\u9019\u7bc7\u6587\u7ae0\u662f\u95dc\u65bc\u4f7f\u7528Kotlin with Spring Boot 1.5\u4f86\u5be6\u73fe\u7c21\u55ae\u7684Rest API\u7684\uff0c\u4f46\u9019\u662fSpring Boot 2.0\u7248\u672c\u7684\u6587\u7ae0\u3002\u6211\u5011\u4f7f\u7528\u76ee\u524d\u6700\u65b0\u7248\u672c\u7684RC2(2018\/2)\u4f86\u9032\u884c\u5be6\u4f5c\u3002<\/p>\n
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\u6e90\u4ee3\u7801\u4f4d\u4e8erubytomato\/demo-kotlin-spring2\u3002<\/p>\n
\u73af\u5883<\/p>\n
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<\/p>\n
<\/p>\n
Spring Framework 5.0.5
\nMySQL 5.7.19
\nGradle 4.5.1<\/p>\n
IntelliJ IDEA 2017.3<\/p>\n
\u8bf7\u53c2\u8003\u3002<\/p>\n
<\/p>\n
\u5982\u679c\u8981\u8fdb\u884c1.5\u7248\u672c\u7684\u8fc1\u79fb<\/p>\n
\u5df2\u7ecf\u51c6\u5907\u597d\u4e86Spring Boot 2.0\u8fc1\u79fb\u6307\u5357\u3002<\/p>\n
\u5e94\u7528\u7a0b\u5e8f\u7684\u6a21\u677f\u662f\u901a\u8fc7Spring Initializr\u751f\u6210\u7684\u3002
\n\u751f\u6210\u7684build.gradle\u6587\u4ef6\u4e2d\u6307\u5b9a\u4e86Kotlin\u7248\u672c\u4e3a1.2.20\uff0c\u4f46\u662fSpring Boot 2.0.0\u652f\u6301\u7684\u7248\u672c\u53ef\u8fbe\u52301.2.21\uff0c\u56e0\u6b64\u5728\u8fd9\u7bc7\u6587\u7ae0\u4e2d\u6211\u4eec\u4f7f\u7528\u4e861.2.21\u7248\u672c\u3002<\/p>\n
buildscript<\/span> {<\/span>\r\n ext<\/span> {<\/span>\r\n kotlinVersion<\/span> =<\/span> \"1.2.31\"<\/span>\r\n springBootVersion<\/span> =<\/span> \"2.0.2.RELEASE\"<\/span>\r\n }<\/span>\r\n repositories<\/span> {<\/span>\r\n mavenCentral<\/span>()<\/span>\r\n }<\/span>\r\n dependencies<\/span> {<\/span>\r\n classpath<\/span>(<\/span>\"org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}\"<\/span>)<\/span>\r\n classpath<\/span>(<\/span>\"org.jetbrains.kotlin:kotlin-gradle-plugin:${kotlinVersion}\"<\/span>)<\/span>\r\n classpath<\/span>(<\/span>\"org.jetbrains.kotlin:kotlin-allopen:${kotlinVersion}\"<\/span>)<\/span>\r\n classpath<\/span>(<\/span>\"org.jetbrains.kotlin:kotlin-noarg:${kotlinVersion}\"<\/span>)<\/span>\r\n }<\/span>\r\n}<\/span>\r\n\r\napply<\/span> plugin:<\/span> \"kotlin\"<\/span>\r\napply<\/span> plugin:<\/span> \"kotlin-spring\"<\/span>\r\napply<\/span> plugin:<\/span> \"kotlin-jpa\"<\/span>\r\napply<\/span> plugin:<\/span> \"org.springframework.boot\"<\/span>\r\napply<\/span> plugin:<\/span> \"io.spring.dependency-management\"<\/span>\r\napply<\/span> plugin:<\/span> \"kotlin-kapt\"<\/span>\r\n\r\ngroup<\/span> =<\/span> \"com.example\"<\/span>\r\nversion<\/span> =<\/span> \"0.0.3-SNAPSHOT\"<\/span>\r\nsourceCompatibility<\/span> =<\/span> 1.8<\/span>\r\ntargetCompatibility<\/span> =<\/span> 1.8<\/span>\r\ncompileKotlin<\/span> {<\/span>\r\n kotlinOptions<\/span> {<\/span>\r\n freeCompilerArgs<\/span> =<\/span> [<\/span>\"-Xjsr305=strict\"<\/span>]<\/span>\r\n jvmTarget<\/span> =<\/span> \"1.8\"<\/span>\r\n }<\/span>\r\n}<\/span>\r\ncompileTestKotlin<\/span> {<\/span>\r\n kotlinOptions<\/span> {<\/span>\r\n freeCompilerArgs<\/span> =<\/span> [<\/span>\"-Xjsr305=strict\"<\/span>]<\/span>\r\n jvmTarget<\/span> =<\/span> \"1.8\"<\/span>\r\n }<\/span>\r\n}<\/span>\r\ncompileJava<\/span> {<\/span>\r\n options<\/span>.<\/span>compilerArgs<\/span> <<<\/span> \"-Xlint:unchecked,deprecation\"<\/span>\r\n}<\/span>\r\ncompileTestJava<\/span> {<\/span>\r\n options<\/span>.<\/span>compilerArgs<\/span> <<<\/span> \"-Xlint:unchecked,deprecation\"<\/span>\r\n}<\/span>\r\n\r\nrepositories<\/span> {<\/span>\r\n mavenCentral<\/span>()<\/span>\r\n}<\/span>\r\n\r\ndependencies<\/span> {<\/span>\r\n \/\/ for web<\/span>\r\n compile<\/span>(<\/span>\"org.springframework.boot:spring-boot-starter-web\"<\/span>)<\/span>\r\n compile<\/span>(<\/span>\"com.fasterxml.jackson.module:jackson-module-kotlin\"<\/span>)<\/span>\r\n \/\/ for db<\/span>\r\n compile<\/span>(<\/span>\"org.springframework.boot:spring-boot-starter-data-jpa\"<\/span>)<\/span>\r\n runtime<\/span>(<\/span>\"mysql:mysql-connector-java\"<\/span>)<\/span>\r\n \/\/ compile(\"javax.xml.bind:jaxb-api:2.1\")<\/span>\r\n \/\/ kotlin<\/span>\r\n compile<\/span>(<\/span>\"org.jetbrains.kotlin:kotlin-stdlib-jdk8\"<\/span>)<\/span>\r\n compile<\/span>(<\/span>\"org.jetbrains.kotlin:kotlin-reflect\"<\/span>)<\/span>\r\n \/\/ for dev<\/span>\r\n kapt<\/span>(<\/span>\"org.springframework.boot:spring-boot-configuration-processor\"<\/span>)<\/span>\r\n runtime<\/span>(<\/span>\"org.springframework.boot:spring-boot-devtools\"<\/span>)<\/span>\r\n compileOnly<\/span>(<\/span>\"org.springframework.boot:spring-boot-configuration-processor\"<\/span>)<\/span>\r\n \/\/ for test<\/span>\r\n testCompile<\/span>(<\/span>\"org.springframework.boot:spring-boot-starter-test\"<\/span>)<\/span>\r\n testCompile<\/span>(<\/span>\"com.h2database:h2\"<\/span>)<\/span>\r\n}<\/span>\r\n<\/code><\/pre>\n-Xjsr305\u7f16\u8bd1\u5668\u6807\u5fd7<\/h3>\n
\u5728\u4f7f\u7528Spring Initializr\u751f\u6210\u7684\u9879\u76ee\u4e2d\uff0c\u9ed8\u8ba4\u60c5\u51b5\u4e0b\u4f1a\u542f\u7528\u4e25\u683c\u6a21\u5f0f\u3002
\n\u5728\u4e25\u683c\u6a21\u5f0f\u4e0b\uff0c\u5982\u679cJava\u7aef\u7684\u5bf9\u8c61\u5b57\u6bb5\u4e0a\u6709Nullable\u6ce8\u89e3\uff0c\u5219\u5728Kotlin\u7aef\u4e0d\u5c06\u5176\u89c6\u4e3aNullable\u5c06\u5bfc\u81f4\u7f16\u8bd1\u9519\u8bef\u3002<\/p>\n
\u4f8b\u5982\uff0c\u4ee5\u4e0b\u4ee3\u7801\u4e2d\u7684result.body.id\u5904\u5c06\u4f1a\u5bfc\u81f4\u7f16\u8bd1\u9519\u8bef\u3002\uff08\u5728\u975e\u4e25\u683c\u6a21\u5f0f\u4e0b\u4e0d\u4f1a\u4ea7\u751f\u7f16\u8bd1\u9519\u8bef\uff0c\u4f46\u4f1a\u4ea7\u751f\u8b66\u544a\u3002\uff09<\/p>\n
@Test<\/span>\r\nfun<\/span> `test<\/span> get<\/span>`<\/span>()<\/span> {<\/span>\r\n val<\/span> result<\/span>:<\/span> ResponseEntity<\/span><<\/span>Memo<\/span>><\/span> =<\/span> testRestTemplate<\/span>.<\/span>getForEntity<\/span>(<\/span>\"\/memo\/1\"<\/span>,<\/span> Memo<\/span>::<\/span>class<\/span>.<\/span>java<\/span>)<\/span>\r\n\r\n assertThat<\/span>(<\/span>result<\/span>.<\/span>body<\/span>.<\/span>id<\/span>).<\/span>isEqualTo<\/span>(<\/span>1L<\/span>)<\/span>\r\n \/\/ Only safe (?.) or non-null asserted (!!.) calls are allowed on a nullable receiver of type Memo? :compileTestKotlin FAILED<\/span>\r\n}<\/span>\r\n<\/code><\/pre>\n\u8fd9\u662f\u56e0\u4e3abody\u5b57\u6bb5\u4e0a\u6709\u4e00\u4e2aNullable\u6ce8\u89e3\u3002<\/p>\n
public<\/span> class<\/span> HttpEntity<\/span><<\/span>T<\/span>><\/span> {<\/span>\r\n\r\n @Nullable<\/span>\r\n private<\/span> final<\/span> T<\/span> body<\/span>;<\/span>\r\n\r\n}<\/span>\r\n<\/code><\/pre>\n\u4e3a\u4e86\u901a\u8fc7\u7f16\u8bd1\uff0c\u9700\u8981\u5c06Nullable\u53c2\u6570\u8fdb\u884c\u5982\u4e0b\u5904\u7406\u3002<\/p>\n
assertThat<\/span>(<\/span>