else {
                /* print each attribute */
                for (NamingEnumeration ae = attrs.getAll();
                     ae.hasMoreElements();) {
                    Attribute attr = (Attribute)ae.next();
                    String attrId = attr.getID();
                    /* print each value */
                    for (NamingEnumeration vals = attr.getAll();
                         vals.hasMoreElements();
                         System.out.println(attrId + ": " + vals.nextElement()))
                        ;
                }
            }
        } catch (NamingException e) {
            System.err.println("Rdentry example failed.");
            e.printStackTrace();
        }
    }
}

我是LDAP新手，请帮忙！

标签： javaldap

java - 引起：java.net.UnknownHostException：www.btechldap.com

问题描述

解决方案

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