利用枚举反射替换hibernate的自定义类型UserType
因为hibernate枚举类型实在配置繁琐，所以直接用枚举换掉，以下是方法:首先要2个工具类：
import java.beans.Introspector;import java.lang.reflect.Array;import java.lang.reflect.Constructor;import java.lang.reflect.Field;import java.lang.reflect.Member;import java.lang.reflect.Method;import java.lang.reflect.Modifier;import java.util.HashSet;import java.util.Set;import java.util.logging.Logger;import org.apache.commons.lang.ArrayUtils;/** ** 反射的工具类 ***/public abstract class ClassUtils {private static Logger logger = Logger.getLogger(ClassUtils.class.getName());public ClassUtils() {}/** * 通过类加载机制返回类对象 ** @param name * @param classLoader * @return * @throws ClassNotFoundException */@SuppressWarnings("unchecked")public static Class forName(String name, ClassLoader classLoader)throws ClassNotFoundException {Class clazz = resolvePrimitiveClassName(name);if (clazz != null)return clazz;if (name.endsWith("[]")) {String elementClassName = name.substring(0, name.length()- "[]".length());Class elementClass = forName(elementClassName, classLoader);return Array.newInstance(elementClass, 0).getClass();} else {return Class.forName(name, true, classLoader);}}/** * 解析原始数据类型 ** @param name * @return */@SuppressWarnings("unchecked")public static Class resolvePrimitiveClassName(String name) {if (name.length() <= 8) {for (int i = 0; i < PRIMITIVE_CLASSES.length; i++) {Class clazz = PRIMITIVE_CLASSES;if (clazz.getName().equals(name))return clazz;}}return null;}/** ** @param clazz * @return */@SuppressWarnings("unchecked")public static String getShortNameAsProperty(Class clazz) {return Introspector.decapitalize(getShortName(clazz));}public static String getShortNameForField(Field field) {return Introspector.decapitalize(field.getName());}/** * 获取方法的名称 ** @param method * @return */public static String getShortNameForMethod(Method method) {String name = method.getName();if (name.startsWith("is"))name = name.substring("is".length());else if (name.startsWith("get"))name = name.substring("get".length());elsethrow new IllegalArgumentException((new StringBuilder()).append("Method [").append(method.getName()).append("] is not formed as a JavaBean property").toString());return Introspector.decapitalize(name);}/** * 获取一个类的ShortName 如：com.easyway.A 返回 A ** @param clazz * @return */@SuppressWarnings("unchecked")public static String getShortName(Class clazz) {return getShortName(clazz.getName());}/** * 判断一个类是否为内部类并获取一个类的ShortName ** @param className * @return */public static String getShortName(String className) {int lastDotIndex = className.lastIndexOf('.');int nameEndIndex = className.indexOf("$$");if (nameEndIndex == -1)nameEndIndex = className.length();String shortName = className.substring(lastDotIndex + 1, nameEndIndex);shortName = shortName.replace('$', '.');return shortName;}/** * 获取一个方法所在类的全名 ** @param method * 方法名称 * @return */public static String getQualifiedMethodName(Method method) {return (new StringBuilder()).append(method.getDeclaringClass().getName()).append(".").append(method.getName()).toString();}/** * 根据类，方法名称和参数查找方法 ** @param clazz * 类名 * @param methodName * 方法名称 * @param paramTypes * 参数类型 * @return */@SuppressWarnings("unchecked")public static boolean hasMethod(Class clazz, String methodName,Class paramTypes[]) {try {clazz.getMethod(methodName, paramTypes);return true;} catch (NoSuchMethodException ex) {return false;}}/** * 根据类和方法名返回方法的个数 ** @param clazz * @param methodName * @return */@SuppressWarnings("unchecked")public static int getMethodCountForName(Class clazz, String methodName) {int count = 0;do {for (int i = 0; i < clazz.getDeclaredMethods().length; i++) {Method method = clazz.getDeclaredMethods();if (methodName.equals(method.getName()))count++;}clazz = clazz.getSuperclass();} while (clazz != null);return count;}/** ** @param clazz * @param methodName * @return */@SuppressWarnings("unchecked")public static boolean hasAtLeastOneMethodWithName(Class clazz,String methodName) {do {for (int i = 0; i < clazz.getDeclaredMethods().length; i++) {Method method = clazz.getDeclaredMethods();if (methodName.equals(method.getName()))return true;}clazz = clazz.getSuperclass();} while (clazz != null);return false;}/** * 获取静态的方法的 ** @param clazz * @param methodName * @param args * @return */@SuppressWarnings("unchecked")public static Method getStaticMethod(Class clazz, String methodName,Class args[]) {try {Method method = clazz.getDeclaredMethod(methodName, args);if ((method.getModifiers() & Modifier.STATIC) != 0)return method;} catch (NoSuchMethodException ex) {}return null;}@SuppressWarnings("unchecked")public static String addResourcePathToPackagePath(Class clazz,String resourceName) {if (!resourceName.startsWith("/"))return (new StringBuilder()).append(classPackageAsResourcePath(clazz)).append("/").append(resourceName).toString();elsereturn (new StringBuilder()).append(classPackageAsResourcePath(clazz)).append(resourceName).toString();}@SuppressWarnings("unchecked")public static String classPackageAsResourcePath(Class clazz) {if (clazz == null || clazz.getPackage() == null)return "";elsereturn clazz.getPackage().getName().replace('.', '/');}/** * 根据对象获取所有的接口 ** @param object * @return */@SuppressWarnings("unchecked")public static Class[] getAllInterfaces(Object object) {Set interfaces = getAllInterfacesAsSet(object);return (Class[]) (Class[]) interfaces.toArray(new Class);}/** * 根据类获取所有的接口 ** @param clazz * @return */@SuppressWarnings("unchecked")public static Class[] getAllInterfacesForClass(Class clazz) {Set interfaces = getAllInterfacesForClassAsSet(clazz);return (Class[]) (Class[]) interfaces.toArray(new Class);}/** * 根据对象获取所有的接口 ** @param object * @return */@SuppressWarnings("unchecked")public static Set getAllInterfacesAsSet(Object object) {return getAllInterfacesForClassAsSet(object.getClass());}/** * 根据类获取所有的接口 ** @param clazz * @return */@SuppressWarnings("unchecked")public static Set getAllInterfacesForClassAsSet(Class clazz) {Set interfaces = new HashSet();for (; clazz != null; clazz = clazz.getSuperclass()) {for (int i = 0; i < clazz.getInterfaces().length; i++) {Class ifc = clazz.getInterfaces();interfaces.add(ifc);}}return interfaces;}/** * 检测一个方法或者一个属性是否为Public 修饰 ** @param object * @return */@SuppressWarnings("unchecked")public static boolean isPublic(Class clazz, Member member) {return Modifier.isPublic(member.getModifiers())&& Modifier.isPublic(clazz.getModifiers());}/** * 检测一个Class是否为Abstract 修饰 ** @param object * @return */@SuppressWarnings("unchecked")public static boolean isAbstractClass(Class clazz) {int modifier = clazz.getModifiers();return Modifier.isAbstract(modifier) || Modifier.isInterface(modifier);}/** * 根据一个类获取一个默认的无参数的构造函数 ** @param object * @return */@SuppressWarnings("unchecked")public static Constructor getDefaultConstructor(Class clazz) {if (isAbstractClass(clazz))return null;try {Constructor constructor = clazz.getDeclaredConstructor(EMPTY_CLASS_ARRAY);if (!isPublic(clazz, constructor))constructor.setAccessible(true);return constructor;} catch (NoSuchMethodException nme) {return null;}}/** * 根据一个类和对应输入参数，获取一个对应参数的构造函数 ** @param object * @return */@SuppressWarnings("unchecked")public static Constructor getConstructor(Class clazz,Class parameterTypes[]) {if (isAbstractClass(clazz))return null;try {Constructor constructor = clazz.getConstructor(parameterTypes);if (!isPublic(clazz, constructor))constructor.setAccessible(true);return constructor;} catch (NoSuchMethodException nme) {return null;}}/** * 将一个完整的类名装换为资源名称路径 ** @param resourcePath * @return */public static String convertResourcePathToClassName(String resourcePath) {return resourcePath.replace('/', '.');}public static String convertClassNameToResourcePath(String className) {return className.replace('.', '/');}/** * 获取一个对象的属性 ** @param <T> * @param object * @param propertyName * @return * @throws NoSuchFieldException */@SuppressWarnings("unchecked")public static <T> T getDeclaredFieldValue(Object object, String propertyName)throws NoSuchFieldException {Field field = getDeclaredField(object.getClass(), propertyName);boolean accessible = field.isAccessible();Object result = null;synchronized (field) {field.setAccessible(true);try {result = field.get(object);} catch (IllegalAccessException e) {throw new NoSuchFieldException("No such field: "+ object.getClass() + '.' + propertyName);} finally {field.setAccessible(accessible);}}return (T) result;}/** * 查找对应类的属性字段 ** @param clazz * @param propertyName * @return * @throws NoSuchFieldException */public static Field getDeclaredField(Class<?> clazz, String propertyName)throws NoSuchFieldException {for (Class<?> superClass = clazz; superClass != Object.class; superClass = superClass.getSuperclass()) {try {return superClass.getDeclaredField(propertyName);} catch (NoSuchFieldException e) {// Field不在当前类定义,继续向上转型e.printStackTrace();}}throw new NoSuchFieldException("No such field: " + clazz.getName()+ '.' + propertyName);}/** * 获取一个类的所有的属性 ** @param clazz * @return */public static Field[] getDeclaredFields(Class<?> clazz) {Field[] fields = clazz.getDeclaredFields();for (Class<?> superClass = clazz; superClass != Object.class; superClass = superClass.getSuperclass()) {fields = (Field[]) ArrayUtils.addAll(fields, superClass.getDeclaredFields());}return fields;}public static final String ARRAY_SUFFIX = "[]";private static Class PRIMITIVE_CLASSES[];private static final Class EMPTY_CLASS_ARRAY[] = new Class;static {PRIMITIVE_CLASSES = (new Class[] { Boolean.TYPE, Byte.TYPE,Character.TYPE, Short.TYPE, Integer.TYPE, Long.TYPE,Float.TYPE, Double.TYPE });}}
import org.apache.commons.lang.ObjectUtils;/** ** 枚举工具类 */public abstract class EnumUtils {public synchronized static <T extends Enum<T>> T getEnumFromValue(Class<T> enumClass,Object value){return fromEnumProperty(enumClass, "value", value);}/** * 从指定的枚举类中根据property搜寻匹配指定值的枚举实例 ** @param <T> * @param enumClass * @param property * @param propValue * @return */private static <T extends Enum<T>> T fromEnumProperty(Class<T> enumClass,String property, Object propValue) {T[] enumConstants = enumClass.getEnumConstants();for (T t : enumConstants) {Object constantPropValue;try {constantPropValue = ClassUtils.getDeclaredFieldValue(t,property);if (ObjectUtils.equals(constantPropValue, propValue)) {return t;}} catch (Exception e) {throw new RuntimeException(e);}}return null;}/** * 从指定的枚举类中根据名称匹配指定值 ** @param <T> * @param enumClass * @param constantName * @return */private static <T extends Enum<T>> T fromEnumConstantName(Class<T> enumClass, String constantName) {T[] enumConstants = enumClass.getEnumConstants();for (T t : enumConstants) {if (((Enum<?>) t).name().equals(constantName)) {return t;}}return null;}}
然后一个测试枚举:
public enum SexEnum {外星人(0) , 男(1) , 女(2);private int value;SexEnum(final int value){this.value = value;}public int getValue() {return value;}public String getName(){return this.name();}}
测试类:
import junit.framework.TestCase;import com.masadora.util.EnumUtils;public class MainTest extends TestCase{public void testEnum() throws Exception{SexEnum sexEnum = EnumUtils.getEnumFromValue(SexEnum.class,1);System.out.println(sexEnum.name());System.out.println(sexEnum.getName());System.out.println(SexEnum.男.getValue());System.out.println(SexEnum.valueOf("男").getValue());}}
最后如何运用到hibernate呢？只需要如下改动hibernate即可:
改动方式以前的POJO中sex的get方法：public int getSex( return this.sex;)现在改为:public SexEnum getSex(){returnEnumUtils.getEnumFromValue(SexEnum.class,this.sex);}页面获取为:${sex.name}和${sex.value}
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