代码生成了,但是控制台报错字符串索引越界

Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String index out of range: 1
	at java.lang.String.substring(String.java:1963)
	at com.itheima.code.util.StringUtils.firstUpper(StringUtils.java:16)
	at com.itheima.code.build.TemplateBuilder.builder(TemplateBuilder.java:180)
	at com.itheima.CodeApplication.main(CodeApplication.java:14)

Process finished with exit code 1
