DynamicBeanUtils.java

package message.jdbc.base;

import javassist.ClassPool;
import javassist.LoaderClassPath;
import message.jdbc.mapper.DynamicRowMapper;

/**
 * dynamic bean create util
 *
 * @author sunhao(sunhao.java@gmail.com)
 * @version V1.0, 2012-4-10 上午12:56:03
 */
public class DynamicBeanUtils {

    public final static ClassPool classPool;

    static {
        ClassPool parent = ClassPool.getDefault();
        ClassPool child = new ClassPool(parent);
        child.appendClassPath(new LoaderClassPath(DynamicRowMapper.class.getClassLoader()));
        child.appendSystemPath(); // the same class path as the default one.
        child.childFirstLookup = true; // changes the behavior of the child.
        classPool = child;
    }

    public static String createMapperKey(Class clazz, String sql) {
        StringBuffer key = new StringBuffer();
        key.append(sql)
                .append("-")
                .append(clazz.getName());

        return key.toString();
    }

    /**
     * 将类中的字段转成数据库中的字段
     * 格式：pkId --> pk_id
     *
     * @param name
     * @return
     */
    public static String underscoreName(String name) {
        StringBuffer result = new StringBuffer();
        if (name != null && name.length() > 0) {
            for (int i = 0; i < name.length(); i++) {
                String tmp = name.substring(i, i + 1);
                //判断截获的字符是否是大写，大写字母的toUpperCase()还是大写的
                if (tmp.equals(tmp.toUpperCase())) {
                    //此字符是大写的
                    result.append("_").append(tmp.toLowerCase());
                } else {
                    result.append(tmp);
                }
            }
        }

        return result.toString();
    }

    /**
     * 将数据库中的字段转成类中的字段
     * 格式：pk_id --> pkId
     *
     * @param name
     * @return
     */
    public static String decodeUnderscoreName(String name) {
        StringBuffer result = new StringBuffer();
        boolean up = false;
        if (name != null && name.length() > 0) {
            //转成小写
            name = name.toLowerCase();
            for (int i = 0; i < name.length(); i++) {
                //取得i位置的字符
                String tmp = name.substring(i, i + 1);
                if ("_".equals(tmp)) {
                    up = true;
                    //结束本次循环，进入下次循环
                    continue;
                }

                if (up) {
                    result.append(tmp.toUpperCase());
                    up = false;
                } else {
                    result.append(tmp);
                }
            }
        }

        return result.toString();
    }

    /**
     * @param clazzs
     * @param sql
     * @param forMap
     * @return
     */
    public static String createMapperKey(Class[] clazzs, String sql, boolean forMap) {
        StringBuffer result = new StringBuffer();
        result.append(sql);
        result.append(forMap ? "true" : "false");
        result.append("-");
        for (Class c : clazzs) {
            result.append(c.getName());
        }

        return result.toString();
    }

}