通用RowMapper封装查询结果到自定义类中

之前项目中利用JdbcTemplate进行查询时经常遇到需要将结果封装到具体自定义类中的情况，每次针对不同的类，不同的查询结果都要重新编写RowMapper，感觉十分繁琐，今天自己写了一个通用的，在系统负载不大的情况下还比较实用

package object;

import java.lang.reflect.Field;
import java.sql.ResultSet;
import java.sql.SQLException;
import org.springframework.jdbc.core.RowMapper;

public class ObjectRowMapper implements RowMapper{
    private Class className;
    
    public ObjectRowMapper(Class className){
        this.className = className;
    }
    
    /*
     * 该方法自动将数据库字段对应到Object中相应字段
     * 要求：数据库与Object中字段名相同
     * 
     */
    public Object mapRow(ResultSet rs, int rowNum) throws SQLException {
        
        
        Object nt = new Object();
        Field[] fields = className.getDeclaredFields();
        try {
            nt = className.newInstance();
            for (Field field : fields) {
                //如果结果中没有改field项则跳过
                try {
                    rs.findColumn(field.getName());
                } catch (Exception e) {
                    continue;
                }
                //修改相应filed的权限
                boolean accessFlag = field.isAccessible();
                field.setAccessible(true);
                String value = rs.getString(field.getName());
                value = value==null?"":value;
                setFieldValue(nt, field, value);
                
                //恢复相应field的权限
                field.setAccessible(accessFlag);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return nt;
    }
    
    /*
     * 根据类型对具体对象属性赋值
     */
    public static void setFieldValue(Object form, Field field, String value) {

        String elemType = field.getType().toString();

        if (elemType.indexOf("boolean") != -1||elemType.indexOf("Boolean") != -1) {
            try {
                field.set(form, Boolean.valueOf(value));
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            }
        } else if (elemType.indexOf("byte") != -1||elemType.indexOf("Byte") != -1) {
            try {
                field.set(form, Byte.valueOf(value));
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            }
        } else if (elemType.indexOf("char") != -1||elemType.indexOf("Character") != -1) {
            try {
                field.set(form, Character.valueOf(value.charAt(0)));
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            }
        } else if (elemType.indexOf("double") != -1||elemType.indexOf("Double") != -1) {
            try {
                field.set(form, Double.valueOf(value));
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            }
        } else if (elemType.indexOf("float") != -1||elemType.indexOf("Float") != -1) {
            try {
                field.set(form, Float.valueOf(value));
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            }
        } else if (elemType.indexOf("int") != -1||elemType.indexOf("Integer") != -1) {
            try {
                field.set(form, Integer.valueOf(value));
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            }
        } else if (elemType.indexOf("long") != -1||elemType.indexOf("Long") != -1) {
            try {
                field.set(form, Long.valueOf(value));
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            }
        } else if (elemType.indexOf("short") != -1||elemType.indexOf("Short") != -1) {
            try {
                field.set(form, Short.valueOf(value));
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            }
        } else {
            try {
                field.set(form, (Object) value);
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            }
        }
    }
}

评论

2 楼 diyunpeng 2012-11-30  

Obejct应该用newInstance吧

1 楼 每个人都可爱 2012-03-23  

BeanPropertyRowMapper 似乎就是这个东西