BeanUtil.java

package com.jarvis.lib.util;

import java.lang.reflect.AccessibleObject;
import java.lang.reflect.Array;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.Calendar;
import java.util.Collection;
import java.util.Date;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.concurrent.ConcurrentHashMap;

/**
 * @author jiayu.qiu
 */
public class BeanUtil {

    @SuppressWarnings("rawtypes")
    private static final ConcurrentHashMap<Class, Field[]> fieldsCahce=new ConcurrentHashMap<Class, Field[]>();

    /**
     * 是否为基础数据类型
     * @param obj Object
     * @return boolean true or false
     */
    public static boolean isPrimitive(Object obj) {
        boolean rv=obj.getClass().isPrimitive() || obj instanceof String || obj instanceof Integer || obj instanceof Long || obj instanceof Byte || obj instanceof Character || obj instanceof Boolean
            || obj instanceof Short || obj instanceof Float || obj instanceof Double || obj instanceof BigDecimal || obj instanceof BigInteger;
        return rv;
    }

    /**
     * 把Bean转换为字符串
     * @param obj Object
     * @return String String
     */
    @SuppressWarnings("rawtypes")
    public static String toString(Object obj) {
        if(obj == null) {
            return "null";
        }
        Class cl=obj.getClass();
        if(isPrimitive(obj)) {
            return String.valueOf(obj);
        } else if(obj instanceof Enum) {
            return ((Enum)obj).name();
        } else if(obj instanceof Date) {
            return String.valueOf(((Date)obj).getTime());
        } else if(obj instanceof Calendar) {
            return String.valueOf(((Calendar)obj).getTime().getTime());
        } else if(cl.isArray()) {
            String r="[";
            int len=Array.getLength(obj);
            for(int i=0; i < len; i++) {
                if(i > 0) {
                    r+=",";
                }
                Object val=Array.get(obj, i);
                r+=toString(val);
            }
            return r + "]";
        } else if(obj instanceof Collection) {
            Collection tempCol=(Collection)obj;
            Iterator it=tempCol.iterator();
            String r="[";
            for(int i=0; it.hasNext(); i++) {
                if(i > 0) {
                    r+=",";
                }
                Object val=it.next();
                r+=toString(val);
            }
            return r + "]";
        } else if(obj instanceof Map) {
            Map tempMap=(Map)obj;
            String r="{";
            Iterator it=tempMap.entrySet().iterator();
            while(it.hasNext()) {
                Map.Entry entry=(Entry)it.next();
                Object key=entry.getKey();
                r+=toString(key);
                r+="=";
                Object val=entry.getValue();
                r+=toString(val);
                if(it.hasNext()) {
                    r+=",";
                }
            }
            return r + "}";
        } else if(obj instanceof Class) {
            Class tmpCls=(Class)obj;
            return tmpCls.getName();
        }
        String r=cl.getName();
        do {
            Field[] fields=fieldsCahce.get(cl);
            if(null == fields) {
                fields=cl.getDeclaredFields();
                if(null != fields) {
                    AccessibleObject.setAccessible(fields, true);
                }
                fieldsCahce.put(cl, fields);
            }
            if(null == fields || fields.length == 0) {
                cl=cl.getSuperclass();
                continue;
            }
            r+="[";
            // get the names and values of all fields
            for(Field f: fields) {
                if(Modifier.isStatic(f.getModifiers())) {
                    continue;
                }
                if(f.isSynthetic() || f.getName().indexOf("this$") != -1) {
                    continue;
                }
                r+=f.getName() + "=";
                try {
                    Object val=f.get(obj);
                    r+=toString(val);
                } catch(Exception e) {
                    e.printStackTrace();
                }
                r+=",";

            }
            if(r.endsWith(",")) {
                r=r.substring(0, r.length() - 1);
            }
            r+="]";
            cl=cl.getSuperclass();
        } while(cl != null);
        return r;
    }

}