MyBatis: Map String to boolean

Question

I have booleans inserted in my database as Y/N. When I try to map the result to a boolean java type, it always set it to a false in any case in my pojo.

Is there any way to map String to boolean? Here's my code:

<resultMap id="getFlag" type="MyPojo">
    <result property="myFlag" column="MY_FLAG"/>
</resultMap>

Solution 1

What you need is a typeHandler for you Y/N Boolean type: (more explained here) Actual Handler:

public class YesNoBooleanTypeHandler extends BaseTypeHandler<Boolean> {

    @Override
    public void setNonNullParameter(PreparedStatement ps, int i, Boolean parameter, JdbcType jdbcType)
            throws SQLException {
        ps.setString(i, convert(parameter));
    }

    @Override
    public Boolean getNullableResult(ResultSet rs, String columnName)
            throws SQLException {
        return convert(rs.getString(columnName));
    }

    @Override
    public Boolean getNullableResult(ResultSet rs, int columnIndex)
            throws SQLException {
        return convert(rs.getString(columnIndex));
    }

    @Override
    public Boolean getNullableResult(CallableStatement cs, int columnIndex)
            throws SQLException {
        return convert(cs.getString(columnIndex));
    }

    private String convert(Boolean b) {
        return b ? "Y" : "N";
    }

    private Boolean convert(String s) {
        return s.equals("Y");
    }

}

Your usage:

<result property="myFlag" column="MY_FLAG" javaType="java.lang.Boolean" jdbcType="VARCHAR" typeHandler="com.foo.bar.YesNoBooleanTypeHandler" />

Solution 2

One way to do it would be to look at implementing a custom TypeHandler. http://www.mybatis.org/mybatis-3/configuration.html#typeHandlers.

Comments

[Pierre]

Rememember to register your Y/N TypeHandler upon creating your SqlSessionFactoryBean like this: factory.setTypeAliases(new Class[]{YesNoBooleanTypeHandler.class}). You must already configure your SqlSesionFactory in your applicationContext.xml [if using Spring XML] or Spring Config @Configuration [if using java annotations].