SpEL拆分属性为数组失败：ParseException异常排查求助

问题背景 #

使用SpEL表达式将配置文件中以|分隔的wisdoms属性拆分为数组时，抛出org.springframework.expression.ParseException，提示存在非终止字符串字面量。相关代码与配置如下：

代码示例 #

@Component
@Qualifier("propertySourceBased")
public class PropertySourceWisdomProvider implements WisdomProvider {
    @Value("#{'${wisdoms}'.split('|')}")
    private String[] wisdoms;
}

配置文件内容 #

wisdoms = Tomorrow is often the busiest day of the week|\
          I have always wanted to be somebody, but I see now I should have been more specific|\
          Knowledge is like underwear. It is useful to have it, but not necessary to show it off|\
          Go to Heaven for the climate, Hell for the company|\
          Going to church doesn't make you a Christian any more than going to a garage makes you an automobile

异常信息 #

Caused by: org.springframework.expression.ParseException: Expression [#{'Tomorrow is often the busiest day of the week|I have always wanted to be somebody, but I see now I should have been more specific|Knowledge is like underwear. It is useful to have it, but not necessary to show it off|Go to Heaven for the climate, Hell for the company|Going to church doesn't make you a Christian any more than going to a garage makes you an automobile'.split('|')}] @381: Found non terminating string literal starting at position 381

问题原因 #

1. 单引号冲突：配置字符串中包含doesn't，其中的单引号'会与SpEL表达式外层包裹字符串的单引号冲突。SpEL解析时会误将这个单引号识别为字符串字面量的结束标记，导致后续内容无法被正确解析，抛出“非终止字符串字面量”异常。
2. 正则特殊字符未转义：split方法接收的参数是正则表达式，|是正则中的特殊元字符（表示逻辑或），直接使用会导致按空字符拆分，无法达到按|分隔字符串的预期效果。

解决方法 #

方案一：转义配置文件中的单引号 #

在配置文件中，用两个连续单引号''表示一个字面量单引号，修改配置行：

wisdoms = Tomorrow is often the busiest day of the week|\
          I have always wanted to be somebody, but I see now I should have been more specific|\
          Knowledge is like underwear. It is useful to have it, but not necessary to show it off|\
          Go to Heaven for the climate, Hell for the company|\
          Going to church doesn''t make you a Christian any more than going to a garage makes you an automobile

同时修改SpEL表达式，转义|为正则字面量：

@Component
@Qualifier("propertySourceBased")
public class PropertySourceWisdomProvider implements WisdomProvider {
    @Value("#{'${wisdoms}'.split('\\\\|')}")
    private String[] wisdoms;
}

注：Java字符串中需要用\\\\表示正则所需的\，最终SpEL解析后会得到split('\|')，实现按字面量|拆分。

方案二：改用双引号包裹SpEL中的字符串 #

在SpEL表达式中改用双引号包裹${wisdoms}替换后的字符串，避免与配置中的单引号冲突，同时转义|：

@Component
@Qualifier("propertySourceBased")
public class PropertySourceWisdomProvider implements WisdomProvider {
    @Value("#{\"${wisdoms}\".split('\\\\|')}")
    private String[] wisdoms;
}

注：Java注解字符串中需要用\"表示双引号，确保SpEL能正确识别字符串边界。

内容的提问来源于stack exchange，提问作者Sergey Zolotarev