private static Wrapper findWrapper()

in java/jakarta/el/Util.java [127:278]
118 lines of code
45 McCabe index (conditional complexity)

    private static <T> Wrapper<T> findWrapper(ELContext context, Class<?> clazz, List<Wrapper<T>> wrappers, String name,
            Class<?>[] paramTypes, Object[] paramValues) {

        Map<Wrapper<T>,MatchResult> candidates = new HashMap<>();

        int paramCount = paramTypes.length;

        for (Wrapper<T> w : wrappers) {
            Class<?>[] mParamTypes = w.getParameterTypes();
            int mParamCount;
            if (mParamTypes == null) {
                mParamCount = 0;
            } else {
                mParamCount = mParamTypes.length;
            }

            // Check the number of parameters
            // Multiple tests to improve readability
            if (!w.isVarArgs() && paramCount != mParamCount) {
                // Method has wrong number of parameters
                continue;
            }
            if (w.isVarArgs() && paramCount < mParamCount - 1) {
                // Method has wrong number of parameters
                continue;
            }
            if (w.isVarArgs() && paramCount == mParamCount && paramValues != null && paramValues.length > paramCount &&
                    !paramTypes[mParamCount - 1].isArray()) {
                // Method arguments don't match
                continue;
            }
            if (w.isVarArgs() && paramCount > mParamCount && paramValues != null && paramValues.length != paramCount) {
                // Might match a different varargs method
                continue;
            }
            if (!w.isVarArgs() && paramValues != null && paramCount != paramValues.length) {
                // Might match a different varargs method
                continue;
            }

            // Check the parameters match
            int exactMatch = 0;
            int assignableMatch = 0;
            int coercibleMatch = 0;
            int varArgsMatch = 0;
            boolean noMatch = false;
            for (int i = 0; i < mParamCount; i++) {
                // Can't be null
                if (w.isVarArgs() && i == (mParamCount - 1)) {
                    if (i == paramCount || (paramValues != null && paramValues.length == i)) {
                        // Var args defined but nothing is passed as varargs
                        // Use MAX_VALUE so this matches only if nothing else does
                        varArgsMatch = Integer.MAX_VALUE;
                        break;
                    }
                    Class<?> varType = mParamTypes[i].getComponentType();
                    for (int j = i; j < paramCount; j++) {
                        if (isAssignableFrom(paramTypes[j], varType)) {
                            assignableMatch++;
                            varArgsMatch++;
                        } else {
                            if (paramValues == null) {
                                noMatch = true;
                                break;
                            } else {
                                if (isCoercibleFrom(context, paramValues[j], varType)) {
                                    coercibleMatch++;
                                    varArgsMatch++;
                                } else {
                                    noMatch = true;
                                    break;
                                }
                            }
                        }
                        // Don't treat a varArgs match as an exact match, it can
                        // lead to a varArgs method matching when the result
                        // should be ambiguous
                    }
                } else {
                    if (mParamTypes[i].equals(paramTypes[i])) {
                        exactMatch++;
                    } else if (paramTypes[i] != null && isAssignableFrom(paramTypes[i], mParamTypes[i])) {
                        assignableMatch++;
                    } else {
                        if (paramValues == null) {
                            noMatch = true;
                            break;
                        } else {
                            if (isCoercibleFrom(context, paramValues[i], mParamTypes[i])) {
                                coercibleMatch++;
                            } else {
                                noMatch = true;
                                break;
                            }
                        }
                    }
                }
            }
            if (noMatch) {
                continue;
            }

            // If a method is found where every parameter matches exactly,
            // and no vars args are present, return it
            if (exactMatch == paramCount && varArgsMatch == 0) {
                return w;
            }

            candidates.put(w, new MatchResult(w.isVarArgs(), exactMatch, assignableMatch, coercibleMatch, varArgsMatch,
                    w.isBridge()));
        }

        // Look for the method that has the highest number of parameters where
        // the type matches exactly
        MatchResult bestMatch = new MatchResult(true, 0, 0, 0, 0, true);
        Wrapper<T> match = null;
        boolean multiple = false;
        for (Map.Entry<Wrapper<T>,MatchResult> entry : candidates.entrySet()) {
            int cmp = entry.getValue().compareTo(bestMatch);
            if (cmp > 0 || match == null) {
                bestMatch = entry.getValue();
                match = entry.getKey();
                multiple = false;
            } else if (cmp == 0) {
                multiple = true;
            }
        }
        if (multiple) {
            if (bestMatch.getExactCount() == paramCount - 1) {
                // Only one parameter is not an exact match - try using the
                // super class
                match = resolveAmbiguousWrapper(candidates.keySet(), paramTypes);
            } else {
                match = null;
            }

            if (match == null) {
                // If multiple methods have the same matching number of parameters
                // the match is ambiguous so throw an exception
                throw new MethodNotFoundException(
                        message(null, "util.method.ambiguous", clazz, name, paramString(paramTypes)));
            }
        }

        // Handle case where no match at all was found
        if (match == null) {
            throw new MethodNotFoundException(
                    message(null, "util.method.notfound", clazz, name, paramString(paramTypes)));
        }

        return match;
    }