Gradle Android Error: MethodHandle.invoke and MethodHandle.invokeExact

Question

I'm trying to consume a SOAP service in my Android app. I'm trying to follow this guide. When I try to run my app I get an error:

Error: MethodHandle.invoke and MethodHandle.invokeExact are only supported starting with Android O (--min-api 26)

I'm on Android N (SDK 25 - I can't bump to 26 like the error message indicates) and it's a brand new project just created by Android Studio.

Here's my project build.gradle file which I haven't changed:

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.4.1'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        google()
        jcenter()
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

And here's my app build.gradle file:

apply plugin: 'com.android.application'

configurations {
    jaxb
}

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:2.1.6.RELEASE")
    }
}

apply plugin: 'org.springframework.boot'
apply plugin: 'io.spring.dependency-management'

repositories {
    mavenCentral()
}

// tag::wsdl[]
task genJaxb {
    ext.sourcesDir = "${buildDir}/generatedjava/jaxb"
    ext.classesDir = "${buildDir}/classes/jaxb"
    ext.schema = "https://lite.realtime.nationalrail.co.uk/OpenLDBWS/wsdl.aspx?ver=2017-10-01"

    outputs.dir classesDir

    doLast() {
        project.ant {
            taskdef name: "xjc", classname: "com.sun.tools.xjc.XJCTask",
                    classpath: configurations.jaxb.asPath
            mkdir(dir: sourcesDir)
            mkdir(dir: classesDir)

            xjc(destdir: sourcesDir, schema: schema,
                    package: "hello.wsdl") {
                arg(value: "-wsdl")
                produces(dir: sourcesDir, includes: "**/*.java")
            }

            javac(destdir: classesDir, source: 1.8, target: 1.8, debug: true,
                    debugLevel: "lines,vars,source",
                    classpath: configurations.jaxb.asPath) {
                src(path: sourcesDir)
                include(name: "**/*.java")
                include(name: "*.java")
            }

            copy(todir: classesDir) {
                fileset(dir: sourcesDir, erroronmissingdir: false) {
                    exclude(name: "**/*.java")
                }
            }
        }
    }
}
// end::wsdl[]

android {
    compileSdkVersion 29
    buildToolsVersion "29.0.0"
    defaultConfig {
        applicationId "com.example.magicmirror"
        minSdkVersion 25
        targetSdkVersion 29
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }

    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }

    packagingOptions {
        exclude 'META-INF/spring.tooling'
        exclude 'META-INF/spring.handlers'
        exclude 'META-INF/spring-configuration-metadata.json'
        exclude 'META-INF/additional-spring-configuration-metadata.json'
        exclude 'META-INF/spring.factories'
        exclude 'META-INF/spring.schemas'
        exclude 'META-INF/DEPENDENCIES'
        exclude 'META-INF/LICENSE'
        exclude 'META-INF/LICENSE.txt'
        exclude 'META-INF/license.txt'
        exclude 'META-INF/NOTICE'
        exclude 'META-INF/NOTICE.txt'
        exclude 'META-INF/notice.txt'
        exclude 'META-INF/ASL2.0'
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'androidx.appcompat:appcompat:1.0.2'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test:runner:1.2.0'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'

    implementation "org.springframework.boot:spring-boot-starter"
    implementation "org.springframework.ws:spring-ws-core"
    implementation(files(genJaxb.classesDir).builtBy(genJaxb))

    jaxb "com.sun.xml.bind:jaxb-xjc:2.1.7"
}

From the logs the exact JAR causing this is org.springframework/spring-core/5.1.8.RELEASE.jar. Adding the compileOptions block is mentioned in other answers as a fix but it hasn't fixed this issue. How can I fix this?

Answer 1

Did you try ksoap?

https://github.com/simpligility/ksoap2-android

Looks like it should do soap, is alive and works for android.

The ksoap2-android project provides a lightweight and efficient SOAP client library for the Android platform.