com.ibm.jaql.lang.expr.core.ExpectExceptionFn.java Source code

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Here is the source code for com.ibm.jaql.lang.expr.core.ExpectExceptionFn.java

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/*
 * Copyright (C) IBM Corp. 2010.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package com.ibm.jaql.lang.expr.core;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.ibm.jaql.json.type.JsonString;
import com.ibm.jaql.json.type.JsonValue;
import com.ibm.jaql.lang.core.Context;
import com.ibm.jaql.lang.expr.function.DefaultBuiltInFunctionDescriptor;
import com.ibm.jaql.util.ClassLoaderMgr;

/**
 * This function is used by tests to mask expected exceptions.
 */
public class ExpectExceptionFn extends Expr {
    protected static final Log LOG = LogFactory.getLog(ExpectExceptionFn.class.getName());
    public static final JsonString EXPECTED = new JsonString("Expected exception occured");

    public static class Descriptor extends DefaultBuiltInFunctionDescriptor.Par1u {
        public Descriptor() {
            super("expectException", ExpectExceptionFn.class);
        }
    }

    public ExpectExceptionFn(Expr... exprs) {
        super(exprs);
    }

    @Override
    public JsonValue eval(final Context context) throws Exception {
        try {
            JsonValue value = exprs[0].eval(context);
            throw new RuntimeException("Expected exception but found " + value);
        } catch (Exception ex) {
            if (exprs.length == 1) {
                LOG.info("any exception expected", ex);
                return EXPECTED;
            }
            Throwable cause = ex;
            while (cause.getCause() != null) {
                cause = cause.getCause();
            }
            Class<?> causeClass = cause.getClass();
            for (int i = 1; i < exprs.length; i++) {
                JsonString js = (JsonString) exprs[1].eval(context);
                Class<?> cls = ClassLoaderMgr.resolveClass(js.toString());
                if (cls.isAssignableFrom(causeClass)) {
                    LOG.info("exception was expected " + cls.getName().toString(), ex);
                    return EXPECTED;
                }
            }
            throw new RuntimeException("expected an exception, but not this one", ex);
        }
    }
}