网上图书商城项目学习笔记-036工具类之CommonUtils及日期转换器

package cn.itcast.commons;

import java.util.Map;
import java.util.UUID;

import org.apache.commons.beanutils.BeanUtils;
import org.apache.commons.beanutils.ConvertUtils;

/**
* 小小工具
* @author qdmmy6
*
*/
public class CommonUtils {
/**
* 返回一个不重复的字符串
* @return
*/
public static String uuid() {
return UUID.randomUUID().toString().replace("-", "").toUpperCase();
}

/**
* 把map转换成对象
* @param map
* @param clazz
* @return
*
* 把Map转换成指定类型
*/
@SuppressWarnings("rawtypes")
public static <T> T toBean(Map map, Class<T> clazz) {
try {
/*
* 1. 通过参数clazz创建实例
* 2. 使用BeanUtils.populate把map的数据封闭到bean中
*/
T bean = clazz.newInstance();
ConvertUtils.register(new DateConverter(), java.util.Date.class);
BeanUtils.populate(bean, map);
return bean;
} catch(Exception e) {
throw new RuntimeException(e);
}
}
}

package cn.itcast.commons;

import java.text.ParseException;
import java.text.SimpleDateFormat;

import org.apache.commons.beanutils.Converter;

/**
* 把String转换成java.util.Date的类型转换器
* @author qdmmy6
*
*/
public class DateConverter implements Converter {

@SuppressWarnings("rawtypes")
@Override
public Object convert(Class type, Object value) {
if(value == null) return null;//如果要转换成值为null，那么直接返回null
if(!(value instanceof String)) {//如果要转换的值不是String，那么就不转换了，直接返回
return value;
}
String val = (String) value;//把值转换成String

// 使用SimpleDateFormat进行转换
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
try {
return sdf.parse(val);
} catch (ParseException e) {
throw new RuntimeException(e);
}
}
}

/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements.  See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.commons.beanutils;

import java.lang.reflect.InvocationTargetException;
import java.util.Map;

/**
* <p>Utility methods for populating JavaBeans properties via reflection.</p>
*
* <p>The implementations are provided by {@link BeanUtilsBean}.
* These static utility methods use the default instance.
* More sophisticated behaviour can be provided by using a <code>BeanUtilsBean</code> instance.</p>
*
* @author Craig R. McClanahan
* @author Ralph Schaer
* @author Chris Audley
* @author Rey Francois
* @author Gregor Rayman
* @version $Revision: 690380 $ $Date: 2008-08-29 21:04:38 +0100 (Fri, 29 Aug 2008) $
* @see BeanUtilsBean
*/

public class BeanUtils {

// ------------------------------------------------------ Private Variables

/**
* The debugging detail level for this component.
*
* Note that this static variable will have unexpected side-effects if
* this class is deployed in a shared classloader within a container.
* However as it is actually completely ignored by this class due to its
* deprecated status, it doesn't do any actual harm.
*
* @deprecated BeanUtils now uses commons-logging for all log messages.
*             Use your favorite logging tool to configure logging for
*             this class.
*/
private static int debug = 0;

/**
* The <code>debug</code> static property is no longer used
* @return debug property
* @deprecated BeanUtils now uses commons-logging for all log messages.
*             Use your favorite logging tool to configure logging for
*             this class.
*/
public static int getDebug() {
return (debug);
}

/**
* The <code>debug</code> static property is no longer used
* @param newDebug debug property
* @deprecated BeanUtils now uses commons-logging for all log messages.
*             Use your favorite logging tool to configure logging for
*             this class.
*/
public static void setDebug(int newDebug) {
debug = newDebug;
}

// --------------------------------------------------------- Class Methods

/**
* <p>Clone a bean based on the available property getters and setters,
* even if the bean class itself does not implement Cloneable.</p>
*
* <p>For more details see <code>BeanUtilsBean</code>.</p>
*
* @param bean Bean to be cloned
* @return the cloned bean
*
* @exception IllegalAccessException if the caller does not have
*  access to the property accessor method
* @exception InstantiationException if a new instance of the bean's
*  class cannot be instantiated
* @exception InvocationTargetException if the property accessor method
*  throws an exception
* @exception NoSuchMethodException if an accessor method for this
*  property cannot be found
* @see BeanUtilsBean#cloneBean
*/
public static Object cloneBean(Object bean)
throws IllegalAccessException, InstantiationException,
InvocationTargetException, NoSuchMethodException {

return BeanUtilsBean.getInstance().cloneBean(bean);

}

/**
* <p>Copy property values from the origin bean to the destination bean
* for all cases where the property names are the same.</p>
*
* <p>For more details see <code>BeanUtilsBean</code>.</p>
*
* @param dest Destination bean whose properties are modified
* @param orig Origin bean whose properties are retrieved
*
* @exception IllegalAccessException if the caller does not have
*  access to the property accessor method
* @exception IllegalArgumentException if the <code>dest</code> or
*  <code>orig</code> argument is null or if the <code>dest</code>
*  property type is different from the source type and the relevant
*  converter has not been registered.
* @exception InvocationTargetException if the property accessor method
*  throws an exception
* @see BeanUtilsBean#copyProperties
*/
public static void copyProperties(Object dest, Object orig)
throws IllegalAccessException, InvocationTargetException {

BeanUtilsBean.getInstance().copyProperties(dest, orig);
}

/**
* <p>Copy the specified property value to the specified destination bean,
* performing any type conversion that is required.</p>
*
* <p>For more details see <code>BeanUtilsBean</code>.</p>
*
* @param bean Bean on which setting is to be performed
* @param name Property name (can be nested/indexed/mapped/combo)
* @param value Value to be set
*
* @exception IllegalAccessException if the caller does not have
*  access to the property accessor method
* @exception InvocationTargetException if the property accessor method
*  throws an exception
* @see BeanUtilsBean#copyProperty
*/
public static void copyProperty(Object bean, String name, Object value)
throws IllegalAccessException, InvocationTargetException {

BeanUtilsBean.getInstance().copyProperty(bean, name, value);
}

/**
* <p>Return the entire set of properties for which the specified bean
* provides a read method.</p>
*
* <p>For more details see <code>BeanUtilsBean</code>.</p>
*
* @param bean Bean whose properties are to be extracted
* @return Map of property descriptors
*
* @exception IllegalAccessException if the caller does not have
*  access to the property accessor method
* @exception InvocationTargetException if the property accessor method
*  throws an exception
* @exception NoSuchMethodException if an accessor method for this
*  property cannot be found
* @see BeanUtilsBean#describe
*/
public static Map describe(Object bean)
throws IllegalAccessException, InvocationTargetException,
NoSuchMethodException {

return BeanUtilsBean.getInstance().describe(bean);
}

/**
* <p>Return the value of the specified array property of the specified
* bean, as a String array.</p>
*
* <p>For more details see <code>BeanUtilsBean</code>.</p>
*
* @param bean Bean whose property is to be extracted
* @param name Name of the property to be extracted
* @return The array property value
*
* @exception IllegalAccessException if the caller does not have
*  access to the property accessor method
* @exception InvocationTargetException if the property accessor method
*  throws an exception
* @exception NoSuchMethodException if an accessor method for this
*  property cannot be found
* @see BeanUtilsBean#getArrayProperty
*/
public static String[] getArrayProperty(Object bean, String name)
throws IllegalAccessException, InvocationTargetException,
NoSuchMethodException {

return BeanUtilsBean.getInstance().getArrayProperty(bean, name);
}

/**
* <p>Return the value of the specified indexed property of the specified
* bean, as a String.</p>
*
* <p>For more details see <code>BeanUtilsBean</code>.</p>
*
* @param bean Bean whose property is to be extracted
* @param name <code>propertyname[index]</code> of the property value
*  to be extracted
* @return The indexed property's value, converted to a String
*
* @exception IllegalAccessException if the caller does not have
*  access to the property accessor method
* @exception InvocationTargetException if the property accessor method
*  throws an exception
* @exception NoSuchMethodException if an accessor method for this
*  property cannot be found
* @see BeanUtilsBean#getIndexedProperty(Object, String)
*/
public static String getIndexedProperty(Object bean, String name)
throws IllegalAccessException, InvocationTargetException,
NoSuchMethodException {

return BeanUtilsBean.getInstance().getIndexedProperty(bean, name);

}

/**
* Return the value of the specified indexed property of the specified
* bean, as a String.  The index is specified as a method parameter and
* must *not* be included in the property name expression
*
* <p>For more details see <code>BeanUtilsBean</code>.</p>
*
* @param bean Bean whose property is to be extracted
* @param name Simple property name of the property value to be extracted
* @param index Index of the property value to be extracted
* @return The indexed property's value, converted to a String
*
* @exception IllegalAccessException if the caller does not have
*  access to the property accessor method
* @exception InvocationTargetException if the property accessor method
*  throws an exception
* @exception NoSuchMethodException if an accessor method for this
*  property cannot be found
* @see BeanUtilsBean#getIndexedProperty(Object, String, int)
*/
public static String getIndexedProperty(Object bean,
String name, int index)
throws IllegalAccessException, InvocationTargetException,
NoSuchMethodException {

return BeanUtilsBean.getInstance().getIndexedProperty(bean, name, index);

}

/**
* </p>Return the value of the specified indexed property of the specified
* bean, as a String.</p>
*
* <p>For more details see <code>BeanUtilsBean</code>.</p>
*
* @param bean Bean whose property is to be extracted
* @param name <code>propertyname(index)</code> of the property value
*  to be extracted
* @return The mapped property's value, converted to a String
*
* @exception IllegalAccessException if the caller does not have
*  access to the property accessor method
* @exception InvocationTargetException if the property accessor method
*  throws an exception
* @exception NoSuchMethodException if an accessor method for this
*  property cannot be found
* @see BeanUtilsBean#getMappedProperty(Object, String)
*/
public static String getMappedProperty(Object bean, String name)
throws IllegalAccessException, InvocationTargetException,
NoSuchMethodException {

return BeanUtilsBean.getInstance().getMappedProperty(bean, name);

}

/**
* </p>Return the value of the specified mapped property of the specified
* bean, as a String.</p>
*
* <p>For more details see <code>BeanUtilsBean</code>.</p>
*
* @param bean Bean whose property is to be extracted
* @param name Simple property name of the property value to be extracted
* @param key Lookup key of the property value to be extracted
* @return The mapped property's value, converted to a String
*
* @exception IllegalAccessException if the caller does not have
*  access to the property accessor method
* @exception InvocationTargetException if the property accessor method
*  throws an exception
* @exception NoSuchMethodException if an accessor method for this
*  property cannot be found
* @see BeanUtilsBean#getMappedProperty(Object, String, String)
*/
public static String getMappedProperty(Object bean,
String name, String key)
throws IllegalAccessException, InvocationTargetException,
NoSuchMethodException {

return BeanUtilsBean.getInstance().getMappedProperty(bean, name, key);

}

/**
* <p>Return the value of the (possibly nested) property of the specified
* name, for the specified bean, as a String.</p>
*
* <p>For more details see <code>BeanUtilsBean</code>.</p>
*
* @param bean Bean whose property is to be extracted
* @param name Possibly nested name of the property to be extracted
* @return The nested property's value, converted to a String
*
* @exception IllegalAccessException if the caller does not have
*  access to the property accessor method
* @exception IllegalArgumentException if a nested reference to a
*  property returns null
* @exception InvocationTargetException if the property accessor method
*  throws an exception
* @exception NoSuchMethodException if an accessor method for this
*  property cannot be found
* @see BeanUtilsBean#getNestedProperty
*/
public static String getNestedProperty(Object bean, String name)
throws IllegalAccessException, InvocationTargetException,
NoSuchMethodException {

return BeanUtilsBean.getInstance().getNestedProperty(bean, name);

}

/**
* <p>Return the value of the specified property of the specified bean,
* no matter which property reference format is used, as a String.</p>
*
* <p>For more details see <code>BeanUtilsBean</code>.</p>
*
* @param bean Bean whose property is to be extracted
* @param name Possibly indexed and/or nested name of the property
*  to be extracted
* @return The property's value, converted to a String
*
* @exception IllegalAccessException if the caller does not have
*  access to the property accessor method
* @exception InvocationTargetException if the property accessor method
*  throws an exception
* @exception NoSuchMethodException if an accessor method for this
*  property cannot be found
* @see BeanUtilsBean#getProperty
*/
public static String getProperty(Object bean, String name)
throws IllegalAccessException, InvocationTargetException,
NoSuchMethodException {

return BeanUtilsBean.getInstance().getProperty(bean, name);

}

/**
* <p>Return the value of the specified simple property of the specified
* bean, converted to a String.</p>
*
* <p>For more details see <code>BeanUtilsBean</code>.</p>
*
* @param bean Bean whose property is to be extracted
* @param name Name of the property to be extracted
* @return The property's value, converted to a String
*
* @exception IllegalAccessException if the caller does not have
*  access to the property accessor method
* @exception InvocationTargetException if the property accessor method
*  throws an exception
* @exception NoSuchMethodException if an accessor method for this
*  property cannot be found
* @see BeanUtilsBean#getSimpleProperty
*/
public static String getSimpleProperty(Object bean, String name)
throws IllegalAccessException, InvocationTargetException,
NoSuchMethodException {

return BeanUtilsBean.getInstance().getSimpleProperty(bean, name);

}

/**
* <p>Populate the JavaBeans properties of the specified bean, based on
* the specified name/value pairs.</p>
*
* <p>For more details see <code>BeanUtilsBean</code>.</p>
*
* @param bean JavaBean whose properties are being populated
* @param properties Map keyed by property name, with the
*  corresponding (String or String[]) value(s) to be set
*
* @exception IllegalAccessException if the caller does not have
*  access to the property accessor method
* @exception InvocationTargetException if the property accessor method
*  throws an exception
* @see BeanUtilsBean#populate
*/
public static void populate(Object bean, Map properties)
throws IllegalAccessException, InvocationTargetException {

BeanUtilsBean.getInstance().populate(bean, properties);
}

/**
* <p>Set the specified property value, performing type conversions as
* required to conform to the type of the destination property.</p>
*
* <p>For more details see <code>BeanUtilsBean</code>.</p>
*
* @param bean Bean on which setting is to be performed
* @param name Property name (can be nested/indexed/mapped/combo)
* @param value Value to be set
*
* @exception IllegalAccessException if the caller does not have
*  access to the property accessor method
* @exception InvocationTargetException if the property accessor method
*  throws an exception
* @see BeanUtilsBean#setProperty
*/
public static void setProperty(Object bean, String name, Object value)
throws IllegalAccessException, InvocationTargetException {

BeanUtilsBean.getInstance().setProperty(bean, name, value);
}

/**
* If we're running on JDK 1.4 or later, initialize the cause for the given throwable.
*
* @param  throwable The throwable.
* @param  cause     The cause of the throwable.
* @return  true if the cause was initialized, otherwise false.
* @since 1.8.0
*/
public static boolean initCause(Throwable throwable, Throwable cause) {
return BeanUtilsBean.getInstance().initCause(throwable, cause);
}

/**
* Create a cache.
* @return a new cache
* @since 1.8.0
*/
public static Map createCache() {
return new WeakFastHashMap();
}

/**
* Return whether a Map is fast
* @param map The map
* @return Whether it is fast or not.
* @since 1.8.0
*/
public static boolean getCacheFast(Map map) {
if (map instanceof WeakFastHashMap) {
return ((WeakFastHashMap)map).getFast();
} else {
return false;
}
}

/**
* Set whether fast on a Map
* @param map The map
* @param fast Whether it should be fast or not.
* @since 1.8.0
*/
public static void setCacheFast(Map map, boolean fast) {
if (map instanceof WeakFastHashMap) {
((WeakFastHashMap)map).setFast(fast);
}
}
}