com.sun.codemodel.TypedAnnotationWriter Maven / Gradle / Ivy
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package com.sun.codemodel;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.lang.reflect.Type;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.InvocationTargetException;
import java.lang.annotation.Annotation;
import java.util.Map;
import java.util.HashMap;
/**
* Dynamically implements the typed annotation writer interfaces.
*
* @author Kohsuke Kawaguchi
*/
class TypedAnnotationWriter>
implements InvocationHandler, JAnnotationWriter {
/**
* This is what we are writing to.
*/
private final JAnnotationUse use;
/**
* The annotation that we are writing.
*/
private final Class annotation;
/**
* The type of the writer.
*/
private final Class writerType;
/**
* Keeps track of writers for array members.
* Lazily created.
*/
private Map arrays;
public TypedAnnotationWriter(Class annotation, Class writer, JAnnotationUse use) {
this.annotation = annotation;
this.writerType = writer;
this.use = use;
}
public JAnnotationUse getAnnotationUse() {
return use;
}
public Class getAnnotationType() {
return annotation;
}
@SuppressWarnings("unchecked")
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
if(method.getDeclaringClass()==JAnnotationWriter.class) {
try {
return method.invoke(this,args);
} catch (InvocationTargetException e) {
throw e.getTargetException();
}
}
String name = method.getName();
Object arg=null;
if(args!=null && args.length>0)
arg = args[0];
// check how it's defined on the annotation
Method m = annotation.getDeclaredMethod(name);
Class rt = m.getReturnType();
// array value
if(rt.isArray()) {
return addArrayValue(proxy,name,rt.getComponentType(),method.getReturnType(),arg);
}
// sub annotation
if(Annotation.class.isAssignableFrom(rt)) {
Class r = (Class)rt;
return new TypedAnnotationWriter(
r,method.getReturnType(),use.annotationParam(name,r)).createProxy();
}
// scalar value
if(arg instanceof JType) {
JType targ = (JType) arg;
checkType(Class.class,rt);
if(m.getDefaultValue()!=null) {
// check the default
if(targ.equals(targ.owner().ref((Class)m.getDefaultValue())))
return proxy; // defaulted
}
use.param(name,targ);
return proxy;
}
// other Java built-in types
checkType(arg.getClass(),rt);
if(m.getDefaultValue()!=null && m.getDefaultValue().equals(arg))
// defaulted. no need to write out.
return proxy;
if(arg instanceof String) {
use.param(name,(String)arg);
return proxy;
}
if(arg instanceof Boolean) {
use.param(name,(Boolean)arg);
return proxy;
}
if(arg instanceof Integer) {
use.param(name,(Integer)arg);
return proxy;
}
if(arg instanceof Class) {
use.param(name,(Class)arg);
return proxy;
}
if(arg instanceof Enum) {
use.param(name,(Enum)arg);
return proxy;
}
throw new IllegalArgumentException("Unable to handle this method call "+method.toString());
}
@SuppressWarnings("unchecked")
private Object addArrayValue(Object proxy,String name, Class itemType, Class expectedReturnType, Object arg) {
if(arrays==null)
arrays = new HashMap();
JAnnotationArrayMember m = arrays.get(name);
if(m==null) {
m = use.paramArray(name);
arrays.put(name,m);
}
// sub annotation
if(Annotation.class.isAssignableFrom(itemType)) {
Class r = (Class)itemType;
if(!JAnnotationWriter.class.isAssignableFrom(expectedReturnType))
throw new IllegalArgumentException("Unexpected return type "+expectedReturnType);
return new TypedAnnotationWriter(r,expectedReturnType,m.annotate(r)).createProxy();
}
// primitive
if(arg instanceof JType) {
checkType(Class.class,itemType);
m.param((JType)arg);
return proxy;
}
checkType(arg.getClass(),itemType);
if(arg instanceof String) {
m.param((String)arg);
return proxy;
}
if(arg instanceof Boolean) {
m.param((Boolean)arg);
return proxy;
}
if(arg instanceof Integer) {
m.param((Integer)arg);
return proxy;
}
if(arg instanceof Class) {
m.param((Class)arg);
return proxy;
}
// TODO: enum constant. how should we handle it?
throw new IllegalArgumentException("Unable to handle this method call ");
}
/**
* Check if the type of the argument matches our expectation.
* If not, report an error.
*/
private void checkType(Class actual, Class expected) {
if(expected==actual || expected.isAssignableFrom(actual))
return; // no problem
if( expected==JCodeModel.boxToPrimitive.get(actual) )
return; // no problem
throw new IllegalArgumentException("Expected "+expected+" but found "+actual);
}
/**
* Creates a proxy and returns it.
*/
@SuppressWarnings("unchecked")
private W createProxy() {
return (W)Proxy.newProxyInstance(
SecureLoader.getClassClassLoader(writerType),new Class[]{writerType},this);
}
/**
* Creates a new typed annotation writer.
*/
@SuppressWarnings("unchecked")
static > W create(Class w, JAnnotatable annotatable) {
Class a = findAnnotationType(w);
return (W)new TypedAnnotationWriter(a,w,annotatable.annotate(a)).createProxy();
}
private static Class findAnnotationType(Class clazz) {
for( Type t : clazz.getGenericInterfaces()) {
if(t instanceof ParameterizedType) {
ParameterizedType p = (ParameterizedType) t;
if(p.getRawType()==JAnnotationWriter.class)
return (Class)p.getActualTypeArguments()[0];
}
if(t instanceof Class) {
// recursive search
Class r = findAnnotationType((Class)t);
if(r!=null) return r;
}
}
return null;
}
}