testpropertysorter.java

介绍java核心技术的pio编程方法以及基本概念

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package org.apache.poi.poifs.filesystem;

import junit.framework.TestCase;
import junit.framework.ComparisonFailure;

import java.io.*;
import java.util.*;

import org.apache.poi.poifs.property.DirectoryProperty;
import org.apache.poi.poifs.property.Property;

/**
 * Verify the order of entries <code>DirectoryProperty</code> .
 * <p>
 * In particular it is important to serialize ROOT._VBA_PROJECT_CUR.VBA node.
 * See bug 39234 in bugzilla. Thanks to Bill Seddon for providing the solution.
 * </p>
 *
 * @author Yegor Kozlov
 */
public class TestPropertySorter extends TestCase {

    //the correct order of entries in the test file
    protected static final String[] _entries = {
        "dir", "JML", "UTIL", "Loader", "Sheet1", "Sheet2", "Sheet3",
        "__SRP_0", "__SRP_1", "__SRP_2", "__SRP_3", "__SRP_4", "__SRP_5",
        "ThisWorkbook", "_VBA_PROJECT",
    };

    protected File testFile;

    public void setUp(){
        String home = System.getProperty("HSSF.testdata.path");
        testFile = new File(home + "/39234.xls");
    }

    /**
     * Test sorting of properties in <code>DirectoryProperty</code>
     */
    public void testSortProperties() throws IOException {
        InputStream is = new FileInputStream(testFile);
        POIFSFileSystem fs = new POIFSFileSystem(is);
        is.close();
        Property[] props = getVBAProperties(fs);

        assertEquals(_entries.length, props.length);

        // (1). See that there is a problem with the old case-sensitive property comparartor
        Arrays.sort(props, new CaseSensitivePropertyComparator());
        try {
            for (int i = 0; i < props.length; i++) {
                assertEquals(_entries[i], props[i].getName());
            }
            fail("case-sensitive property comparator returns properties in wrong order");
        } catch (ComparisonFailure e){
            ; // as expected
        }

        // (2) Verify that the fixed proeprty comparator works right
        Arrays.sort(props, new DirectoryProperty.PropertyComparator());
        for (int i = 0; i < props.length; i++) {
            assertEquals(_entries[i], props[i].getName());
        }
    }

    /**
     * Serialize file system and verify that the order of properties is the same as in the original file.
     */
    public void testSerialization() throws IOException {
        InputStream is = new FileInputStream(testFile);
        POIFSFileSystem fs = new POIFSFileSystem(is);
        is.close();

        ByteArrayOutputStream out = new ByteArrayOutputStream();
        fs.writeFilesystem(out);
        out.close();
        is = new ByteArrayInputStream(out.toByteArray());
        fs = new POIFSFileSystem(is);
        is.close();
        Property[] props = getVBAProperties(fs);
        Arrays.sort(props, new DirectoryProperty.PropertyComparator());

        assertEquals(_entries.length, props.length);
        for (int i = 0; i < props.length; i++) {
            assertEquals(_entries[i], props[i].getName());
        }
    }

    /**
     * @return array of properties read from ROOT._VBA_PROJECT_CUR.VBA node
     */
    protected Property[] getVBAProperties(POIFSFileSystem fs) throws IOException {
        String _VBA_PROJECT_CUR = "_VBA_PROJECT_CUR";
        String VBA = "VBA";

        DirectoryEntry root = fs.getRoot();
        DirectoryEntry vba_project = (DirectoryEntry)root.getEntry(_VBA_PROJECT_CUR);

        DirectoryNode vba = (DirectoryNode)vba_project.getEntry(VBA);
        DirectoryProperty  p = (DirectoryProperty)vba.getProperty();

        ArrayList lst = new ArrayList();
        for (Iterator it = p.getChildren(); it.hasNext();){
            Property ch = (Property)it.next();
            lst.add(ch);
        }
        return (Property [])lst.toArray(new Property[ 0 ]);
    }

    /**
     * Old version of case-sensitive PropertyComparator to demonstrate the problem
     */
    private class CaseSensitivePropertyComparator  implements Comparator
    {

        public boolean equals(Object o)
        {
            return this == o;
        }

        public int compare(Object o1, Object o2)
        {
            String name1  = (( Property ) o1).getName();
            String name2  = (( Property ) o2).getName();
            int    result = name1.length() - name2.length();

            if (result == 0)
            {
                result = name1.compareTo(name2);
            }
            return result;
        }
    }

}