工具类自动生成MybatisXML中的resultMap

拼搏现实的明天。 2023-10-02 10:17 13阅读 0赞

由于时间长没有参与过mybatis的项目了，发现直接restType映射实体会有值映射不上去的情况，也不想写resultMap，话不多说，工具类奉上。

package com.app.admin.framework.menu.utils;
    
    import com.app.admin.framework.menu.common.ProMenu;
    
    import java.lang.reflect.Field;
    import java.util.regex.Matcher;
    import java.util.regex.Pattern;
    
    /**
     * @author: 
     * @createTime: 2021/09/22 18:04
     * @company: 
     * @description:
     */
    public class MyBatisUtil {
        private static Pattern humpPattern = Pattern.compile("[A-Z]");
    
        public static String getUpdateSelective(Class<?> clazz){
    
            Object obj = null;
            try{
                obj = clazz.newInstance();
            }catch (Exception e){
                return "#Exception.反射生成实体异常#";
            }
    
            String clazzName = clazz.getSimpleName();
            String resultMapId = Character.toLowerCase(clazzName.charAt(0))+clazzName.substring(1)+"Map";
            String pkgName = clazz.getName();
    
            StringBuilder resultMap = new StringBuilder();
            resultMap.append("<update id=\"updateSelective\" parameterType=\"");
            resultMap.append(pkgName);
            resultMap.append("\">\n");
            resultMap.append("UPDATE X_TABLE");
            resultMap.append("\n<set>\n");
    
            Field[] fields = clazz.getDeclaredFields();
            for(Field f : fields){
                String property = f.getName();
                String javaType = f.getType().getName();
                if("serialVersionUID".equals(property)){
                    continue;//忽略掉这个属性
                }
                resultMap.append("    <if test=\"");
                resultMap.append(property+"!=null\">");
                resultMap.append(property2Column(property).toUpperCase());
                resultMap.append("=#{"+property+", jdbcType="+javaType2jdbcType(javaType.toLowerCase())+"},</if>\n");
            }
            resultMap.append("</set>\n");
            resultMap.append("where id = #{id,jdbcType=VARCHAR}\n");
            resultMap.append("</update>");
            return resultMap.toString();
        }
        public static void getInsert(Class<?> clazz){
            String text = getUpdateSelective(clazz);
            Pattern p = Pattern.compile("#\\{[^}]+}");
            Matcher m = p.matcher(text);
    
            while (m.find()){
                System.out.println(m.group()+",");
            }
    
        }
    
        /**
         * 获取表的字段
         * @param clazz
         */
        public void getColumns(Class<?> clazz){
            String text = getResultMap(clazz);
            Pattern p = Pattern.compile("column=[\"\\w\"]+");
            Matcher m = p.matcher(text);
            while (m.find()) {
                Pattern p1 = Pattern.compile("[\"\\w\"]+$");
                Matcher m1 = p1.matcher(m.group());
    
                while (m1.find()) {
                    Pattern p2 = Pattern.compile("[\\w]+");
                    Matcher m2 = p2.matcher(m1.group());
                    while (m2.find()) {
                        System.err.println(m2.group().toUpperCase());
                    }
                }
            }
        }
        /**
         * 获取ResultMap
         * @param clazz 实体类的Class
         * @return String
         */
        public static String getResultMap(Class<?> clazz){
    
            Object obj = null;
            try{
                obj = clazz.newInstance();
            }catch (Exception e){
                return "#Exception.反射生成实体异常#";
            }
    
            String clazzName = clazz.getSimpleName();
            String resultMapId = Character.toLowerCase(clazzName.charAt(0))+clazzName.substring(1)+"Map";
            String pkgName = clazz.getName();
    
            StringBuilder resultMap = new StringBuilder();
            resultMap.append("<resultMap id=\"");
            resultMap.append(resultMapId);
            resultMap.append("\" type=\"");
            resultMap.append(pkgName);
            resultMap.append("\">\n");
    
            Field[] fields = clazz.getDeclaredFields();
            for(Field f : fields){
                String property = f.getName();
                String javaType = f.getType().getName();
                if("serialVersionUID".equals(property)){
                    continue;//忽略掉这个属性
                }
                resultMap.append("    <result column=\"");
                resultMap.append(property2Column(property).toUpperCase());
                resultMap.append("\" jdbcType=\"");
                resultMap.append(javaType2jdbcType(javaType.toLowerCase()));
                resultMap.append("\" property=\"");
                resultMap.append(property);
                resultMap.append("\" />\n");
            }
            resultMap.append("</resultMap>");
            return resultMap.toString();
        }
    
        private static String property2Column(String property){
            Matcher matcher = humpPattern.matcher(property);
            StringBuffer sb = new StringBuffer();
            while(matcher.find()){
                matcher.appendReplacement(sb, "_"+matcher.group(0).toLowerCase());
            }
            matcher.appendTail(sb);
            return sb.toString();
        }
    
        private static String javaType2jdbcType(String javaType){
            if(javaType.contains("string")){
                return "VARCHAR";
            }else if(javaType.contains("boolean")){
                return "BIT";
            }else if(javaType.contains("byte")){
                return "TINYINT";
            }else if(javaType.contains("short")){
                return "SMALLINT";
            }else if(javaType.contains("int")){
                return "INTEGER";
            }else if(javaType.contains("long")){
                return "BIGINT";
            }else if(javaType.contains("double")){
                return "DOUBLE";
            }else if(javaType.contains("float")){
                return "REAL";
            }else if(javaType.contains("date")){
                return "DATE";
            }else if(javaType.contains("timestamp")){
                return "TIMESTAMP";
            }else if(javaType.contains("time")){
                return "TIME";
            }else if(javaType.contains("bigdecimal")){
                return "DECIMAL";
            }else{
                return "未知类型";
            }
        }
    
    
        public static void main(String[] args) throws ClassNotFoundException {
            System.out.println(getResultMap(ProMenu.class));
        }
    }