main/src/main/java/org/objenesis/instantiator/sun/MagicInstantiator.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.sun;

 import java.io.ByteArrayOutputStream;
 import java.io.DataOutputStream;
 import java.io.IOException;

 import org.objenesis.ObjenesisException;
 import org.objenesis.instantiator.ObjectInstantiator;
 import org.objenesis.instantiator.annotations.Instantiator;
 import org.objenesis.instantiator.annotations.Typology;
 import org.objenesis.instantiator.basic.ClassDefinitionUtils;

 import static org.objenesis.instantiator.basic.ClassDefinitionUtils.*;

 /**
  * This instantiator will correctly bypass the constructors by instantiating the class using the default
  * constructor from Object. It will be allowed to do so by extending {@code MagicAccessorImpl} which prevents
  * its children to be verified by the class loader
  *
  * @author Henri Tremblay
  */
 @Instantiator(Typology.STANDARD)
 public class MagicInstantiator<T> implements ObjectInstantiator<T> {

    private static final int INDEX_CLASS_THIS = 1;
    private static final int INDEX_CLASS_SUPERCLASS = 2;
    private static final int INDEX_UTF8_CONSTRUCTOR_NAME = 3;
    private static final int INDEX_UTF8_CONSTRUCTOR_DESC = 4;
    private static final int INDEX_UTF8_CODE_ATTRIBUTE = 5;
    private static final int INDEX_UTF8_INSTANTIATOR_CLASS = 7;
    private static final int INDEX_UTF8_SUPERCLASS = 8;
    private static final int INDEX_CLASS_INTERFACE = 9;
    private static final int INDEX_UTF8_INTERFACE = 10;
    private static final int INDEX_UTF8_NEWINSTANCE_NAME = 11;
    private static final int INDEX_UTF8_NEWINSTANCE_DESC = 12;
    private static final int INDEX_METHODREF_OBJECT_CONSTRUCTOR = 13;
    private static final int INDEX_CLASS_OBJECT = 14;
    private static final int INDEX_UTF8_OBJECT = 15;
    private static final int INDEX_NAMEANDTYPE_DEFAULT_CONSTRUCTOR = 16;
    private static final int INDEX_CLASS_TYPE = 17;
    private static final int INDEX_UTF8_TYPE = 18;

    private static int CONSTANT_POOL_COUNT = 19;

    private static final byte[] CONSTRUCTOR_CODE = { OPS_aload_0, OPS_invokespecial, 0, INDEX_METHODREF_OBJECT_CONSTRUCTOR, OPS_return};
    private static final int CONSTRUCTOR_CODE_ATTRIBUTE_LENGTH = 12 + CONSTRUCTOR_CODE.length;

    private static final byte[] NEWINSTANCE_CODE = { OPS_new, 0, INDEX_CLASS_TYPE, OPS_dup, OPS_invokespecial, 0, INDEX_METHODREF_OBJECT_CONSTRUCTOR, OPS_areturn};
    private static final int NEWINSTANCE_CODE_ATTRIBUTE_LENGTH = 12 + NEWINSTANCE_CODE.length;

    private static final String CONSTRUCTOR_NAME = "<init>";
    private static final String CONSTRUCTOR_DESC = "()V";

    private ObjectInstantiator<T> instantiator;

    public MagicInstantiator(Class<T> type) {
       instantiator = newInstantiatorOf(type);
    }

    /**
     * Get the underlying instantiator.
     *
     * {@link MagicInstantiator} is a wrapper around another object
     * which implements {@link ObjectInstantiator} interface.
     * This method exposes that instantiator.
     *
     * @return the underlying instantiator
     */
    public ObjectInstantiator<T> getInstantiator() {
       return instantiator;
    }

    private <T> ObjectInstantiator<T> newInstantiatorOf(Class<T> type) {
       String suffix = type.getSimpleName();
       String className = getClass().getName() + "$$$" + suffix;

       Class<ObjectInstantiator<T>> clazz = getExistingClass(getClass().getClassLoader(), className);

       if(clazz == null) {
          byte[] classBytes = writeExtendingClass(type, className);

          try {
             clazz = ClassDefinitionUtils.defineClass(className, classBytes, getClass().getClassLoader());
          } catch (Exception e) {
             throw new ObjenesisException(e);
          }
       }

       try {
          return clazz.newInstance();
       } catch (InstantiationException e) {
          throw new ObjenesisException(e);
       } catch (IllegalAccessException e) {
          throw new ObjenesisException(e);
       }
    }

    /**
     * Will generate the bytes for a class extending the type passed in parameter. This class will
     * only have an empty default constructor
     *
     * @param type type to extend
     * @param className name of the wrapped instantiator class
     * @return the byte for the class
     * @throws ObjenesisException is something goes wrong
     */
    private byte[] writeExtendingClass(Class<?> type, String className) {
       String clazz = classNameToInternalClassName(className);

       DataOutputStream in = null;
       ByteArrayOutputStream bIn = new ByteArrayOutputStream(1000); // 1000 should be large enough to fit the entire class
       try {
          in = new DataOutputStream(bIn);

          in.write(MAGIC);
          in.write(VERSION);
          in.writeShort(CONSTANT_POOL_COUNT);

          // set all the constant pool here

          // 1. class
          in.writeByte(CONSTANT_Class);
          in.writeShort(INDEX_UTF8_INSTANTIATOR_CLASS);

          // 2. super class
          in.writeByte(CONSTANT_Class);
          in.writeShort(INDEX_UTF8_SUPERCLASS);

          // 3. default constructor name
          in.writeByte(CONSTANT_Utf8);
          in.writeUTF(CONSTRUCTOR_NAME);

          // 4. default constructor description
          in.writeByte(CONSTANT_Utf8);
          in.writeUTF(CONSTRUCTOR_DESC);

          // 5. Code
          in.writeByte(CONSTANT_Utf8);
          in.writeUTF("Code");

          // 6. Class name
          in.writeByte(CONSTANT_Utf8);
          in.writeUTF("L" + clazz + ";");

          // 7. Class name (again)
          in.writeByte(CONSTANT_Utf8);
          in.writeUTF(clazz);

          // 8. Superclass name
          in.writeByte(CONSTANT_Utf8);
 //         in.writeUTF("java/lang/Object");
          in.writeUTF("sun/reflect/MagicAccessorImpl");

          // 9. ObjectInstantiator interface
          in.writeByte(CONSTANT_Class);
          in.writeShort(INDEX_UTF8_INTERFACE);

          // 10. ObjectInstantiator name
          in.writeByte(CONSTANT_Utf8);
          in.writeUTF(ObjectInstantiator.class.getName().replace('.', '/'));

          // 11. newInstance name
          in.writeByte(CONSTANT_Utf8);
          in.writeUTF("newInstance");

          // 12. newInstance desc
          in.writeByte(CONSTANT_Utf8);
          in.writeUTF("()Ljava/lang/Object;");

          // 13. Methodref to the Object constructor
          in.writeByte(CONSTANT_Methodref);
          in.writeShort(INDEX_CLASS_OBJECT);
          in.writeShort(INDEX_NAMEANDTYPE_DEFAULT_CONSTRUCTOR);

          // 14. Object class
          in.writeByte(CONSTANT_Class);
          in.writeShort(INDEX_UTF8_OBJECT);

          // 15. Object class name
          in.writeByte(CONSTANT_Utf8);
          in.writeUTF("java/lang/Object");

          // 16. Default constructor name and type
          in.writeByte(CONSTANT_NameAndType);
          in.writeShort(INDEX_UTF8_CONSTRUCTOR_NAME);
          in.writeShort(INDEX_UTF8_CONSTRUCTOR_DESC);

          // 17. Type to instantiate class
          in.writeByte(CONSTANT_Class);
          in.writeShort(INDEX_UTF8_TYPE);

          // 18. Type to instantiate name
          in.writeByte(CONSTANT_Utf8);
          in.writeUTF(classNameToInternalClassName(type.getName()));

          // end of constant pool

          // access flags: We want public, ACC_SUPER is always there
          in.writeShort(ACC_PUBLIC | ACC_SUPER | ACC_FINAL);

          // this class index in the constant pool
          in.writeShort(INDEX_CLASS_THIS);

          // super class index in the constant pool
          in.writeShort(INDEX_CLASS_SUPERCLASS);

          // interfaces implemented count (we have none)
          in.writeShort(1);
          in.writeShort(INDEX_CLASS_INTERFACE);

          // fields count (we have none)
          in.writeShort(0);

          // method count (we have two: the default constructor and newInstance)
          in.writeShort(2);

          // default constructor method_info
          in.writeShort(ACC_PUBLIC);
          in.writeShort(INDEX_UTF8_CONSTRUCTOR_NAME); // index of the method name (<init>)
          in.writeShort(INDEX_UTF8_CONSTRUCTOR_DESC); // index of the description
          in.writeShort(1); // number of attributes: only one, the code

          // code attribute of the default constructor
          in.writeShort(INDEX_UTF8_CODE_ATTRIBUTE);
          in.writeInt(CONSTRUCTOR_CODE_ATTRIBUTE_LENGTH); // attribute length
          in.writeShort(0); // max_stack
          in.writeShort(1); // max_locals
          in.writeInt(CONSTRUCTOR_CODE.length); // code length
          in.write(CONSTRUCTOR_CODE);
          in.writeShort(0); // exception_table_length = 0
          in.writeShort(0); // attributes count = 0, no need to have LineNumberTable and LocalVariableTable

          // newInstance method_info
          in.writeShort(ACC_PUBLIC);
          in.writeShort(INDEX_UTF8_NEWINSTANCE_NAME); // index of the method name (newInstance)
          in.writeShort(INDEX_UTF8_NEWINSTANCE_DESC); // index of the description
          in.writeShort(1); // number of attributes: only one, the code

          // code attribute of newInstance
          in.writeShort(INDEX_UTF8_CODE_ATTRIBUTE);
          in.writeInt(NEWINSTANCE_CODE_ATTRIBUTE_LENGTH); // attribute length
          in.writeShort(2); // max_stack
          in.writeShort(1); // max_locals
          in.writeInt(NEWINSTANCE_CODE.length); // code length
          in.write(NEWINSTANCE_CODE);
          in.writeShort(0); // exception_table_length = 0
          in.writeShort(0); // attributes count = 0, no need to have LineNumberTable and LocalVariableTable

          // class attributes
          in.writeShort(0); // none. No need to have a source file attribute

       } catch (IOException e) {
          throw new ObjenesisException(e);
       } finally {
          if(in != null) {
             try {
                in.close();
             } catch (IOException e) {
                throw new ObjenesisException(e);
             }
          }
       }

       return bIn.toByteArray();
    }

    public T newInstance() {
       return instantiator.newInstance();
    }
 }
	/**
	* 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.sun;

	import java.io.ByteArrayOutputStream;
	import java.io.DataOutputStream;
	import java.io.IOException;

	import org.objenesis.ObjenesisException;
	import org.objenesis.instantiator.ObjectInstantiator;
	import org.objenesis.instantiator.annotations.Instantiator;
	import org.objenesis.instantiator.annotations.Typology;
	import org.objenesis.instantiator.basic.ClassDefinitionUtils;

	import static org.objenesis.instantiator.basic.ClassDefinitionUtils.*;

	/**
	* This instantiator will correctly bypass the constructors by instantiating the class using the default
	* constructor from Object. It will be allowed to do so by extending {@code MagicAccessorImpl} which prevents
	* its children to be verified by the class loader
	*
	* @author Henri Tremblay
	*/
	@Instantiator(Typology.STANDARD)
	public class MagicInstantiator<T> implements ObjectInstantiator<T> {

	private static final int INDEX_CLASS_THIS = 1;
	private static final int INDEX_CLASS_SUPERCLASS = 2;
	private static final int INDEX_UTF8_CONSTRUCTOR_NAME = 3;
	private static final int INDEX_UTF8_CONSTRUCTOR_DESC = 4;
	private static final int INDEX_UTF8_CODE_ATTRIBUTE = 5;
	private static final int INDEX_UTF8_INSTANTIATOR_CLASS = 7;
	private static final int INDEX_UTF8_SUPERCLASS = 8;
	private static final int INDEX_CLASS_INTERFACE = 9;
	private static final int INDEX_UTF8_INTERFACE = 10;
	private static final int INDEX_UTF8_NEWINSTANCE_NAME = 11;
	private static final int INDEX_UTF8_NEWINSTANCE_DESC = 12;
	private static final int INDEX_METHODREF_OBJECT_CONSTRUCTOR = 13;
	private static final int INDEX_CLASS_OBJECT = 14;
	private static final int INDEX_UTF8_OBJECT = 15;
	private static final int INDEX_NAMEANDTYPE_DEFAULT_CONSTRUCTOR = 16;
	private static final int INDEX_CLASS_TYPE = 17;
	private static final int INDEX_UTF8_TYPE = 18;

	private static int CONSTANT_POOL_COUNT = 19;

	private static final byte[] CONSTRUCTOR_CODE = { OPS_aload_0, OPS_invokespecial, 0, INDEX_METHODREF_OBJECT_CONSTRUCTOR, OPS_return};
	private static final int CONSTRUCTOR_CODE_ATTRIBUTE_LENGTH = 12 + CONSTRUCTOR_CODE.length;

	private static final byte[] NEWINSTANCE_CODE = { OPS_new, 0, INDEX_CLASS_TYPE, OPS_dup, OPS_invokespecial, 0, INDEX_METHODREF_OBJECT_CONSTRUCTOR, OPS_areturn};
	private static final int NEWINSTANCE_CODE_ATTRIBUTE_LENGTH = 12 + NEWINSTANCE_CODE.length;

	private static final String CONSTRUCTOR_NAME = "<init>";
	private static final String CONSTRUCTOR_DESC = "()V";

	private ObjectInstantiator<T> instantiator;

	public MagicInstantiator(Class<T> type) {
	instantiator = newInstantiatorOf(type);
	}

	/**
	* Get the underlying instantiator.
	*
	* {@link MagicInstantiator} is a wrapper around another object
	* which implements {@link ObjectInstantiator} interface.
	* This method exposes that instantiator.
	*
	* @return the underlying instantiator
	*/
	public ObjectInstantiator<T> getInstantiator() {
	return instantiator;
	}

	private <T> ObjectInstantiator<T> newInstantiatorOf(Class<T> type) {
	String suffix = type.getSimpleName();
	String className = getClass().getName() + "$$$" + suffix;

	Class<ObjectInstantiator<T>> clazz = getExistingClass(getClass().getClassLoader(), className);

	if(clazz == null) {
	byte[] classBytes = writeExtendingClass(type, className);

	try {
	clazz = ClassDefinitionUtils.defineClass(className, classBytes, getClass().getClassLoader());
	} catch (Exception e) {
	throw new ObjenesisException(e);
	}
	}

	try {
	return clazz.newInstance();
	} catch (InstantiationException e) {
	throw new ObjenesisException(e);
	} catch (IllegalAccessException e) {
	throw new ObjenesisException(e);
	}
	}

	/**
	* Will generate the bytes for a class extending the type passed in parameter. This class will
	* only have an empty default constructor
	*
	* @param type type to extend
	* @param className name of the wrapped instantiator class
	* @return the byte for the class
	* @throws ObjenesisException is something goes wrong
	*/
	private byte[] writeExtendingClass(Class<?> type, String className) {
	String clazz = classNameToInternalClassName(className);

	DataOutputStream in = null;
	ByteArrayOutputStream bIn = new ByteArrayOutputStream(1000); // 1000 should be large enough to fit the entire class
	try {
	in = new DataOutputStream(bIn);

	in.write(MAGIC);
	in.write(VERSION);
	in.writeShort(CONSTANT_POOL_COUNT);

	// set all the constant pool here

	// 1. class
	in.writeByte(CONSTANT_Class);
	in.writeShort(INDEX_UTF8_INSTANTIATOR_CLASS);

	// 2. super class
	in.writeByte(CONSTANT_Class);
	in.writeShort(INDEX_UTF8_SUPERCLASS);

	// 3. default constructor name
	in.writeByte(CONSTANT_Utf8);
	in.writeUTF(CONSTRUCTOR_NAME);

	// 4. default constructor description
	in.writeByte(CONSTANT_Utf8);
	in.writeUTF(CONSTRUCTOR_DESC);

	// 5. Code
	in.writeByte(CONSTANT_Utf8);
	in.writeUTF("Code");

	// 6. Class name
	in.writeByte(CONSTANT_Utf8);
	in.writeUTF("L" + clazz + ";");

	// 7. Class name (again)
	in.writeByte(CONSTANT_Utf8);
	in.writeUTF(clazz);

	// 8. Superclass name
	in.writeByte(CONSTANT_Utf8);
	// in.writeUTF("java/lang/Object");
	in.writeUTF("sun/reflect/MagicAccessorImpl");

	// 9. ObjectInstantiator interface
	in.writeByte(CONSTANT_Class);
	in.writeShort(INDEX_UTF8_INTERFACE);

	// 10. ObjectInstantiator name
	in.writeByte(CONSTANT_Utf8);
	in.writeUTF(ObjectInstantiator.class.getName().replace('.', '/'));

	// 11. newInstance name
	in.writeByte(CONSTANT_Utf8);
	in.writeUTF("newInstance");

	// 12. newInstance desc
	in.writeByte(CONSTANT_Utf8);
	in.writeUTF("()Ljava/lang/Object;");

	// 13. Methodref to the Object constructor
	in.writeByte(CONSTANT_Methodref);
	in.writeShort(INDEX_CLASS_OBJECT);
	in.writeShort(INDEX_NAMEANDTYPE_DEFAULT_CONSTRUCTOR);

	// 14. Object class
	in.writeByte(CONSTANT_Class);
	in.writeShort(INDEX_UTF8_OBJECT);

	// 15. Object class name
	in.writeByte(CONSTANT_Utf8);
	in.writeUTF("java/lang/Object");

	// 16. Default constructor name and type
	in.writeByte(CONSTANT_NameAndType);
	in.writeShort(INDEX_UTF8_CONSTRUCTOR_NAME);
	in.writeShort(INDEX_UTF8_CONSTRUCTOR_DESC);

	// 17. Type to instantiate class
	in.writeByte(CONSTANT_Class);
	in.writeShort(INDEX_UTF8_TYPE);

	// 18. Type to instantiate name
	in.writeByte(CONSTANT_Utf8);
	in.writeUTF(classNameToInternalClassName(type.getName()));

	// end of constant pool

	// access flags: We want public, ACC_SUPER is always there
	in.writeShort(ACC_PUBLIC \| ACC_SUPER \| ACC_FINAL);

	// this class index in the constant pool
	in.writeShort(INDEX_CLASS_THIS);

	// super class index in the constant pool
	in.writeShort(INDEX_CLASS_SUPERCLASS);

	// interfaces implemented count (we have none)
	in.writeShort(1);
	in.writeShort(INDEX_CLASS_INTERFACE);

	// fields count (we have none)
	in.writeShort(0);

	// method count (we have two: the default constructor and newInstance)
	in.writeShort(2);

	// default constructor method_info
	in.writeShort(ACC_PUBLIC);
	in.writeShort(INDEX_UTF8_CONSTRUCTOR_NAME); // index of the method name (<init>)
	in.writeShort(INDEX_UTF8_CONSTRUCTOR_DESC); // index of the description
	in.writeShort(1); // number of attributes: only one, the code

	// code attribute of the default constructor
	in.writeShort(INDEX_UTF8_CODE_ATTRIBUTE);
	in.writeInt(CONSTRUCTOR_CODE_ATTRIBUTE_LENGTH); // attribute length
	in.writeShort(0); // max_stack
	in.writeShort(1); // max_locals
	in.writeInt(CONSTRUCTOR_CODE.length); // code length
	in.write(CONSTRUCTOR_CODE);
	in.writeShort(0); // exception_table_length = 0
	in.writeShort(0); // attributes count = 0, no need to have LineNumberTable and LocalVariableTable

	// newInstance method_info
	in.writeShort(ACC_PUBLIC);
	in.writeShort(INDEX_UTF8_NEWINSTANCE_NAME); // index of the method name (newInstance)
	in.writeShort(INDEX_UTF8_NEWINSTANCE_DESC); // index of the description
	in.writeShort(1); // number of attributes: only one, the code

	// code attribute of newInstance
	in.writeShort(INDEX_UTF8_CODE_ATTRIBUTE);
	in.writeInt(NEWINSTANCE_CODE_ATTRIBUTE_LENGTH); // attribute length
	in.writeShort(2); // max_stack
	in.writeShort(1); // max_locals
	in.writeInt(NEWINSTANCE_CODE.length); // code length
	in.write(NEWINSTANCE_CODE);
	in.writeShort(0); // exception_table_length = 0
	in.writeShort(0); // attributes count = 0, no need to have LineNumberTable and LocalVariableTable

	// class attributes
	in.writeShort(0); // none. No need to have a source file attribute

	} catch (IOException e) {
	throw new ObjenesisException(e);
	} finally {
	if(in != null) {
	try {
	in.close();
	} catch (IOException e) {
	throw new ObjenesisException(e);
	}
	}
	}

	return bIn.toByteArray();
	}

	public T newInstance() {
	return instantiator.newInstance();
	}
	}