source: java/PlatformTools/src/net/oni2/platformtools/applicationinvoker/Java.java

package net.oni2.platformtools.applicationinvoker;

import java.io.File;

import net.oni2.platformtools.PlatformInformation;
import net.oni2.platformtools.PlatformInformation.Platform;

/**
 * @author Christian Illy
 */
public class Java {
        private static int isFound = -1;
        private static File jre = null;

        /**
         * @return Was a JRE found
         */
        public static boolean isInstalled() {
                if (isFound < 0) {
                        getRuntimeExe();
                }
                return isFound == 1;
        }

        /**
         * @return The JRE executable
         */
        public static File getRuntimeExe() {
                if (isFound < 0) {
                        File jrehome = new File(System.getProperties().getProperty(
                                        "java.home"), "bin");
                        if (PlatformInformation.getPlatform() == Platform.WIN)
                                jre = new File(jrehome, "javaw.exe");
                        else
                                jre = new File(jrehome, "java");
                        if (!jre.exists()) {
                                isFound = 0;
                                jre = null;
                        } else {
                                isFound = 1;
                        }
                }
                return jre;
        }
}