package com.nfwork.dbfound.model.reflector;
/*
* Copyright 2009-2012 The MyBatis Team
*
* 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.
*/
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.ReflectPermission;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.concurrent.Callable;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.Future;
import java.util.concurrent.FutureTask;
import com.nfwork.dbfound.exception.DBFoundPackageException;
import com.nfwork.dbfound.util.LogUtil;
/*
* This class represents a cached set of class definition information that
* allows for easy mapping between property names and getter/setter methods.
*/
public class Reflector {
private static final String[] EMPTY_STRING_ARRAY = new String[0];
private Class<?> type;
private String[] readablePropertyNames = EMPTY_STRING_ARRAY;
private String[] writeablePropertyNames = EMPTY_STRING_ARRAY;
private Map<String, Invoker> setMethods = new HashMap<String, Invoker>();
private Map<String, Invoker> getMethods = new HashMap<String, Invoker>();
private Map<String, Class<?>> setTypes = new HashMap<String, Class<?>>();
private Map<String, Class<?>> getTypes = new HashMap<String, Class<?>>();
private Constructor<?> defaultConstructor;
// 字段的别名-字段名
private Map<String, String> alias_name = new HashMap<String, String>();
// 字段名-字段的别名
private Map<String, String> name_alias = new HashMap<String, String>();
private Map<String, String> caseInsensitivePropertyMap = new HashMap<String, String>();
private Reflector(Class<?> clazz) {
type = clazz;
addDefaultConstructor(clazz);
addGetMethods(clazz);
addSetMethods(clazz);
addFields(clazz);
readablePropertyNames = getMethods.keySet().toArray(new String[getMethods.keySet().size()]);
writeablePropertyNames = setMethods.keySet().toArray(new String[setMethods.keySet().size()]);
for (String propName : readablePropertyNames) {
caseInsensitivePropertyMap.put(propName.toUpperCase(Locale.ENGLISH), propName);
}
for (String propName : writeablePropertyNames) {
caseInsensitivePropertyMap.put(propName.toUpperCase(Locale.ENGLISH), propName);
}
}
private void addDefaultConstructor(Class<?> clazz) {
Constructor<?>[] consts = clazz.getDeclaredConstructors();
for (Constructor<?> constructor : consts) {
if (constructor.getParameterTypes().length == 0) {
if (canAccessPrivateMethods()) {
try {
constructor.setAccessible(true);
} catch (Exception e) {
// Ignored. This is only a final precaution, nothing we
// can do.
}
}
if (constructor.isAccessible()) {
this.defaultConstructor = constructor;
}
}
}
}
private void addGetMethods(Class<?> cls) {
Map<String, List<Method>> conflictingGetters = new HashMap<String, List<Method>>();
Method[] methods = getClassMethods(cls);
for (Method method : methods) {
String name = method.getName();
if (name.startsWith("get") && name.length() > 3) {
if (method.getParameterTypes().length == 0) {
name = PropertyNamer.methodToProperty(name);
addMethodConflict(conflictingGetters, name, method);
}
} else if (name.startsWith("is") && name.length() > 2) {
if (method.getParameterTypes().length == 0) {
name = PropertyNamer.methodToProperty(name);
addMethodConflict(conflictingGetters, name, method);
}
}
}
resolveGetterConflicts(conflictingGetters);
}
private void resolveGetterConflicts(Map<String, List<Method>> conflictingGetters) {
for (String propName : conflictingGetters.keySet()) {
List<Method> getters = conflictingGetters.get(propName);
Iterator<Method> iterator = getters.iterator();
Method firstMethod = iterator.next();
if (getters.size() == 1) {
addGetMethod(propName, firstMethod);
} else {
Method getter = firstMethod;
Class<?> getterType = firstMethod.getReturnType();
while (iterator.hasNext()) {
Method method = iterator.next();
Class<?> methodType = method.getReturnType();
if (methodType.equals(getterType)) {
throw new ReflectionException(
"Illegal overloaded getter method with ambiguous type for property " + propName
+ " in class " + firstMethod.getDeclaringClass()
+ ". This breaks the JavaBeans "
+ "specification and can cause unpredicatble results.");
} else if (methodType.isAssignableFrom(getterType)) {
// OK getter type is descendant
} else if (getterType.isAssignableFrom(methodType)) {
getter = method;
getterType = methodType;
} else {
throw new ReflectionException(
"Illegal overloaded getter method with ambiguous type for property " + propName
+ " in class " + firstMethod.getDeclaringClass()
+ ". This breaks the JavaBeans "
+ "specification and can cause unpredicatble results.");
}
}
addGetMethod(propName, getter);
}
}
}
private void addGetMethod(String name, Method method) {
if (isValidPropertyName(name)) {
getMethods.put(name, new MethodInvoker(method));
getTypes.put(name, method.getReturnType());
}
}
private void addSetMethods(Class<?> cls) {
Map<String, List<Method>> conflictingSetters = new HashMap<String, List<Method>>();
Method[] methods = getClassMethods(cls);
for (Method method : methods) {
String name = method.getName();
if (name.startsWith("set") && name.length() > 3) {
if (method.getParameterTypes().length == 1) {
name = PropertyNamer.methodToProperty(name);
addMethodConflict(conflictingSetters, name, method);
}
}
}
resolveSetterConflicts(conflictingSetters);
}
private void addMethodConflict(Map<String, List<Method>> conflictingMethods, String name, Method method) {
List<Method> list = conflictingMethods.get(name);
if (list == null) {
list = new ArrayList<Method>();
conflictingMethods.put(name, list);
}
list.add(method);
}
private void resolveSetterConflicts(Map<String, List<Method>> conflictingSetters) {
for (String propName : conflictingSetters.keySet()) {
List<Method> setters = conflictingSetters.get(propName);
Method firstMethod = setters.get(0);
if (setters.size() == 1) {
addSetMethod(propName, firstMethod);
} else {
Class<?> expectedType = getTypes.get(propName);
if (expectedType == null) {
throw new ReflectionException("Illegal overloaded setter method with ambiguous type for property "
+ propName + " in class " + firstMethod.getDeclaringClass()
+ ". This breaks the JavaBeans " + "specification and can cause unpredicatble results.");
} else {
Iterator<Method> methods = setters.iterator();
Method setter = null;
while (methods.hasNext()) {
Method method = methods.next();
if (method.getParameterTypes().length == 1
&& expectedType.equals(method.getParameterTypes()[0])) {
setter = method;
break;
}
}
if (setter == null) {
throw new ReflectionException(
"Illegal overloaded setter method with ambiguous type for property " + propName
+ " in class " + firstMethod.getDeclaringClass()
+ ". This breaks the JavaBeans "
+ "specification and can cause unpredicatble results.");
}
addSetMethod(propName, setter);
}
}
}
}
private void addSetMethod(String name, Method method) {
if (isValidPropertyName(name)) {
setMethods.put(name, new MethodInvoker(method));
setTypes.put(name, method.getParameterTypes()[0]);
}
}
private void addFields(Class<?> clazz) {
Field[] fields = clazz.getDeclaredFields();
for (Field field : fields) {
if (canAccessPrivateMethods()) {
try {
field.setAccessible(true);
} catch (Exception e) {
// Ignored. This is only a final precaution, nothing we can
// do.
}
}
if (field.isAccessible()) {
if (!setMethods.containsKey(field.getName())) {
// issue 379 - removed the check for final because JDK 1.5
// allows
// modification of final fields through reflection
// (JSR-133). (JGB)
addSetField(field);
}
if (!getMethods.containsKey(field.getName())) {
addGetField(field);
}
}
// 处理g3db_alias注解
Column alias = field.getAnnotation(Column.class);
if (alias != null) {
alias_name.put(alias.name(), field.getName());
name_alias.put(field.getName(), alias.name());
}
}
if (clazz.getSuperclass() != null) {
addFields(clazz.getSuperclass());
}
}
private void addSetField(Field field) {
if (isValidPropertyName(field.getName())) {
setMethods.put(field.getName(), new SetFieldInvoker(field));
setTypes.put(field.getName(), field.getType());
}
}
private void addGetField(Field field) {
if (isValidPropertyName(field.getName())) {
getMethods.put(field.getName(), new GetFieldInvoker(field));
getTypes.put(field.getName(), field.getType());
}
}
private boolean isValidPropertyName(String name) {
return !(name.startsWith("$") || "serialVersionUID".equals(name) || "class".equals(name));
}
/*
* This method returns an array containing all methods declared in this
* class and any superclass. We use this method, instead of the simpler
* Class.getMethods(), because we want to look for private methods as well.
*
* @param cls The class
*
* @return An array containing all methods in this class
*/
private Method[] getClassMethods(Class<?> cls) {
HashMap<String, Method> uniqueMethods = new HashMap<String, Method>();
Class<?> currentClass = cls;
while (currentClass != null) {
addUniqueMethods(uniqueMethods, currentClass.getDeclaredMethods());
// we also need to look for interface methods -
// because the class may be abstract
Class<?>[] interfaces = currentClass.getInterfaces();
for (Class<?> anInterface : interfaces) {
addUniqueMethods(uniqueMethods, anInterface.getMethods());
}
currentClass = currentClass.getSuperclass();
}
Collection<Method> methods = uniqueMethods.values();
return methods.toArray(new Method[methods.size()]);
}
private void addUniqueMethods(HashMap<String, Method> uniqueMethods, Method[] methods) {
for (Method currentMethod : methods) {
if (!currentMethod.isBridge()) {
String signature = getSignature(currentMethod);
// check to see if the method is already known
// if it is known, then an extended class must have
// overridden a method
if (!uniqueMethods.containsKey(signature)) {
if (canAccessPrivateMethods()) {
try {
currentMethod.setAccessible(true);
} catch (Exception e) {
// Ignored. This is only a final precaution, nothing
// we can do.
}
}
uniqueMethods.put(signature, currentMethod);
}
}
}
}
private String getSignature(Method method) {
StringBuilder sb = new StringBuilder();
Class<?> returnType = method.getReturnType();
if (returnType != null) {
sb.append(returnType.getName()).append('#');
}
sb.append(method.getName());
Class<?>[] parameters = method.getParameterTypes();
for (int i = 0; i < parameters.length; i++) {
if (i == 0) {
sb.append(':');
} else {
sb.append(',');
}
sb.append(parameters[i].getName());
}
return sb.toString();
}
private static boolean canAccessPrivateMethods() {
try {
SecurityManager securityManager = System.getSecurityManager();
if (null != securityManager) {
securityManager.checkPermission(new ReflectPermission("suppressAccessChecks"));
}
} catch (SecurityException e) {
return false;
}
return true;
}
/*
* Gets the name of the class the instance provides information for
*
* @return The class name
*/
public Class<?> getType() {
return type;
}
public Constructor<?> getDefaultConstructor() {
if (defaultConstructor != null) {
return defaultConstructor;
} else {
throw new ReflectionException("There is no default constructor for " + type);
}
}
public Invoker getSetInvoker(String propertyName) {
Invoker method = setMethods.get(propertyName);
if (method == null) {
throw new ReflectionException("There is no setter for property named '" + propertyName + "' in '" + type
+ "'");
}
return method;
}
public Invoker getGetInvoker(String propertyName) {
Invoker method = getMethods.get(propertyName);
if (method == null) {
throw new ReflectionException("There is no getter for property named '" + propertyName + "' in '" + type
+ "'");
}
return method;
}
/*
* Gets the type for a property setter
*
* @param propertyName - the name of the property
*
* @return The Class of the propery setter
*/
public Class<?> getSetterType(String propertyName) {
Class<?> clazz = setTypes.get(propertyName);
if (clazz == null) {
throw new ReflectionException("There is no setter for property named '" + propertyName + "' in '" + type
+ "'");
}
return clazz;
}
/*
* Gets the type for a property getter
*
* @param propertyName - the name of the property
*
* @return The Class of the propery getter
*/
public Class<?> getGetterType(String propertyName) {
Class<?> clazz = getTypes.get(propertyName);
if (clazz == null) {
throw new ReflectionException("There is no getter for property named '" + propertyName + "' in '" + type
+ "'");
}
return clazz;
}
/*
* Gets an array of the readable properties for an object
*
* @return The array
*/
public String[] getGetablePropertyNames() {
return readablePropertyNames;
}
/*
* Gets an array of the writeable properties for an object
*
* @return The array
*/
public String[] getSetablePropertyNames() {
return writeablePropertyNames;
}
/*
* Check to see if a class has a writeable property by name
*
* @param propertyName - the name of the property to check
*
* @return True if the object has a writeable property by the name
*/
public boolean hasSetter(String propertyName) {
return setMethods.keySet().contains(propertyName);
}
/*
* Check to see if a class has a readable property by name
*
* @param propertyName - the name of the property to check
*
* @return True if the object has a readable property by the name
*/
public boolean hasGetter(String propertyName) {
return getMethods.keySet().contains(propertyName);
}
public String findPropertyName(String name) {
return caseInsensitivePropertyMap.get(name.toUpperCase(Locale.ENGLISH));
}
/*
* Gets an instance of ClassInfo for the specified class.
*
* @param clazz The class for which to lookup the method cache.
*
* @return The method cache for the class
*/
private static final ConcurrentMap<Class<?>, Future<Reflector>> REFLECTOR_MAP = new ConcurrentHashMap<Class<?>, Future<Reflector>>();
public static Reflector forClass(final Class<?> clazz) {
Future<Reflector> future = REFLECTOR_MAP.get(clazz);
if (future == null) {
Callable<Reflector> callable = new Callable<Reflector>() {
public Reflector call() throws Exception {
Reflector cached = new Reflector(clazz);
LogUtil.info(String.format("load class %s Constructor success", clazz));
return cached;
}
};
FutureTask<Reflector> task = new FutureTask<Reflector>(callable);
future = REFLECTOR_MAP.putIfAbsent(clazz, task);
if (future == null) {
future = task;
task.run();
}
}
try {
return future.get();
} catch (Exception e) {
REFLECTOR_MAP.remove(clazz);
throw new DBFoundPackageException(e);
}
}
public String getFieldName(String column) {
String name = alias_name.get(column);
if (name != null) {
return name;
} else {
return column;
}
}
public String getColumn(String name) {
String column = name_alias.get(name);
if (column != null) {
return column;
} else {
return name;
}
}
}