Java 相关工具类
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.Validate;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
//import org.springframework.util.Assert;
/**
* 反射工具
*
* 提供调用getter/setter方法, 访问私有变量, 调用私有方法, 获取泛型类型Class, 被AOP过的真实类等工具函数.
*
*/
public class Reflections {
private static final String SETTER_PREFIX = "set";
private static final String GETTER_PREFIX = "get";
private static final String CGLIB_CLASS_SEPARATOR = "$$";
private static Logger logger = LoggerFactory.getLogger(Reflections.class);
/**
* 调用Getter方法.
*/
public static Object invokeGetter(Object obj, String propertyName) {
String getterMethodName = GETTER_PREFIX + StringUtils.capitalize(propertyName);
return invokeMethod(obj, getterMethodName, new Class[] {}, new Object[] {});
}
/**
* 调用Setter方法, 仅匹配方法名�? */
public static void invokeSetter(Object obj, String propertyName, Object value) {
String setterMethodName = SETTER_PREFIX + StringUtils.capitalize(propertyName);
invokeMethodByName(obj, setterMethodName, new Object[] { value });
}
/**
* 直接读取对象属�?�? 无视private/protected修饰�? 不经过getter函数.
*/
public static Object getFieldValue(final Object obj, final String fieldName) {
Field field = getAccessibleField(obj, fieldName);
if (field == null) {
throw new IllegalArgumentException("Could not find field [" + fieldName + "] on target [" + obj + "]");
}
Object result = null;
try {
result = field.get(obj);
} catch (IllegalAccessException e) {
logger.error("不可能抛出的异常{}", e.getMessage());
}
return result;
}
/**
* 直接设置对象属, 无视private/protected修饰, 不经过setter函数.
*/
public static void setFieldValue(final Object obj, final String fieldName, final Object value) {
Field field = getAccessibleField(obj, fieldName);
if (field == null) {
throw new IllegalArgumentException("Could not find field [" + fieldName + "] on target [" + obj + "]");
}
try {
field.set(obj, value);
} catch (IllegalAccessException e) {
logger.error("不可能抛出的异常:{}", e.getMessage());
}
}
/**
* 直接调用对象方法, 无视private/protected修饰
* 用于调用的情况,否则应使用getAccessibleMethod()函数获得Method后反复调
* 同时匹配方法参数类型
*/
public static Object invokeMethod(final Object obj, final String methodName, final Class<?>[] parameterTypes,
final Object[] args) {
Method method = getAccessibleMethod(obj, methodName, parameterTypes);
if (method == null) {
throw new IllegalArgumentException("Could not find method [" + methodName + "] on target [" + obj + "]");
}
try {
return method.invoke(obj, args);
} catch (Exception e) {
throw convertReflectionExceptionToUnchecked(e);
}
}
/**
* 直接调用对象方法, 无视private/protected修饰符,
* 用于�?��性调用的情况,否则应使用getAccessibleMethodByName()函数获得Method后反复调�?
* 只匹配函数名,如果有多个同名函数调用第一个�?
*/
public static Object invokeMethodByName(final Object obj, final String methodName, final Object[] args) {
Method method = getAccessibleMethodByName(obj, methodName);
if (method == null) {
throw new IllegalArgumentException("Could not find method [" + methodName + "] on target [" + obj + "]");
}
try {
return method.invoke(obj, args);
} catch (Exception e) {
throw convertReflectionExceptionToUnchecked(e);
}
}
/**
* 循环向上转型, 获取对象的DeclaredField, 并强制设置为可访�?
*
* 如向上转型到Object仍无法找�? 返回null.
*/
public static Field getAccessibleField(final Object obj, final String fieldName) {
Validate.notNull(obj, "object can't be null");
Validate.notBlank(fieldName, "fieldName can't be blank");
for (Class<?> superClass = obj.getClass(); superClass != Object.class; superClass = superClass.getSuperclass()) {
try {
Field field = superClass.getDeclaredField(fieldName);
makeAccessible(field);
return field;
} catch (NoSuchFieldException e) {//NOSONAR
// Field不在当前类定�?继续向上转型
}
}
return null;
}
/**
* 循环向上转型, 获取对象的DeclaredMethod,并强制设置为可访�?
* 如向上转型到Object仍无法找�? 返回null.
* 匹配函数�?参数类型�? *
* 用于方法�?��被多次调用的情况. 先使用本函数先取得Method,然后调用Method.invoke(Object obj, Object... args)
*/
public static Method getAccessibleMethod(final Object obj, final String methodName,
final Class<?>... parameterTypes) {
Validate.notNull(obj, "object can't be null");
Validate.notBlank(methodName, "methodName can't be blank");
for (Class<?> searchType = obj.getClass(); searchType != Object.class; searchType = searchType.getSuperclass()) {
try {
Method method = searchType.getDeclaredMethod(methodName, parameterTypes);
makeAccessible(method);
return method;
} catch (NoSuchMethodException e) {
// Method不在当前类定�?继续向上转型
}
}
return null;
}
/**
* 循环向上转型, 获取对象的DeclaredMethod,并强制设置为可访�?
* 如向上转型到Object仍无法找�? 返回null.
* 只匹配函数名�? *
* 用于方法�?��被多次调用的情况. 先使用本函数先取得Method,然后调用Method.invoke(Object obj, Object... args)
*/
public static Method getAccessibleMethodByName(final Object obj, final String methodName) {
Validate.notNull(obj, "object can't be null");
Validate.notBlank(methodName, "methodName can't be blank");
for (Class<?> searchType = obj.getClass(); searchType != Object.class; searchType = searchType.getSuperclass()) {
Method[] methods = searchType.getDeclaredMethods();
for (Method method : methods) {
if (method.getName().equals(methodName)) {
makeAccessible(method);
return method;
}
}
}
return null;
}
/**
* 改变private/protected的方法为public,尽量不调用实际改动的语句,避免JDK的SecurityManager抱�?�? */
public static void makeAccessible(Method method) {
if ((!Modifier.isPublic(method.getModifiers()) || !Modifier.isPublic(method.getDeclaringClass().getModifiers()))
&& !method.isAccessible()) {
method.setAccessible(true);
}
}
/**
* 改变private/protected的成员变量为public,尽量不调用实际改动的语句,避免JDK的SecurityManager抱�?�? */
public static void makeAccessible(Field field) {
if ((!Modifier.isPublic(field.getModifiers()) || !Modifier.isPublic(field.getDeclaringClass().getModifiers()) || Modifier
.isFinal(field.getModifiers())) && !field.isAccessible()) {
field.setAccessible(true);
}
}
/**
* 通过反射, 获得Class定义中声明的泛型参数的类�? 注意泛型必须定义在父类处
* 如无法找�? 返回Object.class.
* eg.
* public UserDao extends HibernateDao<User>
*
* @param clazz The class to introspect
* @return the first generic declaration, or Object.class if cannot be determined
*/
public static <T> Class<T> getClassGenricType(final Class clazz) {
return getClassGenricType(clazz, 0);
}
/**
* 通过反射, 获得Class定义中声明的父类的泛型参数的类型.
* 如无法找�? 返回Object.class.
*
* 如public UserDao extends HibernateDao<User,Long>
*
* @param clazz clazz The class to introspect
* @param index the Index of the generic ddeclaration,start from 0.
* @return the index generic declaration, or Object.class if cannot be determined
*/
public static Class getClassGenricType(final Class clazz, final int index) {
Type genType = clazz.getGenericSuperclass();
if (!(genType instanceof ParameterizedType)) {
logger.warn(clazz.getSimpleName() + "'s superclass not ParameterizedType");
return Object.class;
}
Type[] params = ((ParameterizedType) genType).getActualTypeArguments();
if (index >= params.length || index < 0) {
logger.warn("Index: " + index + ", Size of " + clazz.getSimpleName() + "'s Parameterized Type: "
+ params.length);
return Object.class;
}
if (!(params[index] instanceof Class)) {
logger.warn(clazz.getSimpleName() + " not set the actual class on superclass generic parameter");
return Object.class;
}
return (Class) params[index];
}
public static Class<?> getUserClass(Object instance) {
// Assert.notNull(instance, "Instance must not be null");
Class clazz = instance.getClass();
if (clazz != null && clazz.getName().contains(CGLIB_CLASS_SEPARATOR)) {
Class<?> superClass = clazz.getSuperclass();
if (superClass != null && !Object.class.equals(superClass)) {
return superClass;
}
}
return clazz;
}
/**
* 将反射时的checked exception转换为unchecked exception.
*/
public static RuntimeException convertReflectionExceptionToUnchecked(Exception e) {
if (e instanceof IllegalAccessException || e instanceof IllegalArgumentException
|| e instanceof NoSuchMethodException) {
return new IllegalArgumentException(e);
} else if (e instanceof InvocationTargetException) {
return new RuntimeException(((InvocationTargetException) e).getTargetException());
} else if (e instanceof RuntimeException) {
return (RuntimeException) e;
}
return new RuntimeException("Unexpected Checked Exception.", e);
}
}
import java.io.PrintWriter;
import java.io.StringWriter;
/**
* 关于异常的工具类.
*
*/
public class Exceptions {
/**
* 将CheckedException转换为UncheckedException.
*/
public static RuntimeException unchecked(Exception e) {
if (e instanceof RuntimeException) {
return (RuntimeException) e;
} else {
return new RuntimeException(e);
}
}
/**
* 将ErrorStack转化为String.
*/
public static String getStackTraceAsString(Exception e) {
StringWriter stringWriter = new StringWriter();
e.printStackTrace(new PrintWriter(stringWriter));
return stringWriter.toString();
}
/**
* 判断异常是否由某些底层的异常引起.
*/
public static boolean isCausedBy(Exception ex, Class<? extends Exception>... causeExceptionClasses) {
Throwable cause = ex.getCause();
while (cause != null) {
for (Class<? extends Exception> causeClass : causeExceptionClasses) {
if (causeClass.isInstance(cause)) {
return true;
}
}
cause = cause.getCause();
}
return false;
}
}
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;
import org.apache.commons.codec.DecoderException;
import org.apache.commons.codec.binary.Base64;
import org.apache.commons.codec.binary.Hex;
import org.apache.commons.lang3.StringEscapeUtils;
/**
* 封装各种格式的编码解码工具类.
*
* 1.Commons-Codec的 hex/base64 编码
* 2.自制的base62 编码
* 3.Commons-Lang的xml/html escape
* 4.JDK提供的URLEncoder
*
*/
public class Encodes {
private static final String DEFAULT_URL_ENCODING = "UTF-8";
private static final char[] BASE62 = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz".toCharArray();
/**
* Hex编码.
*/
public static String encodeHex(byte[] input) {
return Hex.encodeHexString(input);
}
/**
* Hex解码.
*/
public static byte[] decodeHex(String input) {
try {
return Hex.decodeHex(input.toCharArray());
} catch (DecoderException e) {
throw Exceptions.unchecked(e);
}
}
/**
* Base64编码.
*/
public static String encodeBase64(byte[] input) {
return Base64.encodeBase64String(input);
}
/**
* Base64编码, URL安全(将Base64中的URL非法字符'+'和'/'转为'-'和'_', 见RFC3548).
*/
public static String encodeUrlSafeBase64(byte[] input) {
return Base64.encodeBase64URLSafeString(input);
}
/**
* Base64解码.
*/
public static byte[] decodeBase64(String input) {
return Base64.decodeBase64(input);
}
/**
* Base62编码。
*/
public static String encodeBase62(byte[] input) {
char[] chars = new char[input.length];
for (int i = 0; i < input.length; i++) {
chars[i] = BASE62[((input[i] & 0xFF) % BASE62.length)];
}
return new String(chars);
}
/**
* Html 转码.
*/
public static String escapeHtml(String html) {
return StringEscapeUtils.escapeHtml4(html);
}
/**
* Html 解码.
*/
public static String unescapeHtml(String htmlEscaped) {
return StringEscapeUtils.unescapeHtml4(htmlEscaped);
}
/**
* Xml 转码.
*/
public static String escapeXml(String xml) {
return StringEscapeUtils.escapeXml(xml);
}
/**
* Xml 解码.
*/
public static String unescapeXml(String xmlEscaped) {
return StringEscapeUtils.unescapeXml(xmlEscaped);
}
/**
* URL 编码, Encode默认为UTF-8.
*/
public static String urlEncode(String part) {
try {
return URLEncoder.encode(part, DEFAULT_URL_ENCODING);
} catch (UnsupportedEncodingException e) {
throw Exceptions.unchecked(e);
}
}
/**
* URL 解码, Encode默认为UTF-8.
*/
public static String urlDecode(String part) {
try {
return URLDecoder.decode(part, DEFAULT_URL_ENCODING);
} catch (UnsupportedEncodingException e) {
throw Exceptions.unchecked(e);
}
}
}