package org.jtester.bytecode.reflector.helper;
import static java.lang.reflect.Modifier.isStatic;
import java.lang.reflect.Method;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import org.jtester.bytecode.reflector.MethodAccessor;
import org.jtester.exception.JTesterReflectionException;
import org.jtester.exception.NoSuchMethodRuntimeException;
import org.jtester.utility.PrimitiveHelper;
@SuppressWarnings({ "rawtypes", "unchecked" })
public final class MethodHelper {
/**
* 返回class中名称为name,参数类型为 parametersType的方法
*
* @param cls
* @param name
* @param parametersType
* @return
*/
public static final Method getMethod(Class cls, String name, Class... parametersType) {
while (cls != Object.class) {
try {
Method[] methods = cls.getDeclaredMethods();
for (Method method : methods) {
if (method.getName().equals(name) == false) {
continue;
}
if (matchParasType(parametersType, method.getParameterTypes())) {
method.setAccessible(true);
return method;
}
}
throw new NoSuchMethodException();
} catch (NoSuchMethodException e) {
cls = cls.getSuperclass();
}
}
throw new NoSuchMethodRuntimeException("No such method: " + name + "(" + Arrays.toString(parametersType) + ")");
}
/**
* 查找名为name，参数个数为args的方法列表
*
* @param cls
* @param name
* @param args
* @return
*/
public static final List<Method> getMethod(Class cls, String name, int args) {
List<Method> methods = new ArrayList<Method>();
while (cls != Object.class) {
try {
Method[] declares = cls.getDeclaredMethods();
for (Method method : declares) {
if (method.getName().equals(name) == false) {
continue;
}
if (method.getParameterTypes().length == args) {
methods.add(method);
}
}
throw new NoSuchMethodException();
} catch (NoSuchMethodException e) {
cls = cls.getSuperclass();
}
}
return methods;
}
/**
* Returns all declared setter methods of fields of the given class that are
* assignable from the given type.
*
* @param clazz
* The class to get setters from, not null
* @param type
* The type, not null
* @param isStatic
* True if static setters are to be returned, false for
* non-static
* @return A list of Methods, empty list if none found
*/
public static Set<Method> getSettersAssignableFrom(Class clazz, Type type, boolean isStatic) {
Set<Method> settersAssignableFrom = new HashSet<Method>();
Set<Method> allMethods = getAllMethods(clazz);
for (Method method : allMethods) {
if (isSetterMethod(method) && ClazzHelper.isAssignable(type, method.getGenericParameterTypes()[0])
&& (isStatic == isStatic(method.getModifiers()))) {
settersAssignableFrom.add(method);
}
}
return settersAssignableFrom;
}
/**
* Gets all methods of the given class and all its super-classes.
*
* @param clazz
* The class
* @return The methods, not null
*/
public static Set<Method> getAllMethods(Class clazz) {
Set<Method> result = new HashSet<Method>();
if (clazz == null || clazz.equals(Object.class)) {
return result;
}
// add all methods of this class
Method[] declaredMethods = clazz.getDeclaredMethods();
for (Method declaredMethod : declaredMethods) {
if (declaredMethod.isSynthetic() || declaredMethod.isBridge()) {
// skip methods that were added by the compiler
continue;
}
result.add(declaredMethod);
}
// add all methods of the super-classes
result.addAll(getAllMethods(clazz.getSuperclass()));
return result;
}
/**
* Returns the setter methods in the given class that have an argument with
* the exact given type. The class's superclasses are also investigated.
*
* @param clazz
* The class to get the setter from, not null
* @param type
* The type, not null
* @param isStatic
* True if static setters are to be returned, false for
* non-static
* @return All setters for an object of the given type
*/
public static Set<Method> getSettersOfType(Class clazz, Type type) {
Set<Method> settersOfType = new HashSet<Method>();
Set<Method> allMethods = getAllMethods(clazz);
for (Method method : allMethods) {
if (isSetterMethod(method) && method.getGenericParameterTypes()[0].equals(type)) {
settersOfType.add(method);
}
}
return settersOfType;
}
static boolean matchParasType(Class[] expecteds, Class[] actuals) {
if (expecteds == null && actuals == null) {
return true;
} else if (expecteds == null || actuals == null) {
return false;
} else if (expecteds.length != actuals.length) {
return false;
}
for (int index = 0; index < expecteds.length; index++) {
Class expected = expecteds[index];
Class actual = actuals[index];
if (expected == null || expected == actual) {
continue;
} else if (actual != null && actual.isAssignableFrom(expected)) {
continue;
} else if (PrimitiveHelper.isPrimitiveTypeEquals(expected, actual)) {
continue;
} else {
return false;
}
}
return true;
}
/**
* @param method
* The method to check, not null
* @return True if the given method is the {@link Object#equals} method
*/
public static boolean isEqualsMethod(Method method) {
return "equals".equals(method.getName()) && 1 == method.getParameterTypes().length
&& Object.class.equals(method.getParameterTypes()[0]);
}
/**
* @param method
* The method to check, not null
* @return True if the given method is the {@link Object#hashCode} method
*/
public static boolean isHashCodeMethod(Method method) {
return "hashCode".equals(method.getName()) && 0 == method.getParameterTypes().length;
}
/**
* @param method
* The method to check, not null
* @return True if the given method is the {@link Object#toString} method
*/
public static boolean isToStringMethod(Method method) {
return "toString".equals(method.getName()) && 0 == method.getParameterTypes().length;
}
/**
* @param method
* The method to check, not null
* @return True if the given method is the {@link Object#clone} method
*/
public static boolean isCloneMethod(Method method) {
return "clone".equals(method.getName()) && 0 == method.getParameterTypes().length;
}
public static boolean isFinalizeMethod(Method method) {
return "finalize".equals(method.getName()) && 0 == method.getParameterTypes().length;
}
/**
* 判断方法是否是setter方法<br>
* For each method, check if it can be a setter for an object of the given
* type. A setter is a method with the following properties:
* <ul>
* <li>Method name is > 3 characters long and starts with set</li>
* <li>The fourth character is in uppercase</li>
* <li>The method has one parameter, with the type of the property to set</li>
* </ul>
*
* @param method
* The method to check, not null
* @return True if the given method is a setter, false otherwise
*/
public static boolean isSetterMethod(Method method) {
String methodName = method.getName();
if (methodName.startsWith("set") == false || method.getParameterTypes().length != 1 || methodName.length() < 4) {
return false;
}
String fourthLetter = methodName.substring(3, 4);
if (fourthLetter.toUpperCase().equals(fourthLetter)) {
return true;
} else {
return false;
}
}
/**
* 调用类为clazz,名称为method的方法
*
* @param methodName
* @param paras
* @return
* @throws Exception
*/
public static <T> T invoke(Object target, String method, Object... paras) throws Exception {
Class[] paraClazes = getParameterClazz(paras);
MethodAccessor accessor = new MethodAccessor(target, method, paraClazes);
Object result = accessor.invoke(target, paras);
return (T) result;
}
public static <T> T invokeUnThrow(Object target, String method, Object... paras) {
Class[] paraClazes = getParameterClazz(paras);
MethodAccessor accessor = new MethodAccessor(target, method, paraClazes);
Object result = accessor.invokeUnThrow(target, paras);
return (T) result;
}
public static Class[] getParameterClazz(Object... paras) {
if (paras == null) {
return new Class[0];
}
List<Class> clazes = new ArrayList<Class>();
for (Object para : paras) {
clazes.add(para == null ? null : para.getClass());
}
return clazes.toArray(new Class[0]);
}
/**
* 调用静态方法
*
* @param <T>
* @param targetClass
* @param method
* @param paras
* @return
*/
public static <T> T invokeStatic(Class targetClass, String method, Object... paras) {
List<Class> paraClazz = new ArrayList<Class>();
if (paras != null) {
for (Object para : paras) {
paraClazz.add(para == null ? null : para.getClass());
}
}
MethodAccessor accessor = new MethodAccessor(targetClass, method, paraClazz.toArray(new Class[0]));
return (T) accessor.invokeStaticUnThrow(paras);
}
/**
* 根据方法的名称和参数个数查找方法访问器，如果有多于1个同名且参数个数一样的方法，那么抛出异常
*
* @param target
* @param methodName
* @param args
* @return
*/
public static <T> MethodAccessor<T> findMethodByArgCount(Class targetClazz, String methodName, int args) {
List<Method> methods = MethodHelper.getMethod(targetClazz, methodName, args);
if (methods.size() == 0) {
throw new JTesterReflectionException("No such method: " + methodName + ",parameter count:" + args);
}
if (methods.size() > 1) {
throw new JTesterReflectionException("More then one method: " + methodName + ",parameter count:" + args);
}
Method method = methods.get(0);
return new MethodAccessor<T>(method);
}
/**
* 根据方法的名称和参数个数查找方法访问器，如果有多于1个同名且参数个数一样的方法，那么抛出异常
*
* @param <T>
* @param target
* @param methodName
* @param args
* @return
*/
public static <T> MethodAccessor<T> findMethodByArgCount(Object target, String methodName, int args) {
return findMethodByArgCount(target.getClass(), methodName, args);
}
}