Java example source code file (SourceTreeScannerTest.java)

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

Learn more about this Java project at its project page.

Java - Java tags/keywords

field, file, hashset, illegalaccessexception, javafileobject, jctree, list, object, override, reflection, scantester, set, size, sourcetreescannertest, util, void

The SourceTreeScannerTest.java Java example source code

/*
 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */


/**
 * Utility and test program to check javac's internal TreeScanner class.
 * The program can be run standalone, or as a jtreg test.  For info on
 * command line args, run program with no args.
 *
 * <p>
 * jtreg: Note that by using the -r switch in the test description below, this test
 * will process all java files in the langtools/test directory, thus implicitly
 * covering any new language features that may be tested in this test suite.
 */

/*
 * @test
 * @bug 6923080
 * @summary TreeScanner.visitNewClass should scan tree.typeargs
 * @build AbstractTreeScannerTest SourceTreeScannerTest
 * @run main SourceTreeScannerTest -q -r .
 */

import java.io.*;
import java.lang.reflect.*;
import java.util.*;
import javax.tools.*;

import com.sun.source.tree.Tree;
import com.sun.source.util.TreeScanner;
import com.sun.tools.javac.tree.JCTree;
import com.sun.tools.javac.tree.JCTree.JCCompilationUnit;
import com.sun.tools.javac.tree.JCTree.TypeBoundKind;
import com.sun.tools.javac.util.List;

public class SourceTreeScannerTest extends AbstractTreeScannerTest {
    /**
     * Main entry point.
     * If test.src is set, program runs in jtreg mode, and will throw an Error
     * if any errors arise, otherwise System.exit will be used. In jtreg mode,
     * the default base directory for file args is the value of ${test.src}.
     * In jtreg mode, the -r option can be given to change the default base
     * directory to the root test directory.
     */
    public static void main(String... args) {
        String testSrc = System.getProperty("test.src");
        File baseDir = (testSrc == null) ? null : new File(testSrc);
        boolean ok = new SourceTreeScannerTest().run(baseDir, args);
        if (!ok) {
            if (testSrc != null)  // jtreg mode
                throw new Error("failed");
            else
                System.exit(1);
        }
    }

    int test(JCCompilationUnit tree) {
        return new ScanTester().test(tree);
    }

    /**
     * Main class for testing operation of tree scanner.
     * The set of nodes found by the scanner are compared
     * against the set of nodes found by reflection.
     */
    private class ScanTester extends TreeScanner<Void,Void> {
        /** Main entry method for the class. */
        int test(JCCompilationUnit tree) {
            sourcefile = tree.sourcefile;
            found = new HashSet<Tree>();
            scan(tree, null);
            expect = new HashSet<Tree>();
            reflectiveScan(tree);

            if (found.equals(expect)) {
                //System.err.println(sourcefile.getName() + ": trees compared OK");
                return found.size();
            }

            error(sourcefile.getName() + ": differences found");

            if (found.size() != expect.size())
                error("Size mismatch; found: " + found.size() + ", expected: " + expect.size());

            Set<Tree> missing = new HashSet();
            missing.addAll(expect);
            missing.removeAll(found);
            for (Tree t: missing)
                error(sourcefile, t, "missing");

            Set<Tree> excess = new HashSet();
            excess.addAll(found);
            excess.removeAll(expect);
            for (Tree t: excess)
                error(sourcefile, t, "unexpected");

            return 0;
        }

        /** Record all tree nodes found by scanner. */
        @Override
        public Void scan(Tree tree, Void ignore) {
            if (tree == null)
                return null;
            //System.err.println("FOUND: " + tree.getKind() + " " + trim(tree, 64));
            found.add(tree);
            return super.scan(tree, ignore);
        }

        /** record all tree nodes found by reflection. */
        public void reflectiveScan(Object o) {
            if (o == null)
                return;
            if (o instanceof JCTree) {
                JCTree tree = (JCTree) o;
                //System.err.println("EXPECT: " + tree.getKind() + " " + trim(tree, 64));
                expect.add(tree);
                for (Field f: getFields(tree)) {
                    if (TypeBoundKind.class.isAssignableFrom(f.getType())) {
                        // not part of public API
                        continue;
                    }
                    try {
                        //System.err.println("FIELD: " + f.getName());
                        reflectiveScan(f.get(tree));
                    } catch (IllegalAccessException e) {
                        error(e.toString());
                    }
                }
            } else if (o instanceof List) {
                List<?> list = (List) o;
                for (Object item: list)
                    reflectiveScan(item);
            } else
                error("unexpected item: " + o);
        }

        JavaFileObject sourcefile;
        Set<Tree> found;
        Set<Tree> expect;
    }
}