FileDocCategorySizeDatePackage
ExpressionBuilder.javaAPI DocGlassfish v2 API9793Fri May 04 22:31:18 BST 2007com.sun.el.lang

ExpressionBuilder

public final class ExpressionBuilder extends Object implements NodeVisitor
author
Jacob Hookom [jacob@hookom.net]
version
$Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: tcfujii $

Fields Summary
private static final int
CACHE_INIT_SIZE
private static final ConcurrentHashMap
cache
private FunctionMapper
fnMapper
private VariableMapper
varMapper
private String
expression
Constructors Summary
public ExpressionBuilder(String expression, ELContext ctx)


          
        
              
        this.expression = expression;

        FunctionMapper ctxFn = ctx.getFunctionMapper();
        VariableMapper ctxVar = ctx.getVariableMapper();

        if (ctxFn != null) {
            this.fnMapper = new FunctionMapperFactory(ctxFn);
        }
        if (ctxVar != null) {
            this.varMapper = new VariableMapperFactory(ctxVar);
        }
Methods Summary
private com.sun.el.parser.Nodebuild()

        Node n = createNodeInternal(this.expression);
        this.prepare(n);
        if (n instanceof AstDeferredExpression
                || n instanceof AstDynamicExpression) {
            n = n.jjtGetChild(0);
        }
        return n;
public javax.el.MethodExpressioncreateMethodExpression(java.lang.Class expectedReturnType, java.lang.Class[] expectedParamTypes)

        Node n = this.build();
        if (n instanceof AstValue || n instanceof AstIdentifier) {
            return new MethodExpressionImpl(expression, n,
                    this.fnMapper, this.varMapper, expectedReturnType,
                    expectedParamTypes);
        } else if (n instanceof AstLiteralExpression) {
            return new MethodExpressionLiteral(expression, expectedReturnType,
                    expectedParamTypes);
        } else {
            throw new ELException("Not a Valid Method Expression: "
                    + expression);
        }
public static final com.sun.el.parser.NodecreateNode(java.lang.String expr)

        Node n = createNodeInternal(expr);
        return n;
private static final com.sun.el.parser.NodecreateNodeInternal(java.lang.String expr)

        if (expr == null) {
            throw new ELException(MessageFactory.get("error.null"));
        }

        Node n = (Node) cache.get(expr);
        if (n == null) {
            try {
                n = (new ELParser(new StringReader(expr)))
                        .CompositeExpression();

                // validate composite expression
                if (n instanceof AstCompositeExpression) {
                    int numChildren = n.jjtGetNumChildren();
                    if (numChildren == 1) {
                        n = n.jjtGetChild(0);
                    } else {
                        Class type = null;
                        Node child = null;
                        for (int i = 0; i < numChildren; i++) {
                            child = n.jjtGetChild(i);
                            if (child instanceof AstLiteralExpression)
                                continue;
                            if (type == null)
                                type = child.getClass();
                            else {
                                if (!type.equals(child.getClass())) {
                                    throw new ELException(MessageFactory.get(
                                            "error.mixed", expr));
                                }
                            }
                        }
                    }
                }
                if (n instanceof AstDeferredExpression
                        || n instanceof AstDynamicExpression) {
                    n = n.jjtGetChild(0);
                }
                cache.putIfAbsent(expr, n);
            } catch (ParseException pe) {
                throw new ELException("Error Parsing: " + expr, pe);
            }
        }
        return n;
public javax.el.ValueExpressioncreateValueExpression(java.lang.Class expectedType)

        Node n = this.build();
        return new ValueExpressionImpl(this.expression, n, this.fnMapper,
                this.varMapper, expectedType);
private voidprepare(com.sun.el.parser.Node node)

        node.accept(this);
        if (this.fnMapper instanceof FunctionMapperFactory) {
            this.fnMapper = ((FunctionMapperFactory) this.fnMapper).create();
        }
        if (this.varMapper instanceof VariableMapperFactory) {
            this.varMapper = ((VariableMapperFactory) this.varMapper).create();
        }
public voidvisit(com.sun.el.parser.Node node)

        if (node instanceof AstFunction) {

            AstFunction funcNode = (AstFunction) node;

            if (this.fnMapper == null) {
                throw new ELException(MessageFactory.get("error.fnMapper.null"));
            }
            Method m = fnMapper.resolveFunction(funcNode.getPrefix(), funcNode
                    .getLocalName());
            if (m == null) {
                throw new ELException(MessageFactory.get(
                        "error.fnMapper.method", funcNode.getOutputName()));
            }
            int pcnt = m.getParameterTypes().length;
            if (node.jjtGetNumChildren() != pcnt) {
                throw new ELException(MessageFactory.get(
                        "error.fnMapper.paramcount", funcNode.getOutputName(),
                        "" + pcnt, "" + node.jjtGetNumChildren()));
            }
        } else if (node instanceof AstIdentifier && this.varMapper != null) {
            String variable = ((AstIdentifier) node).getImage();

            // simply capture it
            this.varMapper.resolveVariable(variable);
        }