Android Studio：错误：找不到符号变量AudioSystem

Question

我的项目在运行时出现错误： error: cannot find symbol variable AudioSystem我已确保代码已导入：

import android.media.AudioSystem;

并且已经安装了SDK版本19和我的build.Gradle信息如下：

android {
    compileSdkVersion 23
    buildToolsVersion '23.0.1'
    defaultConfig {

        minSdkVersion 19
        targetSdkVersion 23

如何克服这个错误？ 谢谢

当我在“ import android.media。”之后输入字母“ A”时，“自动”列表未显示AudioSystem让我选择。

  buildscript {
        repositories {
            jcenter()
        }
        dependencies {
            classpath 'com.android.tools.build:gradle:2.2.3'
        }
        tasks.withType(JavaCompile) { options.encoding = "UTF-8" }
    }
    apply plugin: 'com.android.application'

    dependencies {
        compile fileTree(dir: 'libs', include: '*.jar')
        compile files('3rd_party_library/dom4j-1.6.1.jar')
        compile files('3rd_party_library/jaxen-1.1-beta-7.jar')
        compile files('3rd_party_library/core-3.2.1.jar')
        compile fileTree(dir: "$buildDir/native-libs", include: 'native-libs.jar')
    }

    android {
        compileSdkVersion 23
        buildToolsVersion '23.0.1'
        defaultConfig {

            applicationId "com.test.smmitest"
            minSdkVersion 19
            targetSdkVersion 23
            versionCode 20170713
            versionName "4.5.6"
        }

        dexOptions {
            javaMaxHeapSize "4g"
        }
        compileOptions {
            sourceCompatibility JavaVersion.VERSION_1_7
            targetCompatibility JavaVersion.VERSION_1_7
        }

        sourceSets {
            main {
                manifest.srcFile 'AndroidManifest.xml'
                java.srcDirs = ['src']
                resources.srcDirs = ['src']
                aidl.srcDirs = ['src']
                renderscript.srcDirs = ['src']
                res.srcDirs = ['res']
                assets.srcDirs = ['assets']
                jniLibs.srcDirs = ['libs']
            }

            // Move the tests to tests/java, tests/res, etc...
            instrumentTest.setRoot('tests')

            // Move the build types to build-types/<type>
            // For instance, build-types/debug/java, build-types/debug/AndroidManifest.xml, ...
            // This moves them out of them default location under src/<type>/... which would
            // conflict with src/ being used by the main source set.
            // Adding new build types or product flavors should be accompanied
            // by a similar customization.
            debug.setRoot('build-types/debug')
            release.setRoot('build-types/release')
        }
        signingConfigs {
            release {
            }
            debug {
                storeFile file("Keystore/debug.keystore");
                storePassword ("android");
                keyAlias = "androiddebugkey";
                keyPassword = "android";
            }
        }
        buildTypes {
            release {

            }
            debug {

            }
        }
        packagingOptions {
            exclude 'META-INF/LICENSE.txt'
        }
    }