package com.takin.rpc.server.invoke;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.Arrays;
import java.util.Map;
import java.util.WeakHashMap;
import org.apache.commons.lang3.reflect.MethodUtils;
import javassist.ClassPool;
import javassist.CtClass;
import javassist.CtConstructor;
import javassist.CtField;
import javassist.CtMethod;
/**
*
* 快速动态方法调用器
*
* @author
*
*/
public class Javassis {
/**
* 调用器池
*/
final private static Map<Method, Invoker> INVOKER_MAP = new WeakHashMap<Method, Javassis.Invoker>();
/**
* 公共调用器池
*/
final private static Map<Integer, Invoker> PUBLIC_INVOKER_MAP = new WeakHashMap<Integer, Invoker>();
public static interface Invoker {
Method method();
Object invoke(Object host, Object[] args);
}
/**
* 输出类型信息
*
* @param argTypes
* @return
*/
private static String argumentTypesToString(Class<?>[] argTypes) {
StringBuilder buf = new StringBuilder();
buf.append("(");
if (argTypes != null) {
for (int i = 0; i < argTypes.length; i++) {
if (i > 0) {
buf.append(", ");
}
Class<?> c = argTypes[i];
buf.append((c == null) ? "null" : c.getName());
}
}
buf.append(")");
return buf.toString();
}
/**
*
* 快捷调用公共方法（性能较差）
*
* @param host
* 宿主对象
* @param name
* 方法名
* @param args
* 方法参数
* @return 执行结果
* @throws NoSuchMethodException
* 如果没有相应的方法
*/
public static Object invokePublic(Object host, String name, Object... args) throws NoSuchMethodException {
final Class<?> clazz = host instanceof Class ? (Class<?>) host : host.getClass();
args = args == null ? new Object[] { null } : args;
Class<?>[] paramTypes = new Class[args.length];
for (int i = 0; i < paramTypes.length; i++) {
paramTypes[i] = args[i] == null ? null : args[i].getClass();
}
int[] keys = new int[3];
keys[0] = clazz.hashCode();
keys[1] = name.hashCode();
keys[2] = Arrays.hashCode(paramTypes);
int key = Arrays.hashCode(keys);
Invoker invoker = PUBLIC_INVOKER_MAP.get(key);
if (invoker == null) {
Method method = MethodUtils.getMatchingAccessibleMethod(clazz, name, paramTypes);
if (method == null) {
throw new NoSuchMethodException(clazz.getName() + "." + name + argumentTypesToString(paramTypes));
}
invoker = newInvoker(method);
PUBLIC_INVOKER_MAP.put(key, invoker);
}
return invoker.invoke(host, args);
}
/**
*
* 根据传入的方法创建快速调用器。 比cglib的性能快4到40倍之间。
*
* @param method
* 方法对象
* @return 调用器
*/
public static Invoker newInvoker(Method method) {
Invoker invoker = INVOKER_MAP.get(method);
if (invoker == null) {
StringBuilder proxyClassNameBuilder = new StringBuilder();
proxyClassNameBuilder.append("proxy.invoker.method$");
proxyClassNameBuilder.append(method.hashCode());
String proxyClassName = proxyClassNameBuilder.toString();
try {
Class<?> proxyClass;
try {
proxyClass = Class.forName(proxyClassName);
} catch (Throwable e) {
ClassPool cp = new ClassPool(true);
CtClass cc = cp.makeClass(proxyClassName);
cc.addField(CtField.make("private java.lang.reflect.Method m;", cc));
CtConstructor ctConstructor = new CtConstructor(new CtClass[] { cp.get(Method.class.getName()) }, cc);
ctConstructor.setBody("{this.m=(java.lang.reflect.Method)$1;}");
cc.addConstructor(ctConstructor);
cc.addInterface(cp.get(Invoker.class.getName()));
cc.addMethod(CtMethod.make("public java.lang.reflect.Method method(){return m;}", cc));
StringBuilder invokeCode = new StringBuilder();
invokeCode.append("public Object invoke(Object host, Object[] args){");
StringBuilder parameterCode = new StringBuilder();
for (int i = 0; i < method.getParameterTypes().length; i++) {
if (i > 0) {
parameterCode.append(",");
}
Class<?> parameterType = method.getParameterTypes()[i];
parameterCode.append(generateCast("args[" + i + "]", Object.class, parameterType));
}
if (method.getParameterTypes().length > 0) {
invokeCode.append("if(args==null||args.length!=");
invokeCode.append(method.getParameterTypes().length);
invokeCode.append(")throw new IllegalArgumentException(\"wrong number of arguments\");");
}
StringBuilder executeCode = new StringBuilder();
executeCode.append("((");
executeCode.append(method.getDeclaringClass().getCanonicalName());
executeCode.append(")");
String objCode = Modifier.isStatic(method.getModifiers()) ? "" : "host";
executeCode.append(objCode);
executeCode.append(").");
executeCode.append(method.getName());
executeCode.append("(");
executeCode.append(parameterCode);
executeCode.append(")");
if (!method.getReturnType().equals(Void.TYPE)) {
invokeCode.append("return ");
invokeCode.append(generateCast(executeCode.toString(), method.getReturnType(), Object.class));
invokeCode.append(";");
} else {
invokeCode.append(executeCode.toString());
invokeCode.append(";return null;");
}
invokeCode.append("}");
cc.addMethod(CtMethod.make(invokeCode.toString(), cc));
proxyClass = cc.toClass();
}
invoker = (Invoker) proxyClass.getConstructor(Method.class).newInstance(method);
INVOKER_MAP.put(method, invoker);
} catch (Throwable e) {
if (e instanceof RuntimeException) {
throw (RuntimeException) e;
}
throw new RuntimeException(e);
}
}
return invoker;
}
/**
*
* 快速动态调用宿主方法。 如果指定了方法名，则执行方法时只会调用指定了的方法。 <br/>
* 如果没有指定方法名，则调用宿主中对应接口类的同名方法。
*
* @param superClass
* 接口类
* @param hostClass
* 宿主类
* @param methodName
* 宿主方法名（可选）
* @param hostMethodParameterTypes
* 宿主方法参数（可选）
* @param hostMethodReturnType
* 宿主方法返回类型（可选）
* @return 代理实例
*/
@SuppressWarnings("unchecked")
public static <T> T newInvoker(Class<T> superClass, Class<?> hostClass, String methodName, Class<?>[] hostMethodParameterTypes, Class<?> hostMethodReturnType) {
try {
methodName = methodName == null ? null : methodName.trim();
StringBuilder proxyClassNameBuilder = new StringBuilder();
proxyClassNameBuilder.append("proxy.invoker$");
proxyClassNameBuilder.append(superClass.hashCode() + 10000000000L);
proxyClassNameBuilder.append("$");
proxyClassNameBuilder.append(hostClass.hashCode() + 10000000000L);
proxyClassNameBuilder.append("$");
if (methodName != null && !methodName.equals("")) {
proxyClassNameBuilder.append(methodName);
}
proxyClassNameBuilder.append("$");
if (hostMethodParameterTypes != null && hostMethodParameterTypes.length > 0) {
proxyClassNameBuilder.append(10000000000L + Arrays.hashCode(hostMethodParameterTypes));
}
proxyClassNameBuilder.append("$");
if (hostMethodReturnType != null) {
proxyClassNameBuilder.append(10000000000L + hostMethodReturnType.hashCode());
}
String proxyClassName = proxyClassNameBuilder.toString();
Class<?> proxyClass;
try {
proxyClass = Class.forName(proxyClassName);
} catch (Exception ex) {
ClassPool cp = new ClassPool(true);
CtClass cc = cp.makeClass(proxyClassName);
if (superClass.isInterface()) {
cc.addInterface(cp.get(superClass.getName()));
} else {
cc.setSuperclass(cp.get(superClass.getName()));
}
Method[] methods = superClass.getMethods();
for (Method method : methods) {
int mod = method.getModifiers();
if (Modifier.isFinal(mod) || Modifier.isStatic(mod)) {
continue;
}
Class<?>[] parameterTypes = method.getParameterTypes();
if (parameterTypes.length < 1 || (!hostClass.isAssignableFrom(parameterTypes[0]) && !parameterTypes[0].isAssignableFrom(hostClass))) {
throw new IllegalArgumentException("The first argument is not a host instance");
}
if (hostMethodParameterTypes != null && hostMethodParameterTypes.length != parameterTypes.length - 1) {
throw new IllegalArgumentException(String.format("The host method parameter types'number should be %d", parameterTypes.length - 1));
}
Class<?> returnType = method.getReturnType();
StringBuilder methodCode = new StringBuilder();
StringBuilder paramCode = new StringBuilder();
methodCode.append("public ");
methodCode.append(returnType.getCanonicalName());
methodCode.append(" ");
methodCode.append(method.getName());
methodCode.append("(");
for (int i = 0; i < parameterTypes.length; i++) {
String canonicalName = parameterTypes[i].getCanonicalName();
if (i > 0) {
methodCode.append(",");
if (i > 1) {
paramCode.append(",");
}
if (hostMethodParameterTypes != null) {
String param = generateCast("p" + i, parameterTypes[i], hostMethodParameterTypes[i - 1]);
paramCode.append(param);
} else {
String param = generateCast("p" + i, parameterTypes[i], parameterTypes[i - 1]);
paramCode.append(param);
}
}
methodCode.append(canonicalName);
methodCode.append(" p");
methodCode.append(i);
}
methodCode.append("){");
StringBuilder executeCode = new StringBuilder();
executeCode.append("((");
executeCode.append(hostClass.getCanonicalName());
executeCode.append(")p0).");
if (methodName == null) {
executeCode.append(method.getName());
} else {
executeCode.append(methodName);
}
executeCode.append("(");
executeCode.append(paramCode);
executeCode.append(")");
if (!returnType.equals(Void.TYPE)) {
methodCode.append("return ");
hostMethodReturnType = hostMethodReturnType == null ? returnType : hostMethodReturnType;
String returnCode = generateCast(executeCode.toString(), hostMethodReturnType, returnType);
methodCode.append(returnCode);
} else {
methodCode.append(executeCode);
}
methodCode.append(";");
methodCode.append("}");
cc.addMethod(CtMethod.make(methodCode.toString(), cc));
}
proxyClass = cc.toClass();
}
return (T) proxyClass.newInstance();
} catch (Exception e) {
if (e instanceof RuntimeException) {
throw (RuntimeException) e;
}
throw new RuntimeException(e);
}
}
private static String generateCast(String arg, Class<?> fromClass, Class<?> toClass) {
StringBuilder cast = new StringBuilder();
if (fromClass.isPrimitive() && !toClass.isPrimitive()) {
Class<?> wraperClass = toClass;
if (!isWraper(toClass)) {
wraperClass = getWraper(fromClass);
}
cast.append("(");
cast.append(toClass.getCanonicalName());
cast.append(")");
cast.append(wraperClass.getCanonicalName());
cast.append(".valueOf((");
cast.append(getPrimitive(wraperClass).getCanonicalName());
cast.append(")");
cast.append(arg);
cast.append(")");
} else if (!fromClass.isPrimitive() && toClass.isPrimitive()) {
cast.append("(");
cast.append(toClass.getCanonicalName());
cast.append(")");
Class<?> wraperClass = fromClass;
if (!isWraper(fromClass)) {
wraperClass = getWraper(toClass);
cast.append("((");
if (Number.class.isAssignableFrom(wraperClass)) {
cast.append(Number.class.getCanonicalName());
} else {
cast.append(wraperClass.getCanonicalName());
}
cast.append(")");
cast.append(arg);
cast.append(")");
} else {
cast.append(arg);
}
cast.append(".");
cast.append(getPrimitive(wraperClass).getCanonicalName());
cast.append("Value()");
} else {
cast.append("(");
cast.append(toClass.getCanonicalName());
cast.append(")");
cast.append(arg);
}
return cast.toString();
}
private static Class<?> getPrimitive(Class<?> wraperClass) {
if (wraperClass.equals(Integer.class)) {
return Integer.TYPE;
}
if (wraperClass.equals(Short.class)) {
return Short.TYPE;
}
if (wraperClass.equals(Long.class)) {
return Long.TYPE;
}
if (wraperClass.equals(Float.class)) {
return Float.TYPE;
}
if (wraperClass.equals(Double.class)) {
return Double.TYPE;
}
if (wraperClass.equals(Byte.class)) {
return Byte.TYPE;
}
if (wraperClass.equals(Character.class)) {
return Character.TYPE;
}
if (wraperClass.equals(Boolean.class)) {
return Boolean.TYPE;
}
if (wraperClass.equals(Void.class)) {
return Void.TYPE;
}
return wraperClass;
}
private static Class<?> getWraper(Class<?> toClass) {
if (toClass.equals(Integer.TYPE)) {
return Integer.class;
}
if (toClass.equals(Short.TYPE)) {
return Short.class;
}
if (toClass.equals(Long.TYPE)) {
return Long.class;
}
if (toClass.equals(Float.TYPE)) {
return Float.class;
}
if (toClass.equals(Double.TYPE)) {
return Double.class;
}
if (toClass.equals(Byte.TYPE)) {
return Byte.class;
}
if (toClass.equals(Character.TYPE)) {
return Character.class;
}
if (toClass.equals(Boolean.TYPE)) {
return Boolean.class;
}
if (toClass.equals(Void.TYPE)) {
return Void.class;
}
return toClass;
}
private static boolean isWraper(Class<?> toClass) {
if (toClass.equals(Integer.class)) {
return true;
}
if (toClass.equals(Short.class)) {
return true;
}
if (toClass.equals(Long.class)) {
return true;
}
if (toClass.equals(Float.class)) {
return true;
}
if (toClass.equals(Double.class)) {
return true;
}
if (toClass.equals(Byte.class)) {
return true;
}
if (toClass.equals(Character.class)) {
return true;
}
if (toClass.equals(Boolean.class)) {
return true;
}
if (toClass.equals(Void.class)) {
return true;
}
return false;
}
/**
* 快速动态调用宿主方法。 如果指定了方法名，则执行方法时只会调用指定了的方法。 <br/>
* 如果没有指定方法名，则调用宿主中对应接口类的同名方法。
*
* @param superClass
* 接口类
* @param hostClass
* 宿主类
* @param methodName
* 方法名（可选）
* @return 代理实例
*/
public static <T> T newInvoker(Class<T> superClass, Class<?> hostClass, String methodName) {
return newInvoker(superClass, hostClass, methodName, null, null);
}
/**
* 快速动态调用宿主方法。调用宿主中对应接口类的同名方法。
*
* @param superClass
* 接口类
* @param hostClass
* 宿主类
* @return 代理实例
*/
public static <T> T newInvoker(Class<T> superClass, Class<?> hostClass) {
return newInvoker(superClass, hostClass, null);
}
}
