Spring Boot upgrade to 2.1.6 release

时间：2020-01-31 15:28:19 阅读：81 评论：0 收藏：0 [点我收藏+]

Process

To upgrade Spring Boot, you have to upgrade the tools and libs as well, including Gradle, Tomcat, Kafka, Redis, Zoomkeeper, Hanadb .etc

Find the dependency versions suit for your Spring Boot at here.
Do as the guideline said.
Not only the Spring Boot migration guideline, but also the tools you will upgrade.

Problems happened and solutions

bootJar and jar: jar is default disabled and bootJar is default abled, if you are using project dependency(e.g. compile/implementation project(":projectname")), you need to care about this.
ConfigurationProperties: the prefix name must be lowercase, that means the first level of the profile‘s properties must be lowercase.
WARN Message for Implicit ‘open-in-view‘: a new feature that can avoid lazy loading exception from controller(web views), can disabled it by set
```
spring.jpa.open-in-view: false
```

New id generator(sequence generator): SequenceStyleGenerator is default abled, you can disabled it by set

spring.jpa.hibernate.use-new-id-generator-mappings: false

Or you can use replace the deprecated @SequenceGenerator, refer here .

This is a simple example:

@Id
@GeneratedValue(strategy= GenerationType.SEQUENCE,  generator="ID_SEQ")
@GenericGenerator(name = "ID_SEQ",
    strategy = "org.hibernate.id.enhanced.SequenceStyleGenerator",
    parameters = {
        @Parameter(name = SEQUENCE_PARAM, value = "ID_SEQ")
    })
private Long id;

Json date format: The date format which json returned has been changed form timestamps(createTime: 1544693261000) to UTC string("2018-12-13T09:27:41.000+0000") at Spring Boot2, you can use old format by set
```
pring.jackson.serialization.write-dates-as-timestamps: true
```
Tomcat URI check: if you‘re using tomcat8 then no "_" is available for an URI.
Additional profiles for Spring Boot2: use spring.config.additional-location instead of spring.config.location.
Get rid of lightadmin:lightadmin is an inspect tool but intergrated with Spring Boot1.
Hana upgrade: have to add columnDefinition for tinyint clumns and set 0/1 to replace false/true.