[BAEL-9555] - Created a core-java-modules folder
This commit is contained in:
amit2103
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package com.baeldung.javac;
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import org.junit.Test;
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import static org.junit.Assert.assertEquals;
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public class SampleJavacPluginIntegrationTest {
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private static final String CLASS_TEMPLATE =
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"package com.baeldung.javac;\n" +
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"\n" +
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"public class Test {\n" +
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" public static %1$s service(@Positive %1$s i) {\n" +
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" return i;\n" +
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" }\n" +
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"}\n" +
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"";
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private TestCompiler compiler = new TestCompiler();
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private TestRunner runner = new TestRunner();
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@Test(expected = IllegalArgumentException.class)
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public void givenInt_whenNegative_thenThrowsException() throws Throwable {
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compileAndRun(double.class,-1);
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}
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@Test(expected = IllegalArgumentException.class)
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public void givenInt_whenZero_thenThrowsException() throws Throwable {
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compileAndRun(int.class,0);
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}
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@Test
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public void givenInt_whenPositive_thenSuccess() throws Throwable {
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assertEquals(1, compileAndRun(int.class, 1));
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}
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private Object compileAndRun(Class<?> argumentType, Object argument) throws Throwable {
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String qualifiedClassName = "com.baeldung.javac.Test";
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byte[] byteCode = compiler.compile(qualifiedClassName, String.format(CLASS_TEMPLATE, argumentType.getName()));
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return runner.run(byteCode, qualifiedClassName, "service", new Class[] {argumentType}, argument);
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}
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}
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@@ -0,0 +1,26 @@
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package com.baeldung.javac;
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import javax.tools.SimpleJavaFileObject;
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import java.io.ByteArrayOutputStream;
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import java.io.IOException;
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import java.io.OutputStream;
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import java.net.URI;
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/** Holds compiled byte code in a byte array */
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public class SimpleClassFile extends SimpleJavaFileObject {
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private ByteArrayOutputStream out;
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public SimpleClassFile(URI uri) {
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super(uri, Kind.CLASS);
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}
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@Override
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public OutputStream openOutputStream() throws IOException {
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return out = new ByteArrayOutputStream();
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}
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public byte[] getCompiledBinaries() {
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return out.toByteArray();
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}
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}
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@@ -0,0 +1,34 @@
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package com.baeldung.javac;
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import javax.tools.*;
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import java.net.URI;
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import java.util.ArrayList;
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import java.util.List;
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/** Adapts {@link SimpleClassFile} to the {@link JavaCompiler} */
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public class SimpleFileManager extends ForwardingJavaFileManager<StandardJavaFileManager> {
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private final List<SimpleClassFile> compiled = new ArrayList<>();
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public SimpleFileManager(StandardJavaFileManager delegate) {
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super(delegate);
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}
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@Override
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public JavaFileObject getJavaFileForOutput(Location location,
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String className,
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JavaFileObject.Kind kind,
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FileObject sibling)
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{
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SimpleClassFile result = new SimpleClassFile(URI.create("string://" + className));
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compiled.add(result);
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return result;
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}
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/**
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* @return compiled binaries processed by the current class
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*/
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public List<SimpleClassFile> getCompiled() {
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return compiled;
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}
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}
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@@ -0,0 +1,23 @@
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package com.baeldung.javac;
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import javax.tools.SimpleJavaFileObject;
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import java.net.URI;
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/** Exposes given test source to the compiler. */
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public class SimpleSourceFile extends SimpleJavaFileObject {
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private final String content;
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public SimpleSourceFile(String qualifiedClassName, String testSource) {
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super(URI.create(String.format("file://%s%s",
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qualifiedClassName.replaceAll("\\.", "/"),
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Kind.SOURCE.extension)),
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Kind.SOURCE);
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content = testSource;
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}
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@Override
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public CharSequence getCharContent(boolean ignoreEncodingErrors) {
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return content;
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}
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}
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@@ -0,0 +1,35 @@
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package com.baeldung.javac;
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import javax.tools.JavaCompiler;
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import javax.tools.ToolProvider;
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import java.io.StringWriter;
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import java.util.ArrayList;
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import java.util.List;
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import static java.util.Arrays.asList;
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import static java.util.Collections.singletonList;
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public class TestCompiler {
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public byte[] compile(String qualifiedClassName, String testSource) {
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StringWriter output = new StringWriter();
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JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
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SimpleFileManager fileManager = new SimpleFileManager(compiler.getStandardFileManager(
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null,
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null,
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null
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));
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List<SimpleSourceFile> compilationUnits = singletonList(new SimpleSourceFile(qualifiedClassName, testSource));
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List<String> arguments = new ArrayList<>();
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arguments.addAll(asList("-classpath", System.getProperty("java.class.path"),
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"-Xplugin:" + SampleJavacPlugin.NAME));
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JavaCompiler.CompilationTask task = compiler.getTask(output,
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fileManager,
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null,
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arguments,
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null,
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compilationUnits);
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task.call();
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return fileManager.getCompiled().iterator().next().getCompiledBinaries();
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}
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}
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@@ -0,0 +1,41 @@
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package com.baeldung.javac;
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import java.lang.reflect.InvocationTargetException;
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import java.lang.reflect.Method;
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public class TestRunner {
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public Object run(byte[] byteCode,
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String qualifiedClassName,
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String methodName,
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Class<?>[] argumentTypes,
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Object... args)
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throws Throwable
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{
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ClassLoader classLoader = new ClassLoader() {
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@Override
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protected Class<?> findClass(String name) throws ClassNotFoundException {
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return defineClass(name, byteCode, 0, byteCode.length);
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}
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};
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Class<?> clazz;
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try {
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clazz = classLoader.loadClass(qualifiedClassName);
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} catch (ClassNotFoundException e) {
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throw new RuntimeException("Can't load compiled test class", e);
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}
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Method method;
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try {
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method = clazz.getMethod(methodName, argumentTypes);
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} catch (NoSuchMethodException e) {
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throw new RuntimeException("Can't find the 'main()' method in the compiled test class", e);
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}
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try {
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return method.invoke(null, args);
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} catch (InvocationTargetException e) {
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throw e.getCause();
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}
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}
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}
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@@ -0,0 +1,33 @@
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package com.baeldung.unsafe;
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import sun.misc.Unsafe;
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import java.lang.reflect.Field;
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class CASCounter {
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private final Unsafe unsafe;
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private volatile long counter = 0;
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private long offset;
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private Unsafe getUnsafe() throws IllegalAccessException, NoSuchFieldException {
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Field f = Unsafe.class.getDeclaredField("theUnsafe");
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f.setAccessible(true);
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return (Unsafe) f.get(null);
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}
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public CASCounter() throws Exception {
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unsafe = getUnsafe();
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offset = unsafe.objectFieldOffset(CASCounter.class.getDeclaredField("counter"));
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}
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public void increment() {
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long before = counter;
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while (!unsafe.compareAndSwapLong(this, offset, before, before + 1)) {
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before = counter;
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}
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}
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public long getCounter() {
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return counter;
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}
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}
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@@ -0,0 +1,39 @@
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package com.baeldung.unsafe;
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import sun.misc.Unsafe;
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import java.lang.reflect.Field;
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class OffHeapArray {
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private final static int BYTE = 1;
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private long size;
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private long address;
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private Unsafe getUnsafe() throws IllegalAccessException, NoSuchFieldException {
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Field f = Unsafe.class.getDeclaredField("theUnsafe");
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f.setAccessible(true);
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return (Unsafe) f.get(null);
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}
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OffHeapArray(long size) throws NoSuchFieldException, IllegalAccessException {
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this.size = size;
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address = getUnsafe().allocateMemory(size * BYTE);
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}
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public void set(long i, byte value) throws NoSuchFieldException, IllegalAccessException {
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getUnsafe().putByte(address + i * BYTE, value);
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}
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public int get(long idx) throws NoSuchFieldException, IllegalAccessException {
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return getUnsafe().getByte(address + idx * BYTE);
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}
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public long size() {
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return size;
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}
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void freeMemory() throws NoSuchFieldException, IllegalAccessException {
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getUnsafe().freeMemory(address);
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}
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}
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@@ -0,0 +1,125 @@
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package com.baeldung.unsafe;
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import org.junit.Before;
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import org.junit.Ignore;
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import org.junit.Test;
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import sun.misc.Unsafe;
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import java.io.IOException;
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import java.lang.reflect.Field;
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import java.util.concurrent.ExecutorService;
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import java.util.concurrent.Executors;
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import java.util.concurrent.TimeUnit;
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import java.util.stream.IntStream;
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import static junit.framework.Assert.assertTrue;
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import static junit.framework.TestCase.assertEquals;
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public class UnsafeUnitTest {
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private Unsafe unsafe;
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@Before
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public void setup() throws NoSuchFieldException, IllegalAccessException {
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Field f = Unsafe.class.getDeclaredField("theUnsafe");
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f.setAccessible(true);
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unsafe = (Unsafe) f.get(null);
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}
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@Test
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public void givenClass_whenInitializeIt_thenShouldHaveDifferentStateWhenUseUnsafe() throws IllegalAccessException, InstantiationException {
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//when
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InitializationOrdering o1 = new InitializationOrdering();
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assertEquals(o1.getA(), 1);
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//when
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InitializationOrdering o3 = (InitializationOrdering) unsafe.allocateInstance(InitializationOrdering.class);
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assertEquals(o3.getA(), 0);
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}
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@Test
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public void givenPrivateMethod_whenUsingUnsafe_thenCanModifyPrivateField() throws NoSuchFieldException {
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//given
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SecretHolder secretHolder = new SecretHolder();
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//when
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Field f = secretHolder.getClass().getDeclaredField("SECRET_VALUE");
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unsafe.putInt(secretHolder, unsafe.objectFieldOffset(f), 1);
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//then
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assertTrue(secretHolder.secretIsDisclosed());
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}
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@Test(expected = IOException.class)
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public void givenUnsafeThrowException_whenThrowCheckedException_thenNotNeedToCatchIt() {
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unsafe.throwException(new IOException());
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}
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@Test
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@Ignore // Uncomment for local
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public void givenArrayBiggerThatMaxInt_whenAllocateItOffHeapMemory_thenSuccess() throws NoSuchFieldException, IllegalAccessException {
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//given
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long SUPER_SIZE = (long) Integer.MAX_VALUE * 2;
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OffHeapArray array = new OffHeapArray(SUPER_SIZE);
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//when
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int sum = 0;
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for (int i = 0; i < 100; i++) {
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array.set((long) Integer.MAX_VALUE + i, (byte) 3);
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sum += array.get((long) Integer.MAX_VALUE + i);
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}
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long arraySize = array.size();
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array.freeMemory();
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//then
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assertEquals(arraySize, SUPER_SIZE);
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assertEquals(sum, 300);
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}
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@Test
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public void givenUnsafeCompareAndSwap_whenUseIt_thenCounterYildCorrectLockFreeResults() throws Exception {
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//given
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int NUM_OF_THREADS = 1_000;
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int NUM_OF_INCREMENTS = 10_000;
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ExecutorService service = Executors.newFixedThreadPool(NUM_OF_THREADS);
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CASCounter casCounter = new CASCounter();
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//when
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IntStream.rangeClosed(0, NUM_OF_THREADS - 1)
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.forEach(i -> service.submit(() -> IntStream
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.rangeClosed(0, NUM_OF_INCREMENTS - 1)
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.forEach(j -> casCounter.increment())));
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service.shutdown();
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service.awaitTermination(1, TimeUnit.MINUTES);
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//then
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assertEquals(NUM_OF_INCREMENTS * NUM_OF_THREADS, casCounter.getCounter());
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}
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class InitializationOrdering {
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private long a;
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public InitializationOrdering() {
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this.a = 1;
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}
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public long getA() {
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return this.a;
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}
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}
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class SecretHolder {
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private int SECRET_VALUE = 0;
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public boolean secretIsDisclosed() {
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return SECRET_VALUE == 1;
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}
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}
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}
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13
core-java-modules/core-java-sun/src/test/resources/.gitignore
vendored
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13
core-java-modules/core-java-sun/src/test/resources/.gitignore
vendored
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@@ -0,0 +1,13 @@
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*.class
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#folders#
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/target
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/neoDb*
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/data
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/src/main/webapp/WEB-INF/classes
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*/META-INF/*
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# Packaged files #
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*.jar
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*.war
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*.ear
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Reference in New Issue
Block a user