org.apache.wink.common.internal.registry.metadata.AbstractMetadataCollector Maven / Gradle / Ivy
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package org.apache.wink.common.internal.registry.metadata;
import java.beans.PropertyDescriptor;
import java.lang.annotation.Annotation;
import java.lang.reflect.AccessibleObject;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import javax.ws.rs.Encoded;
import org.apache.wink.common.internal.registry.Injectable;
import org.apache.wink.common.internal.registry.InjectableFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Collects common class meta data of JAX-RS Resources and Providers
*/
public abstract class AbstractMetadataCollector {
private static final Logger logger = LoggerFactory.getLogger(AbstractMetadataCollector.class);
private final ClassMetadata metadata;
public AbstractMetadataCollector(Class clazz) {
metadata = new ClassMetadata(clazz);
}
/**
* Parses fields.
*
* Warning! Don't call this method from constructor, since it invoked an
* abstract method parseField()! It's possible to call this method from
* constructor only, when you override parseField() and set it to be final.
*/
protected final void parseFields() {
logger.trace("parseFields() entry");
Class resourceClass = metadata.getResourceClass();
logger.trace("Class is {}", resourceClass);
List injectableFields = metadata.getInjectableFields();
logger.trace("Injectable fields: {}", injectableFields);
// add fields
while (resourceClass != Object.class && resourceClass != null) {
for (Field field : resourceClass.getDeclaredFields()) {
Type fieldType = field.getGenericType();
Injectable injectable = parseAccessibleObject(field, fieldType);
logger.trace("Field is {} and injectable is {}", fieldType, injectable);
if (injectable != null) {
injectableFields.add(injectable);
}
}
resourceClass = resourceClass.getSuperclass();
}
logger.trace("Injectable fields: {}", injectableFields);
// add properties
PropertyDescriptor[] propertyDescriptors = metadata.getBeanInfo().getPropertyDescriptors();
if(logger.isTraceEnabled()) {
logger.trace("Property descriptors are: {}", Arrays.asList(propertyDescriptors));
}
if (propertyDescriptors != null) {
l: for (PropertyDescriptor pd : propertyDescriptors) {
Method writeMethod = pd.getWriteMethod();
if (writeMethod == null) {
// the property cannot be written, ignore it.
continue l;
}
if(logger.isTraceEnabled()) {
logger.trace("Method under inspection: {}", writeMethod.getName());
}
Type genericReturnType = writeMethod.getParameterTypes()[0];
Injectable injectable = parseAccessibleObject(writeMethod, genericReturnType);
if (injectable != null) {
injectableFields.add(injectable);
}
if(logger.isTraceEnabled()) {
logger.trace("Injectable under inspection: {}", injectable);
}
}
}
logger.trace("parseFields() exit");
}
protected abstract Injectable parseAccessibleObject(AccessibleObject field, Type fieldType);
protected abstract boolean isConstructorParameterValid(Injectable fp);
/**
* Parses constructors.
*
* Warning! Don't call this method from constructor, since it invoked an
* abstract method isConstructorParameterValid()! It's possible to call
* this method from constructor only, when you override
* isConstructorParameterValid() and set it to be final.
*/
protected final void parseConstructors() {
logger.trace("parseConstructors() entry");
ConstructorMetadata constructorMetadata = new ConstructorMetadata();
List formalParameters = new ArrayList();
Class resourceClass = metadata.getResourceClass();
L1: for (Constructor constructor : resourceClass.getDeclaredConstructors()) {
logger.trace("Constructor is {}", constructor);
int modifiers = constructor.getModifiers();
if (!Modifier.isPublic(modifiers)) {
logger.trace("Constructor is skipped because not public");
continue;
}
constructorMetadata.setEncoded(constructor.getAnnotation(Encoded.class) != null);
// gather all formal parameters
formalParameters.clear();
// TODO: Notice that due to the bug
// http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6332964 in
// Java 1.5, this method will throw
// and exception for inner non-static classes
// need to catch an exception and print warning message
// In addition need to check that it works in Java 1.6
Annotation[][] parameterAnnotations = constructor.getParameterAnnotations();
Type[] paramTypes = constructor.getGenericParameterTypes();
// boolean isValidConstructor = true;
// gather all formal parameters as list of injectable data
for (int pos = 0, limit = paramTypes.length; pos < limit; pos++) {
Injectable fp =
InjectableFactory.getInstance()
.create(paramTypes[pos],
parameterAnnotations[pos],
constructor,
getMetadata().isEncoded() || constructorMetadata.isEncoded(),
null);
if (!isConstructorParameterValid(fp)) {
continue L1;
}
formalParameters.add(fp);
}
// if this is the first valid constructor found or
// if found another valid constructor with more parameters
if ((constructorMetadata.getConstructor() == null) || (constructorMetadata
.getFormalParameters().size() < paramTypes.length)) {
constructorMetadata.setConstructor(constructor);
constructorMetadata.getFormalParameters().clear();
constructorMetadata.getFormalParameters().addAll(formalParameters);
} else if (constructorMetadata.getFormalParameters().size() == paramTypes.length) {
// TODO: log warning about finding another valid constructor
// with the same number
// of parameters
} else {
// this is a constructor will less parameters, nothing to do
}
}
logger.trace("Set constructor to {}", constructorMetadata);
metadata.setConstructor(constructorMetadata);
logger.trace("parseConstructors() exit");
}
protected void parseEncoded(Class cls) {
logger.trace("parseEncoded({}) entry", cls);
Encoded encoded = cls.getAnnotation(Encoded.class);
if (encoded != null) {
metadata.setEncoded(true);
logger.trace("parseEncoded() setEncoded to true");
}
logger.trace("parseEncoded() exit");
}
public ClassMetadata getMetadata() {
return metadata;
}
}