使用 swagger codegen for openapi 3.0 生成代碼時出現 NullPointer 異常

Question

通過 swagger codegen 生成代碼時遇到 NullPointer 問題。 我是 gradle 的新手，並更新了 build.gradle 以反映為給定 API 規范生成代碼所需的最新更改。

請提供您的寶貴意見。

我的 build.gradle 如下圖所示：

import io.swagger.codegen.v3.CodegenConfigLoader
import io.swagger.codegen.v3.DefaultGenerator
import io.swagger.codegen.v3.ClientOptInput
import io.swagger.codegen.v3.ClientOpts
import io.swagger.v3.parser.OpenAPIV3Parser

buildscript {
    ext {
        springBootVersion = '2.0.5.RELEASE'
        jacocoWorkspaceDirectory = "/jacoco/"
    }
    repositories {
        mavenLocal()
        maven { url "http://repo.maven.apache.org/maven2" }
    }
    dependencies {
        classpath "org.springframework.boot:spring-boot-gradle-plugin:$springBootVersion"
        classpath group: "io.spring.gradle", name: "dependency-management-plugin", version: "1.0.6.RELEASE"
        classpath 'co.bambo.sonar:bambo-sonar-gradle-plugin:2.7.1.RELEASE'
        classpath group: "org.unbroken-dome.gradle-plugins", name: "gradle-testsets-plugin", version: "1.4.2"
        classpath('io.swagger.codegen.v3:swagger-codegen-maven-plugin:3.0.16')
        classpath("io.swagger.core.v3:swagger-core:2.1.1")
    }
}

apply plugin: 'java'
apply plugin: 'maven'
apply plugin: 'maven-publish'
apply plugin: "io.spring.dependency-management"
apply plugin: "org.springframework.boot"
apply plugin: 'bambo-sonar'
apply plugin: "jacoco"
apply plugin: "findbugs"
apply plugin: "checkstyle"
apply plugin: "pmd"
apply plugin: 'org.unbroken-dome.test-sets'


project.buildDir = 'target'

ext {
    appName = 'school-management'
    apiPackage = 'co.bambo.school.management.generated.api'
    modelPackage = 'co.bambo.school.management.generated.model'
    swaggerFile = "${rootDir}/src/main/resources/schoolmanagement.v1.yaml"
    swaggerBuildDir = "${project.buildDir}/" + appName
}


// NOTE :-> Following are to be included as and when required.
// These variables are defined for the purpose of exclusion from the sonar scan. Packages mentioned will be exluded
// from Sonar Scans.
def excludeschoolmanagementConstants = "src/main/java/co/bambo/school/management/constants/schoolmanagementConstants.java"
def excludeCaasConstants = "src/main/java/co/bambo/school/management/pcf/constants/CaasConstants.java"

sourceCompatibility = 1.8
targetCompatibility = 1.8

group = 'co.bambo.schoolmanagement'
version = '1.0.0-SNAPSHOT'

tasks.withType(JavaCompile) {
    options.encoding = 'UTF-8'
}

repositories {
    mavenLocal()
    maven { url "http://repo.maven.apache.org/maven2" }
}

configurations {
    testUtilCompile.extendsFrom testImplementation
    testUtilRuntime.extendsFrom testRuntime
}

sourceSets {
    testUtil {
        java {
            srcDir 'src/test-util/java'
        }
    }
}

testSets {
    funcTest { dirName = "func-test" }
}


// PLUGIN CONFIGs
springBoot {
    mainClassName = 'co.bambo.school.management.schoolmanagementApplication'
    buildInfo()
}

bootJar {
    baseName = 'school-management'
    destinationDir = project.buildDir
    archiveName = 'school-management.jar'
}

// FIXME - IN FUTURE WE NEED TO MAKE THIS to Zero.
checkstyle {
    maxErrors = 70
    maxWarnings = 70
    toolVersion = 8.17
}

[checkstyleMain, checkstyleTest].each { task ->
    task.logging.setLevel(LogLevel.LIFECYCLE)
    // FIXME -  This is to be updated with False.
    task.ignoreFailures = true
}

findbugs {
    toolVersion = "3.0.1"
    sourceSets = [sourceSets.main]
    // FIXME - Make this false.
    ignoreFailures = true
    effort = "max"
    reportLevel = "medium"
    excludeFilter = file("$rootDir/config/findbugs/exclude.xml")
}

pmd {
    toolVersion = "5.6.1"
    ignoreFailures = true
    sourceSets = [sourceSets.main]
    reportsDir = file("${project.buildDir}/reports/pmdTest")
    ruleSets = [
            'java-basic'
    ]
}

tasks.withType(FindBugs) {
    reports {
        xml.enabled = false
        html.enabled = true
    }
}

tasks.withType(Pmd) {
    reports {
        xml.enabled = false
        html.enabled = true
    }
}


sonarqube {
    properties {
        property "sonar.projectName", "school-management"
        property "sonar.projectKey", "school-management"
        property "sonar.jacoco.reportPath", "build/jacoco/test.exec"
        property "sonar.junit.reportPaths", "build/test-results/test"
        property "sonar.host.url", "https://fusion.bambo.int/sonar"
        property "sonar.gateId", "307"
        property "sonar.projectDescription", "school management microservice."
        property "sonar.skip.qualityGate", "false"
        property "sonar.exclusions", [excludeschoolmanagementConstants, excludeCaasConstants]
    }
}

// Actual task for generating the server
task generateServer {
    doLast {
        def openAPI = new OpenAPIV3Parser().read(rootProject.swaggerFile.toString(), null, null)
        def clientOptInput = new ClientOptInput().openAPI(openAPI)
        def codeGenConfig = CodegenConfigLoader.forName('spring')
        codeGenConfig.setApiPackage(rootProject.ext.apiPackage)            // Package to be used for the API interfaces
        codeGenConfig.setModelPackage(rootProject.ext.modelPackage)        // Package to be used for the API models
        codeGenConfig.setInputSpec(rootProject.ext.swaggerFile.toString()) // The swagger API file
        codeGenConfig.setOutputDir(rootProject.ext.swaggerBuildDir)
        // The output directory, user-service-contract/build/user-service-server/
//        codegenConfig.addSystemProperty("models", "");
//        codegenConfig.addSystemProperty("apis", "");

        def clientOps = new ClientOpts()
        clientOps.setProperties([
                'dateLibrary'  : 'java8', // Date library to use
                'useTags'      : 'true',  // Use tags for the naming
                'interfaceOnly': 'false'// Generating the Controller API interface and the models only
        ])
        clientOptInput.setOpts(clientOps)
        def generator = new DefaultGenerator().opts(clientOptInput)
        generator.generate() // Executing the generation
    }
}

compileJava {
    dependsOn generateServer
}

build {
    dependsOn generateServer
}

// ---- PLUGIN CONFIG ENDs


dependencyManagement {
    imports {
        mavenBom "org.springframework.boot:spring-boot-dependencies:$springBootVersion"
    }
}

funcTest {
    doFirst {
        jacoco {
            destinationFile = file("${buildDir}" + jacocoWorkspaceDirectory + "test.exec")
        }
    }

    dependsOn cleanTest
    dependsOn compileTestUtilJava
    dependsOn cleanJacocoTestReport
    dependsOn cleanJacocoTestCoverageVerification
    finalizedBy jacocoTestReport
    finalizedBy jacocoTestCoverageVerification
    environment SPRING_PROFILES_ACTIVE: environment.SPRING_PROFILES_ACTIVE ?: "local"
}

dependencies {
    // Spring specific dependencies
    implementation('org.springframework:spring-tx')
    implementation('org.springframework:spring-core')
    implementation('org.springframework:spring-context')
    implementation('org.springframework:spring-beans')
    implementation('org.springframework:spring-expression')
    implementation group: 'org.springframework.boot', name: 'spring-boot-starter-actuator'
    implementation group: 'org.springframework.boot', name: 'spring-boot-starter-aop'
    implementation group: 'org.springframework.retry', name: 'spring-retry'

    implementation group: 'org.springframework.boot', name: "spring-boot-starter-data-jpa"

    // Spring cloud
    // Upgraded springcloud-starter-vault from 2.0.0.RC1 to 2.0.1.RELEASE.
    implementation group: 'org.springframework.cloud', name: 'spring-cloud-starter-vault-config', version: '2.0.1.RELEASE'
    implementation group: 'io.pivotal.spring.cloud', name: 'spring-cloud-services-starter-config-client', version: '2.0.1.RELEASE'
    // Upgraded "spring-cloud-starter-bus-amqp" following from 2.0.0.RC1 to 2.0.1.RELEASE
    implementation group: 'org.springframework.cloud', name: 'spring-cloud-starter-bus-amqp', version: '2.0.1.RELEASE'

    // SWagger dependencies
    implementation group: 'io.swagger', name: 'swagger-parser', version: '1.0.23'
    implementation group: 'io.springfox', name: 'springfox-swagger2', version: '2.9.2'
    implementation group: 'io.springfox', name: 'springfox-swagger-ui', version: '2.9.2'
    implementation group: 'com.atlassian.oai', name: 'swagger-request-validator-core', version: '1.3.9'

    // Apache - Commons
    implementation group: 'commons-io', name: 'commons-io', version: '2.6'

    // Oracle dependencies
    implementation group: 'com.oracle', name: 'ojdbc7', version: '12.1.0'

    //2nd level cache dependency
    implementation group: 'org.hibernate', name: 'hibernate-ehcache'

    // Logback
    implementation group: 'ch.qos.logback', name: 'logback-classic', version: '1.2.3'
    implementation group: 'ch.qos.logback', name: 'logback-core', version: '1.2.3'

    implementation group: 'org.apache.camel', name: 'camel-jsonpath', version: '2.22.0'
    implementation group: 'com.google.gdata', name: 'core', version: '1.47.1'
    implementation group: 'com.google.guava', name: 'guava', version: '20.0'

    // FIXME - Eventually phase - out this Mapper
    implementation group: 'ma.glasnost.orika', name: 'orika-core', version: '1.5.4'

    // JSON
    implementation group: 'com.fasterxml.jackson.dataformat', name: 'jackson-dataformat-xml', version: '2.8.10'
    implementation group: 'com.googlecode.json-simple', name: 'json-simple', version: '1.1.1'

    // Mapstruct
    implementation 'org.mapstruct:mapstruct:1.3.0.Final'
    implementation 'org.mapstruct:mapstruct-processor:1.3.0.Final'

    implementation group: 'ch.qos.logback.contrib', name: 'logback-json-classic', version: '0.1.5'
    implementation group: 'ch.qos.logback.contrib', name: 'logback-jackson', version: '0.1.5'

    testImplementation "junit:junit:4.12"
    testImplementation group: "org.springframework.boot", name: "spring-boot-starter-test"
    testImplementation group: 'com.github.tomakehurst', name: 'wiremock', version: '2.21.0'

    testUtilCompile sourceSets.main.output
    funcTestCompile sourceSets.testUtil.output
}

我在這一行遇到NullPointer問題def generator = new DefaultGenerator().opts(clientOptInput) 。

Update-1我理解這個問題對於 Java 中的 NullPointer 異常來說似乎很容易。 但是相信我，我無法在 build.gradle 中弄清楚為什么它會失敗，因為它甚至沒有顯示正確的錯誤消息，說明缺少什么。 下面顯示的消息是我所得到的。 即使調試 groovy 腳本也無濟於事。

Execution failed for task ':generateServer'.
> java.lang.NullPointerException (no error message)

Update-2我剛剛在 DefaultGenerator.java 的第 77 行看到了這一行。 這是我得到 NullPointerException this.config.additionalProperties().putAll(opts.getOpts().getProperties());

我不確定參數中缺少什么。 我正在傳遞opts並且getOpts()也在填充屬性文件。

使用 gradle 4.9 版。

Answer 1

好吧，我想通了，這在理解和代碼中也是一個愚蠢的錯誤。

在調試和瀏覽swagger-codegen代碼后，我才知道這個錯誤。 我意識到生成代碼需要配置，基於此配置指定它正在生成代碼。 我正在生成基於spring的 CodeGenConfiguration，但我沒有將它傳遞到 clientOptInput。 我的理解是錯誤的，我認為它會加載 CodeGenConfig 的類（它確實加載了它），就是這樣。 但是，您還需要將其傳遞給clientOptInput變量。

def codeGenConfig = CodegenConfigLoader.forName('spring')
clientOptInput.setConfig(codeGenConfig)

因為， DefaultGenerator.java的代碼如下：

    @Override
    public Generator opts(ClientOptInput opts) {
        this.opts = opts;
        this.openAPI = opts.getOpenAPI();
        this.config = opts.getConfig();

我需要將它設置為ClientOptInput實例。 這就是原因。 為像我這樣犯錯的人發帖:) :)