swagger study notes 3 java.lang.NumberFormatException: For input string: ““

Problem phenomenon:

In the process of learning swagger today, after starting the swaggerUI page, an error was reported in the background:

java.lang.NumberFormatException: For input string: ""

---

problem analysis:

This error means that the format of the integer data type is abnormal: an empty string is passed in to the integer data type, which causes the error.

By consulting online information, we can know:

This is because  springfox-swagger2 (2.9.2)  depends on  swagger-models (1.5.20);

And this version of swagger will be entity class type of China-Africa String property defaults assigned to an empty string.

Therefore, you need to manually add a higher version of swagger-models dependency!!!!!!

So after starting the swaggerUI page, the non-String attribute of the entity class at this time has no default value, and NumberFormatException: For input string: "" will appear.

---

Solution:

        <!--swaggerUI-->
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
            <version>2.9.2</version>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
            <version>2.9.2</version>
        </dependency>

Just add the dependency of swagger-models (1.5.21) :

        <!--swaggerUI-->
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
            <version>2.9.2</version>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
            <version>2.9.2</version>
        </dependency>
        <!--规范model实体类注解-->
        <!--如果不加，则当实体类非String属性没有默认值时,会出现NumberFormatException: For input string:""，
        这是因为springfox-swagger2(2.9.2)依赖于swagger-models(1.5.20)
        该版本的swagger只判断了null没有判断空字串符
        所以会将实体类中非String类型的属性默认赋值为空字符串;
        而1.5.21版本之后新增了空串判断,所以就不会有该问题了-->
        <!--<dependency>-->
            <!--<groupId>io.swagger</groupId>-->
            <!--<artifactId>swagger-models</artifactId>-->
            <!--<version>1.5.21</version>-->
        <!--</dependency>-->

Restart, no more errors: