Java example source code file (SJavac.java)

This example Java source code file (SJavac.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.

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Java - Java tags/keywords

aaaaa, aint, exception, expected, filevisitresult, ioexception, map, net, network, override, path, runnable, set, sjavac, string, util

The SJavac.java Java example source code

/*
 * Copyright (c) 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.
 */

import java.util.*;
import java.io.*;
import java.net.*;
import java.nio.file.*;
import java.nio.file.attribute.*;
import java.nio.charset.*;

import com.sun.tools.sjavac.Main;

public
class SJavac {

    public static void main(String... args) throws Exception {
        SJavac s = new SJavac();
        s.test();
    }

    FileSystem defaultfs = FileSystems.getDefault();

    // Where to put generated sources that will
    // test aspects of sjavac, ie JTWork/scratch/gensrc
    Path gensrc;
    // More gensrc dirs are used to test merging of serveral source roots.
    Path gensrc2;
    Path gensrc3;

    // Where to put compiled classes.
    Path bin;
    // Where to put c-header files.
    Path headers;

    // The sjavac compiler.
    Main main = new Main();

    // Remember the previous bin and headers state here.
    Map<String,Long> previous_bin_state;
    Map<String,Long> previous_headers_state;

    public void test() throws Exception {
        gensrc = defaultfs.getPath("gensrc");
        gensrc2 = defaultfs.getPath("gensrc2");
        gensrc3 = defaultfs.getPath("gensrc3");
        bin = defaultfs.getPath("bin");
        headers = defaultfs.getPath("headers");

        Files.createDirectory(gensrc);
        Files.createDirectory(gensrc2);
        Files.createDirectory(gensrc3);
        Files.createDirectory(bin);
        Files.createDirectory(headers);

        initialCompile();
        incrementalCompileNoChanges();
        incrementalCompileDroppingClasses();
        incrementalCompileWithChange();
        incrementalCompileDropAllNatives();
        incrementalCompileAddNative();
        incrementalCompileChangeNative();
        compileWithOverrideSource();
        compileWithInvisibleSources();
        compileCircularSources();
        compileExcludingDependency();

        delete(gensrc);
        delete(gensrc2);
        delete(gensrc3);
        delete(bin);
        delete(headers);
    }

    void initialCompile() throws Exception {
        System.out.println("\nInitial compile of gensrc.");
        System.out.println("----------------------------");
        populate(gensrc,
            "alfa/AINT.java",
            "package alfa; public interface AINT { void aint(); }",

            "alfa/A.java",
            "package alfa; public class A implements AINT { "+
                 "public final static int DEFINITION = 17; public void aint() { } }",

            "alfa/AA.java",
            "package alfa;"+
            "// A package private class, not contributing to the public api.\n"+
            "class AA {"+
            "   // A properly nested static inner class.\n"+
            "    static class AAA { }\n"+
            "    // A properly nested inner class.\n"+
            "    class AAAA { }\n"+
            "    Runnable foo() {\n"+
            "        // A proper anonymous class.\n"+
            "        return new Runnable() { public void run() { } };\n"+
            "    }\n"+
            "    AAA aaa;\n"+
            "    AAAA aaaa;\n"+
            "    AAAAA aaaaa;\n"+
            "}\n"+
            "class AAAAA {\n"+
            "    // A bad auxiliary class, but no one is referencing it\n"+
            "    // from outside of this source file, therefore it is ok.\n"+
            "}\n",

            "beta/BINT.java",
            "package beta;public interface BINT { void foo(); }",

            "beta/B.java",
            "package beta; import alfa.A; public class B {"+
            "private int b() { return A.DEFINITION; } native void foo(); }");

        compile("gensrc", "-d", "bin", "-h", "headers", "-j", "1",
                "--server:portfile=testserver,background=false", "--log=debug");
        previous_bin_state = collectState(bin);
        previous_headers_state = collectState(headers);
    }

    void incrementalCompileNoChanges() throws Exception {
        System.out.println("\nTesting that no change in sources implies no change in binaries.");
        System.out.println("------------------------------------------------------------------");
        compile("gensrc", "-d", "bin", "-h", "headers", "-j", "1",
                "--server:portfile=testserver,background=false", "--log=debug");
        Map<String,Long> new_bin_state = collectState(bin);
        verifyEqual(new_bin_state, previous_bin_state);
        Map<String,Long> new_headers_state = collectState(headers);
        verifyEqual(previous_headers_state, new_headers_state);
    }

    void incrementalCompileDroppingClasses() throws Exception {
        System.out.println("\nTesting that deleting AA.java deletes all");
        System.out.println("generated inner class as well as AA.class");
        System.out.println("-----------------------------------------");
        removeFrom(gensrc, "alfa/AA.java");
        compile("gensrc", "-d", "bin", "-h", "headers", "-j", "1",
                "--server:portfile=testserver,background=false", "--log=debug");
        Map<String,Long> new_bin_state = collectState(bin);
        verifyThatFilesHaveBeenRemoved(previous_bin_state, new_bin_state,
                                       "bin/alfa/AA$1.class",
                                       "bin/alfa/AA$AAAA.class",
                                       "bin/alfa/AA$AAA.class",
                                       "bin/alfa/AAAAA.class",
                                       "bin/alfa/AA.class");

        previous_bin_state = new_bin_state;
        Map<String,Long> new_headers_state = collectState(headers);
        verifyEqual(previous_headers_state, new_headers_state);
    }

    void incrementalCompileWithChange() throws Exception {
        System.out.println("\nNow update the A.java file with a new timestamps and");
        System.out.println("new final static definition. This should trigger a recompile,");
        System.out.println("not only of alfa, but also beta.");
        System.out.println("But check that the generated native header was not updated!");
        System.out.println("Since we did not modify the native api of B.");
        System.out.println("-------------------------------------------------------------");

        populate(gensrc,"alfa/A.java",
                       "package alfa; public class A implements AINT { "+
                 "public final static int DEFINITION = 18; public void aint() { } private void foo() { } }");

        compile("gensrc", "-d", "bin", "-h", "headers", "-j", "1",
                "--server:portfile=testserver,background=false", "--log=debug");
        Map<String,Long> new_bin_state = collectState(bin);

        verifyNewerFiles(previous_bin_state, new_bin_state,
                         "bin/alfa/A.class",
                         "bin/alfa/AINT.class",
                         "bin/beta/B.class",
                         "bin/beta/BINT.class",
                         "bin/javac_state");
        previous_bin_state = new_bin_state;

        Map<String,Long> new_headers_state = collectState(headers);
        verifyEqual(new_headers_state, previous_headers_state);
    }

    void incrementalCompileDropAllNatives() throws Exception {
        System.out.println("\nNow update the B.java file with one less native method,");
        System.out.println("ie it has no longer any methods!");
        System.out.println("Verify that beta_B.h is removed!");
        System.out.println("---------------------------------------------------------");

        populate(gensrc,"beta/B.java",
                       "package beta; import alfa.A; public class B {"+
                       "private int b() { return A.DEFINITION; } }");

        compile("gensrc", "-d", "bin", "-h", "headers", "-j", "1",
                "--server:portfile=testserver,background=false", "--log=debug");
        Map<String,Long> new_bin_state = collectState(bin);
        verifyNewerFiles(previous_bin_state, new_bin_state,
                         "bin/beta/B.class",
                         "bin/beta/BINT.class",
                         "bin/javac_state");
        previous_bin_state = new_bin_state;

        Map<String,Long> new_headers_state = collectState(headers);
        verifyThatFilesHaveBeenRemoved(previous_headers_state, new_headers_state,
                                       "headers/beta_B.h");
        previous_headers_state = new_headers_state;
    }

    void incrementalCompileAddNative() throws Exception {
        System.out.println("\nNow update the B.java file with a final static annotated with @Native.");
        System.out.println("Verify that beta_B.h is added again!");
        System.out.println("------------------------------------------------------------------------");

        populate(gensrc,"beta/B.java",
                       "package beta; import alfa.A; public class B {"+
                       "private int b() { return A.DEFINITION; } "+
                 "@java.lang.annotation.Native final static int alfa = 42; }");

        compile("gensrc", "-d", "bin", "-h", "headers", "-j", "1",
                "--server:portfile=testserver,background=false", "--log=debug");
        Map<String,Long> new_bin_state = collectState(bin);
        verifyNewerFiles(previous_bin_state, new_bin_state,
                         "bin/beta/B.class",
                         "bin/beta/BINT.class",
                         "bin/javac_state");
        previous_bin_state = new_bin_state;

        Map<String,Long> new_headers_state = collectState(headers);
        verifyThatFilesHaveBeenAdded(previous_headers_state, new_headers_state,
                                     "headers/beta_B.h");
        previous_headers_state = new_headers_state;
    }

    void incrementalCompileChangeNative() throws Exception {
        System.out.println("\nNow update the B.java file with a new value for the final static"+
                           " annotated with @Native.");
        System.out.println("Verify that beta_B.h is rewritten again!");
        System.out.println("-------------------------------------------------------------------");

        populate(gensrc,"beta/B.java",
                       "package beta; import alfa.A; public class B {"+
                       "private int b() { return A.DEFINITION; } "+
                 "@java.lang.annotation.Native final static int alfa = 43; }");

        compile("gensrc", "-d", "bin", "-h", "headers", "-j", "1",
                "--server:portfile=testserver,background=false", "--log=debug");
        Map<String,Long> new_bin_state = collectState(bin);
        verifyNewerFiles(previous_bin_state, new_bin_state,
                         "bin/beta/B.class",
                         "bin/beta/BINT.class",
                         "bin/javac_state");
        previous_bin_state = new_bin_state;

        Map<String,Long> new_headers_state = collectState(headers);
        verifyNewerFiles(previous_headers_state, new_headers_state,
                         "headers/beta_B.h");
        previous_headers_state = new_headers_state;
    }

    void compileWithOverrideSource() throws Exception {
        System.out.println("\nNow verify that we can override sources to be compiled.");
        System.out.println("Compile gensrc and gensrc2. However do not compile broken beta.B in gensrc,");
        System.out.println("only compile ok beta.B in gensrc2.");
        System.out.println("---------------------------------------------------------------------------");

        delete(gensrc);
        delete(gensrc2);
        delete(bin);
        previous_bin_state = collectState(bin);

        populate(gensrc,"alfa/A.java",
                 "package alfa; import beta.B; import gamma.C; public class A { B b; C c; }",
                 "beta/B.java",
                 "package beta; public class B { broken",
                 "gamma/C.java",
                 "package gamma; public class C { }");

        populate(gensrc2,
                 "beta/B.java",
                 "package beta; public class B { }");

        compile("-x", "beta", "gensrc", "gensrc2", "-d", "bin", "-h", "headers", "-j", "1",
                "--server:portfile=testserver,background=false");
        Map<String,Long> new_bin_state = collectState(bin);
        verifyThatFilesHaveBeenAdded(previous_bin_state, new_bin_state,
                                     "bin/alfa/A.class",
                                     "bin/beta/B.class",
                                     "bin/gamma/C.class",
                                     "bin/javac_state");

        System.out.println("----- Compile with exluded beta went well!");
        delete(bin);
        compileExpectFailure("gensrc", "gensrc2", "-d", "bin", "-h", "headers", "-j", "1",
                             "--server:portfile=testserver,background=false");

        System.out.println("----- Compile without exluded beta failed, as expected! Good!");
        delete(bin);
    }

    void compileWithInvisibleSources() throws Exception {
        System.out.println("\nNow verify that we can make sources invisible to linking (sourcepath).");
        System.out.println("Compile gensrc and link against gensrc2 and gensrc3, however");
        System.out.println("gensrc2 contains broken code in beta.B, thus we must exclude that package");
        System.out.println("fortunately gensrc3 contains a proper beta.B.");
        System.out.println("------------------------------------------------------------------------");

        // Start with a fresh gensrcs and bin.
        delete(gensrc);
        delete(gensrc2);
        delete(gensrc3);
        delete(bin);
        previous_bin_state = collectState(bin);

        populate(gensrc,"alfa/A.java",
                 "package alfa; import beta.B; import gamma.C; public class A { B b; C c; }");
        populate(gensrc2,"beta/B.java",
                 "package beta; public class B { broken",
                 "gamma/C.java",
                 "package gamma; public class C { }");
        populate(gensrc3, "beta/B.java",
                 "package beta; public class B { }");

        compile("gensrc", "-x", "beta", "-sourcepath", "gensrc2",
                "-sourcepath", "gensrc3", "-d", "bin", "-h", "headers", "-j", "1",
                "--server:portfile=testserver,background=false");

        System.out.println("The first compile went well!");
        Map<String,Long> new_bin_state = collectState(bin);
        verifyThatFilesHaveBeenAdded(previous_bin_state, new_bin_state,
                                     "bin/alfa/A.class",
                                     "bin/javac_state");

        System.out.println("----- Compile with exluded beta went well!");
        delete(bin);
        compileExpectFailure("gensrc", "-sourcepath", "gensrc2", "-sourcepath", "gensrc3",
                             "-d", "bin", "-h", "headers", "-j", "1",
                             "--server:portfile=testserver,background=false");

        System.out.println("----- Compile without exluded beta failed, as expected! Good!");
        delete(bin);
    }

    void compileCircularSources() throws Exception {
        System.out.println("\nNow verify that circular sources split on multiple cores can be compiled.");
        System.out.println("---------------------------------------------------------------------------");

        // Start with a fresh gensrcs and bin.
        delete(gensrc);
        delete(gensrc2);
        delete(gensrc3);
        delete(bin);
        previous_bin_state = collectState(bin);

        populate(gensrc,"alfa/A.java",
                 "package alfa; public class A { beta.B b; }",
                 "beta/B.java",
                 "package beta; public class B { gamma.C c; }",
                 "gamma/C.java",
                 "package gamma; public class C { alfa.A a; }");

        compile("gensrc", "-d", "bin", "-h", "headers", "-j", "3",
                "--server:portfile=testserver,background=false","--log=debug");
        Map<String,Long> new_bin_state = collectState(bin);
        verifyThatFilesHaveBeenAdded(previous_bin_state, new_bin_state,
                                     "bin/alfa/A.class",
                                     "bin/beta/B.class",
                                     "bin/gamma/C.class",
                                     "bin/javac_state");
        delete(bin);
    }

    /**
     * Tests compiling class A that depends on class B without compiling class B
     * @throws Exception If test fails
     */
    void compileExcludingDependency() throws Exception {
        System.out.println("\nVerify that excluding classes from compilation but not from linking works.");
        System.out.println("---------------------------------------------------------------------------");

        delete(gensrc);
        delete(bin);
        previous_bin_state = collectState(bin);

        populate(gensrc,
                 "alfa/A.java",
                 "package alfa; public class A { beta.B b; }",
                 "beta/B.java",
                 "package beta; public class B { }");

        compile("-x", "beta", "-src", "gensrc", "-x", "alfa", "-sourcepath", "gensrc",
                "-d", "bin", "--server:portfile=testserver,background=false");

        Map<String,Long> new_bin_state = collectState(bin);
        verifyThatFilesHaveBeenAdded(previous_bin_state, new_bin_state,
                                     "bin/alfa/A.class",
                                     "bin/javac_state");
    }

    void removeFrom(Path dir, String... args) throws IOException {
        for (String filename : args) {
            Path p = dir.resolve(filename);
            Files.delete(p);
        }
    }

    void populate(Path src, String... args) throws IOException {
        if (!Files.exists(src)) {
            Files.createDirectory(src);
        }
        String[] a = args;
        for (int i = 0; i<a.length; i+=2) {
            String filename = a[i];
            String content = a[i+1];
            Path p = src.resolve(filename);
            Files.createDirectories(p.getParent());
            PrintWriter out = new PrintWriter(Files.newBufferedWriter(p,
                                                                      Charset.defaultCharset()));
            out.println(content);
            out.close();
        }
    }

    void delete(final Path root) throws IOException {
        if (!Files.exists(root)) return;
        Files.walkFileTree(root, new SimpleFileVisitor<Path>() {
                 @Override
                 public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException
                 {
                     Files.delete(file);
                     return FileVisitResult.CONTINUE;
                 }

                 @Override
                 public FileVisitResult postVisitDirectory(Path dir, IOException e) throws IOException
                 {
                     if (e == null) {
                         if (!dir.equals(root)) Files.delete(dir);
                         return FileVisitResult.CONTINUE;
                     } else {
                         // directory iteration failed
                         throw e;
                     }
                 }
            });
    }

    void compile(String... args) throws Exception {
        int rc = main.go(args, System.out, System.err);
        if (rc != 0) throw new Exception("Error during compile!");

        // Wait a second, to get around the (temporary) problem with
        // second resolution in the Java file api. But do not do this
        // on windows where the timestamps work.
        long in_a_sec = System.currentTimeMillis()+1000;
        while (in_a_sec > System.currentTimeMillis()) {
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
            }
        }
    }

    void compileExpectFailure(String... args) throws Exception {
        int rc = main.go(args, System.out, System.err);
        if (rc == 0) throw new Exception("Expected error during compile! Did not fail!");
    }

    Map<String,Long> collectState(Path dir) throws IOException
    {
        final Map<String,Long> files = new HashMap<>();
        Files.walkFileTree(dir, new SimpleFileVisitor<Path>() {
                 @Override
                 public FileVisitResult visitFile(Path file, BasicFileAttributes attrs)
                   throws IOException
                 {
                     files.put(file.toString(),new Long(Files.getLastModifiedTime(file).toMillis()));
                     return FileVisitResult.CONTINUE;
                 }
            });
        return files;
    }

    void verifyThatFilesHaveBeenRemoved(Map<String,Long> from,
                                        Map<String,Long> to,
                                        String... args) throws Exception {

        Set<String> froms = from.keySet();
        Set<String> tos = to.keySet();

        if (froms.equals(tos)) {
            throw new Exception("Expected new state to have fewer files than previous state!");
        }

        for (String t : tos) {
            if (!froms.contains(t)) {
                throw new Exception("Expected "+t+" to exist in previous state!");
            }
        }

        for (String f : args) {
            f = f.replace("/", File.separator);
            if (!froms.contains(f)) {
                throw new Exception("Expected "+f+" to exist in previous state!");
            }
            if (tos.contains(f)) {
                throw new Exception("Expected "+f+" to have been removed from the new state!");
            }
        }

        if (froms.size() - args.length != tos.size()) {
            throw new Exception("There are more removed files than the expected list!");
        }
    }

    void verifyThatFilesHaveBeenAdded(Map<String,Long> from,
                                      Map<String,Long> to,
                                      String... args) throws Exception {

        Set<String> froms = from.keySet();
        Set<String> tos = to.keySet();

        if (froms.equals(tos)) {
            throw new Exception("Expected new state to have more files than previous state!");
        }

        for (String t : froms) {
            if (!tos.contains(t)) {
                throw new Exception("Expected "+t+" to exist in new state!");
            }
        }

        for (String f : args) {
            f = f.replace("/", File.separator);
            if (!tos.contains(f)) {
                throw new Exception("Expected "+f+" to have been added to new state!");
            }
            if (froms.contains(f)) {
                throw new Exception("Expected "+f+" to not exist in previous state!");
            }
        }

        if (froms.size() + args.length != tos.size()) {
            throw new Exception("There are more added files than the expected list!");
        }
    }

    void verifyNewerFiles(Map<String,Long> from,
                          Map<String,Long> to,
                          String... args) throws Exception {
        if (!from.keySet().equals(to.keySet())) {
            throw new Exception("Expected the set of files to be identical!");
        }
        Set<String> files = new HashSet();
        for (String s : args) {
            files.add(s.replace("/", File.separator));
        }
        for (String fn : from.keySet()) {
            long f = from.get(fn);
            long t = to.get(fn);
            if (files.contains(fn)) {
                if (t <= f) {
                    throw new Exception("Expected "+fn+" to have a more recent timestamp!");
                }
            } else {
                if (t != f) {
                    throw new Exception("Expected "+fn+" to have the same timestamp!");
                }
            }
        }
    }

    String print(Map<String,Long> m) {
        StringBuilder b = new StringBuilder();
        Set<String> keys = m.keySet();
        for (String k : keys) {
            b.append(k+" "+m.get(k)+"\n");
        }
        return b.toString();
    }

    void verifyEqual(Map<String,Long> from, Map to) throws Exception {
        if (!from.equals(to)) {
            System.out.println("FROM---"+print(from));
            System.out.println("TO-----"+print(to));
            throw new Exception("The dir should not differ! But it does!");
        }
    }
}