runEclipseTask '''
apply plugin: 'java'
apply plugin: 'eclipse'

eclipse.jdt {
    sourceCompatibility = '1.4'
    targetCompatibility = 1.3
}
'''

        def jdt = parseJdtFile()
        assert jdt.contains('source=1.4')
        assert jdt.contains('targetPlatform=1.3')
    }

    @Test
    @ToBeFixedForConfigurationCache

        ['scala', 'groovy']         | ['org.eclipse.jdt.groovy.core.groovyNature', 'org.scala-ide.sdt.core.scalanature', 'org.eclipse.jdt.core.javanature']
        ['java', 'scala', 'groovy'] | ['org.eclipse.jdt.groovy.core.groovyNature', 'org.scala-ide.sdt.core.scalanature', 'org.eclipse.jdt.core.javanature']
    }

    @TargetGradleVersion(">=3.0")

        then:
        project.classpathContainers.find { it.path.startsWith('org.eclipse.jdt.launching.JRE_CONTAINER') && it.path.contains('1.4') }
    }

    def "Respects javaRuntimeName customization"() {
        setup:
        buildFile <<
        """apply plugin: 'java'
           apply plugin: 'eclipse'
           eclipse {
               jdt {
                    javaRuntimeName = "customJavaRuntime"
               }

        given:
        buildFile << """
        apply plugin:'java'
        apply plugin:'eclipse'

        ${javaTargetCompatibility(targetVersion, JavaVersion.VERSION_1_6)}

        eclipse {
            jdt {
                targetCompatibility = 1.5
            }
        }
        """
        when:
        EclipseProject rootProject = loadToolingModel(EclipseProject)

        then:

                eclipse {
                    jdt {
                        sourceCompatibility = 1.2
                    }
                }
            }
            project(':subproject-c') {
                apply plugin: 'java'
                apply plugin: 'eclipse'
                ${javaSourceCompatibility(targetVersion, JavaVersion.VERSION_1_6)}
                eclipse {
                    jdt {

    static final def JAVA_NATURES = ['org.eclipse.jdt.core.javanature']
    static final def WTP_NATURES = ['org.eclipse.wst.common.project.facet.core.nature', 'org.eclipse.wst.common.modulecore.ModuleCoreNature', 'org.eclipse.jem.workbench.JavaEMFNature']
    static final def JAVA_BUILD_COMMANDS = ['org.eclipse.jdt.core.javabuilder']

        new Container("org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.6"),
        new Library(fileReferenceFactory.fromPath("/apache-ant-1.7.1/lib/ant-antlr.jar")),
        new SourceFolder("src", "bin2"),
        new Variable(fileReferenceFactory.fromVariablePath("GRADLE_CACHE/ant-1.6.5.jar")),
        new Container("org.eclipse.jdt.USER_LIBRARY/gradle"),
        new Output("bin")]

          <item index="12" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.qual.Nullable" />
          <item index="13" class="java.lang.String" itemvalue="org.eclipse.jdt.annotation.Nullable" />
          <item index="14" class="java.lang.String" itemvalue="org.jetbrains.annotations.Nullable" />
          <item index="15" class="java.lang.String" itemvalue="org.jspecify.annotations.Nullable" />

    }

    private static void populateEclipseProjectJdt(DefaultEclipseProject eclipseProject, EclipseJdt jdt) {
        if (jdt != null) {
            eclipseProject.setJavaSourceSettings(new DefaultEclipseJavaSourceSettings().setSourceLanguageLevel(jdt.getSourceCompatibility()).setTargetBytecodeVersion(jdt.getTargetCompatibility()).setJdk(DefaultInstalledJdk.current()));
        }
    }

Class <org.gradle.plugins.ide.eclipse.model.Jdt> extends/implements org.gradle.plugins.ide.internal.generator.PropertiesPersistableConfigurationObject that is Gradle Internal API in (Jdt.java:0)