LDAP：如何返回超过 1000 个结果（java）

Question

我正在使用来自此站点的 LDAP SDK：https://www.unboundid.com/products/ldap-sdk/。 我想做一个返回很多条目的搜索操作。

根据常见问题解答的网站，（https://www.unboundid.com/products/ldap-sdk/docs/ldapsdk-faq.php#search）我必须使用 SearchResultListener 实现。

这就是我所做的：

 public class UpdateThread extends Thread implements SearchResultListener {
 ...
 // create request
 final SearchRequest request = new SearchRequest(this, instance.getBaseDN(),SearchScope.SUB, filter);
 // Setting size limit of results.
 request.setSizeLimit(2000);

 ...

 // Get every result one by one.
 @Override
public void searchEntryReturned(SearchResultEntry arg0) {
    System.out.println("entry "+arg0.getDN());

}

问题是“searchEntryReturned”最多返回 1000 个结果。即使我将大小限制设置为“2000”。

Answer 1

使用标准 java 实现分页 LDAP 查询非常简单，方法是使用将 PagedResultsControl 添加到 LdapContext，而不使用上面 Neil 的回答的第三方 API。

Hashtable<String, Object> env = new Hashtable<String, Object>(11);
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://localhost:389/ou=People,o=JNDITutorial");

try {
  LdapContext ctx = new InitialLdapContext(env, null);

  // Activate paged results
  int pageSize = 5;
  byte[] cookie = null;
  ctx.setRequestControls(new Control[] { new PagedResultsControl(pageSize,
      Control.NONCRITICAL) });
  int total;

  do {
    /* perform the search */
    NamingEnumeration results = ctx.search("", "(objectclass=*)",
        new SearchControls());

    /* for each entry print out name + all attrs and values */
    while (results != null && results.hasMore()) {
      SearchResult entry = (SearchResult) results.next();
      System.out.println(entry.getName());
    }

    // Examine the paged results control response
    Control[] controls = ctx.getResponseControls();
    if (controls != null) {
      for (int i = 0; i < controls.length; i++) {
        if (controls[i] instanceof PagedResultsResponseControl) {
          PagedResultsResponseControl prrc = (PagedResultsResponseControl) controls[i];
          total = prrc.getResultSize();
          if (total != 0) {
            System.out.println("***************** END-OF-PAGE "
                + "(total : " + total + ") *****************\n");
          } else {
            System.out.println("***************** END-OF-PAGE "
                + "(total: unknown) ***************\n");
          }
          cookie = prrc.getCookie();
        }
      }
    } else {
      System.out.println("No controls were sent from the server");
    }
    // Re-activate paged results
    ctx.setRequestControls(new Control[] { new PagedResultsControl(
        pageSize, cookie, Control.CRITICAL) });

  } while (cookie != null);

  ctx.close();

从here复制的示例。

Answer 2

虽然几乎可以肯定服务器强制执行 1000 个条目的大小限制，但有可能通过分多个部分发出请求来解决这个问题。

如果服务器支持使用简单的分页结果控件（在 RFC 2696 中定义并在 LDAP SDK 中根据 https://docs.ldap.com/ldap-sdk/docs/javadoc/com/unboundid/ldap/sdk/controls/SimplePagedResultsControl.html 支持），那么您可以使用它来遍历包含指定的条目数。

或者，可以使用虚拟列表视图 (VLV) 请求控件 (https://www.unboundid.com/products/ldap-sdk/docs/javadoc/index.html?com/unboundid/ldap/sdk/controls/VirtualListViewRequestControl.html)，但我可能只建议如果服务器不支持简单的分页结果控件，因为 VLV 请求控件也需要对结果进行排序，这可能需要在服务器中进行特殊配置或进行一些非常昂贵的处理才能为请求提供服务。

Answer 3

我像 @PeterK 一样解决了，但做了一些修改

    public List<MyUser> listUsers() {
    LOG.info("listUsers() inicio");
    List<MyUser> users = new ArrayList<MyUser>();

    Hashtable env = new Hashtable();
    env.put(Context.INITIAL_CONTEXT_FACTORY, INITIAL_CTX);
    env.put(Context.PROVIDER_URL, 'ldap://192.168.10.10:389');
    env.put(Context.SECURITY_AUTHENTICATION, CONNECTION_TYPE);
    env.put(Context.SECURITY_PRINCIPAL, USER_ADMIN_PASSWORD);
    env.put(Context.SECURITY_CREDENTIALS, USER_ADMIN);

    try {
        LdapContext ctx = new InitialLdapContext(env, null);

        // Activate paged results
        int pageSize = 1000;
        byte[] cookie = null;
        ctx.setRequestControls(new Control[] { new PagedResultsControl(pageSize, Control.NONCRITICAL) });
        int total;

        do {
            /* perform the search */
            SearchControls sc = new SearchControls();
            sc.setSearchScope(SearchControls.SUBTREE_SCOPE);
            String filtro = "(&(sAMAccountName=*)&(objectClass=user))";
            NamingEnumeration results = ctx.search(getBaseDn(ctx), filtro, sc);

            /* for each entry */
            while (results.hasMoreElements()) {
                SearchResult result = (SearchResult) results.nextElement();
                Attributes attributes = result.getAttributes();
                //convert to MyUser class
                MyUser user = toUser(attributes);
                users.add(user);
            }

            // Examine the paged results control response
            Control[] controls = ctx.getResponseControls();
            if (controls != null) {
                for (int i = 0; i < controls.length; i++) {
                    if (controls[i] instanceof PagedResultsResponseControl) {
                        PagedResultsResponseControl prrc = (PagedResultsResponseControl) controls[i];
                        total = prrc.getResultSize();
                        if (total != 0) {
                            System.out.println("***************** END-OF-PAGE " + "(total : " + total + ") *****************\n");
                        } else {
                            System.out.println("***************** END-OF-PAGE " + "(total: unknown) ***************\n");
                        }
                        cookie = prrc.getCookie();
                    }
                }
            } else {
                System.out.println("No controls were sent from the server");
            }
            // Re-activate paged results
            ctx.setRequestControls(new Control[] { new PagedResultsControl(pageSize, cookie, Control.CRITICAL) });

        } while (cookie != null);

        ctx.close();

    } catch (NamingException e) {
        System.err.println("PagedSearch failed.");
        e.printStackTrace();
    } catch (IOException ie) {
        System.err.println("PagedSearch failed.");
        ie.printStackTrace();
    } catch (Exception ie) {
        System.err.println("PagedSearch failed.");
        ie.printStackTrace();
    }

    LOG.info("listUsers() size = " + (users.size()));
    LOG.info("listUsers() fim");

    return users;
}


private MyUser toUser(Attributes attributes) throws NamingException {
    if (attributes != null) {
        String fullName = attributes.get("distinguishedName") != null ? attributes.get("distinguishedName").get().toString() : null;
        String mail = attributes.get("mail") != null ? attributes.get("mail").get().toString() : null;
        String userName = attributes.get("cn") != null ? attributes.get("cn").get().toString() : null;
        String userPrincipalName = attributes.get("userPrincipalName") != null ? attributes.get("userPrincipalName").get().toString() : null;

        if (userPrincipalName != null) {
            String[] user = userPrincipalName.split("@");
            if (user != null && user.length > 0) {
                userName = user[0];
            }
        }

        MyUser user = new MyUser();
        user.setFullName(fullName);
        user.setEmail(mail);
        user.setName(userName);
        user.setUserPrincipalName(userPrincipalName);
        user.setRoles(getRolesUser(attributes));

        return user;
    }

    return null;
}

Answer 4

LDAP 客户端将“客户端请求”的大小限制设置为 2000。此客户端请求的限制不能覆盖服务器配置中设置的限制。无论客户端请求的大小限制是什么，服务器的大小限制都会覆盖它。请联系您的目录服务器管理员并要求增加大小限制。