searchtimelimit.java

java tutorial.sun公司官方出品。java入门书籍。最新版

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 * Copyright (c) 1995 - 2008 Sun Microsystems, Inc.  All rights reserved.
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 *
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 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Redistributions in binary form must reproduce the above copyright
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 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
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import javax.naming.*;
import javax.naming.directory.*;

import java.util.Hashtable;

/**
 * Demonstrates how to perform a search and limit the time
 * that the search takes.
 *
 * usage: java SearchTimeLimit
 */
class SearchTimeLimit {
    static int timeout = 1000; // 1 second == 1000 ms
    public static void printSearchEnumeration(NamingEnumeration srhEnum) {
	int count = 0;
	try {
	    while (srhEnum.hasMore()) {
		SearchResult sr = (SearchResult) srhEnum.next();
		System.out.println(">>>" + sr.getName());
		++count;
	    }
	    System.out.println("number of answers: " + count);
	} catch (TimeLimitExceededException e) {
	    System.out.println("search took more than " + timeout +"ms");
	} catch (NamingException e) {
	    e.printStackTrace();
	}
    }

    public static void main(String[] args) {

	// 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, "ldap://localhost:389/o=JNDITutorial");

	try {
	    // Create initial context
	    DirContext ctx = new InitialDirContext(env);

	    // Set search controls to limit count to 'timeout'
	    SearchControls ctls = new SearchControls();
	    ctls.setSearchScope(SearchControls.SUBTREE_SCOPE);
	    ctls.setTimeLimit(timeout); //

	    // Search for objects with those matching attributes
	    NamingEnumeration answer = 
		ctx.search("","(objectclass=*)", ctls );

	    // Print the answer
	    printSearchEnumeration(answer);

	    // Close the context when we're done
	    ctx.close();
	} catch (TimeLimitExceededException e) {
	    System.out.println("time limit exceeded");
	} catch (Exception e) {
	    System.err.println(e);
	}
    }
}