Commons Collections example source code file (TestClosureUtils.java)

This example Commons Collections source code file (TestClosureUtils.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

closure, closure, hashmap, hello, hello, illegalargumentexception, illegalargumentexception, mockclosure, mockclosure, object, predicate, stringbuffer, there, util, well

The Commons Collections TestClosureUtils.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.HashMap;
import java.util.Map;

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

import org.apache.commons.collections.functors.NOPClosure;

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

    private static final Object cString = "Hello";

    /**
     * Construct
     */
    public TestClosureUtils(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(TestClosureUtils.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() {
    }
    
    static class MockClosure implements Closure {
        int count = 0;
        
        public void execute(Object object) {
            count++;
        }
    }
    static class MockTransformer implements Transformer {
        int count = 0;
        
        public Object transform(Object object) {
            count++;
            return object;
        }
    }

    // exceptionClosure
    //------------------------------------------------------------------

    public void testExceptionClosure() {
        assertNotNull(ClosureUtils.exceptionClosure());
        assertSame(ClosureUtils.exceptionClosure(), ClosureUtils.exceptionClosure());
        try {
            ClosureUtils.exceptionClosure().execute(null);
        } catch (FunctorException ex) {
            try {
                ClosureUtils.exceptionClosure().execute(cString);
            } catch (FunctorException ex2) {
                return;
            }
        }
        fail();
    }
    
    // nopClosure
    //------------------------------------------------------------------

    public void testNopClosure() {
        StringBuffer buf = new StringBuffer("Hello");
        ClosureUtils.nopClosure().execute(null);
        assertEquals("Hello", buf.toString());
        ClosureUtils.nopClosure().execute("Hello");
        assertEquals("Hello", buf.toString());
    }

    // invokeClosure
    //------------------------------------------------------------------

    public void testInvokeClosure() {
        StringBuffer buf = new StringBuffer("Hello");
        ClosureUtils.invokerClosure("reverse").execute(buf);
        assertEquals("olleH", buf.toString());
        buf = new StringBuffer("Hello");
        ClosureUtils.invokerClosure("setLength", new Class[] {Integer.TYPE}, new Object[] {new Integer(2)}).execute(buf);
        assertEquals("He", buf.toString());
    }

    // forClosure
    //------------------------------------------------------------------

    public void testForClosure() {
        MockClosure cmd = new MockClosure();
        ClosureUtils.forClosure(5, cmd).execute(null);
        assertEquals(5, cmd.count);
        assertSame(NOPClosure.INSTANCE, ClosureUtils.forClosure(0, new MockClosure()));
        assertSame(NOPClosure.INSTANCE, ClosureUtils.forClosure(-1, new MockClosure()));
        assertSame(NOPClosure.INSTANCE, ClosureUtils.forClosure(1, null));
        assertSame(NOPClosure.INSTANCE, ClosureUtils.forClosure(3, null));
        assertSame(cmd, ClosureUtils.forClosure(1, cmd));
    }

    // whileClosure
    //------------------------------------------------------------------

    public void testWhileClosure() {
        MockClosure cmd = new MockClosure();
        ClosureUtils.whileClosure(PredicateUtils.falsePredicate(), cmd).execute(null);
        assertEquals(0, cmd.count);
        
        cmd = new MockClosure();
        ClosureUtils.whileClosure(PredicateUtils.uniquePredicate(), cmd).execute(null);
        assertEquals(1, cmd.count);
        
        try {
            ClosureUtils.whileClosure(null, ClosureUtils.nopClosure());
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            ClosureUtils.whileClosure(PredicateUtils.falsePredicate(), null);
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            ClosureUtils.whileClosure(null, null);
            fail();
        } catch (IllegalArgumentException ex) {}
    }

    // doWhileClosure
    //------------------------------------------------------------------

    public void testDoWhileClosure() {
        MockClosure cmd = new MockClosure();
        ClosureUtils.doWhileClosure(cmd, PredicateUtils.falsePredicate()).execute(null);
        assertEquals(1, cmd.count);
        
        cmd = new MockClosure();
        ClosureUtils.doWhileClosure(cmd, PredicateUtils.uniquePredicate()).execute(null);
        assertEquals(2, cmd.count);
        
        try {
            ClosureUtils.doWhileClosure(null, null);
            fail();
        } catch (IllegalArgumentException ex) {}
    }

    // chainedClosure
    //------------------------------------------------------------------

    public void testChainedClosure() {
        MockClosure a = new MockClosure();
        MockClosure b = new MockClosure();
        ClosureUtils.chainedClosure(a, b).execute(null);
        assertEquals(1, a.count);
        assertEquals(1, b.count);
        
        a = new MockClosure();
        b = new MockClosure();
        ClosureUtils.chainedClosure(new Closure[] {a, b, a}).execute(null);
        assertEquals(2, a.count);
        assertEquals(1, b.count);
        
        a = new MockClosure();
        b = new MockClosure();
        Collection coll = new ArrayList();
        coll.add(b);
        coll.add(a);
        coll.add(b);
        ClosureUtils.chainedClosure(coll).execute(null);
        assertEquals(1, a.count);
        assertEquals(2, b.count);
        
        assertSame(NOPClosure.INSTANCE, ClosureUtils.chainedClosure(new Closure[0]));
        assertSame(NOPClosure.INSTANCE, ClosureUtils.chainedClosure(Collections.EMPTY_LIST));
        
        try {
            ClosureUtils.chainedClosure(null, null);
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            ClosureUtils.chainedClosure((Closure[]) null);
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            ClosureUtils.chainedClosure((Collection) null);
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            ClosureUtils.chainedClosure(new Closure[] {null, null});
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            coll = new ArrayList();
            coll.add(null);
            coll.add(null);
            ClosureUtils.chainedClosure(coll);
            fail();
        } catch (IllegalArgumentException ex) {}
    }
    
    // ifClosure
    //------------------------------------------------------------------

    public void testIfClosure() {
        MockClosure a = new MockClosure();
        MockClosure b = null;
        ClosureUtils.ifClosure(PredicateUtils.truePredicate(), a).execute(null);
        assertEquals(1, a.count);

        a = new MockClosure();
        ClosureUtils.ifClosure(PredicateUtils.falsePredicate(), a).execute(null);
        assertEquals(0, a.count);

        a = new MockClosure();
        b = new MockClosure();
        ClosureUtils.ifClosure(PredicateUtils.truePredicate(), a, b).execute(null);
        assertEquals(1, a.count);
        assertEquals(0, b.count);
        
        a = new MockClosure();
        b = new MockClosure();
        ClosureUtils.ifClosure(PredicateUtils.falsePredicate(), a, b).execute(null);
        assertEquals(0, a.count);
        assertEquals(1, b.count);
    }        

    // switchClosure
    //------------------------------------------------------------------

    public void testSwitchClosure() {
        MockClosure a = new MockClosure();
        MockClosure b = new MockClosure();
        ClosureUtils.switchClosure(
            new Predicate[] {PredicateUtils.equalPredicate("HELLO"), PredicateUtils.equalPredicate("THERE")}, 
            new Closure[] {a, b}).execute("WELL");
        assertEquals(0, a.count);
        assertEquals(0, b.count);
        
        a = new MockClosure();
        b = new MockClosure();
        ClosureUtils.switchClosure(
            new Predicate[] {PredicateUtils.equalPredicate("HELLO"), PredicateUtils.equalPredicate("THERE")}, 
            new Closure[] {a, b}).execute("HELLO");
        assertEquals(1, a.count);
        assertEquals(0, b.count);
        
        a = new MockClosure();
        b = new MockClosure();
        MockClosure c = new MockClosure();
        ClosureUtils.switchClosure(
            new Predicate[] {PredicateUtils.equalPredicate("HELLO"), PredicateUtils.equalPredicate("THERE")}, 
            new Closure[] {a, b}, c).execute("WELL");
        assertEquals(0, a.count);
        assertEquals(0, b.count);
        assertEquals(1, c.count);
        
        a = new MockClosure();
        b = new MockClosure();
        Map map = new HashMap();
        map.put(PredicateUtils.equalPredicate("HELLO"), a);
        map.put(PredicateUtils.equalPredicate("THERE"), b);
        ClosureUtils.switchClosure(map).execute(null);
        assertEquals(0, a.count);
        assertEquals(0, b.count);

        a = new MockClosure();
        b = new MockClosure();
        map = new HashMap();
        map.put(PredicateUtils.equalPredicate("HELLO"), a);
        map.put(PredicateUtils.equalPredicate("THERE"), b);
        ClosureUtils.switchClosure(map).execute("THERE");
        assertEquals(0, a.count);
        assertEquals(1, b.count);

        a = new MockClosure();
        b = new MockClosure();
        c = new MockClosure();
        map = new HashMap();
        map.put(PredicateUtils.equalPredicate("HELLO"), a);
        map.put(PredicateUtils.equalPredicate("THERE"), b);
        map.put(null, c);
        ClosureUtils.switchClosure(map).execute("WELL");
        assertEquals(0, a.count);
        assertEquals(0, b.count);
        assertEquals(1, c.count);
        
        assertSame(NOPClosure.INSTANCE, ClosureUtils.switchClosure(new Predicate[0], new Closure[0]));
        assertSame(NOPClosure.INSTANCE, ClosureUtils.switchClosure(new HashMap()));
        map = new HashMap();
        map.put(null, null);
        assertSame(NOPClosure.INSTANCE, ClosureUtils.switchClosure(map));

        try {
            ClosureUtils.switchClosure(null, null);
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            ClosureUtils.switchClosure((Predicate[]) null, (Closure[]) null);
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            ClosureUtils.switchClosure((Map) null);
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            ClosureUtils.switchClosure(new Predicate[2], new Closure[2]);
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            ClosureUtils.switchClosure(
                    new Predicate[] {PredicateUtils.truePredicate()},
                    new Closure[] {a,b});
            fail();
        } catch (IllegalArgumentException ex) {}
    }
    
    // switchMapClosure
    //------------------------------------------------------------------

    public void testSwitchMapClosure() {
        MockClosure a = new MockClosure();
        MockClosure b = new MockClosure();
        Map map = new HashMap();
        map.put("HELLO", a);
        map.put("THERE", b);
        ClosureUtils.switchMapClosure(map).execute(null);
        assertEquals(0, a.count);
        assertEquals(0, b.count);

        a = new MockClosure();
        b = new MockClosure();
        map = new HashMap();
        map.put("HELLO", a);
        map.put("THERE", b);
        ClosureUtils.switchMapClosure(map).execute("THERE");
        assertEquals(0, a.count);
        assertEquals(1, b.count);

        a = new MockClosure();
        b = new MockClosure();
        MockClosure c = new MockClosure();
        map = new HashMap();
        map.put("HELLO", a);
        map.put("THERE", b);
        map.put(null, c);
        ClosureUtils.switchMapClosure(map).execute("WELL");
        assertEquals(0, a.count);
        assertEquals(0, b.count);
        assertEquals(1, c.count);

        assertSame(NOPClosure.INSTANCE, ClosureUtils.switchMapClosure(new HashMap()));
        
        try {
            ClosureUtils.switchMapClosure(null);
            fail();
        } catch (IllegalArgumentException ex) {}
    }
    
    // asClosure
    //------------------------------------------------------------------

    public void testTransformerClosure() {
        MockTransformer mock = new MockTransformer();
        Closure closure = ClosureUtils.asClosure(mock);
        closure.execute(null);
        assertEquals(1, mock.count);
        closure.execute(null);
        assertEquals(2, mock.count);
        
        assertSame(ClosureUtils.nopClosure(), ClosureUtils.asClosure(null));
    }
    
}