/*
* Distributed as part of mchange-commons-java 0.2.11
*
* Copyright (C) 2015 Machinery For Change, Inc.
*
* Author: Steve Waldman <swaldman@mchange.com>
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of EITHER:
*
* 1) The GNU Lesser General Public License (LGPL), version 2.1, as
* published by the Free Software Foundation
*
* OR
*
* 2) The Eclipse Public License (EPL), version 1.0
*
* You may choose which license to accept if you wish to redistribute
* or modify this work. You may offer derivatives of this work
* under the license you have chosen, or you may provide the same
* choice of license which you have been offered here.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
* You should have received copies of both LGPL v2.1 and EPL v1.0
* along with this software; see the files LICENSE-EPL and LICENSE-LGPL.
* If not, the text of these licenses are currently available at
*
* LGPL v2.1: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* EPL v1.0: http://www.eclipse.org/org/documents/epl-v10.php
*
*/
package com.mchange.v2.codegen.intfc;
import java.io.*;
import java.util.*;
import java.lang.reflect.*;
import com.mchange.v2.codegen.*;
import com.mchange.v1.lang.ClassUtils;
public class DelegatorGenerator
{
int class_modifiers = Modifier.PUBLIC | Modifier.ABSTRACT;
int method_modifiers = Modifier.PUBLIC;
int wrapping_ctor_modifiers = Modifier.PUBLIC;
int default_ctor_modifiers = Modifier.PUBLIC;
boolean wrapping_constructor = true;
boolean default_constructor = true;
boolean inner_getter = true;
boolean inner_setter = true;
Class superclass = null;
Class[] extraInterfaces = null;
// A rarely used feature, see below
Method[] reflectiveDelegateMethods = null; //by default, none of this
ReflectiveDelegationPolicy reflectiveDelegationPolicy = ReflectiveDelegationPolicy.USE_MAIN_DELEGATE_INTERFACE;
final static Comparator classComp = new Comparator()
{
public int compare(Object a, Object b)
{ return ((Class) a).getName().compareTo(((Class) b).getName()); }
};
public void setGenerateInnerSetter( boolean b )
{ this.inner_setter = b; }
public boolean isGenerateInnerSetter()
{ return inner_setter; }
public void setGenerateInnerGetter( boolean b )
{ this.inner_getter = b; }
public boolean isGenerateInnerGetter()
{ return inner_getter; }
public void setGenerateNoArgConstructor( boolean b )
{ this.default_constructor = b; }
public boolean isGenerateNoArgConstructor()
{ return default_constructor; }
public void setGenerateWrappingConstructor( boolean b )
{ this.wrapping_constructor = b; }
public boolean isGenerateWrappingConstructor()
{ return wrapping_constructor; }
public void setWrappingConstructorModifiers( int modifiers )
{ this.wrapping_ctor_modifiers = modifiers; }
public int getWrappingConstructorModifiers()
{ return wrapping_ctor_modifiers; }
public void setNoArgConstructorModifiers( int modifiers )
{ this.default_ctor_modifiers = modifiers; }
public int getNoArgConstructorModifiers()
{ return default_ctor_modifiers; }
public void setMethodModifiers( int modifiers )
{ this.method_modifiers = modifiers; }
public int getMethodModifiers()
{ return method_modifiers; }
public void setClassModifiers( int modifiers )
{ this.class_modifiers = modifiers; }
public int getClassModifiers()
{ return class_modifiers; }
public void setSuperclass( Class superclass )
{ this.superclass = superclass; }
public Class getSuperclass()
{ return superclass; }
public void setExtraInterfaces( Class[] extraInterfaces )
{ this.extraInterfaces = extraInterfaces; }
public Class[] getExtraInterfaces()
{ return extraInterfaces; }
public Method[] getReflectiveDelegateMethods()
{ return reflectiveDelegateMethods; }
/**
* Reflectively delegated methods are methods that are not declared in the interface at
* build time, but that should reflectively be forwarded at runtime to the inner delegate.
* This permits support of public methods not exposed via the interface, or support of
* methods added to versions of the interface newer than the build version.
*
* Note that the declaring class of these methods is simply ignored. Methods will ve
* delegated solely by name and parameter.
*/
public void setReflectiveDelegateMethods(Method[] reflectiveDelegateMethods)
{ this.reflectiveDelegateMethods = reflectiveDelegateMethods; }
public ReflectiveDelegationPolicy getReflectiveDelegationPolicy()
{ return reflectiveDelegationPolicy; }
/**
* If ReflectiveDelegationPolicy.USE_MAIN_DELEGATE_INTERFACE, delegate via the same interface we are generating methods against.
* (This is useful for supporting methods in versions of the interface with methods that don't appear in the version we are generating against.)
*
* If ReflectiveDelegationPolicy.USE_RUNTIME_CLASS, delegate via the runtime class of the delegate. (This is useful if
* the methods come from multiple interfaces, or we want to be able to forward to methods of the delegate class not captured
* by an interface.
*
* Otherwise, use the delegateClass set in the constructor of ReflectiveDelegationPolicy.
*
* Note that if the delegate class is not public or otherwise accessible to the generated proxy, IllegalAccessExceptions may ensue.
*/
public void setReflectiveDelegationPolicy(ReflectiveDelegationPolicy reflectiveDelegationPolicy)
{ this.reflectiveDelegationPolicy = reflectiveDelegationPolicy; }
// public boolean isDelegateViaRuntimeClass()
// { return delegate_via_runtime_class; }
// /**
// * If true, reflective delegate methods are reflected via the runtime Class of the delegate object,
// * rather than via an interface. Nice because the runtime class hopefully supports all the reflective
// * delegates. Not so nice because the runtime class may not be accessible, so reflection may fail
// * with IllegalAccessExceptions.
// */
// public void setDelegateRuntimeClass( boolean delegate_via_runtime_class )
// { this.delegate_via_runtime_class = delegate_via_runtime_class; }
public void writeDelegator(Class intfcl, String genclass, Writer w) throws IOException
{
IndentedWriter iw = CodegenUtils.toIndentedWriter(w);
String pkg = genclass.substring(0, genclass.lastIndexOf('.'));
String sgc = CodegenUtils.fqcnLastElement( genclass );
String scn = (superclass != null ? ClassUtils.simpleClassName( superclass ) : null);
String sin = ClassUtils.simpleClassName( intfcl );
String[] eins = null;
if (extraInterfaces != null)
{
eins = new String[ extraInterfaces.length ];
for (int i = 0, len = extraInterfaces.length; i < len; ++i)
eins[i] = ClassUtils.simpleClassName( extraInterfaces[i] );
}
Set imports = new TreeSet( classComp );
Method[] methods = intfcl.getMethods();
//TODO: don't add array classes!
//build import set
if (! CodegenUtils.inSamePackage( intfcl.getName(), genclass ) )
imports.add( intfcl );
if (superclass != null && ! CodegenUtils.inSamePackage( superclass.getName(), genclass ) )
imports.add( superclass );
if (extraInterfaces != null)
{
for (int i = 0, len = extraInterfaces.length; i < len; ++i)
{
Class checkMe = extraInterfaces[i];
if (! CodegenUtils.inSamePackage( checkMe.getName(), genclass ) )
imports.add( checkMe );
}
}
ensureImports(genclass, imports, methods );
if ( reflectiveDelegateMethods != null )
ensureImports(genclass, imports, reflectiveDelegateMethods );
if ( reflectiveDelegationPolicy.delegateClass != null && !CodegenUtils.inSamePackage( reflectiveDelegationPolicy.delegateClass.getName(), genclass ) )
imports.add( reflectiveDelegationPolicy.delegateClass );
generateBannerComment( iw );
iw.println("package " + pkg + ';');
iw.println();
for (Iterator ii = imports.iterator(); ii.hasNext(); )
iw.println("import "+ ((Class) ii.next()).getName() + ';');
generateExtraImports( iw );
iw.println();
generateClassJavaDocComment( iw );
iw.print(CodegenUtils.getModifierString( class_modifiers ) + " class " + sgc);
if (superclass != null)
iw.print(" extends " + scn);
iw.print(" implements " + sin);
if (eins != null)
for (int i = 0, len = eins.length; i < len; ++i)
iw.print(", " + eins[i]);
iw.println();
iw.println("{");
iw.upIndent();
iw.println("protected " + sin + " inner;");
iw.println();
if (reflectiveDelegateMethods != null)
iw.println("protected Class __delegateClass = null;");
iw.println();
iw.println("private void __setInner( " + sin + " inner )");
iw.println("{");
iw.upIndent();
iw.println("this.inner = inner;");
if (reflectiveDelegateMethods != null)
{
String delegateClassExpr;
if ( reflectiveDelegationPolicy == ReflectiveDelegationPolicy.USE_MAIN_DELEGATE_INTERFACE )
delegateClassExpr = sin + ".class";
else if ( reflectiveDelegationPolicy == ReflectiveDelegationPolicy.USE_RUNTIME_CLASS )
delegateClassExpr = "inner.getClass()";
else
delegateClassExpr = ClassUtils.simpleClassName( reflectiveDelegationPolicy.delegateClass ) + ".class";
iw.println("this.__delegateClass = inner == null ? null : " + delegateClassExpr + ";");
}
iw.downIndent();
iw.println("}");
iw.println();
if ( wrapping_constructor )
{
//System.err.println("WRAPPING CTOR MODIFIERS: " + CodegenUtils.getModifierString( wrapping_ctor_modifiers ) + " (intval: " + wrapping_ctor_modifiers + ")");
iw.println(CodegenUtils.getModifierString( wrapping_ctor_modifiers ) + ' ' + sgc + '(' + sin + " inner)");
iw.println("{ __setInner( inner ); }");
}
if (default_constructor)
{
iw.println();
iw.println(CodegenUtils.getModifierString( default_ctor_modifiers ) + ' ' + sgc + "()");
iw.println("{}");
}
if (inner_setter)
{
iw.println();
iw.println( CodegenUtils.getModifierString( method_modifiers ) + " void setInner( " + sin + " inner )");
iw.println( "{ __setInner( inner ); }" );
}
if (inner_getter)
{
iw.println();
iw.println( CodegenUtils.getModifierString( method_modifiers ) + ' ' + sin + " getInner()");
iw.println( "{ return inner; }" );
}
iw.println();
for (int i = 0, len = methods.length; i < len; ++i)
{
Method method = methods[i];
if (i != 0) iw.println();
iw.println( CodegenUtils.methodSignature( method_modifiers, method, null ) );
iw.println("{");
iw.upIndent();
generatePreDelegateCode( intfcl, genclass, method, iw );
generateDelegateCode( intfcl, genclass, method, iw );
generatePostDelegateCode( intfcl, genclass, method, iw );
iw.downIndent();
iw.println("}");
}
if ( reflectiveDelegateMethods != null )
{
iw.println("// Methods not in core interface to be delegated via reflection");
for (int i = 0, len = reflectiveDelegateMethods.length; i < len; ++i)
{
Method method = reflectiveDelegateMethods[i];
if (i != 0) iw.println();
iw.println( CodegenUtils.methodSignature( method_modifiers, method, null ) );
iw.println("{");
iw.upIndent();
generatePreDelegateCode( intfcl, genclass, method, iw );
generateReflectiveDelegateCode( intfcl, genclass, method, iw );
generatePostDelegateCode( intfcl, genclass, method, iw );
iw.downIndent();
iw.println("}");
}
}
iw.println();
generateExtraDeclarations( intfcl, genclass, iw );
iw.downIndent();
iw.println("}");
}
private void ensureImports(String genclass, Set imports, Method[] methods )
{
for (int i = 0, len = methods.length; i < len; ++i)
{
Class[] args = methods[i].getParameterTypes();
for (int j = 0, jlen = args.length; j < jlen; ++j)
{
if (! CodegenUtils.inSamePackage( args[j].getName(), genclass ) )
imports.add( CodegenUtils.unarrayClass( args[j] ) );
}
Class[] excClasses = methods[i].getExceptionTypes();
for (int j = 0, jlen = excClasses.length; j < jlen; ++j)
{
if (! CodegenUtils.inSamePackage( excClasses[j].getName(), genclass ) )
{
//System.err.println("Adding exception type: " + excClasses[j]);
imports.add( CodegenUtils.unarrayClass( excClasses[j] ) );
}
}
if (! CodegenUtils.inSamePackage( methods[i].getReturnType().getName(), genclass ) )
imports.add( CodegenUtils.unarrayClass( methods[i].getReturnType() ) );
}
}
protected void generateDelegateCode( Class intfcl, String genclass, Method method, IndentedWriter iw ) throws IOException
{
Class retType = method.getReturnType();
iw.println( (retType == void.class ? "" : "return " ) + "inner." + CodegenUtils.methodCall( method ) + ";" );
}
protected void generateReflectiveDelegateCode( Class intfcl, String genclass, Method method, IndentedWriter iw ) throws IOException
{
Class retType = method.getReturnType();
String paramTypesArrayStr = CodegenUtils.reflectiveMethodParameterTypeArray( method );
String argArrayStr = CodegenUtils.reflectiveMethodObjectArray( method );
Class[] exceptionsArray = method.getExceptionTypes();
Set exceptionsSet = new HashSet();
exceptionsSet.addAll( Arrays.asList( exceptionsArray ) );
iw.println("try");
iw.println("{");
iw.upIndent();
iw.println("Method m = __delegateClass.getMethod(\042" + method.getName() + "\042, " + paramTypesArrayStr + ");");
iw.println( (retType == void.class ? "" : "return (" + ClassUtils.simpleClassName( retType ) + ") ") +
"m.invoke( inner, " + argArrayStr + " );" );
iw.downIndent();
iw.println("}");
if (! exceptionsSet.contains( IllegalAccessException.class ) )
{
iw.println("catch (IllegalAccessException iae)");
iw.println("{");
iw.upIndent();
iw.println( "throw new RuntimeException(\042A reflectively delegated method '" +
method.getName() +
"' cannot access the object to which the call is delegated\042, iae);" );
iw.downIndent();
iw.println("}");
}
iw.println("catch (InvocationTargetException ite)");
iw.println("{");
iw.upIndent();
iw.println("Throwable cause = ite.getCause();");
iw.println("if (cause instanceof RuntimeException) throw (RuntimeException) cause;");
iw.println("if (cause instanceof Error) throw (Error) cause;");
int len = exceptionsArray.length;
if (len > 0)
{
for (int i = 0; i < len; ++i)
{
String ecn = ClassUtils.simpleClassName( exceptionsArray[i] );
iw.println("if (cause instanceof " + ecn + ") throw (" + ecn + ") cause;");
}
}
iw.println( "throw new RuntimeException(\042Target of reflectively delegated method '" + method.getName() + "' threw an Exception.\042, cause);" );
iw.downIndent();
iw.println("}");
}
protected void generateBannerComment( IndentedWriter iw ) throws IOException
{
iw.println("/*");
iw.println(" * This class generated by " + this.getClass().getName());
iw.println(" * " + new Date());
iw.println(" * DO NOT HAND EDIT!!!!");
iw.println(" */");
}
protected void generateClassJavaDocComment( IndentedWriter iw ) throws IOException
{
iw.println("/**");
iw.println(" * This class was generated by " + this.getClass().getName() + ".");
iw.println(" */");
}
protected void generateExtraImports( IndentedWriter iw ) throws IOException {}
protected void generatePreDelegateCode( Class intfcl, String genclass, Method method, IndentedWriter iw ) throws IOException {}
protected void generatePostDelegateCode( Class intfcl, String genclass, Method method, IndentedWriter iw ) throws IOException {}
protected void generateExtraDeclarations( Class intfcl, String genclass, IndentedWriter iw ) throws IOException {}
}