我正在关注有关安装本机的全新视频的youtube视频。我输入命令来运行android for react native project并弹出一个构建错误，说我缺少tools.jar。我在这里看到一个先前的支持线程，说该人没有Android支持存储库，但我确实安装了它。这是错误
Starting JS server...
Starting the packager in a new window is not supported on Windows yet.
Please start it manually using 'react-native start'.
We believe the best Windows support will come from a community of people
using React Native on Windows on a daily basis.
Would you be up for sending a pull request?
Building and installing the app on the device (cd android && gradlew.bat installDebug)...
Download https://jcenter.bintray.com/net/sf/proguard/proguard-gradle/5.2.1/proguard-gradle-5.2.1.pom
Download https://jcenter.bintray.com/net/sf/proguard/proguard-parent/5.2.1/proguard-parent-5.2.1.pom
Download https://jcenter.bintray.com/com/squareup/javawriter/2.5.0/javawriter-2.5.0.pom
Download https://jcenter.bintray.com/org/bouncycastle/bcpkix-jdk15on/1.48/bcpkix-jdk15on-1.48.pom
Download https://jcenter.bintray.com/org/bouncycastle/bcprov-jdk15on/1.48/bcprov-jdk15on-1.48.pom
Download https://jcenter.bintray.com/org/ow2/asm/asm/5.0.3/asm-5.0.3.pom
Download https://jcenter.bintray.com/org/ow2/asm/asm-parent/5.0.3/asm-parent-5.0.3.pom
Download https://jcenter.bintray.com/org/ow2/ow2/1.3/ow2-1.3.pom
Download https://jcenter.bintray.com/org/ow2/asm/asm-tree/5.0.3/asm-tree-5.0.3.pom
Download https://jcenter.bintray.com/com/android/tools/jack/jack-api/0.9.0/jack-api-0.9.0.pom
Download https://jcenter.bintray.com/com/android/tools/jill/jill-api/0.9.0/jill-api-0.9.0.pom
Download https://jcenter.bintray.com/org/eclipse/jdt/core/compiler/ecj/4.4.2/ecj-4.4.2.pom
Download https://jcenter.bintray.com/net/sf/proguard/proguard-base/5.2.1/proguard-base-5.2.1.pom
Download https://jcenter.bintray.com/com/google/code/gson/gson/2.2.4/gson-2.2.4.pom
Download https://jcenter.bintray.com/org/apache/commons/commons-compress/1.8.1/commons-compress-1.8.1.pom
Download https://jcenter.bintray.com/org/apache/commons/commons-parent/33/commons-parent-33.pom
Download https://jcenter.bintray.com/org/apache/apache/13/apache-13.pom
Download https://jcenter.bintray.com/org/apache/httpcomponents/httpclient/4.1.1/httpclient-4.1.1.pom
Download https://jcenter.bintray.com/org/apache/httpcomponents/httpcomponents-client/4.1.1/httpcomponents-client-4.1.1.pom
Download https://jcenter.bintray.com/org/apache/httpcomponents/project/4.1.1/project-4.1.1.pom
Download https://jcenter.bintray.com/org/apache/httpcomponents/httpmime/4.1/httpmime-4.1.pom
Download https://jcenter.bintray.com/org/apache/httpcomponents/httpcomponents-client/4.1/httpcomponents-client-4.1.pom
Download https://jcenter.bintray.com/com/google/guava/guava/17.0/guava-17.0.pom
Download https://jcenter.bintray.com/com/google/guava/guava-parent/17.0/guava-parent-17.0.pom
Download https://jcenter.bintray.com/net/sf/kxml/kxml2/2.3.0/kxml2-2.3.0.pom
Download https://jcenter.bintray.com/org/ow2/asm/asm-analysis/5.0.3/asm-analysis-5.0.3.pom
Download https://jcenter.bintray.com/com/intellij/annotations/12.0/annotations-12.0.pom
Download https://jcenter.bintray.com/org/apache/httpcomponents/httpcore/4.1/httpcore-4.1.pom
Download https://jcenter.bintray.com/org/apache/httpcomponents/httpcomponents-core/4.1/httpcomponents-core-4.1.pom
Download https://jcenter.bintray.com/commons-logging/commons-logging/1.1.1/commons-logging-1.1.1.pom
Download https://jcenter.bintray.com/org/apache/commons/commons-parent/5/commons-parent-5.pom
Download https://jcenter.bintray.com/commons-codec/commons-codec/1.4/commons-codec-1.4.pom
Download https://jcenter.bintray.com/com/android/tools/external/lombok/lombok-ast/0.2.3/lombok-ast-0.2.3.pom
Download https://jcenter.bintray.com/net/sf/proguard/proguard-gradle/5.2.1/proguard-gradle-5.2.1.jar
Download https://jcenter.bintray.com/com/squareup/javawriter/2.5.0/javawriter-2.5.0.jar
Download https://jcenter.bintray.com/org/bouncycastle/bcpkix-jdk15on/1.48/bcpkix-jdk15on-1.48.jar
Download https://jcenter.bintray.com/org/bouncycastle/bcprov-jdk15on/1.48/bcprov-jdk15on-1.48.jar
Download https://jcenter.bintray.com/org/ow2/asm/asm/5.0.3/asm-5.0.3.jar
Download https://jcenter.bintray.com/org/ow2/asm/asm-tree/5.0.3/asm-tree-5.0.3.jar
Download https://jcenter.bintray.com/com/android/tools/jack/jack-api/0.9.0/jack-api-0.9.0.jar
Download https://jcenter.bintray.com/com/android/tools/jill/jill-api/0.9.0/jill-api-0.9.0.jar
Download https://jcenter.bintray.com/org/eclipse/jdt/core/compiler/ecj/4.4.2/ecj-4.4.2.jar
Download https://jcenter.bintray.com/net/sf/proguard/proguard-base/5.2.1/proguard-base-5.2.1.jar
Download https://jcenter.bintray.com/com/google/code/gson/gson/2.2.4/gson-2.2.4.jar
Download https://jcenter.bintray.com/org/apache/commons/commons-compress/1.8.1/commons-compress-1.8.1.jar
Download https://jcenter.bintray.com/org/apache/httpcomponents/httpclient/4.1.1/httpclient-4.1.1.jar
Download https://jcenter.bintray.com/org/apache/httpcomponents/httpmime/4.1/httpmime-4.1.jar
Download https://jcenter.bintray.com/com/google/guava/guava/17.0/guava-17.0.jar
Download https://jcenter.bintray.com/net/sf/kxml/kxml2/2.3.0/kxml2-2.3.0.jar
Download https://jcenter.bintray.com/org/ow2/asm/asm-analysis/5.0.3/asm-analysis-5.0.3.jar
Download https://jcenter.bintray.com/com/intellij/annotations/12.0/annotations-12.0.jar
Download https://jcenter.bintray.com/org/apache/httpcomponents/httpcore/4.1/httpcore-4.1.jar
Download https://jcenter.bintray.com/commons-logging/commons-logging/1.1.1/commons-logging-1.1.1.jar
Download https://jcenter.bintray.com/commons-codec/commons-codec/1.4/commons-codec-1.4.jar
Download https://jcenter.bintray.com/com/android/tools/external/lombok/lombok-ast/0.2.3/lombok-ast-0.2.3.jar
:app:preBuild UP-TO-DATE
:app:preDebugBuild UP-TO-DATE
:app:checkDebugManifest
:app:preReleaseBuild UP-TO-DATE
:app:prepareComAndroidSupportAppcompatV72301Library UP-TO-DATE
:app:prepareComAndroidSupportRecyclerviewV72301Library UP-TO-DATE
:app:prepareComAndroidSupportSupportV42301Library UP-TO-DATE
:app:prepareComFacebookFrescoDrawee081Library UP-TO-DATE
:app:prepareComFacebookFrescoFbcore081Library UP-TO-DATE
:app:prepareComFacebookFrescoFresco081Library UP-TO-DATE
:app:prepareComFacebookFrescoImagepipeline081Library UP-TO-DATE
:app:prepareComFacebookFrescoImagepipelineOkhttp081Library UP-TO-DATE
:app:prepareComFacebookReactReactNative0191Library UP-TO-DATE
:app:prepareOrgWebkitAndroidJscR174650Library UP-TO-DATE
:app:prepareDebugDependencies
:app:compileDebugAidl UP-TO-DATE
:app:compileDebugRenderscript UP-TO-DATE
:app:generateDebugBuildConfig UP-TO-DATE
:app:generateDebugAssets UP-TO-DATE
:app:mergeDebugAssets UP-TO-DATE
:app:generateDebugResValues UP-TO-DATE
:app:generateDebugResources UP-TO-DATE
:app:mergeDebugResources UP-TO-DATE
:app:bundleDebugJsAndAssets SKIPPED
:app:processDebugManifest UP-TO-DATE
:app:processDebugResources UP-TO-DATE
:app:generateDebugSources UP-TO-DATE
:app:processDebugJavaRes UP-TO-DATE
:app:compileDebugJavaWithJavac FAILED
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':app:compileDebugJavaWithJavac'.
> Could not find tools.jar
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
BUILD FAILED
Total time: 30.123 secs
Could not install the app on the device, read the error above for details.
Make sure you have an Android emulator running or a device connected and have
set up your Android development environment:
https://facebook.github.io/react-native/docs/android-setup.html
我感谢任何帮助。如果有可能，我可以得到简单的说明，很多这些东西对我来说都是新的，但我会试试。
派对有点晚了，但我希望这有帮助！
您的计算机上可能未安装Java开发工具包（JDK）（不要与您的常规Java安装JRE混淆），或者未正确设置环境变量。
JDK可以在这里下载 - > http://www.oracle.com/technetwork/java/javase/downloads/index-jsp-138363.html
要设置环境变量，请转到控制面板 - >系统和安全 - >系统，然后转到高级系统设置并设置为新变量：变量名= JAVA_HOME变量值= C：\ Program Files \ Java \ jdk1.8.0_121 （！这可能因您的安装而异！）
小费！确定tools.jar的安装位置只需通过Windows资源管理器搜索工具查找，但使用根目录（例如jdk1.8.0_121）作为变量值。
关闭并打开您的终端并再次运行react-native run-android;）
选项＃2在选项1中下载JDK之后，转到JDK的安装目录，然后查找lib，然后查找文件夹中的tools.jar。
例如C：\ Program Files \ Java \ jdk1.8.0_121 \ lib
将tools.jar复制到android studio安装库
例如C：\ Program Files \ Android \ Android Studio \ lib（再次取决于你的安装）
我希望这很精致！
如果您使用的是Linux，请运行此命令以安装缺少的JDK：
sudo apt-get install default-jdk
设置JDK的路径 - JAVA_HOME。 例如：export JAVA_HOME = / home / user / install / jdk1.7.0_79
这个对我有用）
我设法通过重新安装jdk1.8.0_201和jre1.8.0_201来解决此错误。