Commons Collections example source code file (TestTransformerUtils.java)

This example Commons Collections source code file (TestTransformerUtils.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Commons Collections tags/keywords

a, a, b, class, hello, illegalargumentexception, illegalargumentexception, integer, object, object, predicate, there, transformer, transformer, util

The Commons Collections TestTransformerUtils.java source code

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You 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 org.apache.commons.collections;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import junit.framework.Test;
import junit.framework.TestSuite;
import junit.textui.TestRunner;

import org.apache.commons.collections.functors.ConstantTransformer;
import org.apache.commons.collections.functors.NOPTransformer;

/**
 * Tests the org.apache.commons.collections.TransformerUtils class.
 * 
 * @since Commons Collections 3.0
 * @version $Revision: 646780 $ $Date: 2008-04-10 13:48:07 +0100 (Thu, 10 Apr 2008) $
 *
 * @author Stephen Colebourne
 * @author James Carman
 */
public class TestTransformerUtils extends junit.framework.TestCase {

    private static final Object cObject = new Object();
    private static final Object cString = "Hello";
    private static final Object cInteger = new Integer(6);

    /**
     * Construct
     */
    public TestTransformerUtils(String name) {
        super(name);
    }

    /**
     * Main.
     * @param args
     */    
    public static void main(String[] args) {
        TestRunner.run(suite());
    }

    /**
     * Return class as a test suite.
     */
    public static Test suite() {
        return new TestSuite(TestTransformerUtils.class);
    }

    /**
     * Set up instance variables required by this test case.
     */
    public void setUp() {
    }

    /**
     * Tear down instance variables required by this test case.
     */
    public void tearDown() {
    }

    // exceptionTransformer
    //------------------------------------------------------------------

    public void testExceptionTransformer() {
        assertNotNull(TransformerUtils.exceptionTransformer());
        assertSame(TransformerUtils.exceptionTransformer(), TransformerUtils.exceptionTransformer());
        try {
            TransformerUtils.exceptionTransformer().transform(null);
        } catch (FunctorException ex) {
            try {
                TransformerUtils.exceptionTransformer().transform(cString);
            } catch (FunctorException ex2) {
                return;
            }
        }
        fail();
    }
    
    // nullTransformer
    //------------------------------------------------------------------

    public void testNullTransformer() {
        assertNotNull(TransformerUtils.nullTransformer());
        assertSame(TransformerUtils.nullTransformer(), TransformerUtils.nullTransformer());
        assertEquals(null, TransformerUtils.nullTransformer().transform(null));
        assertEquals(null, TransformerUtils.nullTransformer().transform(cObject));
        assertEquals(null, TransformerUtils.nullTransformer().transform(cString));
        assertEquals(null, TransformerUtils.nullTransformer().transform(cInteger));
    }

    // nopTransformer
    //------------------------------------------------------------------

    public void testNopTransformer() {
        assertNotNull(TransformerUtils.nullTransformer());
        assertSame(TransformerUtils.nullTransformer(), TransformerUtils.nullTransformer());
        assertEquals(null, TransformerUtils.nopTransformer().transform(null));
        assertEquals(cObject, TransformerUtils.nopTransformer().transform(cObject));
        assertEquals(cString, TransformerUtils.nopTransformer().transform(cString));
        assertEquals(cInteger, TransformerUtils.nopTransformer().transform(cInteger));
    }

    // constantTransformer
    //------------------------------------------------------------------

    public void testConstantTransformer() {
        assertEquals(cObject, TransformerUtils.constantTransformer(cObject).transform(null));
        assertEquals(cObject, TransformerUtils.constantTransformer(cObject).transform(cObject));
        assertEquals(cObject, TransformerUtils.constantTransformer(cObject).transform(cString));
        assertEquals(cObject, TransformerUtils.constantTransformer(cObject).transform(cInteger));
        assertSame(ConstantTransformer.NULL_INSTANCE, TransformerUtils.constantTransformer(null));
    }

    // cloneTransformer
    //------------------------------------------------------------------

    public void testCloneTransformer() {
        assertEquals(null, TransformerUtils.cloneTransformer().transform(null));
        assertEquals(cString, TransformerUtils.cloneTransformer().transform(cString));
        assertEquals(cInteger, TransformerUtils.cloneTransformer().transform(cInteger));
        try {
            assertEquals(cObject, TransformerUtils.cloneTransformer().transform(cObject));
        } catch (IllegalArgumentException ex) {
            return;
        }
        fail();
    }

    // mapTransformer
    //------------------------------------------------------------------

    public void testMapTransformer() {
        Map map = new HashMap();
        map.put(null, new Integer(0));
        map.put(cObject, new Integer(1));
        map.put(cString, new Integer(2));
        assertEquals(new Integer(0), TransformerUtils.mapTransformer(map).transform(null));
        assertEquals(new Integer(1), TransformerUtils.mapTransformer(map).transform(cObject));
        assertEquals(new Integer(2), TransformerUtils.mapTransformer(map).transform(cString));
        assertEquals(null, TransformerUtils.mapTransformer(map).transform(cInteger));
        assertSame(ConstantTransformer.NULL_INSTANCE, TransformerUtils.mapTransformer(null));
    }

    // commandTransformer
    //------------------------------------------------------------------

    public void testExecutorTransformer() {
        assertEquals(null, TransformerUtils.asTransformer(ClosureUtils.nopClosure()).transform(null));
        assertEquals(cObject, TransformerUtils.asTransformer(ClosureUtils.nopClosure()).transform(cObject));
        assertEquals(cString, TransformerUtils.asTransformer(ClosureUtils.nopClosure()).transform(cString));
        assertEquals(cInteger, TransformerUtils.asTransformer(ClosureUtils.nopClosure()).transform(cInteger));
        try {
            TransformerUtils.asTransformer((Closure) null);
        } catch (IllegalArgumentException ex) {
            return;
        }
        fail();
    }

    // predicateTransformer
    //------------------------------------------------------------------

    public void testPredicateTransformer() {
        assertEquals(Boolean.TRUE, TransformerUtils.asTransformer(PredicateUtils.truePredicate()).transform(null));
        assertEquals(Boolean.TRUE, TransformerUtils.asTransformer(PredicateUtils.truePredicate()).transform(cObject));
        assertEquals(Boolean.TRUE, TransformerUtils.asTransformer(PredicateUtils.truePredicate()).transform(cString));
        assertEquals(Boolean.TRUE, TransformerUtils.asTransformer(PredicateUtils.truePredicate()).transform(cInteger));
        try {
            TransformerUtils.asTransformer((Predicate) null);
        } catch (IllegalArgumentException ex) {
            return;
        }
        fail();
    }

    // factoryTransformer
    //------------------------------------------------------------------

    public void testFactoryTransformer() {
        assertEquals(null, TransformerUtils.asTransformer(FactoryUtils.nullFactory()).transform(null));
        assertEquals(null, TransformerUtils.asTransformer(FactoryUtils.nullFactory()).transform(cObject));
        assertEquals(null, TransformerUtils.asTransformer(FactoryUtils.nullFactory()).transform(cString));
        assertEquals(null, TransformerUtils.asTransformer(FactoryUtils.nullFactory()).transform(cInteger));
        try {
            TransformerUtils.asTransformer((Factory) null);
        } catch (IllegalArgumentException ex) {
            return;
        }
        fail();
    }

    // chainedTransformer
    //------------------------------------------------------------------

    public void testChainedTransformer() {
        Transformer a = TransformerUtils.constantTransformer("A");
        Transformer b = TransformerUtils.constantTransformer("B");
        
        assertEquals("A", TransformerUtils.chainedTransformer(b, a).transform(null));
        assertEquals("B", TransformerUtils.chainedTransformer(a, b).transform(null));
        assertEquals("A", TransformerUtils.chainedTransformer(new Transformer[] {b, a}).transform(null));
        Collection coll = new ArrayList();
        coll.add(b);
        coll.add(a);
        assertEquals("A", TransformerUtils.chainedTransformer(coll).transform(null));

        assertSame(NOPTransformer.INSTANCE, TransformerUtils.chainedTransformer(new Transformer[0]));
        assertSame(NOPTransformer.INSTANCE, TransformerUtils.chainedTransformer(Collections.EMPTY_LIST));
        
        try {
            TransformerUtils.chainedTransformer(null, null);
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            TransformerUtils.chainedTransformer((Transformer[]) null);
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            TransformerUtils.chainedTransformer((Collection) null);
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            TransformerUtils.chainedTransformer(new Transformer[] {null, null});
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            coll = new ArrayList();
            coll.add(null);
            coll.add(null);
            TransformerUtils.chainedTransformer(coll);
            fail();
        } catch (IllegalArgumentException ex) {}
    }
    
    // switchTransformer
    //------------------------------------------------------------------

    public void testSwitchTransformer() {
        Transformer a = TransformerUtils.constantTransformer("A");
        Transformer b = TransformerUtils.constantTransformer("B");
        Transformer c = TransformerUtils.constantTransformer("C");
        
        assertEquals("A", TransformerUtils.switchTransformer(PredicateUtils.truePredicate(), a, b).transform(null));
        assertEquals("B", TransformerUtils.switchTransformer(PredicateUtils.falsePredicate(), a, b).transform(null));
        
        assertEquals(null, TransformerUtils.switchTransformer(
            new Predicate[] {PredicateUtils.equalPredicate("HELLO"), PredicateUtils.equalPredicate("THERE")}, 
            new Transformer[] {a, b}).transform("WELL"));
        assertEquals("A", TransformerUtils.switchTransformer(
            new Predicate[] {PredicateUtils.equalPredicate("HELLO"), PredicateUtils.equalPredicate("THERE")}, 
            new Transformer[] {a, b}).transform("HELLO"));
        assertEquals("B", TransformerUtils.switchTransformer(
            new Predicate[] {PredicateUtils.equalPredicate("HELLO"), PredicateUtils.equalPredicate("THERE")}, 
            new Transformer[] {a, b}).transform("THERE"));
            
        assertEquals("C", TransformerUtils.switchTransformer(
            new Predicate[] {PredicateUtils.equalPredicate("HELLO"), PredicateUtils.equalPredicate("THERE")}, 
            new Transformer[] {a, b}, c).transform("WELL"));
            
        Map map = new HashMap();
        map.put(PredicateUtils.equalPredicate("HELLO"), a);
        map.put(PredicateUtils.equalPredicate("THERE"), b);
        assertEquals(null, TransformerUtils.switchTransformer(map).transform("WELL"));
        assertEquals("A", TransformerUtils.switchTransformer(map).transform("HELLO"));
        assertEquals("B", TransformerUtils.switchTransformer(map).transform("THERE"));
        map.put(null, c);
        assertEquals("C", TransformerUtils.switchTransformer(map).transform("WELL"));

        assertSame(ConstantTransformer.NULL_INSTANCE, TransformerUtils.switchTransformer(new Predicate[0], new Transformer[0]));
        assertSame(ConstantTransformer.NULL_INSTANCE, TransformerUtils.switchTransformer(new HashMap()));
        map = new HashMap();
        map.put(null, null);
        assertSame(ConstantTransformer.NULL_INSTANCE, TransformerUtils.switchTransformer(map));
            
        try {
            TransformerUtils.switchTransformer(null, null);
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            TransformerUtils.switchTransformer((Predicate[]) null, (Transformer[]) null);
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            TransformerUtils.switchTransformer((Map) null);
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            TransformerUtils.switchTransformer(new Predicate[2], new Transformer[2]);
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            TransformerUtils.switchTransformer(
                    new Predicate[] {PredicateUtils.truePredicate()},
                    new Transformer[] {a,b});
            fail();
        } catch (IllegalArgumentException ex) {}
    }
    
    // switchMapTransformer
    //------------------------------------------------------------------

    public void testSwitchMapTransformer() {
        Transformer a = TransformerUtils.constantTransformer("A");
        Transformer b = TransformerUtils.constantTransformer("B");
        Transformer c = TransformerUtils.constantTransformer("C");
        
        Map map = new HashMap();
        map.put("HELLO", a);
        map.put("THERE", b);
        assertEquals(null, TransformerUtils.switchMapTransformer(map).transform("WELL"));
        assertEquals("A", TransformerUtils.switchMapTransformer(map).transform("HELLO"));
        assertEquals("B", TransformerUtils.switchMapTransformer(map).transform("THERE"));
        map.put(null, c);
        assertEquals("C", TransformerUtils.switchMapTransformer(map).transform("WELL"));

        assertSame(ConstantTransformer.NULL_INSTANCE, TransformerUtils.switchMapTransformer(new HashMap()));
        map = new HashMap();
        map.put(null, null);
        assertSame(ConstantTransformer.NULL_INSTANCE, TransformerUtils.switchMapTransformer(map));
        
        try {
            TransformerUtils.switchMapTransformer(null);
            fail();
        } catch (IllegalArgumentException ex) {}
    }
    
    // invokerTransformer
    //------------------------------------------------------------------

    public void testInvokerTransformer() {
        List list = new ArrayList();
        assertEquals(new Integer(0), TransformerUtils.invokerTransformer("size").transform(list));
        list.add(new Object());
        assertEquals(new Integer(1), TransformerUtils.invokerTransformer("size").transform(list));
        assertEquals(null, TransformerUtils.invokerTransformer("size").transform(null));

        try {
            TransformerUtils.invokerTransformer(null);
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            TransformerUtils.invokerTransformer("noSuchMethod").transform(new Object());
            fail();
        } catch (FunctorException ex) {}
    }
    
    // invokerTransformer2
    //------------------------------------------------------------------

    public void testInvokerTransformer2() {
        List list = new ArrayList();
        assertEquals(Boolean.FALSE, TransformerUtils.invokerTransformer(
            "contains", new Class[] {Object.class}, new Object[] {cString}).transform(list));
        list.add(cString);
        assertEquals(Boolean.TRUE, TransformerUtils.invokerTransformer(
            "contains", new Class[] {Object.class}, new Object[] {cString}).transform(list));
        assertEquals(null, TransformerUtils.invokerTransformer(
            "contains", new Class[] {Object.class}, new Object[] {cString}).transform(null));

        try {
            TransformerUtils.invokerTransformer(null, null, null);
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            TransformerUtils.invokerTransformer(
                "noSuchMethod", new Class[] {Object.class}, new Object[] {cString}).transform(new Object());
            fail();
        } catch (FunctorException ex) {}
        try {
            TransformerUtils.invokerTransformer("badArgs", null, new Object[] { cString });
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            TransformerUtils.invokerTransformer("badArgs", new Class[] {Object.class}, null);
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            TransformerUtils.invokerTransformer("badArgs", new Class[] {}, new Object[] { cString });
            fail();
        } catch (IllegalArgumentException ex) {}
    }
    
    // stringValueTransformer
    //------------------------------------------------------------------
    
    public void testStringValueTransformer() {
        assertNotNull( "StringValueTransformer should NEVER return a null value.",
           TransformerUtils.stringValueTransformer().transform(null));
        assertEquals( "StringValueTransformer should return \"null\" when given a null argument.", "null",
            TransformerUtils.stringValueTransformer().transform(null));
        assertEquals( "StringValueTransformer should return toString value", "6",
            TransformerUtils.stringValueTransformer().transform(new Integer(6)));
    }
    
    // instantiateFactory
    //------------------------------------------------------------------
    
    public void testInstantiateTransformerNull() {
        try {
            Transformer trans = TransformerUtils.instantiateTransformer(null, new Object[] {"str"});
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            Transformer trans = TransformerUtils.instantiateTransformer(new Class[] {}, new Object[] {"str"});
            fail();
        } catch (IllegalArgumentException ex) {}
        
        Transformer trans = TransformerUtils.instantiateTransformer(new Class[] {Long.class}, new Object[] {null});
        try {
            trans.transform(String.class);
            fail();
        } catch (FunctorException ex) {}
        
        trans = TransformerUtils.instantiateTransformer();
        assertEquals("", trans.transform(String.class));
        
        trans = TransformerUtils.instantiateTransformer(new Class[] {Long.TYPE}, new Object[] {new Long(1000L)});
        assertEquals(new Date(1000L), trans.transform(Date.class));
    }

}