JavaInJava/JavaInJava/src/com/sun/max/lang/Classes.java at master · guanminwei/JavaInJava

431 lines (402 loc) · 17.9 KB
/*
 * Copyright (c) 2007 Sun Microsystems, Inc.  All rights reserved.
 *
 * Sun Microsystems, Inc. has intellectual property rights relating to technology embodied in the product
 * that is described in this document. In particular, and without limitation, these intellectual property
 * rights may include one or more of the U.S. patents listed at http://www.sun.com/patents and one or
 * more additional patents or pending patent applications in the U.S. and in other countries.
 *
 * U.S. Government Rights - Commercial software. Government users are subject to the Sun
 * Microsystems, Inc. standard license agreement and applicable provisions of the FAR and its
 * supplements.
 *
 * Use is subject to license terms. Sun, Sun Microsystems, the Sun logo, Java and Solaris are trademarks or
 * registered trademarks of Sun Microsystems, Inc. in the U.S. and other countries. All SPARC trademarks
 * are used under license and are trademarks or registered trademarks of SPARC International, Inc. in the
 * U.S. and other countries.
 *
 * UNIX is a registered trademark in the U.S. and other countries, exclusively licensed through X/Open
 * Company, Ltd.
 */
package com.sun.max.lang;

import java.lang.reflect.*;

import com.sun.max.*;

/**
 * Methods that might be members of java.lang.Class.
 *
 * @author Bernd Mathiske
 * @author Doug Simon
 */
public final class Classes {

    private Classes() {
    }

    /**
     * Wraps a call to {@link ClassLoader#loadClass(String)} that is expected not to fail. Should a
     * {@link ClassNotFoundException} occur, it is converted to {@link NoClassDefFoundError}
     *
     * @return the value returned by calling {@link ClassLoader#loadClass(String)} on {@code classLoader}
     */
    public static Class load(ClassLoader classLoader, String name) {
        try {
            return classLoader.loadClass(name);
        } catch (ClassNotFoundException e) {
            throw (NoClassDefFoundError) new NoClassDefFoundError(name).initCause(e);
        }
    }

    /**
     * Wraps a call to {@link Class#forName(String)} that is expected not to fail. Should a
     * {@link ClassNotFoundException} occur, it is converted to {@link NoClassDefFoundError}
     */
    public static Class forName(String name) {
        try {
            return Class.forName(name);
        } catch (ClassNotFoundException e) {
            throw (NoClassDefFoundError) new NoClassDefFoundError(name).initCause(e);
        }
    }

    /**
     * Wraps a call to {@link Class#forName(String, boolean, ClassLoader)} that is expected not to fail. Should a
     * {@link ClassNotFoundException} occur, it is converted to {@link NoClassDefFoundError}
     */
    public static Class forName(String name, boolean initialize, ClassLoader loader) {
        try {
            return Class.forName(name, initialize, loader);
        } catch (ClassNotFoundException e) {
            throw (NoClassDefFoundError) new NoClassDefFoundError(name).initCause(e);
        }
    }

    /**
     * Links a given class. If the class {@code c} has already been linked, then this method simply returns. Otherwise,
     * the class is linked as described in the "Execution" chapter of the <a
     * href="http://java.sun.com/docs/books/jls/">Java Language Specification</a>.
     *
     * @param c the class to link
     */
    public static void link(Class c) {
        if (c != null) {
            try {
                final Class<?> linkedClass = Class.forName(c.getName(), false, c.getClassLoader());
                assert linkedClass == c;
            } catch (ClassNotFoundException classNotFoundException) {
                throw (NoClassDefFoundError) new NoClassDefFoundError(c.getName()).initCause(classNotFoundException);
            }
        }
    }

    /**
     * Initializes a given class. If the class {@code c} has already been initialized, then this method simply returns. Otherwise,
     * the class is linked as described in the "Execution" chapter of the <a
     * href="http://java.sun.com/docs/books/jls/">Java Language Specification</a>.
     *
     * @param c the class to link
     */
    public static void initialize(Class c) {
        try {
            Class.forName(c.getName(), true, c.getClassLoader());
        } catch (ClassNotFoundException classNotFoundException) {
            throw (NoClassDefFoundError) new NoClassDefFoundError(c.getName()).initCause(classNotFoundException);
        }
    }

    public static boolean areRelated(Class<?> class1, Class<?> class2) {
        return class1.isAssignableFrom(class2) || class2.isAssignableFrom(class1);
    }

    public static boolean areAssignableFrom(Class<?>[] superTypes, Class<?>... subTypes) {
        if (superTypes.length != subTypes.length) {
            return false;
        }
        for (int i = 0; i < superTypes.length; i++) {
            if (!superTypes[i].isAssignableFrom(subTypes[i])) {
                return false;
            }
        }
        return true;
    }

    /**
     * Extends the functionality of {@link Class#getConstructor(Class...)} to find a constructor whose formal parameter
     * types are assignable from the types of a list of arguments.
     *
     * @param javaClass the class to search in
     * @param arguments the list of arguments that will be passed to the constructor
     * @return the first constructor in {@link Class#getConstructors() javaClass.getConstructors()} that will accept
     *         {@code arguments} or null if no such constructor exists
     */
    public static Constructor<?> findConstructor(Class<?> javaClass, Object... arguments) {
    nextConstructor:
        for (Constructor<?> constructor : javaClass.getConstructors()) {
            final Class<?>[] parameterTypes = constructor.getParameterTypes();
            if (parameterTypes.length == arguments.length) {
                for (int i = 0; i != arguments.length; ++i) {
                    if (!parameterTypes[i].isAssignableFrom(arguments[i].getClass())) {
                        continue nextConstructor;
                    }
                }
                return constructor;
            }
        }
        return null;
    }

    /**
     * Extends the functionality of {@link Class#getMethod(String, Class...)} to find a method whose formal parameter
     * types are assignable from the types of a list of arguments.
     *
     * @param javaClass the class to search in
     * @param name the name of the method to search for
     * @param arguments the list of arguments that will be passed to the constructor
     * @return the first method in {@link Class#getMethods() javaClass.getMethods()} that will accept {@code arguments}
     *         or null if no such method exists
     */
    public static Method findMethod(Class<?> javaClass, String name, Object... arguments) {
    nextMethod:
        for (Method method : javaClass.getMethods()) {
            final Class<?>[] parameterTypes = method.getParameterTypes();
            if (method.getName().equals(name) && parameterTypes.length == arguments.length) {
                for (int i = 0; i != arguments.length; ++i) {
                    if (!parameterTypes[i].isAssignableFrom(arguments[i].getClass())) {
                        continue nextMethod;
                    }
                }
                return method;
            }
        }
        return null;
    }

    /**
     * Extends the functionality of {@link Class#getDeclaredMethod(String, Class...)} to find a method whose formal
     * parameter types are assignable from the types of a list of arguments.
     *
     * @param javaClass the class to search in
     * @param name the name of the method to search for
     * @param arguments the list of arguments that will be passed to the constructor
     * @return the first method in {@link Class#getDeclaredMethods() javaClass.getDeclaredMethods()} that will accept
     *         {@code arguments} or null if no such method exists
     */
    public static Method findDeclaredMethod(Class<?> javaClass, String name, Object... arguments) {
    nextMethod:
        for (Method declaredMethod : javaClass.getDeclaredMethods()) {
            final Class<?>[] parameterTypes = declaredMethod.getParameterTypes();
            if (declaredMethod.getName().equals(name) && parameterTypes.length == arguments.length) {
                for (int i = 0; i != arguments.length; ++i) {
                    if (!parameterTypes[i].isAssignableFrom(arguments[i].getClass())) {
                        continue nextMethod;
                    }
                }
                return declaredMethod;
            }
        }
        return null;
    }

    /**
     * Performs method resolution as detailed in section 5.4.3.3 of the JVM specification except for the accessibility
     * checks detailed in section 5.4.4.
     *
     * @param javaClass the class to start the resolution from
     * @param returnType the return type of the method to resolve
     * @param name the name of the method to resolve
     * @param parameterTypes the parameter types of the method to resolve
     * @return the resolved method
     * @throws NoSuchMethodError if the method resolution fails
     * @throws AbstractMethodError if the resolved method is abstract
     */
    public static Method resolveMethod(Class<?> javaClass, Class returnType, String name, Class... parameterTypes) {
        if (!name.equals("<init>") && !name.equals("<clinit>")) {
            Class<?> declaringClass = javaClass;
            if (javaClass.isInterface()) {
                try {
                    return javaClass.getMethod(name, parameterTypes);
                } catch (NoSuchMethodException e) {
                    throw new NoSuchMethodError(e.getMessage());
                }
            }
            do {
                try {
                    final Method method = getDeclaredMethod(declaringClass, returnType, name, parameterTypes);
                    if (Modifier.isAbstract(method.getModifiers()) && !Modifier.isAbstract(declaringClass.getModifiers())) {
                        throw new AbstractMethodError();
                    }
                    return method;
                } catch (NoSuchMethodError e) {
                    declaringClass = declaringClass.getSuperclass();
                }
            } while (declaringClass != null);
        }
        throw new NoSuchMethodError(returnType.getName() + " " + javaClass.getName() + "." + name + "(" + Utils.toString(parameterTypes, ", ") + ")");
    }

    /**
     * Performs field resolution as detailed in section 5.4.3.2 of the JVM specification except for the accessibility
     * checks detailed in section 5.4.4.
     * @param javaClass the class to start the resolution from
     * @param type the type of the field to resolve
     * @param name the name of the field to resolve
     *
     * @return the resolved field
     * @throws NoSuchFieldError if the field resolution fails
     */
    public static Field resolveField(Class<?> javaClass, Class type, String name) {
        Class<?> declaringClass = javaClass;
        do {
            try {
                return getDeclaredField(declaringClass, name, type);
            } catch (NoSuchFieldError e) {
                for (Class superInterface : javaClass.getInterfaces()) {
                    try {
                        return resolveField(superInterface, type, name);
                    } catch (NoSuchFieldError noSuchFieldError) {
                        // Ignore
                    }
                }
                declaringClass = declaringClass.getSuperclass();
            }
        } while (declaringClass != null);
        throw new NoSuchFieldError(type.getName() + " " + javaClass.getName() + "." + name);
    }

    /**
     * Gets the class or interface that declares the method, field or constructor represented by {@code member}.
     */
    public static Class<?> getDeclaringClass(AccessibleObject member) {
        if (member instanceof Method) {
            final Method method = (Method) member;
            return method.getDeclaringClass();
        }
        if (member instanceof Field) {
            final Field field = (Field) member;
            return field.getDeclaringClass();
        }
        assert member instanceof Constructor;
        final Constructor constructor = (Constructor) member;
        return constructor.getDeclaringClass();
    }

    /**
     * Get hold of a non-public inner class.
     */
    public static Class getInnerClass(Class outerClass, String innerClassSimpleName) {
        for (Class innerClass : outerClass.getDeclaredClasses()) {
            if (innerClass.getSimpleName().equals(innerClassSimpleName)) {
                return innerClass;
            }
        }
        return null;
    }

    /**
     * Extracts a package name from a fully qualified class name.
     *
     * @return "" if {@code className} denotes a class in the unnamed package
     */
    public static String getPackageName(String className) {
        final int index = className.lastIndexOf('.');
        if (index < 0) {
            return "";
        }
        return className.substring(0, index);
    }

    /**
     * Extracts a simple class name from a fully qualified class name.
     */
    public static String getSimpleName(String className) {
        final int index = className.lastIndexOf('.');
        if (index < 0) {
            return className;
        }
        return className.substring(index + 1);
    }

    /**
     * Extends the functionality of {@link Class#getSimpleName()} to include a non-empty string for anonymous and local
     * classes.
     *
     * @param clazz the class for which the simple name is being requested
     * @param withEnclosingClass specifies if the returned name should be qualified with the name(s) of the enclosing
     *            class/classes of {@code clazz} (if any). This option is ignored if {@code clazz} denotes an anonymous
     *            or local class.
     * @return
     */
    public static String getSimpleName(Class<?> clazz, boolean withEnclosingClass) {
        final String simpleName = clazz.getSimpleName();
        if (simpleName.length() != 0) {
            if (withEnclosingClass) {
                String prefix = "";
                Class enclosingClass = clazz;
                while ((enclosingClass = enclosingClass.getEnclosingClass()) != null) {
                    prefix = prefix + enclosingClass.getSimpleName() + ".";
                }
                return prefix + simpleName;
            }
            return simpleName;
        }
        // Must be an anonymous or local class
        final String name = clazz.getName();
        int index = name.indexOf('$');
        if (index == -1) {
            return name;
        }
        index = name.lastIndexOf('.', index);
        if (index == -1) {
            return name;
        }
        return name.substring(index + 1);
    }

    /**
     * Similar to {@link Class#getDeclaredMethod(String, Class...)} except that
     * the search takes into account the return type.
     */
    public static Method getDeclaredMethod(Class<?> clazz, Class returnType, String name, Class... parameterTypes)  throws NoSuchMethodError {
        for (Method javaMethod : clazz.getDeclaredMethods()) {
            if (javaMethod.getName().equals(name) && javaMethod.getReturnType().equals(returnType)) {
                final Class[] declaredParameterTypes = javaMethod.getParameterTypes();
                if (java.util.Arrays.equals(declaredParameterTypes, parameterTypes)) {
                    return javaMethod;
                }
            }
        }
        throw new NoSuchMethodError(returnType.getName() + " " + clazz.getName() + "." + name + "(" + Utils.toString(parameterTypes, ",") + ")");
    }

    /**
     * A wrapper for a call to {@link Class#getDeclaredMethod(String, Class...)} that must succeed.
     */
    public static Method getDeclaredMethod(Class<?> clazz, String name, Class... parameterTypes) {
        try {
            return clazz.getDeclaredMethod(name, parameterTypes);
        } catch (NoSuchMethodException noSuchMethodException) {
            throw (NoSuchMethodError) new NoSuchMethodError(clazz.getName() + "." + name + "(" + Utils.toString(parameterTypes, ",") + ")").initCause(noSuchMethodException);
        }
    }

    /**
     * A wrapper for a call to {@link Class#getDeclaredConstructor(Class...)} that must succeed.
     */
    public static Constructor getDeclaredConstructor(Class<?> clazz, Class... parameterTypes) {
        try {
            return clazz.getDeclaredConstructor(parameterTypes);
        } catch (NoSuchMethodException noSuchMethodException) {
            throw (NoSuchMethodError) new NoSuchMethodError(clazz.getName() + "(" + Utils.toString(parameterTypes, ",") + ")").initCause(noSuchMethodException);
        }
    }

    /**
     * A wrapper for a call to {@link Class#getDeclaredField(String)} that must succeed.
     */
    public static Field getDeclaredField(Class<?> clazz, String name) {
        try {
            return clazz.getDeclaredField(name);
        } catch (NoSuchFieldException noSuchFieldException) {
            throw (NoSuchFieldError) new NoSuchFieldError(clazz.getName() + "." + name).initCause(noSuchFieldException);
        }
    }

    /**
     * Similar to {@link Class#getDeclaredField(String)} except that the lookup takes into account a given field type.
     */
    public static Field getDeclaredField(Class<?> clazz, String name, Class type) throws NoSuchFieldError {
        for (Field field : clazz.getDeclaredFields()) {
            if (field.getName().equals(name) && field.getType().equals(type)) {
                return field;
            }
        }
        throw new NoSuchFieldError(type.getName() + " " + clazz.getName() + "." + name);
    }

    public static void main(Class<?> classToRun, String[] args) {
        try {
            final Method mainMethod = classToRun.getMethod("main", String[].class);
            mainMethod.invoke(null, (Object) args);
        } catch (Exception e) {
            throw (Error) new Error().initCause(e);
        }
    }

    public static void main(String classToRun, String[] args) {
        main(forName(classToRun), args);
    }

}
Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Expand file tree

Search code, repositories, users, issues, pull requests...

FilesExpand file tree

Classes.java

Latest commit

History

Classes.java

File metadata and controls

Expand file tree
