<jsp:useBean id="monBean" scope="session" class="package.MonObject" >
    <jsp:setProperty name="monBean" property="monAttribut" value="1.0" />
</jsp:useBean>
<jsp:include page="maPage.jsp"/>
<jsp:redirect page="maPage.jsp"/>
etc.

<prefixe:nomDuTag attribut="valeur">
	Corps du tag
</prefix:nomDuTag>

<prefixe:nomDuTag attribut="valeur" attribut2="valeur2" attribut3="valeur3"
	attribut4="valeur4" attribut5="valeur5" />

<prefixe:nomDuTag attribut="valeur"></prefixe:nomDuTag>

<prefixe:nomDuTag attribut="valeur">
	<prefixe:nomDuTag>corps</prefixe:nomDuTag>
</prefixe:nomDuTag>

<prefixe:nomDuTag/>

	<%@ taglib uri="/WEB-INF/taglib.tld" prefix="tag-prefix" %> 
	// ou si le fichier tld est dans le Jar :
	<%@ taglib uri="/WEB-INF/lib/taglib.jar" prefix="tag-prefix" %>

<tag>
	<name>hello</name>
	<tagclass>tutoriel.taglib.HelloTag</tagclass>
	<bodycontent>empty</bodycontent>
	<attribute>
		<name>name</name>
	</attribute>
</tag>

public class HelloTag extends TagSupport {
	private String name = null;
	
	public void setName (String string) {
		this.name = string;
	}
	
	public int doStartTag() throws JspException {
		if (this.name==null)
			this.name = "World";
		try {
			pageContext.getOut().println ("Hello " + this.name + " !");
		} catch (IOException e) {
			throw new JspException ("I/O Error", e);
		}
		return SKIP_BODY;
	}
}

<tag11:hello/><br/>
<tag11:hello name="Fred"/>

Hello World !
Hello Fred !

public class ParamPresentTag extends TagSupport {
	private String name = null;
	
	public void setName (String string) {
		this.name = string;
	}

	public int doStartTag() throws JspException {
		String value = pageContext.getRequest().getParameter(this.name);
		if (value!=null)
			return EVAL_BODY_INCLUDE;
		return SKIP_BODY;
	}
}

	<tag>
		<name>paramPresent</name>
		<tagclass>tutoriel.taglib.ParamPresentTag</tagclass>
		<bodycontent>JSP</bodycontent>
		<attribute>
			<name>name</name>
			<required>true</required>
		</attribute>
	</tag>

<tag11:paramPresent name="page">
	Le paramètre page vaut : <%=request.getParameter("page")%>.
</tag11:paramPresent>

Le paramètre page vaut : valeur.

public class SwitchTag extends TagSupport {

	private Object test = null;
	
	public void setTest (Object obj) {
		this.test = obj;
	}
	
	public int doStartTag() throws JspException {
		return EVAL_BODY_INCLUDE;
	}

	public boolean isValid (Object caseValue) {
		if (this.test==caseValue) return true;
		if (this.test!=null && this.test.equals(caseValue)) return true;
		return false;
	}
}

public class CaseTag extends TagSupport {

	public Object value = null;
	
	public void setValue (Object object) {
		this.value = object;
	}

	public int doStartTag() throws JspException {
		
		if ( getParent() instanceof SwitchTag ) {
			SwitchTag parent = (SwitchTag) getParent();
			if (parent.isValid(this.value))
				return EVAL_BODY_INCLUDE;
			return SKIP_BODY;
		}
		throw new JspException ("Le tag case doit être à l'intérieur du tag swith.");
	}
}

<tag11:switch test="2">
	<tag11:case value="0">Zéro</tag11:case>
	<tag11:case value="1">Un</tag11:case>
	<tag11:case value="2">Deux</tag11:case>
	<tag11:case value="3">Trois</tag11:case>
</tag11:switch>

Deux

public class IterateTag extends BodyTagSupport {
   
    private int count = 0;
    private int current;

    public void setCount(int i) {
        count = i;
    }

    public int doStartTag() throws JspException {
        current = 0;
        if (current < count)
            return Tag.EVAL_BODY_TAG;
        return Tag.SKIP_BODY;
    }
   
    public int doAfterBody() throws JspException {
        current++;
        if (current < count)
            return IterationTag.EVAL_BODY_TAG;
        return Tag.SKIP_BODY;
    }
}

<tag11:iterate count="3">
	Cette ligne sera affichée trois fois<br/>
</tag11:iterate>

Cette ligne sera affichée trois fois
Cette ligne sera affichée trois fois
Cette ligne sera affichée trois fois

public class UpperCaseTag extends BodyTagSupport {

	public int doStartTag() throws JspException {
		return EVAL_BODY_TAG;
	}

	public int doAfterBody() throws JspException {
		
		try {
			if ( getBodyContent()!=null ) {
				String bodyString = getBodyContent().getString();
				bodyString = bodyString.toUpperCase();
				getBodyContent().getEnclosingWriter().println( bodyString );
			}
		} catch (IOException e) {
			throw new JspException (e);
		}
		
		return EVAL_PAGE;
	}
}

<tag11:upperCase>Ce texte sera mis en majuscule, ainsi que le résultat de ce <%="scriptlet"%>.</tag11:upperCase>

CE TEXTE SERA MIS EN MAJUSCULE, AINSI QUE LE RÉSULTAT DE CE SCRIPTLET.

public class PerlTag extends BodyTagSupport {
	
	private Process process = null;

	protected void startProcess () throws JspException {
		try {
			process = Runtime.getRuntime().exec("perl");
		} catch (IOException e) { 
			throw new JspException ("Erreur de creation du process 'perl'.", e);
		}
	}
	
	protected void writeBody () throws JspException {
		// On recupere les flux STDIN du process 'perl'
		OutputStream stdin = process.getOutputStream();
		OutputStreamWriter stdinWriter = new OutputStreamWriter (stdin);
		
		try {
			// On écrit dans le STDIN du process le contenu du tag :
			getBodyContent().writeOut( stdinWriter );
		} catch (IOException e) { 
			throw new JspException ("Erreur d'ecriture du body.", e);
		} finally {
			// Fermeture des flux ...
			try { stdinWriter.close(); } catch (IOException e) {}
			try { stdin.close(); } catch (IOException e) {}
		}
	}
	
	protected void readErrors () throws JspException {
		// On recupere les flux STDERR du process 'perl'
		InputStream stdout = process.getErrorStream();
		InputStreamReader stdoutReader = new InputStreamReader (stdout);
		BufferedReader stdoutBuffer = new BufferedReader (stdoutReader);
		StringBuffer errorBuffer = null;
	
		try {
			// On récupère chaque ligne du STDERR dans un buffer :
			String line = null;
			while ( ( line = stdoutBuffer.readLine() ) != null ) {
				if (errorBuffer==null)
					errorBuffer = new StringBuffer ();
				errorBuffer.append(line);
			}
		} catch (IOException e) {
			throw new JspException ("Erreur de lecture du résultat.", e);
		} finally {
			// Fermeture des flux ...
			try { stdoutBuffer.close(); } catch (IOException e) {}
			try { stdoutReader.close(); } catch (IOException e) {}
			try { stdout.close(); } catch (IOException e) {}
		}
		
		// Si le buffer n'est pas vide, on envoi une exception
		if (errorBuffer!=null)
			throw new JspException ("Perl Script Error : " + errorBuffer);
	}
	
	protected void readResult () throws JspException {
		// On recupere les flux STDOUT du process 'perl'
		InputStream stdout = process.getInputStream();
		InputStreamReader stdoutReader = new InputStreamReader (stdout);
		BufferedReader stdoutBuffer = new BufferedReader (stdoutReader);
		
		try {
			// On récupère chaque ligne du STDOUT et on l'affiche :
			String line = null;
			while ( ( line = stdoutBuffer.readLine() ) != null ) {
				getPreviousOut().print(line);
			}
		} catch (IOException e) {
			throw new JspException ("Erreur de lecture du résultat.", e);
		} finally {
			// Fermeture des flux ...
			try { stdoutBuffer.close(); } catch (IOException e) {}
			try { stdoutReader.close(); } catch (IOException e) {}
			try { stdout.close(); } catch (IOException e) {}
		}
	}
	
	public int doStartTag() throws JspException {
		return EVAL_BODY_TAG;
	}
	
	public int doAfterBody() throws JspException {
		startProcess();
		writeBody ();
		readErrors ();
		readResult ();

		return SKIP_BODY;
	}
}

<tag11:perl> 
$lang = "perl";
printf ( "Utilisation du langage %s dans une page JSP", $lang );
</tag11:perl>

Utilisation du langage perl dans une page JSP

public class ParamPresentTag extends TagSupport {
	private String name = null;
	
	public void setName (String string) {
		this.name = string;
	}

	public int doStartTag() throws JspException {
		String value = pageContext.getRequest().getParameter(this.name);
		if (value!=null) {
			pageContext.setAttribute("value", value);
			return EVAL_BODY_INCLUDE;
		}
		return SKIP_BODY;
	}
	
	public int doEndTag() throws JspException {
		pageContext.removeAttribute("value");
		return EVAL_PAGE;
	}
}

<tag11:paramPresent name="page">
	Le paramètre page vaut : <%=pageContext.getAttribute("value")%>.
</tag11:paramPresent>