Java对象之间的复制，反射 (简单对象间属性一致时的值拷贝)

[java]代码库

public class TwoBeanUtils {

    /** 日志输出 */
    final static Logger log = LoggerFactory.getLogger(TwoBeanUtils.class);
    /**
     * 简单对象间属性一致时的值拷贝
     * @param from 
     * @param to
     */
    public static void copyFormToBean(Object from,Object to){
        try{
            Field[] field = from.getClass().getDeclaredFields();
            for (int i = 0; i < field.length; i++) {
                try{
                    String fieldname = field[i].getName();
                    String setMethodname = new StringBuffer("set").append(
                            fieldname.substring(0, 1).toUpperCase()).append(
                            fieldname.substring(1)).toString();
                    String getMethodname = new StringBuffer("get").append(
                            fieldname.substring(0, 1).toUpperCase()).append(
                            fieldname.substring(1)).toString();
                    Method method = from.getClass().getMethod(getMethodname, null);
                    Class[] cla = new Class[1];
                    cla[0] = field[i].getType();
                    Object[] paras=new Object[1];
                    paras[0]=method.invoke(from,null);
                    if ( paras[0]!=null){
                        to.getClass().getMethod(setMethodname, cla).invoke(
                                to, paras);
                    }
                }catch(Exception e){

                }
            }
        }catch(Exception e){
            log.error("form表单拷贝到对象", e);
        }
    }
    /**
     * 简单对象间属性一致时的值拷贝
     * @param from 
     * @param to
     */
    public static void copyBeanToForm(Object from,Object to){
        try{
            Field[] field = to.getClass().getDeclaredFields();
            for (int i = 0; i < field.length; i++) {
                try{
                    String fieldname = field[i].getName();
                    String setMethodname = new StringBuffer("set").append(
                            fieldname.substring(0, 1).toUpperCase()).append(
                            fieldname.substring(1)).toString();
                    String getMethodname = new StringBuffer("get").append(
                            fieldname.substring(0, 1).toUpperCase()).append(
                            fieldname.substring(1)).toString();
    //              System.out.println(fieldname);
                    Method method = from.getClass().getMethod(getMethodname, null);
                    Class[] cla = new Class[1];
                    cla[0] = field[i].getType();
                    Object[] paras=new Object[1];
                    paras[0]=method.invoke(from,null);
                    //System.out.println(fieldname+"="+paras[0]);
                    to.getClass().getMethod(setMethodname, cla).invoke(
                            to, paras);
                }catch(Exception e){
                }
            }
        }catch(Exception e){
            log.error("对象拷贝到form表单", e);
        }
    }
    /**
     * 简单对象间属性名一致时的值拷贝
     * @param bean其为一组简单属性的对象
     * @param beans其属性为bean元素对象属性的数组
     */
    public static void copyBeanToBeans(List bean, Object beans) {

        try {
            if (bean != null) {
                Field[] field = beans.getClass().getDeclaredFields();
                String claname[]=new String[field.length];
                //System.out.println(field.length);
                for (int i = 0; i < field.length; i++) {
                    try{
                        List list = new ArrayList();
                        String fieldname = field[i].getName();
                        String setMethodname = new StringBuffer("set").append(
                                fieldname.substring(0, 1).toUpperCase()).append(
                                fieldname.substring(1)).toString();
                        String getMethodname = new StringBuffer("get").append(
                                fieldname.substring(0, 1).toUpperCase()).append(
                                fieldname.substring(1)).toString();
                        int k = 0;
                        Iterator enmu = bean.iterator();
                        while (enmu.hasNext()) {
                            Object temp = enmu.next();

                                claname[i]=temp.getClass().getDeclaredField(fieldname).getType().getName();
                                Method method = temp.getClass().getMethod(getMethodname, null);
                                list.add(method.invoke(temp, null));

                            k++;
                        }
                        Class[] cla = new Class[1];
                        cla[0] = beans.getClass().getDeclaredField(fieldname)
                                .getType();
                        //System.out.println(cla[0]);
                        Object[] paras=new Object[1];
                        Object obj=null;
                        obj= Array.newInstance(Class.forName(claname[i]),bean.size());
                        list.toArray((Object[])obj);
                        paras[0]=obj;
                        beans.getClass().getMethod(setMethodname, cla).invoke(
                                beans, paras);
                    }catch(Exception ex){
                        //有可能beans中的属性，List的对象没有
                    }
                }
            }

        } catch (Exception e) {
            log.error("List拷贝到Beans表单", e);
        }
    }
    /**
     * 简单对象间属性名一致时的值拷贝
     * @param bean为简单属性的对象类
     * @param beans其属性为bean对象属性的数组
     * @param size beans属性数组的长度
     * @return List 一组元素为bean的ArrayList
     */
    public static List copyBeansToBean(Object beans, Class bean,int size) {
        List list = new ArrayList();
        try {
            if (beans != null) {
                int start=0;
                while(start<size){
                    Object addobj=Class.forName(bean.getName()).getConstructor(null).newInstance(null);
                    Field[] field = bean.getDeclaredFields();
                    for (int i = 0; i < field.length; i++) {

                        String fieldname = field[i].getName();
                        String setMethodname = new StringBuffer("set").append(
                                fieldname.substring(0, 1).toUpperCase()).append(
                                fieldname.substring(1)).toString();
                        String getMethodname = new StringBuffer("get").append(
                                fieldname.substring(0, 1).toUpperCase()).append(
                                fieldname.substring(1)).toString();
                        try{
                            Method method = beans.getClass().getMethod(getMethodname, null);
                            Object arr=method.invoke(beans,null);
                            //System.out.println(fieldname+"===="+arr);
                            int tempsize=arr==null ? 0:Array.getLength(arr);
                            //System.out.println("tempsize="+tempsize);
                            if (tempsize>=size){
                                Class[] cla = new Class[1];
                                cla[0] = bean.getDeclaredField(fieldname)
                                        .getType(); 
                                //System.out.println(cla[0].getName());
                                Object[] paras=new Object[1];
                                paras[0]=Array.get(arr,start);
                                //System.out.println(Array.get(arr,start));
                                bean.getMethod(setMethodname, cla).invoke(
                                        addobj, paras);
                            }else{
                                Class[] cla = new Class[1];
                                cla[0] = bean.getDeclaredField(fieldname)
                                        .getType(); 
                                //System.out.println(cla[0].getName());
                                Object[] paras=new Object[1];
                                paras[0]=null;
                                //System.out.println(Array.get(arr,start));
                                bean.getMethod(setMethodname, cla).invoke(
                                        addobj, paras);
                            }
                        }catch(Exception ex){
                            Class[] cla = new Class[1];
                            cla[0] = bean.getDeclaredField(fieldname)
                                    .getType(); 
                            //System.out.println(cla[0].getName());
                            Object[] paras=new Object[1];
                            paras[0]=null;
                            //System.out.println(Array.get(arr,start));
                            bean.getMethod(setMethodname, cla).invoke(
                                    addobj, paras);
                        }

                    }
                    list.add(addobj);
                    start++;
                }
                //System.out.println("list size="+start);
            }

        } catch (Exception e) {
            log.error("Beans拷贝到List,元素为bean", e);
        }
        //System.out.println("list size="+list.size());
        return list;
    }
    /**
     * 简单对象间属性名一致时的值拷贝
     * @param list 每一个元素bean为简单属性的对象类
     * @param beans其属性为bean对象属性的数组
     * @param size beans属性数组的长度
     * @return List 一组元素为bean的ArrayList
     */
    public static List copyBeansToBean(Object beans, List bean) {
        List list = bean;
        int size=list.size();
        try {
            if (beans != null) {
                int start=0;
                while(start<size){
                    Object addobj=list.get(start);
                    Class beanclass=addobj.getClass();
                    Field[] field = beanclass.getDeclaredFields();
                    for (int i = 0; i < field.length; i++) {
                        try{
                            String fieldname = field[i].getName();
                            String setMethodname = new StringBuffer("set").append(
                                    fieldname.substring(0, 1).toUpperCase()).append(
                                    fieldname.substring(1)).toString();
                            String getMethodname = new StringBuffer("get").append(
                                    fieldname.substring(0, 1).toUpperCase()).append(
                                    fieldname.substring(1)).toString();
                            Method method = beans.getClass().getMethod(getMethodname, null);
                            Object arr=method.invoke(beans,null);
                            //System.out.println(fieldname+"===="+arr);
                            int tempsize=arr==null ? 0:Array.getLength(arr);
                            //System.out.println("tempsize="+tempsize);
                            if (tempsize==size){
                                Class[] cla = new Class[1];
                                cla[0] = beanclass.getDeclaredField(fieldname)
                                        .getType(); 
                                //System.out.println(cla[0].getName());
                                Object[] paras=new Object[1];
                                paras[0]=Array.get(arr,start);
                                //System.out.println(Array.get(arr,start));
                                beanclass.getMethod(setMethodname, cla).invoke(
                                        addobj, paras);
                            }
                        }catch(Exception ex){}

                    }
                    start++;
                }
//              System.out.println("list size="+start);
            }

        } catch (Exception e) {
            log.error("Beans拷贝到List,元素为bean", e);
        }
        //System.out.println("list size="+list.size());
        return list;
    }

}

//源代码片段来自云代码http://yuncode.net