/*
* Copyright 1999-2011 Alibaba Group.
*
* 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.
*/
package com.alibaba.dubbo.common.utils;
import java.lang.reflect.Array;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.GenericArrayType;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.ParameterizedType;
import java.net.URL;
import java.security.CodeSource;
import java.security.ProtectionDomain;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javassist.CtClass;
import javassist.CtConstructor;
import javassist.CtMethod;
import javassist.NotFoundException;
/**
* ReflectUtils
*
* @author qian.lei
*/
public final class ReflectUtils {
/**
* void(V).
*/
public static final char JVM_VOID = 'V';
/**
* boolean(Z).
*/
public static final char JVM_BOOLEAN = 'Z';
/**
* byte(B).
*/
public static final char JVM_BYTE = 'B';
/**
* char(C).
*/
public static final char JVM_CHAR = 'C';
/**
* double(D).
*/
public static final char JVM_DOUBLE = 'D';
/**
* float(F).
*/
public static final char JVM_FLOAT = 'F';
/**
* int(I).
*/
public static final char JVM_INT = 'I';
/**
* long(J).
*/
public static final char JVM_LONG = 'J';
/**
* short(S).
*/
public static final char JVM_SHORT = 'S';
public static final Class<?>[] EMPTY_CLASS_ARRAY = new Class<?>[0];
public static final String JAVA_IDENT_REGEX = "(?:[_$a-zA-Z][_$a-zA-Z0-9]*)";
public static final String JAVA_NAME_REGEX = "(?:" + JAVA_IDENT_REGEX + "(?:\\." + JAVA_IDENT_REGEX + ")*)";
public static final String CLASS_DESC = "(?:L" + JAVA_IDENT_REGEX + "(?:\\/" + JAVA_IDENT_REGEX + ")*;)";
public static final String ARRAY_DESC = "(?:\\[+(?:(?:[VZBCDFIJS])|" + CLASS_DESC + "))";
public static final String DESC_REGEX = "(?:(?:[VZBCDFIJS])|" + CLASS_DESC + "|" + ARRAY_DESC + ")";
public static final Pattern DESC_PATTERN = Pattern.compile(DESC_REGEX);
public static final String METHOD_DESC_REGEX = "(?:("+JAVA_IDENT_REGEX+")?\\(("+DESC_REGEX+"*)\\)("+DESC_REGEX+")?)";
public static final Pattern METHOD_DESC_PATTERN = Pattern.compile(METHOD_DESC_REGEX);
public static final Pattern GETTER_METHOD_DESC_PATTERN = Pattern.compile("get([A-Z][_a-zA-Z0-9]*)\\(\\)(" + DESC_REGEX + ")");
public static final Pattern SETTER_METHOD_DESC_PATTERN = Pattern.compile("set([A-Z][_a-zA-Z0-9]*)\\((" + DESC_REGEX + ")\\)V");
public static final Pattern IS_HAS_CAN_METHOD_DESC_PATTERN = Pattern.compile("(?:is|has|can)([A-Z][_a-zA-Z0-9]*)\\(\\)Z");
private static final ConcurrentMap<String, Class<?>> DESC_CLASS_CACHE = new ConcurrentHashMap<String, Class<?>>();
private static final ConcurrentMap<String, Class<?>> NAME_CLASS_CACHE = new ConcurrentHashMap<String, Class<?>>();
private static final ConcurrentMap<String, Method> Signature_METHODS_CACHE = new ConcurrentHashMap<String, Method>();
public static boolean isPrimitives(Class<?> cls) {
if (cls.isArray()) {
return isPrimitive(cls.getComponentType());
}
return isPrimitive(cls);
}
public static boolean isPrimitive(Class<?> cls) {
return cls.isPrimitive() || cls == String.class || cls == Boolean.class || cls == Character.class
|| Number.class.isAssignableFrom(cls) || Date.class.isAssignableFrom(cls);
}
public static Class<?> getBoxedClass(Class<?> c) {
if( c == int.class )
c = Integer.class;
else if( c == boolean.class )
c = Boolean.class;
else if( c == long.class )
c = Long.class;
else if( c == float.class )
c = Float.class;
else if( c == double.class )
c = Double.class;
else if( c == char.class )
c = Character.class;
else if( c == byte.class )
c = Byte.class;
else if( c == short.class )
c = Short.class;
return c;
}
/**
* is compatible.
*
* @param c class.
* @param o instance.
* @return compatible or not.
*/
public static boolean isCompatible(Class<?> c, Object o)
{
boolean pt = c.isPrimitive();
if( o == null )
return !pt;
if( pt )
{
if( c == int.class )
c = Integer.class;
else if( c == boolean.class )
c = Boolean.class;
else if( c == long.class )
c = Long.class;
else if( c == float.class )
c = Float.class;
else if( c == double.class )
c = Double.class;
else if( c == char.class )
c = Character.class;
else if( c == byte.class )
c = Byte.class;
else if( c == short.class )
c = Short.class;
}
if( c == o.getClass() )
return true;
return c.isInstance(o);
}
/**
* is compatible.
*
* @param cs class array.
* @param os object array.
* @return compatible or not.
*/
public static boolean isCompatible(Class<?>[] cs, Object[] os)
{
int len = cs.length;
if( len != os.length ) return false;
if( len == 0 ) return true;
for(int i=0;i<len;i++)
if( !isCompatible(cs[i], os[i]) ) return false;
return true;
}
public static String getCodeBase(Class<?> cls) {
if (cls == null)
return null;
ProtectionDomain domain = cls.getProtectionDomain();
if (domain == null)
return null;
CodeSource source = domain.getCodeSource();
if (source == null)
return null;
URL location = source.getLocation();
if (location == null)
return null;
return location.getFile();
}
/**
* get name.
* java.lang.Object[][].class => "java.lang.Object[][]"
*
* @param c class.
* @return name.
*/
public static String getName(Class<?> c)
{
if( c.isArray() )
{
StringBuilder sb = new StringBuilder();
do
{
sb.append("[]");
c = c.getComponentType();
}
while( c.isArray() );
return c.getName() + sb.toString();
}
return c.getName();
}
public static Class<?> getGenericClass(Class<?> cls) {
return getGenericClass(cls, 0);
}
public static Class<?> getGenericClass(Class<?> cls, int i) {
try {
ParameterizedType parameterizedType = ((ParameterizedType) cls.getGenericInterfaces()[0]);
Object genericClass = parameterizedType.getActualTypeArguments()[i];
if (genericClass instanceof ParameterizedType) { // 处理多级泛型
return (Class<?>) ((ParameterizedType) genericClass).getRawType();
} else if (genericClass instanceof GenericArrayType) { // 处理数组泛型
return (Class<?>) ((GenericArrayType) genericClass).getGenericComponentType();
} else if (((Class)genericClass).isArray()) {
// 在 JDK 7 以上的版本, Foo<int[]> 不再是 GenericArrayType
return ((Class)genericClass).getComponentType();
} else {
return (Class<?>) genericClass;
}
} catch (Throwable e) {
throw new IllegalArgumentException(cls.getName()
+ " generic type undefined!", e);
}
}
/**
* get method name.
* "void do(int)", "void do()", "int do(java.lang.String,boolean)"
*
* @param m method.
* @return name.
*/
public static String getName(final Method m)
{
StringBuilder ret = new StringBuilder();
ret.append(getName(m.getReturnType())).append(' ');
ret.append(m.getName()).append('(');
Class<?>[] parameterTypes = m.getParameterTypes();
for(int i=0;i<parameterTypes.length;i++)
{
if( i > 0 )
ret.append(',');
ret.append(getName(parameterTypes[i]));
}
ret.append(')');
return ret.toString();
}
public static String getSignature(String methodName, Class<?>[] parameterTypes) {
StringBuilder sb = new StringBuilder(methodName);
sb.append("(");
if (parameterTypes != null && parameterTypes.length > 0) {
boolean first = true;
for (Class<?> type : parameterTypes) {
if (first) {
first = false;
} else {
sb.append(",");
}
sb.append(type.getName());
}
}
sb.append(")");
return sb.toString();
}
/**
* get constructor name.
* "()", "(java.lang.String,int)"
*
* @param c constructor.
* @return name.
*/
public static String getName(final Constructor<?> c)
{
StringBuilder ret = new StringBuilder("(");
Class<?>[] parameterTypes = c.getParameterTypes();
for(int i=0;i<parameterTypes.length;i++)
{
if( i > 0 )
ret.append(',');
ret.append(getName(parameterTypes[i]));
}
ret.append(')');
return ret.toString();
}
/**
* get class desc.
* boolean[].class => "[Z"
* Object.class => "Ljava/lang/Object;"
*
* @param c class.
* @return desc.
* @throws NotFoundException
*/
public static String getDesc(Class<?> c)
{
StringBuilder ret = new StringBuilder();
while( c.isArray() )
{
ret.append('[');
c = c.getComponentType();
}
if( c.isPrimitive() )
{
String t = c.getName();
if( "void".equals(t) ) ret.append(JVM_VOID);
else if( "boolean".equals(t) ) ret.append(JVM_BOOLEAN);
else if( "byte".equals(t) ) ret.append(JVM_BYTE);
else if( "char".equals(t) ) ret.append(JVM_CHAR);
else if( "double".equals(t) ) ret.append(JVM_DOUBLE);
else if( "float".equals(t) ) ret.append(JVM_FLOAT);
else if( "int".equals(t) ) ret.append(JVM_INT);
else if( "long".equals(t) ) ret.append(JVM_LONG);
else if( "short".equals(t) ) ret.append(JVM_SHORT);
}
else
{
ret.append('L');
ret.append(c.getName().replace('.', '/'));
ret.append(';');
}
return ret.toString();
}
/**
* get class array desc.
* [int.class, boolean[].class, Object.class] => "I[ZLjava/lang/Object;"
*
* @param cs class array.
* @return desc.
* @throws NotFoundException
*/
public static String getDesc(final Class<?>[] cs)
{
if( cs.length == 0 )
return "";
StringBuilder sb = new StringBuilder(64);
for( Class<?> c : cs )
sb.append(getDesc(c));
return sb.toString();
}
/**
* get method desc.
* int do(int arg1) => "do(I)I"
* void do(String arg1,boolean arg2) => "do(Ljava/lang/String;Z)V"
*
* @param m method.
* @return desc.
*/
public static String getDesc(final Method m)
{
StringBuilder ret = new StringBuilder(m.getName()).append('(');
Class<?>[] parameterTypes = m.getParameterTypes();
for(int i=0;i<parameterTypes.length;i++)
ret.append(getDesc(parameterTypes[i]));
ret.append(')').append(getDesc(m.getReturnType()));
return ret.toString();
}
/**
* get constructor desc.
* "()V", "(Ljava/lang/String;I)V"
*
* @param c constructor.
* @return desc
*/
public static String getDesc(final Constructor<?> c)
{
StringBuilder ret = new StringBuilder("(");
Class<?>[] parameterTypes = c.getParameterTypes();
for(int i=0;i<parameterTypes.length;i++)
ret.append(getDesc(parameterTypes[i]));
ret.append(')').append('V');
return ret.toString();
}
/**
* get method desc.
* "(I)I", "()V", "(Ljava/lang/String;Z)V"
*
* @param m method.
* @return desc.
*/
public static String getDescWithoutMethodName(Method m)
{
StringBuilder ret = new StringBuilder();
ret.append('(');
Class<?>[] parameterTypes = m.getParameterTypes();
for(int i=0;i<parameterTypes.length;i++)
ret.append(getDesc(parameterTypes[i]));
ret.append(')').append(getDesc(m.getReturnType()));
return ret.toString();
}
/**
* get class desc.
* Object.class => "Ljava/lang/Object;"
* boolean[].class => "[Z"
*
* @param c class.
* @return desc.
* @throws NotFoundException
*/
public static String getDesc(final CtClass c) throws NotFoundException
{
StringBuilder ret = new StringBuilder();
if( c.isArray() )
{
ret.append('[');
ret.append(getDesc(c.getComponentType()));
}
else if( c.isPrimitive() )
{
String t = c.getName();
if( "void".equals(t) ) ret.append(JVM_VOID);
else if( "boolean".equals(t) ) ret.append(JVM_BOOLEAN);
else if( "byte".equals(t) ) ret.append(JVM_BYTE);
else if( "char".equals(t) ) ret.append(JVM_CHAR);
else if( "double".equals(t) ) ret.append(JVM_DOUBLE);
else if( "float".equals(t) ) ret.append(JVM_FLOAT);
else if( "int".equals(t) ) ret.append(JVM_INT);
else if( "long".equals(t) ) ret.append(JVM_LONG);
else if( "short".equals(t) ) ret.append(JVM_SHORT);
}
else
{
ret.append('L');
ret.append(c.getName().replace('.','/'));
ret.append(';');
}
return ret.toString();
}
/**
* get method desc.
* "do(I)I", "do()V", "do(Ljava/lang/String;Z)V"
*
* @param m method.
* @return desc.
*/
public static String getDesc(final CtMethod m) throws NotFoundException
{
StringBuilder ret = new StringBuilder(m.getName()).append('(');
CtClass[] parameterTypes = m.getParameterTypes();
for(int i=0;i<parameterTypes.length;i++)
ret.append(getDesc(parameterTypes[i]));
ret.append(')').append(getDesc(m.getReturnType()));
return ret.toString();
}
/**
* get constructor desc.
* "()V", "(Ljava/lang/String;I)V"
*
* @param c constructor.
* @return desc
*/
public static String getDesc(final CtConstructor c) throws NotFoundException
{
StringBuilder ret = new StringBuilder("(");
CtClass[] parameterTypes = c.getParameterTypes();
for(int i=0;i<parameterTypes.length;i++)
ret.append(getDesc(parameterTypes[i]));
ret.append(')').append('V');
return ret.toString();
}
/**
* get method desc.
* "(I)I", "()V", "(Ljava/lang/String;Z)V".
*
* @param m method.
* @return desc.
*/
public static String getDescWithoutMethodName(final CtMethod m) throws NotFoundException
{
StringBuilder ret = new StringBuilder();
ret.append('(');
CtClass[] parameterTypes = m.getParameterTypes();
for(int i=0;i<parameterTypes.length;i++)
ret.append(getDesc(parameterTypes[i]));
ret.append(')').append(getDesc(m.getReturnType()));
return ret.toString();
}
/**
* name to desc.
* java.util.Map[][] => "[[Ljava/util/Map;"
*
* @param name name.
* @return desc.
*/
public static String name2desc(String name)
{
StringBuilder sb = new StringBuilder();
int c = 0,index = name.indexOf('[');
if( index > 0 )
{
c = ( name.length() - index ) / 2;
name = name.substring(0,index);
}
while( c-- > 0 ) sb.append("[");
if( "void".equals(name) ) sb.append(JVM_VOID);
else if( "boolean".equals(name) ) sb.append(JVM_BOOLEAN);
else if( "byte".equals(name) ) sb.append(JVM_BYTE);
else if( "char".equals(name) ) sb.append(JVM_CHAR);
else if( "double".equals(name) ) sb.append(JVM_DOUBLE);
else if( "float".equals(name) ) sb.append(JVM_FLOAT);
else if( "int".equals(name) ) sb.append(JVM_INT);
else if( "long".equals(name) ) sb.append(JVM_LONG);
else if( "short".equals(name) ) sb.append(JVM_SHORT);
else sb.append('L').append(name.replace('.', '/')).append(';');
return sb.toString();
}
/**
* desc to name.
* "[[I" => "int[][]"
*
* @param desc desc.
* @return name.
*/
public static String desc2name(String desc)
{
StringBuilder sb = new StringBuilder();
int c = desc.lastIndexOf('[') + 1;
if( desc.length() == c+1 )
{
switch( desc.charAt(c) )
{
case JVM_VOID: { sb.append("void"); break; }
case JVM_BOOLEAN: { sb.append("boolean"); break; }
case JVM_BYTE: { sb.append("byte"); break; }
case JVM_CHAR: { sb.append("char"); break; }
case JVM_DOUBLE: { sb.append("double"); break; }
case JVM_FLOAT: { sb.append("float"); break; }
case JVM_INT: { sb.append("int"); break; }
case JVM_LONG: { sb.append("long"); break; }
case JVM_SHORT: { sb.append("short"); break; }
default:
throw new RuntimeException();
}
}
else
{
sb.append(desc.substring(c+1, desc.length()-1).replace('/','.'));
}
while( c-- > 0 ) sb.append("[]");
return sb.toString();
}
public static Class<?> forName(String name) {
try {
return name2class(name);
} catch (ClassNotFoundException e) {
throw new IllegalStateException("Not found class " + name + ", cause: " + e.getMessage(), e);
}
}
/**
* name to class.
* "boolean" => boolean.class
* "java.util.Map[][]" => java.util.Map[][].class
*
* @param name name.
* @return Class instance.
*/
public static Class<?> name2class(String name) throws ClassNotFoundException
{
return name2class(ClassHelper.getClassLoader(), name);
}
/**
* name to class.
* "boolean" => boolean.class
* "java.util.Map[][]" => java.util.Map[][].class
*
* @param cl ClassLoader instance.
* @param name name.
* @return Class instance.
*/
private static Class<?> name2class(ClassLoader cl, String name) throws ClassNotFoundException
{
int c = 0, index = name.indexOf('[');
if( index > 0 )
{
c = ( name.length() - index ) / 2;
name = name.substring(0, index);
}
if( c > 0 )
{
StringBuilder sb = new StringBuilder();
while( c-- > 0 )
sb.append("[");
if( "void".equals(name) ) sb.append(JVM_VOID);
else if( "boolean".equals(name) ) sb.append(JVM_BOOLEAN);
else if( "byte".equals(name) ) sb.append(JVM_BYTE);
else if( "char".equals(name) ) sb.append(JVM_CHAR);
else if( "double".equals(name) ) sb.append(JVM_DOUBLE);
else if( "float".equals(name) ) sb.append(JVM_FLOAT);
else if( "int".equals(name) ) sb.append(JVM_INT);
else if( "long".equals(name) ) sb.append(JVM_LONG);
else if( "short".equals(name) ) sb.append(JVM_SHORT);
else sb.append('L').append(name).append(';'); // "java.lang.Object" ==> "Ljava.lang.Object;"
name = sb.toString();
}
else
{
if( "void".equals(name) ) return void.class;
else if( "boolean".equals(name) ) return boolean.class;
else if( "byte".equals(name) ) return byte.class;
else if( "char".equals(name) ) return char.class;
else if( "double".equals(name) ) return double.class;
else if( "float".equals(name) ) return float.class;
else if( "int".equals(name) ) return int.class;
else if( "long".equals(name) ) return long.class;
else if( "short".equals(name) ) return short.class;
}
if( cl == null )
cl = ClassHelper.getClassLoader();
Class<?> clazz = NAME_CLASS_CACHE.get(name);
if(clazz == null){
clazz = Class.forName(name, true, cl);
NAME_CLASS_CACHE.put(name, clazz);
}
return clazz;
}
/**
* desc to class.
* "[Z" => boolean[].class
* "[[Ljava/util/Map;" => java.util.Map[][].class
*
* @param desc desc.
* @return Class instance.
* @throws ClassNotFoundException
*/
public static Class<?> desc2class(String desc) throws ClassNotFoundException
{
return desc2class(ClassHelper.getClassLoader(), desc);
}
/**
* desc to class.
* "[Z" => boolean[].class
* "[[Ljava/util/Map;" => java.util.Map[][].class
*
* @param cl ClassLoader instance.
* @param desc desc.
* @return Class instance.
* @throws ClassNotFoundException
*/
private static Class<?> desc2class(ClassLoader cl, String desc) throws ClassNotFoundException
{
switch( desc.charAt(0) )
{
case JVM_VOID: return void.class;
case JVM_BOOLEAN: return boolean.class;
case JVM_BYTE: return byte.class;
case JVM_CHAR: return char.class;
case JVM_DOUBLE: return double.class;
case JVM_FLOAT: return float.class;
case JVM_INT: return int.class;
case JVM_LONG: return long.class;
case JVM_SHORT: return short.class;
case 'L':
desc = desc.substring(1, desc.length()-1).replace('/', '.'); // "Ljava/lang/Object;" ==> "java.lang.Object"
break;
case '[':
desc = desc.replace('/', '.'); // "[[Ljava/lang/Object;" ==> "[[Ljava.lang.Object;"
break;
default:
throw new ClassNotFoundException("Class not found: " + desc);
}
if( cl == null )
cl = ClassHelper.getClassLoader();
Class<?> clazz = DESC_CLASS_CACHE.get(desc);
if(clazz==null){
clazz = Class.forName(desc, true, cl);
DESC_CLASS_CACHE.put(desc, clazz);
}
return clazz;
}
/**
* get class array instance.
*
* @param desc desc.
* @return Class class array.
* @throws ClassNotFoundException
*/
public static Class<?>[] desc2classArray(String desc) throws ClassNotFoundException
{
Class<?>[] ret = desc2classArray(ClassHelper.getClassLoader(), desc);
return ret;
}
/**
* get class array instance.
*
* @param cl ClassLoader instance.
* @param desc desc.
* @return Class[] class array.
* @throws ClassNotFoundException
*/
private static Class<?>[] desc2classArray(ClassLoader cl, String desc) throws ClassNotFoundException
{
if( desc.length() == 0 )
return EMPTY_CLASS_ARRAY;
List<Class<?>> cs = new ArrayList<Class<?>>();
Matcher m = DESC_PATTERN.matcher(desc);
while(m.find())
cs.add(desc2class(cl, m.group()));
return cs.toArray(EMPTY_CLASS_ARRAY);
}
/**
* 根据方法签名从类中找出方法。
*
* @param clazz 查找的类。
* @param methodName 方法签名，形如method1(int, String)。也允许只给方法名不参数只有方法名，形如method2。
* @return 返回查找到的方法。
* @throws NoSuchMethodException
* @throws ClassNotFoundException
* @throws IllegalStateException 给定的方法签名找到多个方法（方法签名中没有指定参数，又有有重载的方法的情况）
*/
public static Method findMethodByMethodSignature(Class<?> clazz, String methodName, String[] parameterTypes)
throws NoSuchMethodException, ClassNotFoundException {
String signature = clazz.getName() + "." + methodName;
if(parameterTypes != null && parameterTypes.length > 0){
signature += StringUtils.join(parameterTypes);
}
Method method = Signature_METHODS_CACHE.get(signature);
if(method != null){
return method;
}
if (parameterTypes == null) {
List<Method> finded = new ArrayList<Method>();
for (Method m : clazz.getMethods()) {
if (m.getName().equals(methodName)) {
finded.add(m);
}
}
if (finded.isEmpty()) {
throw new NoSuchMethodException("No such method " + methodName + " in class " + clazz);
}
if(finded.size() > 1) {
String msg = String.format("Not unique method for method name(%s) in class(%s), find %d methods.",
methodName, clazz.getName(), finded.size());
throw new IllegalStateException(msg);
}
method = finded.get(0);
} else {
Class<?>[] types = new Class<?>[parameterTypes.length];
for (int i = 0; i < parameterTypes.length; i ++) {
types[i] = ReflectUtils.name2class(parameterTypes[i]);
}
method = clazz.getMethod(methodName, types);
}
Signature_METHODS_CACHE.put(signature, method);
return method;
}
public static Method findMethodByMethodName(Class<?> clazz, String methodName)
throws NoSuchMethodException, ClassNotFoundException {
return findMethodByMethodSignature(clazz, methodName, null);
}
public static Constructor<?> findConstructor(Class<?> clazz, Class<?> paramType) throws NoSuchMethodException {
Constructor<?> targetConstructor;
try {
targetConstructor = clazz.getConstructor(new Class<?>[] {paramType});
} catch (NoSuchMethodException e) {
targetConstructor = null;
Constructor<?>[] constructors = clazz.getConstructors();
for (Constructor<?> constructor : constructors) {
if (Modifier.isPublic(constructor.getModifiers())
&& constructor.getParameterTypes().length == 1
&& constructor.getParameterTypes()[0].isAssignableFrom(paramType)) {
targetConstructor = constructor;
break;
}
}
if (targetConstructor == null) {
throw e;
}
}
return targetConstructor;
}
/**
* 检查对象是否是指定接口的实现。
* <p>
* 不会触发到指定接口的{@link Class}，所以如果ClassLoader中没有指定接口类时，也不会出错。
*
* @param obj 要检查的对象
* @param interfaceClazzName 指定的接口名
* @return 返回{@code true}，如果对象实现了指定接口；否则返回{@code false}。
*/
public static boolean isInstance(Object obj, String interfaceClazzName) {
for (Class<?> clazz = obj.getClass();
clazz != null && !clazz.equals(Object.class);
clazz = clazz.getSuperclass()) {
Class<?>[] interfaces = clazz.getInterfaces();
for (Class<?> itf : interfaces) {
if (itf.getName().equals(interfaceClazzName)) {
return true;
}
}
}
return false;
}
public static Object getEmptyObject(Class<?> returnType) {
return getEmptyObject(returnType, new HashMap<Class<?>, Object>(), 0);
}
private static Object getEmptyObject(Class<?> returnType, Map<Class<?>, Object> emptyInstances, int level) {
if (level > 2)
return null;
if (returnType == null) {
return null;
} else if (returnType == boolean.class || returnType == Boolean.class) {
return false;
} else if (returnType == char.class || returnType == Character.class) {
return '\0';
} else if (returnType == byte.class || returnType == Byte.class) {
return (byte)0;
} else if (returnType == short.class || returnType == Short.class) {
return (short)0;
} else if (returnType == int.class || returnType == Integer.class) {
return 0;
} else if (returnType == long.class || returnType == Long.class) {
return 0L;
} else if (returnType == float.class || returnType == Float.class) {
return 0F;
} else if (returnType == double.class || returnType == Double.class) {
return 0D;
} else if (returnType.isArray()) {
return Array.newInstance(returnType.getComponentType(), 0);
} else if (returnType.isAssignableFrom(ArrayList.class)) {
return new ArrayList<Object>(0);
} else if (returnType.isAssignableFrom(HashSet.class)) {
return new HashSet<Object>(0);
} else if (returnType.isAssignableFrom(HashMap.class)) {
return new HashMap<Object, Object>(0);
} else if (String.class.equals(returnType)) {
return "";
} else if (! returnType.isInterface()) {
try {
Object value = emptyInstances.get(returnType);
if (value == null) {
value = returnType.newInstance();
emptyInstances.put(returnType, value);
}
Class<?> cls = value.getClass();
while (cls != null && cls != Object.class) {
Field[] fields = cls.getDeclaredFields();
for (Field field : fields) {
Object property = getEmptyObject(field.getType(), emptyInstances, level + 1);
if (property != null) {
try {
if (! field.isAccessible()) {
field.setAccessible(true);
}
field.set(value, property);
} catch (Throwable e) {
}
}
}
cls = cls.getSuperclass();
}
return value;
} catch (Throwable e) {
return null;
}
} else {
return null;
}
}
public static boolean isBeanPropertyReadMethod(Method method) {
return method != null
&& Modifier.isPublic(method.getModifiers())
&& ! Modifier.isStatic(method.getModifiers())
&& method.getReturnType() != void.class
&& method.getDeclaringClass() != Object.class
&& method.getParameterTypes().length == 0
&& ((method.getName().startsWith("get") && method.getName().length() > 3)
|| (method.getName().startsWith("is") && method.getName().length() > 2));
}
public static String getPropertyNameFromBeanReadMethod(Method method) {
if (isBeanPropertyReadMethod(method)) {
if (method.getName().startsWith("get")) {
return method.getName().substring(3, 4).toLowerCase()
+ method.getName().substring(4);
}
if (method.getName().startsWith("is")) {
return method.getName().substring(2, 3).toLowerCase()
+ method.getName().substring(3);
}
}
return null;
}
public static boolean isBeanPropertyWriteMethod(Method method) {
return method != null
&& Modifier.isPublic(method.getModifiers())
&& ! Modifier.isStatic(method.getModifiers())
&& method.getDeclaringClass() != Object.class
&& method.getParameterTypes().length == 1
&& method.getName().startsWith("set")
&& method.getName().length() > 3;
}
public static String getPropertyNameFromBeanWriteMethod(Method method) {
if (isBeanPropertyWriteMethod(method)) {
return method.getName().substring(3, 4).toLowerCase()
+ method.getName().substring(4);
}
return null;
}
public static boolean isPublicInstanceField(Field field) {
return Modifier.isPublic(field.getModifiers())
&& !Modifier.isStatic(field.getModifiers())
&& !Modifier.isFinal(field.getModifiers())
&& !field.isSynthetic();
}
public static Map<String, Field> getBeanPropertyFields(Class cl) {
Map<String, Field> properties = new HashMap<String, Field>();
for(; cl != null; cl = cl.getSuperclass()) {
Field[] fields = cl.getDeclaredFields();
for(Field field : fields) {
if (Modifier.isTransient(field.getModifiers())
|| Modifier.isStatic(field.getModifiers())) {
continue;
}
field.setAccessible(true);
properties.put(field.getName(), field);
}
}
return properties;
}
public static Map<String, Method> getBeanPropertyReadMethods(Class cl) {
Map<String, Method> properties = new HashMap<String, Method>();
for(; cl != null; cl = cl.getSuperclass()) {
Method[] methods = cl.getDeclaredMethods();
for(Method method : methods) {
if (isBeanPropertyReadMethod(method)) {
method.setAccessible(true);
String property = getPropertyNameFromBeanReadMethod(method);
properties.put(property, method);
}
}
}
return properties;
}
private ReflectUtils(){}
}
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