分析：
那么什么情况下会发生“There is no getter for property named in ‘class java.lang.String’”错误呢？
其实是在这种情况下：
<select id="getRiskMember" resultMap="BaseResultMap" parameterType="String">
<include refid="selectMember"/>
and safetylevel > 1
and stauts = 1 <if test="username != null">
and username = #{username}
</if>
</select>
注意看，是在if test=验证的时候发生的 “There is no getter for property named in ‘class java.lang.String’”，
而并非是and username = #{username} 的时候发生的错误。
解决办法：
<select id="getRiskMember" resultMap="BaseResultMap" parameterType="String">
<include refid="selectMember"/>
and safetylevel > 1
and stauts = 1 <if test="_parameter != null">
and username = #{username}
</if>
</select>