1public class Params {
2    private String arr1;
3}

比如传参 {arr1: "ss"}

1<if test="arr1 != null and arr1 == 'a'"></if>

通过字符串相等 arr1 == 'a' 会自动把 arr1 的数据转化为 number,而出现报错

1Error querying database.  Cause: java.lang.NumberFormatException: For input string: "ss"

而正确写法应该这样 arr1 == "a"

1<if test='arr1 != null and arr1 == "a"'></if>