main/src/main/java/org/objenesis/instantiator/basic/ClassDefinitionUtils.java - platform/external/objenesis - Git at Google

 /**
  * Copyright 2006-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 package org.objenesis.instantiator.basic;

 /*
  * Copyright 2003,2004 The Apache Software Foundation
  *
  *  Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  *  Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 import org.objenesis.ObjenesisException;

 import java.io.BufferedOutputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.lang.reflect.Method;
 import java.security.AccessController;
 import java.security.PrivilegedAction;
 import java.security.ProtectionDomain;

 /**
  * Helper class for ProxyObjectInstantiator. We can see the details of a class specification
  * <a href="http://docs.oracle.com/javase/specs/jvms/se7/html/jvms-4.html">here</a>
  *
  * @author Henri Tremblay
  */
 public final class ClassDefinitionUtils {

    public static final byte OPS_aload_0 = 42;
    public static final byte OPS_invokespecial = -73; // has two bytes parameters
    public static final byte OPS_return = -79;
    public static final byte OPS_new = -69;
    public static final byte OPS_dup = 89;
    public static final byte OPS_areturn = -80;

    public static final int CONSTANT_Utf8 = 1;
    public static final int CONSTANT_Integer = 3;
    public static final int CONSTANT_Float = 4;
    public static final int CONSTANT_Long = 5;
    public static final int CONSTANT_Double = 6;
    public static final int CONSTANT_Class = 7;
    public static final int CONSTANT_String = 8;
    public static final int CONSTANT_Fieldref = 9;
    public static final int CONSTANT_Methodref = 10;
    public static final int CONSTANT_InterfaceMethodref = 11;
    public static final int CONSTANT_NameAndType = 12;
    public static final int CONSTANT_MethodHandle = 15;
    public static final int CONSTANT_MethodType = 16;
    public static final int CONSTANT_InvokeDynamic = 18;

    public static final int ACC_PUBLIC = 0x0001; // Declared public; may be accessed from outside its package.
    public static final int ACC_FINAL = 0x0010; // Declared final; no subclasses allowed.
    public static final int ACC_SUPER = 0x0020; // Treat superclass methods specially when invoked by the invokespecial instruction.
    public static final int ACC_INTERFACE = 0x0200; // Is an interface, not a class.
    public static final int ACC_ABSTRACT = 0x0400; // Declared abstract; must not be instantiated.
    public static final int ACC_SYNTHETIC = 0x1000; // Declared synthetic; not present in the source code.
    public static final int ACC_ANNOTATION = 0x2000; // Declared as an annotation type.
    public static final int ACC_ENUM = 0x4000; // Declared as an enum type.

    public static final byte[] MAGIC = { (byte) 0xca, (byte) 0xfe, (byte) 0xba, (byte) 0xbe };
    public static final byte[] VERSION = { (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x31 }; // minor_version, major_version (Java 5)

    private ClassDefinitionUtils() { }

    private static Method DEFINE_CLASS;
    private static final ProtectionDomain PROTECTION_DOMAIN;

    static {
       PROTECTION_DOMAIN = AccessController.doPrivileged(new PrivilegedAction<ProtectionDomain>() {
          public ProtectionDomain run() {
             return ClassDefinitionUtils.class.getProtectionDomain();
          }
       });

       AccessController.doPrivileged(new PrivilegedAction<Object>() {
          public Object run() {
             try {
                Class<?> loader = Class.forName("java.lang.ClassLoader"); // JVM crash w/o this
                DEFINE_CLASS = loader.getDeclaredMethod("defineClass",
                   new Class[]{ String.class,
                      byte[].class,
                      Integer.TYPE,
                      Integer.TYPE,
                      ProtectionDomain.class });
                DEFINE_CLASS.setAccessible(true);
             } catch (ClassNotFoundException e) {
                throw new ObjenesisException(e);
             } catch (NoSuchMethodException e) {
                throw new ObjenesisException(e);
             }
             return null;
          }
       });
    }

    /**
     * Define a class in the provided class loader from the array of bytes. Inspired by cglib
     * <code>ReflectUtils.defineClass</code>
     *
     * @param <T> type of the class returned
     * @param className class name in the format <code>org.objenesis.MyClass</code>
     * @param b bytes representing the class
     * @param loader the class loader where the class will be loaded
     * @return the newly loaded class
     * @throws Exception whenever something goes wrong
     */
    @SuppressWarnings("unchecked")
    public static <T> Class<T> defineClass(String className, byte[] b, ClassLoader loader)
       throws Exception {
       Object[] args = new Object[]{className, b, new Integer(0), new Integer(b.length), PROTECTION_DOMAIN };
       Class<T> c = (Class<T>) DEFINE_CLASS.invoke(loader, args);
       // Force static initializers to run.
       Class.forName(className, true, loader);
       return c;
    }

    /**
     * Read the bytes of a class from the classpath
     *
     * @param className full class name including the package
     * @return the bytes representing the class
     * @throws IllegalArgumentException if the class is longer than 2500 bytes
     * @throws IOException if we fail to read the class
     */
    public static byte[] readClass(String className) throws IOException {
       // convert to a resource
       className = classNameToResource(className);

       byte[] b = new byte[2500]; // I'm assuming that I'm reading class that are not too big

       int length;

       InputStream in = ClassDefinitionUtils.class.getClassLoader().getResourceAsStream(className);
       try {
          length = in.read(b);
       }
       finally {
          in.close();
       }

       if(length >= 2500) {
          throw new IllegalArgumentException("The class is longer that 2500 bytes which is currently unsupported");
       }

       byte[] copy = new byte[length];
       System.arraycopy(b, 0, copy, 0, length);
       return copy;
    }

    /**
     * Write all class bytes to a file.
     *
     * @param fileName file where the bytes will be written
     * @param bytes bytes representing the class
     * @throws IOException if we fail to write the class
     */
    public static void writeClass(String fileName, byte[] bytes) throws IOException {
       BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream(fileName));
       try {
          out.write(bytes);
       }
       finally {
          out.close();
       }
    }

    /**
     * Will convert a class name to its name in the class definition format (e.g {@code org.objenesis.EmptyClass}
     * becomes {@code org/objenesis/EmptyClass})
     *
     * @param className full class name including the package
     * @return the internal name
     */
    public static String classNameToInternalClassName(String className) {
       return className.replace('.', '/');
    }

    /**
     * Will convert a class name to its class loader resource name (e.g {@code org.objenesis.EmptyClass}
     * becomes {@code org/objenesis/EmptyClass.class})
     *
     * @param className full class name including the package
     * @return the resource name
     */
    public static String classNameToResource(String className) {
       return classNameToInternalClassName(className) + ".class";
    }

    /**
     * Check if this class already exists in the class loader and return it if it does
     *
     * @param <T> type of the class returned
     * @param classLoader Class loader where to search the class
     * @param className Class name with full path
     * @return the class if it already exists or null
     */
    @SuppressWarnings("unchecked")
    public static <T> Class<T> getExistingClass(ClassLoader classLoader, String className) {
       try {
          return (Class<T>) Class.forName(className, true, classLoader);
       }
       catch (ClassNotFoundException e) {
          return null;
       }
    }
 }
	/**
	* Copyright 2006-2017 the original author or authors.
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/
	package org.objenesis.instantiator.basic;

	/*
	* Copyright 2003,2004 The Apache Software Foundation
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	import org.objenesis.ObjenesisException;

	import java.io.BufferedOutputStream;
	import java.io.FileOutputStream;
	import java.io.IOException;
	import java.io.InputStream;
	import java.lang.reflect.Method;
	import java.security.AccessController;
	import java.security.PrivilegedAction;
	import java.security.ProtectionDomain;

	/**
	* Helper class for ProxyObjectInstantiator. We can see the details of a class specification
	* <a href="http://docs.oracle.com/javase/specs/jvms/se7/html/jvms-4.html">here</a>
	*
	* @author Henri Tremblay
	*/
	public final class ClassDefinitionUtils {

	public static final byte OPS_aload_0 = 42;
	public static final byte OPS_invokespecial = -73; // has two bytes parameters
	public static final byte OPS_return = -79;
	public static final byte OPS_new = -69;
	public static final byte OPS_dup = 89;
	public static final byte OPS_areturn = -80;

	public static final int CONSTANT_Utf8 = 1;
	public static final int CONSTANT_Integer = 3;
	public static final int CONSTANT_Float = 4;
	public static final int CONSTANT_Long = 5;
	public static final int CONSTANT_Double = 6;
	public static final int CONSTANT_Class = 7;
	public static final int CONSTANT_String = 8;
	public static final int CONSTANT_Fieldref = 9;
	public static final int CONSTANT_Methodref = 10;
	public static final int CONSTANT_InterfaceMethodref = 11;
	public static final int CONSTANT_NameAndType = 12;
	public static final int CONSTANT_MethodHandle = 15;
	public static final int CONSTANT_MethodType = 16;
	public static final int CONSTANT_InvokeDynamic = 18;

	public static final int ACC_PUBLIC = 0x0001; // Declared public; may be accessed from outside its package.
	public static final int ACC_FINAL = 0x0010; // Declared final; no subclasses allowed.
	public static final int ACC_SUPER = 0x0020; // Treat superclass methods specially when invoked by the invokespecial instruction.
	public static final int ACC_INTERFACE = 0x0200; // Is an interface, not a class.
	public static final int ACC_ABSTRACT = 0x0400; // Declared abstract; must not be instantiated.
	public static final int ACC_SYNTHETIC = 0x1000; // Declared synthetic; not present in the source code.
	public static final int ACC_ANNOTATION = 0x2000; // Declared as an annotation type.
	public static final int ACC_ENUM = 0x4000; // Declared as an enum type.

	public static final byte[] MAGIC = { (byte) 0xca, (byte) 0xfe, (byte) 0xba, (byte) 0xbe };
	public static final byte[] VERSION = { (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x31 }; // minor_version, major_version (Java 5)

	private ClassDefinitionUtils() { }

	private static Method DEFINE_CLASS;
	private static final ProtectionDomain PROTECTION_DOMAIN;

	static {
	PROTECTION_DOMAIN = AccessController.doPrivileged(new PrivilegedAction<ProtectionDomain>() {
	public ProtectionDomain run() {
	return ClassDefinitionUtils.class.getProtectionDomain();
	}
	});

	AccessController.doPrivileged(new PrivilegedAction<Object>() {
	public Object run() {
	try {
	Class<?> loader = Class.forName("java.lang.ClassLoader"); // JVM crash w/o this
	DEFINE_CLASS = loader.getDeclaredMethod("defineClass",
	new Class[]{ String.class,
	byte[].class,
	Integer.TYPE,
	Integer.TYPE,
	ProtectionDomain.class });
	DEFINE_CLASS.setAccessible(true);
	} catch (ClassNotFoundException e) {
	throw new ObjenesisException(e);
	} catch (NoSuchMethodException e) {
	throw new ObjenesisException(e);
	}
	return null;
	}
	});
	}

	/**
	* Define a class in the provided class loader from the array of bytes. Inspired by cglib
	* <code>ReflectUtils.defineClass</code>
	*
	* @param <T> type of the class returned
	* @param className class name in the format <code>org.objenesis.MyClass</code>
	* @param b bytes representing the class
	* @param loader the class loader where the class will be loaded
	* @return the newly loaded class
	* @throws Exception whenever something goes wrong
	*/
	@SuppressWarnings("unchecked")
	public static <T> Class<T> defineClass(String className, byte[] b, ClassLoader loader)
	throws Exception {
	Object[] args = new Object[]{className, b, new Integer(0), new Integer(b.length), PROTECTION_DOMAIN };
	Class<T> c = (Class<T>) DEFINE_CLASS.invoke(loader, args);
	// Force static initializers to run.
	Class.forName(className, true, loader);
	return c;
	}

	/**
	* Read the bytes of a class from the classpath
	*
	* @param className full class name including the package
	* @return the bytes representing the class
	* @throws IllegalArgumentException if the class is longer than 2500 bytes
	* @throws IOException if we fail to read the class
	*/
	public static byte[] readClass(String className) throws IOException {
	// convert to a resource
	className = classNameToResource(className);

	byte[] b = new byte[2500]; // I'm assuming that I'm reading class that are not too big

	int length;

	InputStream in = ClassDefinitionUtils.class.getClassLoader().getResourceAsStream(className);
	try {
	length = in.read(b);
	}
	finally {
	in.close();
	}

	if(length >= 2500) {
	throw new IllegalArgumentException("The class is longer that 2500 bytes which is currently unsupported");
	}

	byte[] copy = new byte[length];
	System.arraycopy(b, 0, copy, 0, length);
	return copy;
	}

	/**
	* Write all class bytes to a file.
	*
	* @param fileName file where the bytes will be written
	* @param bytes bytes representing the class
	* @throws IOException if we fail to write the class
	*/
	public static void writeClass(String fileName, byte[] bytes) throws IOException {
	BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream(fileName));
	try {
	out.write(bytes);
	}
	finally {
	out.close();
	}
	}

	/**
	* Will convert a class name to its name in the class definition format (e.g {@code org.objenesis.EmptyClass}
	* becomes {@code org/objenesis/EmptyClass})
	*
	* @param className full class name including the package
	* @return the internal name
	*/
	public static String classNameToInternalClassName(String className) {
	return className.replace('.', '/');
	}

	/**
	* Will convert a class name to its class loader resource name (e.g {@code org.objenesis.EmptyClass}
	* becomes {@code org/objenesis/EmptyClass.class})
	*
	* @param className full class name including the package
	* @return the resource name
	*/
	public static String classNameToResource(String className) {
	return classNameToInternalClassName(className) + ".class";
	}

	/**
	* Check if this class already exists in the class loader and return it if it does
	*
	* @param <T> type of the class returned
	* @param classLoader Class loader where to search the class
	* @param className Class name with full path
	* @return the class if it already exists or null
	*/
	@SuppressWarnings("unchecked")
	public static <T> Class<T> getExistingClass(ClassLoader classLoader, String className) {
	try {
	return (Class<T>) Class.forName(className, true, classLoader);
	}
	catch (ClassNotFoundException e) {
	return null;
	}
	}
	}