bundles/org.apache.jasper.glassfish/src/org/apache/jasper/tagplugins/jstl/ForEach.java
private void doCollection(TagPluginContext ctxt) {

	ctxt.generateImport("java.util.*");
	generateIterators(ctxt);

        String itemsV = ctxt.getTemporaryVariableName();
        ctxt.generateJavaSource("Object " + itemsV + "= ");
        ctxt.generateAttribute("items");
        ctxt.generateJavaSource(";");
	
	String indexV=null, beginV=null, endV=null, stepV=null;
	if (hasBegin) {
	    beginV = ctxt.getTemporaryVariableName();
	    ctxt.generateJavaSource("int " + beginV + " = ");
	    ctxt.generateAttribute("begin");
	    ctxt.generateJavaSource(";");
	}
	if (hasEnd) {
	    indexV = ctxt.getTemporaryVariableName();
	    ctxt.generateJavaSource("int " + indexV + " = 0;");
	    endV = ctxt.getTemporaryVariableName();
	    ctxt.generateJavaSource("int " + endV + " = ");
	    ctxt.generateAttribute("end");
	    ctxt.generateJavaSource(";");
	}
	if (hasStep) {
	    stepV = ctxt.getTemporaryVariableName();
	    ctxt.generateJavaSource("int " + stepV + " = ");
	    ctxt.generateAttribute("step");
	    ctxt.generateJavaSource(";");
	}

        String iterV = ctxt.getTemporaryVariableName();
        ctxt.generateJavaSource("Iterator " + iterV + " = null;");
	// Object[]
	ctxt.generateJavaSource("if (" + itemsV + " instanceof Object[])");
	ctxt.generateJavaSource(iterV + "=toIterator((Object[])" + itemsV + ");");
	// boolean[]
	ctxt.generateJavaSource("else if (" + itemsV + " instanceof boolean[])");
	ctxt.generateJavaSource(iterV + "=toIterator((boolean[])" + itemsV + ");");
	// byte[]
	ctxt.generateJavaSource("else if (" + itemsV + " instanceof byte[])");
	ctxt.generateJavaSource(iterV + "=toIterator((byte[])" + itemsV + ");");
	// char[]
	ctxt.generateJavaSource("else if (" + itemsV + " instanceof char[])");
	ctxt.generateJavaSource(iterV + "=toIterator((char[])" + itemsV + ");");
	// short[]
	ctxt.generateJavaSource("else if (" + itemsV + " instanceof short[])");
	ctxt.generateJavaSource(iterV + "=toIterator((short[])" + itemsV + ");");
	// int[]
	ctxt.generateJavaSource("else if (" + itemsV + " instanceof int[])");
	ctxt.generateJavaSource(iterV + "=toIterator((int[])" + itemsV + ");");
	// long[]
	ctxt.generateJavaSource("else if (" + itemsV + " instanceof long[])");
	ctxt.generateJavaSource(iterV + "=toIterator((long[])" + itemsV + ");");
	// float[]
	ctxt.generateJavaSource("else if (" + itemsV + " instanceof float[])");
	ctxt.generateJavaSource(iterV + "=toIterator((float[])" + itemsV + ");");
	// double[]
	ctxt.generateJavaSource("else if (" + itemsV + " instanceof double[])");
	ctxt.generateJavaSource(iterV + "=toIterator((double[])" + itemsV + ");");

        // Collection
        ctxt.generateJavaSource("else if (" + itemsV + " instanceof Collection)");
        ctxt.generateJavaSource(iterV + "=((Collection)" + itemsV + ").iterator();");

        // Iterator
        ctxt.generateJavaSource("else if (" + itemsV + " instanceof Iterator)");
        ctxt.generateJavaSource(iterV + "=(Iterator)" + itemsV + ";");

	// Enumeration
	ctxt.generateJavaSource("else if (" + itemsV + " instanceof Enumeration)");
	ctxt.generateJavaSource(iterV + "=toIterator((Enumeration)" + itemsV + ");");

        // Map
        ctxt.generateJavaSource("else if (" + itemsV + " instanceof Map)");
        ctxt.generateJavaSource(iterV + "=((Map)" + itemsV + ").entrySet().iterator();");

	if (hasBegin) {
            String tV = ctxt.getTemporaryVariableName();
	    ctxt.generateJavaSource("for (int " + tV + "=" + beginV + ";" +
			tV + ">0 && " + iterV + ".hasNext(); " +
			tV + "--)");
	    ctxt.generateJavaSource(iterV + ".next();");
	}

	ctxt.generateJavaSource("while (" + iterV + ".hasNext()){");
	if (hasVar) {
	    ctxt.generateJavaSource("_jspx_page_context.setAttribute(");
	    ctxt.generateAttribute("var");
	    ctxt.generateJavaSource(", " + iterV + ".next());");
	}

	ctxt.generateBody();

	if (hasStep) {
	    String tV = ctxt.getTemporaryVariableName();
	    ctxt.generateJavaSource("for (int " + tV + "=" + stepV + "-1;" +
			tV + ">0 && " + iterV + ".hasNext(); " +
			tV + "--)");
	    ctxt.generateJavaSource(iterV + ".next();");
	}
	if (hasEnd) {
	    if (hasStep) {
		ctxt.generateJavaSource(indexV + "+=" + stepV + ";");
	    }
	    else {
		ctxt.generateJavaSource(indexV + "++;");
	    }
	    if (hasBegin) {
		ctxt.generateJavaSource("if(" + beginV + "+" + indexV +
			">"+ endV + ")");
	    }
	    else {
		ctxt.generateJavaSource("if(" + indexV + ">" + endV + ")");
	    }
	    ctxt.generateJavaSource("break;");
	}
	ctxt.generateJavaSource("}");	// while
    }
private void doCollection(TagPluginContext ctxt) {

	ctxt.generateImport("java.util.*");
	generateIterators(ctxt);

        String itemsV = ctxt.getTemporaryVariableName();
        ctxt.generateJavaSource("Object " + itemsV + "= ");
        ctxt.generateAttribute("items");
        ctxt.generateJavaSource(";");
	
	String indexV=null, beginV=null, endV=null, stepV=null;
	if (hasBegin) {
	    beginV = ctxt.getTemporaryVariableName();
	    ctxt.generateJavaSource("int " + beginV + " = ");
	    ctxt.generateAttribute("begin");
	    ctxt.generateJavaSource(";");
	}
	if (hasEnd) {
	    indexV = ctxt.getTemporaryVariableName();
	    ctxt.generateJavaSource("int " + indexV + " = 0;");
	    endV = ctxt.getTemporaryVariableName();
	    ctxt.generateJavaSource("int " + endV + " = ");
	    ctxt.generateAttribute("end");
	    ctxt.generateJavaSource(";");
	}
	if (hasStep) {
	    stepV = ctxt.getTemporaryVariableName();
	    ctxt.generateJavaSource("int " + stepV + " = ");
	    ctxt.generateAttribute("step");
	    ctxt.generateJavaSource(";");
	}

        String iterV = ctxt.getTemporaryVariableName();
        ctxt.generateJavaSource("Iterator " + iterV + " = null;");
	// Object[]
	ctxt.generateJavaSource("if (" + itemsV + " instanceof Object[])");
	ctxt.generateJavaSource(iterV + "=toIterator((Object[])" + itemsV + ");");
	// boolean[]
	ctxt.generateJavaSource("else if (" + itemsV + " instanceof boolean[])");
	ctxt.generateJavaSource(iterV + "=toIterator((boolean[])" + itemsV + ");");
	// byte[]
	ctxt.generateJavaSource("else if (" + itemsV + " instanceof byte[])");
	ctxt.generateJavaSource(iterV + "=toIterator((byte[])" + itemsV + ");");
	// char[]
	ctxt.generateJavaSource("else if (" + itemsV + " instanceof char[])");
	ctxt.generateJavaSource(iterV + "=toIterator((char[])" + itemsV + ");");
	// short[]
	ctxt.generateJavaSource("else if (" + itemsV + " instanceof short[])");
	ctxt.generateJavaSource(iterV + "=toIterator((short[])" + itemsV + ");");
	// int[]
	ctxt.generateJavaSource("else if (" + itemsV + " instanceof int[])");
	ctxt.generateJavaSource(iterV + "=toIterator((int[])" + itemsV + ");");
	// long[]
	ctxt.generateJavaSource("else if (" + itemsV + " instanceof long[])");
	ctxt.generateJavaSource(iterV + "=toIterator((long[])" + itemsV + ");");
	// float[]
	ctxt.generateJavaSource("else if (" + itemsV + " instanceof float[])");
	ctxt.generateJavaSource(iterV + "=toIterator((float[])" + itemsV + ");");
	// double[]
	ctxt.generateJavaSource("else if (" + itemsV + " instanceof double[])");
	ctxt.generateJavaSource(iterV + "=toIterator((double[])" + itemsV + ");");

        // Collection
        ctxt.generateJavaSource("else if (" + itemsV + " instanceof Collection)");
        ctxt.generateJavaSource(iterV + "=((Collection)" + itemsV + ").iterator();");

        // Iterator
        ctxt.generateJavaSource("else if (" + itemsV + " instanceof Iterator)");
        ctxt.generateJavaSource(iterV + "=(Iterator)" + itemsV + ";");

	// Enumeration
	ctxt.generateJavaSource("else if (" + itemsV + " instanceof Enumeration)");
	ctxt.generateJavaSource(iterV + "=toIterator((Enumeration)" + itemsV + ");");

        // Map
        ctxt.generateJavaSource("else if (" + itemsV + " instanceof Map)");
        ctxt.generateJavaSource(iterV + "=((Map)" + itemsV + ").entrySet().iterator();");

	if (hasBegin) {
            String tV = ctxt.getTemporaryVariableName();
	    ctxt.generateJavaSource("for (int " + tV + "=" + beginV + ";" +
			tV + ">0 && " + iterV + ".hasNext(); " +
			tV + "--)");
	    ctxt.generateJavaSource(iterV + ".next();");
	}

	ctxt.generateJavaSource("while (" + iterV + ".hasNext()){");
	if (hasVar) {
	    ctxt.generateJavaSource("_jspx_page_context.setAttribute(");
	    ctxt.generateAttribute("var");
	    ctxt.generateJavaSource(", " + iterV + ".next());");
	}

	ctxt.generateBody();

	if (hasStep) {
	    String tV = ctxt.getTemporaryVariableName();
	    ctxt.generateJavaSource("for (int " + tV + "=" + stepV + "-1;" +
			tV + ">0 && " + iterV + ".hasNext(); " +
			tV + "--)");
	    ctxt.generateJavaSource(iterV + ".next();");
	}
	if (hasEnd) {
	    if (hasStep) {
		ctxt.generateJavaSource(indexV + "+=" + stepV + ";");
	    }
	    else {
		ctxt.generateJavaSource(indexV + "++;");
	    }
	    if (hasBegin) {
		ctxt.generateJavaSource("if(" + beginV + "+" + indexV +
			">"+ endV + ")");
	    }
	    else {
		ctxt.generateJavaSource("if(" + indexV + ">" + endV + ")");
	    }
	    ctxt.generateJavaSource("break;");
	}
	ctxt.generateJavaSource("}");	// while
    }
Generate codes for Collections
The pseudo code is: