src/main/java/org/apache/bcel/classfile/Method.java - commons-bcel - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you 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
  *
  *   https://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.apache.bcel.classfile;

 import java.io.DataInput;
 import java.io.IOException;
 import java.util.Objects;

 import org.apache.bcel.generic.Type;
 import org.apache.bcel.util.BCELComparator;

 /**
  * This class represents the method info structure, that is, the representation for a method in the class. See JVM
  * specification for details. A method has access flags, a name, a signature and a number of attributes.
  */
 public final class Method extends FieldOrMethod {

     /**
      * Empty array constant.
      *
      * @since 6.6.0
      */
     public static final Method[] EMPTY_ARRAY = {};

     private static BCELComparator<Method> bcelComparator = new BCELComparator<Method>() {

         @Override
         public boolean equals(final Method a, final Method b) {
             return a == b || a != null && b != null && Objects.equals(a.getName(), b.getName()) && Objects.equals(a.getSignature(), b.getSignature());
         }

         @Override
         public int hashCode(final Method o) {
             return o != null ? Objects.hash(o.getSignature(), o.getName()) : 0;
         }
     };

     /**
      * Gets the comparison strategy object.
      *
      * @return Comparison strategy object.
      */
     public static BCELComparator<Method> getComparator() {
         return bcelComparator;
     }

     /**
      * Sets the comparison strategy object.
      *
      * @param comparator Comparison strategy object.
      */
     public static void setComparator(final BCELComparator<Method> comparator) {
         bcelComparator = comparator;
     }

     /** Annotations defined on the parameters of a method. */
     private ParameterAnnotationEntry[] parameterAnnotationEntries;

     /**
      * Empty constructor, all attributes have to be defined via 'setXXX' methods. Use at your own risk.
      */
     public Method() {
     }

     /**
      * Constructs object from file stream.
      *
      * @param file Input stream.
      * @throws IOException if an I/O error occurs.
      * @throws ClassFormatException if a class is malformed or cannot be interpreted as a class file.
      */
     Method(final DataInput file, final ConstantPool constantPool) throws IOException, ClassFormatException {
         super(file, constantPool);
     }

     /**
      * Constructs a Method.
      *
      * @param accessFlags Access rights of method.
      * @param nameIndex Points to field name in constant pool.
      * @param signatureIndex Points to encoded signature.
      * @param attributes Collection of attributes.
      * @param constantPool Array of constants.
      */
     public Method(final int accessFlags, final int nameIndex, final int signatureIndex, final Attribute[] attributes, final ConstantPool constantPool) {
         super(accessFlags, nameIndex, signatureIndex, attributes, constantPool);
     }

     /**
      * Initialize from another object. Note that both objects use the same references (shallow copy). Use clone() for a
      * physical copy.
      *
      * @param c Source to copy.
      */
     public Method(final Method c) {
         super(c);
     }

     /**
      * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class.
      * I.e., the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
      *
      * @param v Visitor object.
      */
     @Override
     public void accept(final Visitor v) {
         v.visitMethod(this);
     }

     /**
      * Creates a deep copy of this method.
      *
      * @param constantPool the constant pool.
      * @return deep copy of this method.
      */
     public Method copy(final ConstantPool constantPool) {
         return (Method) copy_(constantPool);
     }

     /**
      * Return value as defined by given BCELComparator strategy. By default two method objects are said to be equal when
      * their names and signatures are equal.
      *
      * @see Object#equals(Object)
      */
     @Override
     public boolean equals(final Object obj) {
         return obj instanceof Method && bcelComparator.equals(this, (Method) obj);
     }

     /**
      * Gets array of method argument types.
      *
      * @return array of method argument types.
      */
     public Type[] getArgumentTypes() {
         return Type.getArgumentTypes(getSignature());
     }

     /**
      * Gets Code attribute of method, if any.
      *
      * @return Code attribute of method, if any.
      */
     public Code getCode() {
         for (final Attribute attribute : super.getAttributes()) {
             if (attribute instanceof Code) {
                 return (Code) attribute;
             }
         }
         return null;
     }

     /**
      * Gets ExceptionTable attribute of method, if any.
      *
      * @return ExceptionTable attribute of method, if any, that is, list all exceptions the method may throw not exception handlers.
      */
     public ExceptionTable getExceptionTable() {
         for (final Attribute attribute : super.getAttributes()) {
             if (attribute instanceof ExceptionTable) {
                 return (ExceptionTable) attribute;
             }
         }
         return null;
     }

     /**
      * Gets LineNumberTable of code attribute if any.
      *
      * @return LineNumberTable of code attribute if any, for example the call is forwarded to the Code attribute.
      */
     public LineNumberTable getLineNumberTable() {
         final Code code = getCode();
         if (code == null) {
             return null;
         }
         return code.getLineNumberTable();
     }

     /**
      * Gets LocalVariableTable of code attribute if any.
      *
      * @return LocalVariableTable of code attribute if any, for example the call is forwarded to the Code attribute.
      */
     public LocalVariableTable getLocalVariableTable() {
         final Code code = getCode();
         if (code == null) {
             return null;
         }
         return code.getLocalVariableTable();
     }

     /**
      * Gets the local variable type table attribute {@link LocalVariableTypeTable}.
      *
      * @return LocalVariableTypeTable of code attribute if any, for example the call is forwarded to the Code attribute.
      * @since 6.10.0
      */
     public LocalVariableTypeTable getLocalVariableTypeTable() {
         final Code code = getCode();
         if (code == null) {
             return null;
         }
         return code.getLocalVariableTypeTable();
     }

     /**
      * Gets Annotations on the parameters of a method.
      *
      * @return Annotations on the parameters of a method.
      * @since 6.0
      */
     public ParameterAnnotationEntry[] getParameterAnnotationEntries() {
         if (parameterAnnotationEntries == null) {
             parameterAnnotationEntries = ParameterAnnotationEntry.createParameterAnnotationEntries(getAttributes());
         }
         return parameterAnnotationEntries;
     }

     /**
      * Gets return type of method.
      *
      * @return return type of method.
      */
     public Type getReturnType() {
         return Type.getReturnType(getSignature());
     }

     /**
      * Return value as defined by given BCELComparator strategy. By default return the hash code of the method's name XOR
      * signature.
      *
      * @see Object#hashCode()
      */
     @Override
     public int hashCode() {
         return bcelComparator.hashCode(this);
     }

     /**
      * Return string representation close to declaration format, 'public static void main(String[] args) throws
      * IOException', for example.
      *
      * @return String representation of the method.
      */
     @Override
     public String toString() {
         final String access = Utility.accessToString(super.getAccessFlags());
         // Get name and signature from constant pool
         ConstantUtf8 c = super.getConstantPool().getConstantUtf8(super.getSignatureIndex());
         String signature = c.getBytes();
         c = super.getConstantPool().getConstantUtf8(super.getNameIndex());
         final String name = c.getBytes();
         signature = Utility.methodSignatureToString(signature, name, access, true, getLocalVariableTable());
         final StringBuilder buf = new StringBuilder(signature);
         for (final Attribute attribute : super.getAttributes()) {
             if (!(attribute instanceof Code || attribute instanceof ExceptionTable)) {
                 buf.append(" [").append(attribute).append("]");
             }
         }
         final ExceptionTable e = getExceptionTable();
         if (e != null) {
             final String str = e.toString();
             if (!str.isEmpty()) {
                 buf.append("\n\t\tthrows ").append(str);
             }
         }
         return buf.toString();
     }
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you 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
	*
	* https://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.apache.bcel.classfile;

	import java.io.DataInput;
	import java.io.IOException;
	import java.util.Objects;

	import org.apache.bcel.generic.Type;
	import org.apache.bcel.util.BCELComparator;

	/**
	* This class represents the method info structure, that is, the representation for a method in the class. See JVM
	* specification for details. A method has access flags, a name, a signature and a number of attributes.
	*/
	public final class Method extends FieldOrMethod {

	/**
	* Empty array constant.
	*
	* @since 6.6.0
	*/
	public static final Method[] EMPTY_ARRAY = {};

	private static BCELComparator<Method> bcelComparator = new BCELComparator<Method>() {

	@Override
	public boolean equals(final Method a, final Method b) {
	return a == b \|\| a != null && b != null && Objects.equals(a.getName(), b.getName()) && Objects.equals(a.getSignature(), b.getSignature());
	}

	@Override
	public int hashCode(final Method o) {
	return o != null ? Objects.hash(o.getSignature(), o.getName()) : 0;
	}
	};

	/**
	* Gets the comparison strategy object.
	*
	* @return Comparison strategy object.
	*/
	public static BCELComparator<Method> getComparator() {
	return bcelComparator;
	}

	/**
	* Sets the comparison strategy object.
	*
	* @param comparator Comparison strategy object.
	*/
	public static void setComparator(final BCELComparator<Method> comparator) {
	bcelComparator = comparator;
	}

	/** Annotations defined on the parameters of a method. */
	private ParameterAnnotationEntry[] parameterAnnotationEntries;

	/**
	* Empty constructor, all attributes have to be defined via 'setXXX' methods. Use at your own risk.
	*/
	public Method() {
	}

	/**
	* Constructs object from file stream.
	*
	* @param file Input stream.
	* @throws IOException if an I/O error occurs.
	* @throws ClassFormatException if a class is malformed or cannot be interpreted as a class file.
	*/
	Method(final DataInput file, final ConstantPool constantPool) throws IOException, ClassFormatException {
	super(file, constantPool);
	}

	/**
	* Constructs a Method.
	*
	* @param accessFlags Access rights of method.
	* @param nameIndex Points to field name in constant pool.
	* @param signatureIndex Points to encoded signature.
	* @param attributes Collection of attributes.
	* @param constantPool Array of constants.
	*/
	public Method(final int accessFlags, final int nameIndex, final int signatureIndex, final Attribute[] attributes, final ConstantPool constantPool) {
	super(accessFlags, nameIndex, signatureIndex, attributes, constantPool);
	}

	/**
	* Initialize from another object. Note that both objects use the same references (shallow copy). Use clone() for a
	* physical copy.
	*
	* @param c Source to copy.
	*/
	public Method(final Method c) {
	super(c);
	}

	/**
	* Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class.
	* I.e., the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
	*
	* @param v Visitor object.
	*/
	@Override
	public void accept(final Visitor v) {
	v.visitMethod(this);
	}

	/**
	* Creates a deep copy of this method.
	*
	* @param constantPool the constant pool.
	* @return deep copy of this method.
	*/
	public Method copy(final ConstantPool constantPool) {
	return (Method) copy_(constantPool);
	}

	/**
	* Return value as defined by given BCELComparator strategy. By default two method objects are said to be equal when
	* their names and signatures are equal.
	*
	* @see Object#equals(Object)
	*/
	@Override
	public boolean equals(final Object obj) {
	return obj instanceof Method && bcelComparator.equals(this, (Method) obj);
	}

	/**
	* Gets array of method argument types.
	*
	* @return array of method argument types.
	*/
	public Type[] getArgumentTypes() {
	return Type.getArgumentTypes(getSignature());
	}

	/**
	* Gets Code attribute of method, if any.
	*
	* @return Code attribute of method, if any.
	*/
	public Code getCode() {
	for (final Attribute attribute : super.getAttributes()) {
	if (attribute instanceof Code) {
	return (Code) attribute;
	}
	}
	return null;
	}

	/**
	* Gets ExceptionTable attribute of method, if any.
	*
	* @return ExceptionTable attribute of method, if any, that is, list all exceptions the method may throw not exception handlers.
	*/
	public ExceptionTable getExceptionTable() {
	for (final Attribute attribute : super.getAttributes()) {
	if (attribute instanceof ExceptionTable) {
	return (ExceptionTable) attribute;
	}
	}
	return null;
	}

	/**
	* Gets LineNumberTable of code attribute if any.
	*
	* @return LineNumberTable of code attribute if any, for example the call is forwarded to the Code attribute.
	*/
	public LineNumberTable getLineNumberTable() {
	final Code code = getCode();
	if (code == null) {
	return null;
	}
	return code.getLineNumberTable();
	}

	/**
	* Gets LocalVariableTable of code attribute if any.
	*
	* @return LocalVariableTable of code attribute if any, for example the call is forwarded to the Code attribute.
	*/
	public LocalVariableTable getLocalVariableTable() {
	final Code code = getCode();
	if (code == null) {
	return null;
	}
	return code.getLocalVariableTable();
	}

	/**
	* Gets the local variable type table attribute {@link LocalVariableTypeTable}.
	*
	* @return LocalVariableTypeTable of code attribute if any, for example the call is forwarded to the Code attribute.
	* @since 6.10.0
	*/
	public LocalVariableTypeTable getLocalVariableTypeTable() {
	final Code code = getCode();
	if (code == null) {
	return null;
	}
	return code.getLocalVariableTypeTable();
	}

	/**
	* Gets Annotations on the parameters of a method.
	*
	* @return Annotations on the parameters of a method.
	* @since 6.0
	*/
	public ParameterAnnotationEntry[] getParameterAnnotationEntries() {
	if (parameterAnnotationEntries == null) {
	parameterAnnotationEntries = ParameterAnnotationEntry.createParameterAnnotationEntries(getAttributes());
	}
	return parameterAnnotationEntries;
	}

	/**
	* Gets return type of method.
	*
	* @return return type of method.
	*/
	public Type getReturnType() {
	return Type.getReturnType(getSignature());
	}

	/**
	* Return value as defined by given BCELComparator strategy. By default return the hash code of the method's name XOR
	* signature.
	*
	* @see Object#hashCode()
	*/
	@Override
	public int hashCode() {
	return bcelComparator.hashCode(this);
	}

	/**
	* Return string representation close to declaration format, 'public static void main(String[] args) throws
	* IOException', for example.
	*
	* @return String representation of the method.
	*/
	@Override
	public String toString() {
	final String access = Utility.accessToString(super.getAccessFlags());
	// Get name and signature from constant pool
	ConstantUtf8 c = super.getConstantPool().getConstantUtf8(super.getSignatureIndex());
	String signature = c.getBytes();
	c = super.getConstantPool().getConstantUtf8(super.getNameIndex());
	final String name = c.getBytes();
	signature = Utility.methodSignatureToString(signature, name, access, true, getLocalVariableTable());
	final StringBuilder buf = new StringBuilder(signature);
	for (final Attribute attribute : super.getAttributes()) {
	if (!(attribute instanceof Code \|\| attribute instanceof ExceptionTable)) {
	buf.append(" [").append(attribute).append("]");
	}
	}
	final ExceptionTable e = getExceptionTable();
	if (e != null) {
	final String str = e.toString();
	if (!str.isEmpty()) {
	buf.append("\n\t\tthrows ").append(str);
	}
	}
	return buf.toString();
	}
	}