JdbcTemplate 结果封装对象

水深无声 2022-03-10 06:48 253阅读 0赞

基于JdbcTemplate，将结果自动封装为对象，待优化

import org.springframework.jdbc.core.RowMapper;
    
    import java.lang.reflect.Field;
    import java.lang.reflect.InvocationTargetException;
    import java.lang.reflect.Method;
    import java.sql.ResultSet;
    import java.sql.SQLException;
    import java.util.ArrayList;
    import java.util.HashMap;
    import java.util.List;
    import java.util.Map;
    
    /** * 可以自动填充的mapper * * @param <T> */
    public class AutoRowMapper<T> implements RowMapper<T> { 
    
        private static Map<String, Field[]> fields = new HashMap<>();
    
        private Class clazz;
    
        public AutoRowMapper(Class clazz) { 
            this.clazz = clazz;
        }
    
        @Override
        public T mapRow(ResultSet rs, int rowNum) { 
            try { 
                T t = (T) clazz.newInstance();
                Field[] fs = getFields();
                for (int i = 0; i < fs.length; i++) { 
                    setValue(t, fs[i], rs.getObject(fs[i].getName()));
                }
                return t;
            } catch (InstantiationException e) { 
                e.printStackTrace();
            } catch (IllegalAccessException e) { 
                e.printStackTrace();
            } catch (SQLException e) { 
                e.printStackTrace();
            }
    
    
            return null;
        }
    
        Field[] getFields() { 
            if (null != fields.get(clazz.getName())) { 
                return fields.get(clazz.getName());
            }
            List<Field> list = new ArrayList<>();
            Class c = clazz;
            while (c != Object.class) { 
                Field[] declaredFields = c.getDeclaredFields();
                for (int i = 0; i < declaredFields.length; i++) { 
                    list.add(declaredFields[i]);
                }
                c = c.getSuperclass();
            }
            fields.put(clazz.getName(), list.toArray(new Field[list.size()]));
            return getFields();
    
        }
    
        void setValue(Object object, Field field, Object value) { 
            String name = field.getName();
            try { 
                Method method = clazz.getMethod(getMethodName(name), field.getType());
                method.invoke(object, value);
            } catch (NoSuchMethodException e) { 
                e.printStackTrace();
            } catch (IllegalAccessException e) { 
                e.printStackTrace();
            } catch (InvocationTargetException e) { 
                e.printStackTrace();
            }
        }
    
        String getMethodName(String field) { 
            return "set" + field.substring(0, 1).toUpperCase() + field.substring(1);
        }
    
    
    }