MyBatis报OgnlException: source is null for getProperty(null, "id")异常

MyBatis报OgnlException: source is null for getProperty(null, “id”)异常

• 代码如下

    <sql id="where">

            <if test="requestStudent.id!=null and requestStudent.id!=''">
                and tb.id = #{requestStudent.id}
            </if>

            <if test="requestStudent.name!=null and requestStudent.name!=''">
                and tb.name = #{requestStudent.name}
            </if>
            <if test="requestStudent.age!=null and requestStudent.age!=''">
                and tb.age = #{requestStudent.age}
            </if>
            <if test="requestStudent.height!=null and requestStudent.height!=''">
                and tb.height = #{requestStudent.height}
            </if>
    </sql>

• 原因：

  • 以前的MyBatis可以像上面那样直接”“判断是否为null，现在不行了，要先判断requestStudent是否为null才行，否则即使requestStudent不为null也会报source is null for getProperty(null, “id”)异常，即可能会有NPE空指针异常。

• 解决办法：在外层加一个if判断就行了

    <sql id="where">
        <if test="requestStudent!=null">
            <if test="requestStudent.id!=null and requestStudent.id!=''">
                and tb.id = #{requestStudent.id}
            </if>

            <if test="requestStudent.name!=null and requestStudent.name!=''">
                and tb.name = #{requestStudent.name}
            </if>
            <if test="requestStudent.age!=null and requestStudent.age!=''">
                and tb.age = #{requestStudent.age}
            </if>
            <if test="requestStudent.height!=null and requestStudent.height!=''">
                and tb.height = #{requestStudent.height}
            </if>
        </if>
    </sql>