Gradle does not find tools.jar

问题:

I am using javadoc doclets with gradle, so I need to use the package tools.jar, which is in the lib folder from the jdk (1.6.0_26 in my case).

The point is that gradle does not take it automatically, so I was adding that tools package to my libs folder, and then adding it to dependencies.gradle .

Now I want to take it directly from my JDK home into my dependencies.gradle. Is there a way to do that? I have tried the next in my dependencies.gradle:

compile files("${System.properties['java.home']}/lib/tools.jar")

But it does not find it while compiling.

回答1:

I had this problem when I was trying to run commands through CLI.

It was a problem with system looking at the JRE folder i.e. D:\Program Files\Java\jre8\bin. If we look in there, there is no Tools.jar, hence the error.

You need to find where the JDK is, in my case: D:\Program Files\Java\jdk1.8.0_11, and if you look in the lib directory, you will see Tools.jar.

What I did I created a new environment variable JAVA_HOME:

And then you need to edit your PATH variable to include JAVA_HOME, i.e. %JAVA_HOME%/bin;

Re-open command prompt and should run.

回答2:

Found it. System property 'java.home' is not JAVA_HOME environment variable. JAVA_HOME points to the JDK, while java.home points to the JRE. See that page for more info.

Soo... My problem was that my startpoint was the jre folder (C:\jdk1.6.0_26\jre) and not the jdk folder (C:\jdk1.6.0_26) as I thought(tools.jar is on the C:\jdk1.6.0_26\lib folder ). The compile line in dependencies.gradle should be:

compile files("${System.properties['java.home']}/../lib/tools.jar")

回答3:

I got the same error using Eclipse trying to execute a Gradle Task. Every time I run a command (i.e. war) the process threw an exception like:

Could not find tools.jar. Please check that C:\Program Files\Java\Jre8" is a valid JDK install.

I tried the solution listed in this post but none of them solved this issue. Here my solution :

1. Go to the "Gradle Task" view
2. Right Click on the task you want to execute
3. Select Open Gradle Run Configuration
4. In the tab "Java Home" select your local JDK repository then click OK

Run again, Enjoy!

回答4:

I just added a gradle.properties file with the following content:

org.gradle.java.home=C:\\Program Files\\Java\\jdk1.8.0_45

回答5:

I had a similar case using Ubuntu. The machine had only the JRE installed. So, I just executed the command below to install the JDK.

sudo apt install openjdk-8-jdk

回答6:

I was struggling as well for this Solution. Found a better way to it with Gradle as described here. We can get the JVM/JDK information from Gradle itself.

dependencies {
   runtime files(org.gradle.internal.jvm.Jvm.current().toolsJar)
}

So simple.

回答7:

Add this to gradle.properties:

org.gradle.java.home=C:\Program Files\Java\jdk1.8.0_91

回答8:

In CentOS7 the development package will install tools.jar. The file is not present in java-1.8.0-openjdk

sudo yum install java-1.8.0-openjdk-devel

回答9:

It may be two years too late, but I ran into the same problem recently and this is the solution I ended up with after finding this post:

import javax.tools.ToolProvider

dependencies {
  compile (
    files(((URLClassLoader) ToolProvider.getSystemToolClassLoader()).getURLs()),
    ...
  }
}

It should work if java.home points to a directory that's not under the JDK directory and even on Mac OS where you'd have classes.jar instead of tools.jar.

回答10:

On windows 10, I encounter the same problem and this how I fixed the issue;

1. Access Advance System Settings>Environment Variables>System Variables
2. Select PATH overwrite the default C:\ProgramData\Oracle\Java\javapath
3. With your own jdk installation that is JAVA_HOME=C:\Program Files\Java\jdk1.8.0_162

回答11:

On my system (Win 10, JRE 1.8.0, Android Studio 3.1.2, Gradle 4.1) there is no tools.jar in the JRE directory (C:\Program Files\Java\jre1.8.0_171).

However, I found it in C:\Program Files\Android\Android Studio\jre\lib and tried setting JAVA_HOME=C:\Program Files\Android\Android Studio\jre

That works (for me)!

回答12:

Linux

Open /etc/environment in any text editor like nano or gedit and add the following line:

JAVA_HOME="/usr/lib/jvm/open-jdk"

Windows

1. Start the System Control Panel applet (Start - Settings - Control Panel - System).
2. Select the Advanced tab.
3. Click the Environment Variables button.

4. Under System Variables, click add button, then past the following lines:

   in Variable Name : JAVA_HOME

   in Variable Value : C:\Program Files\Java\jdk1.x.x_xxx

   where x.x_xxx jdk version you can get your jdk version from here C:\Program Files\Java

5. Under System Variables, select Path, then click Edit,then click new button then past the following line:

   %JAVA_HOME%/bin;

回答13:

With Centos 7, I have found that only JDK has tools.jar, while JRE has not. I have installed the Java 8 JRE(yum install java-1.8.0-openjdk), but not the JDK(yum install java-1.8.0-openjdk-devel).

Installing the latter solves the problem. Also, remember to set JAVA_HOME.

回答14:

Like other answers I set org.gradle.java.home property in gradle.properties file. But path with \ separators did not work (building on windows 10):

Java home supplied via 'org.gradle.java.home' is invalid. Invalid directory: C:Program FilesJavajdk1.8.0_65

So instead of

org.gradle.java.home=C:\Program Files\Java\jdk1.8.0_65

i had to use

org.gradle.java.home=C:/Program Files/Java/jdk1.8.0_65

then the build was successful

Problem is that project is build with JRE instead of JDK and since I was building it from eclipse this also worked:

• In Window>Preferences>Gradle>Arguments specify Workspace JRE and specify your JDK.
• In Window>Preferences>Java>InstalledJREs specify your JDK as default

回答15:

In my case (Windows 10) after Java update I lost my Enviroment Variables, so I fixed added the variables again, based in the following steps https://confluence.atlassian.com/doc/setting-the-java_home-variable-in-windows-8895.html

回答16:

Did you make sure that tools.jar made it on the compile class path? Maybe the path is incorrect.

task debug << {
    configurations.compile.each { println it }
}

回答17:

Adding JDK path through JAVA_HOME tab in "Open Gradle Run Configuration" will solve the problem.

回答18:

This worked for me:

I was getting message

Execution failed for task ':app:compileDebugJavaWithJavac'.

Could not find tools.jar. Please check that C:\Program Files\Java\jre1.8.0_121 contains a valid JDK installation.

• In Android Studio, check your SDK Location.
• File, Project Structure, SDK Location, JDK Location.
• Example: C:\android-studio\android-studio\jre
• Copy the tools.jar file in the C:\android-studio\android-studio\jre\lib folder into the C:\Program Files\Java\jre1.8.0_121\lib folder.
• Retry.

回答19:

If you use terminal to build and you have this error you can point to jdk bundled with android studio in your gradle.properties file:

org.gradle.java.home=/usr/local/android-studio/jre

回答20:

I've tried most of the top options but it seems that I had something wrong with my environment setup so they didn't help. What solved the issue for me was to re-install jdk1.8.0_201 and jre1.8.0_201 and this solved the error for me. Hope that helps someone.

回答21:

I solved problem on this way:

• download file tools-1.8.0.jar on http://www.java2s.com/Code/Jar/t/Downloadtools180jar.htm
• unzip file and rename to tools.jar
• copy to C:\Program Files\Java\jre1.8.0_191\lib folder
• Retry