利用Java的反射机制实现Bean实体与Map自动转换的工具类

在实际项目中，我们通常会以Map的形式装载一些参数进行传参，而在一些特定的场合我们总是希望这些松散的属性能以java Bean的实体形式进行传递，于是，我们需要写很多相同的但又简单的不能再简单的语句重复一万遍.....例如：

<span style="white-space:pre">		</span>Map<String ,Object> map = new HashMap<String ,Object>();
map.put("status", ex1.getStatus());
map.put("gender",  ex1.getGender());
map.put("age",  ex1.getAge());
map.put("temp",  ex1.getTemp());
map.put("name",  ex1.getName()); 

这仅仅是5个属性，在实际情况中，随便的实体恐怕都有十几个属性，这样会有大量的冗余代码，鉴于Map这种松散的传参和Bean紧凑传参的方式不可避免而又各有优劣，我们有理由找到一个高效的方式使这两种结构无缝互转，我们知道Bean和Map的数据（逻辑）结构都相对简单，我们需要的仅仅是能获取到Bean的内部字段的名称和值，对应到Map的key-value即可，因此，Java的反射机制成了不二之选。废话少说，talk is cheap ！show
me the code！

package prs.rfh.test.flex;

import java.lang.reflect.Field;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * @category Util
 * @author renfh
 * @since 2016-1-9
 * @version 1.0
 */
public class TransBeanMapUtil {
<span style="white-space:pre">	</span>
<span style="white-space:pre">	</span>private static Log log = LogFactory.getLog(TransBeanMapUtil.class);
<span style="white-space:pre">	</span>
<span style="white-space:pre">	</span>/**
<span style="white-space:pre">	</span> * trans elem from map to a bean
<span style="white-space:pre">	</span> * @param map 
<span style="white-space:pre">	</span> * @param t Bean
<span style="white-space:pre">	</span> */
<span style="white-space:pre">	</span>public static <T extends Object,O> void  transMapToBean(T t,Map<String ,Object> map){
<span style="white-space:pre">		</span>
<span style="white-space:pre">		</span>if(t!=null&&map!=null){
<span style="white-space:pre">			</span>Class clazz = t.getClass();

<span style="white-space:pre">			</span>for(;clazz!=Object.class;clazz = clazz.getSuperclass()){
<span style="white-space:pre">				</span>Field [] fields = clazz.getDeclaredFields();
<span style="white-space:pre">				</span>for(int i=0 ;i<fields.length;i++){
<span style="white-space:pre">					</span>String name = fields[i].getName();
<span style="white-space:pre">					</span>Object value = map.get(name);
<span style="white-space:pre">					</span>fields[i].setAccessible(true);
<span style="white-space:pre">					</span>try {
<span style="white-space:pre">						</span>fields[i].set(t,value);
<span style="white-space:pre">					</span>} catch (IllegalArgumentException e) {
<span style="white-space:pre">						</span>e.printStackTrace();
<span style="white-space:pre">					</span>} catch (IllegalAccessException e) {
<span style="white-space:pre">						</span>e.printStackTrace();
<span style="white-space:pre">					</span>}
<span style="white-space:pre">				</span>}
<span style="white-space:pre">			</span>}
<span style="white-space:pre">		</span>}
<span style="white-space:pre">	</span>}
<span style="white-space:pre">	</span>
<span style="white-space:pre">	</span>/**
<span style="white-space:pre">	</span> * trans entity from bean to a map
<span style="white-space:pre">	</span> * @param map 
<span style="white-space:pre">	</span> * @param b Bean
<span style="white-space:pre">	</span> */
<span style="white-space:pre">	</span>public static <B extends Object> Map<String,Object> transBeanToMap( B b ){
<span style="white-space:pre">		</span>Class clazz = b.getClass();
<span style="white-space:pre">		</span>Map<String ,Object> map = new HashMap<String , Object>();
<span style="white-space:pre">		</span>if(b!=null){
<span style="white-space:pre">			</span>do {
<span style="white-space:pre">				</span>Field [] fields = clazz.getDeclaredFields();
<span style="white-space:pre">				</span>for(int i = 0 ;i < fields.length; i++){
<span style="white-space:pre">					</span>fields[i].setAccessible(true);
<span style="white-space:pre">					</span>try {
<span style="white-space:pre">						</span>map.put(fields[i].getName(),fields[i].get(b));
<span style="white-space:pre">					</span>} catch (IllegalArgumentException e) {
<span style="white-space:pre">						</span>e.printStackTrace();
<span style="white-space:pre">					</span>} catch (IllegalAccessException e) {
<span style="white-space:pre">						</span>e.printStackTrace();
<span style="white-space:pre">					</span>}
<span style="white-space:pre">				</span>}
<span style="white-space:pre">				</span>clazz = clazz.getSuperclass();
<span style="white-space:pre">			</span>}while(clazz!=Object.class);
<span style="white-space:pre">		</span>}else if(log.isDebugEnabled()){
<span style="white-space:pre">				</span>log.debug("["+new Date()+"]"+TransBeanMapUtil.class+" occured a error while the bean is null");
<span style="white-space:pre">		</span>}
<span style="white-space:pre">		</span>return map;
<span style="white-space:pre">	</span>}
<span style="white-space:pre">	</span>
<span style="white-space:pre">	</span>public static void main(String[] args) {
<span style="white-space:pre">		</span>Map<String ,Object> map = new HashMap<String ,Object>();
<span style="white-space:pre">		</span>map.put("status", 1);
<span style="white-space:pre">		</span>map.put("gender", "nan");
<span style="white-space:pre">		</span>map.put("age", "12");
<span style="white-space:pre">		</span>map.put("temp", "bad");
<span style="white-space:pre">		</span>map.put("name", "tom");
<span style="white-space:pre">		</span>Father tom  = new Son();
<span style="white-space:pre">		</span>TransBeanMapUtil.transMapToBean(tom, map);
<span style="white-space:pre">		</span>System.out.println(map);
<span style="white-space:pre">		</span>Map<String ,Object> map_kate = TransBeanMapUtil.transBeanToMap(tom);
<span style="white-space:pre">		</span>System.out.println(map_kate);
<span style="white-space:pre">	</span>}
}

附具有继承关系的Bean实体类两个：

父类

package prs.rfh.test.flex;

public class Father {
private String name;
private String age;
private String gender;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAge() {
return age;
}
public void setAge(String age) {
this.age = age;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}

}

子类

package prs.rfh.test.flex;

public class Son extends Father {
private String status ;
private String temp;
public String getStatus() {
return status;
}
public void setStatus(String status) {
this.status = status;
}
public String getTemp() {
return temp;
}
public void setTemp(String temp) {
this.temp = temp;
}
}

以上完成了一个简单的Map与Bean互转的Util工具类，可以实现对任何可见性的Bean及其父类的属性的值到Map的相互转换。由于只是实现了一个简单的功能，可能不够完善，不足之处还望指正，不胜感谢！