getSystemJavaCompiler 空指针----未解决问题

本想测试下动态编译结果报错baidu的答案几乎都是相互抄袭没解决问题
贴代码

package top.demo.com;

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLClassLoader;

import javax.tools.JavaCompiler;
import javax.tools.ToolProvider;

public class Test {

    public static void main(String argv[]) throws IOException, ClassNotFoundException, NoSuchMethodException, SecurityException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {


        //String clstr="public class Demo{ public static void main(String argv[])"
        //      + " {System.out.println(\"这是测试动态编译的类\");} }";

        //File file=new File("f:/Dome.class");
        //System.out.println(file.createNewFile()?"创建类文件成功":"创建类文件失败");

        //BufferedWriter bufferedWriter=new BufferedWriter(new FileWriter(file));
        //bufferedWriter.write(clstr);
        //bufferedWriter.close();

        System.out.println(System.getProperty("java.home"));

        JavaCompiler compiler=ToolProvider.getSystemJavaCompiler();

        System.out.println(compiler);

        File file=new File("F:\\Develepment\\Environment\\JAVA\\jre\\lib\\tools.jar");
        File file2=new File("F:\\Develepment\\Environment\\JAVA\\jre\\tools.jar");
        System.out.println(file.exists());
        System.out.println(file2.exists());


        /*int res=compiler.run(null, null, null, "f:/Dome.class");
        System.out.println(res==0?"动态编译成功":"动态编译失败");

        URL[] url=new URL[]{new URL("file:/"+"f:/Dome.class")};
        URLClassLoader loader=new URLClassLoader(url);
        Class cl=loader.loadClass("Demo");

        Method m=cl.getMethod("main", String[].class);
        m.invoke(null, (Object)new String[] {});*/


    }


}

注意 已经测试了 百度的解决方案 把tools移动了位置 可惜还是不能解决

        System.out.println(System.getProperty("java.home"));

        JavaCompiler compiler=ToolProvider.getSystemJavaCompiler();

        System.out.println(compiler);

        File file=new File("F:\\Develepment\\Environment\\JAVA\\jre\\lib\\tools.jar");
        File file2=new File("F:\\Develepment\\Environment\\JAVA\\jre\\tools.jar");
        System.out.println(file.exists());
        System.out.println(file2.exists());

结果

F:\Develepment\Environment\JAVA\jre
null
true
true

待知情者留言解决