如何在 JSP 中找到 LDAP 用户的 DN？答案

【问题标题】：How can I find an LDAP user's DN in JSP?如何在 JSP 中找到 LDAP 用户的 DN？
【发布时间】：2015-07-20 13:17:11
【问题描述】：

我试图在 JSP 的 LDAP 树中查找用户的 OU。我可以使用以下代码检索许多用户的 LDAP 属性：

Hashtable<String, String> tenv = new Hashtable<String, String>();

tenv.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.ldap.LdapCtxFactory");
tenv.put(Context.PROVIDER_URL, "ldap://xx.xx.xx.xx:389/");

SearchControls sc = new SearchControls();
sc.setSearchScope(SearchControls.SUBTREE_SCOPE);   

LdapContext lctx = new InitialLdapContext(tenv, null);
String filter = "cn=" + userid;
NamingEnumeration res = lctx.search ("dc=my,dc=dom,dc=org", filter, sc);

while (res.hasMore()) 
{
   SearchResult s = (SearchResult) res.next();
   Attributes attrs = s.getAttributes();
   Attribute attr = attrs.get("SN");
   out.println ("<font color=red>" + attr + "</font>");
}

当我在 Linux 命令行中使用类似的搜索参数运行 ldapsearch 时，我可以看到一个 DN：它显示了用户所在的 OU (dn: uid=username,ou=users,dc=my, dc=dom,dc=org）。我试过 attrs.get("DN") 并返回 null。如何在 JSP 中检索此 DN：？

【问题讨论】：

标签： java jsp openldap

【解决方案1】：

显然有“there is no direct way of obtaining the Distinguished Name (DN) from the search results.”

这段代码可以做到：

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;
import javax.naming.ldap.*;
import javax.naming.directory.SearchControls;
import javax.naming.directory.SearchResult;
class GetAllAttrs 
{

  public static void main(String[] args) 
  {
    String filter = "cn=myuser";    // this is the user to look for
    String baseDN = "dc=my,dc=dom,dc=org";
    String ldapURL = "ldap://192.168.101.1:389";

    // Set up the environment for creating the initial context
    Hashtable<String, Object> env = new Hashtable<String, Object>(11);
    env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.ldap.LdapCtxFactory");
    env.put(Context.PROVIDER_URL, ldapURL);

    try 
    {
      // Create the initial context
      LdapContext ctx = new InitialLdapContext(env, null);

      SearchControls sc = new SearchControls();
      sc.setSearchScope(SearchControls.SUBTREE_SCOPE);
      NamingEnumeration res = ctx.search (baseDN, filter, sc);

      while (res.hasMore()) 
      {
         SearchResult s = (SearchResult) res.next();

         // print user's DN
         System.out.println(">>" + s.getNameInNamespace());
      }

      // Close the context when we're done
      ctx.close();

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

【讨论】：