Request To JavaBean(请求对象转换为JavaBean对象)

时间:2022-11-20 21:00:08

背景: 
经常要从request等对象取出值来赋入bean中,如果不用MVC框架的绑定功能的话,麻烦Request To JavaBean(请求对象转换为JavaBean对象)  
一 参考资料 
http://jc-dreaming.iteye.com/blog/563893 
http://www.iteye.com/topic/76043 
http://xubindehao.iteye.com/blog/754807 
http://javafenger.iteye.com/blog/96829 
http://www.kaila.com.cn/space.php?uid=7114&do=blog&id=458578 
http://blog.csdn.net/zsx923/archive/2010/01/19/5210325.aspx 
二 代码示例

import java.beans.IntrospectionException;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Enumeration;
import javax.servlet.http.HttpServletRequest;
import org.apache.commons.beanutils.BeanUtils; public class RequestToBean { /**
* ConvertUtilsBean convertUtils = new ConvertUtilsBean();
* DateConverter dateConverter = new DateConverter();
* convertUtils.register(dateConverter,Date.class);
* */ /**
* @param <T>
* @param newSource 现将要设置新值的对象
* @param source 源数据对象
*/
public static <T> void beanConvert(T newSource,T source){
try {
BeanUtils.copyProperties(newSource,source);
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
} /**
* @param request 请求对象
* @param obj 要设置Bean的类型,传入试为: Bean.class
* @return
*/
@SuppressWarnings("unchecked")
public static <T> T getBeanToRequest(HttpServletRequest request,Class<T> clazz){ //获取页面所有的请求参数名称
Enumeration<String> enume = request.getParameterNames();
T beanObj = getObjectByClass(clazz);
try{
while(enume.hasMoreElements()){
//参数名称
String propertyName = enume.nextElement();
//判断是否存在此属性
if(isCheckBeanExitsPropertyName(clazz,propertyName)){
//获取请求值
Object propertyValue = request.getParameter(propertyName);
setProperties(beanObj,propertyName,propertyValue);
} }
}catch(Exception e){} return beanObj;
} private static <T> T getObjectByClass(Class<T> clazz){
T t = null;
try {
t = clazz.newInstance();
} catch (InstantiationException e1) {
e1.printStackTrace();
} catch (IllegalAccessException e1) {
e1.printStackTrace();
}
return t;
} /**
* @param clazz Class对象
* @param propertyName 属性名称
* @return true || false 检查对象中是否存在该属性名称
*/
private static boolean isCheckBeanExitsPropertyName(Class<?> clazz,String propertyName){
boolean retValue = false;
try {
Field field = clazz.getDeclaredField(propertyName);
if(null != field){
retValue = true;
}
} catch (NoSuchFieldException e) {
Out.println("类: " + clazz.getSimpleName()+",不存在属性名: "+propertyName+" ,详细错误信息: "+e.getMessage());
}
return retValue; } /**
* 设置字段值
* @param obj 实例对象
* @param propertyName 属性名
* @param value 新的字段值
* @return
*/
public static void setProperties(Object object, String propertyName,Object value) throws IntrospectionException,
IllegalAccessException, InvocationTargetException {
PropertyDescriptor pd = new PropertyDescriptor(propertyName,object.getClass());
Method methodSet = pd.getWriteMethod();
methodSet.invoke(object,value);
}
}

  三 使用common beanutils组件 
代码: 
User user = new User(); 
BeanUtils.populate(user,request.getParameterMap());