Eseguibile trovare Java a 32 bit quando dovrebbe trovare 64 bit


Sto scrivendo un eseguibile da uno script PowerShell che deve mettere la versione corretta di Java3D sul computer client. Con la versione corretta, intendo che quando l'utente apre CMD e digita "java-version", fornisce 32 o 64 bit. Ho bisogno di scegliere i file dll per l'architettura giusta.

Il problema è che ho trovato un test case di un sistema W7 a 64 bit con JDK sia a 32 bit che a 64 bit installato. Solo la versione a 64 bit è inclusa nella variabile d'ambiente PATH. Tuttavia, quando Eseguo il mio script batch o eseguibile ed echo java-version, viene visualizzato il java a 32 bit. Come tale, installa le dll a 32 bit e quando l'utente passa al cmd utilizza 64 bit quindi non è compatibile.

Poiché il JDK a 32 bit non è incluso nella variabile PATH, perché lo script esegue java a 32 bit e dove ottiene questo collegamento?

Author: hayk.mart, 2011-08-23

1 answers

Google Chrome e Firefox sono ancora applicazioni a 32 bit con un sistema operativo Windows a 64 bit, quindi probabilmente stai eseguendo un java a 32 bit installato da loro sotto SysWOW64-specialmente se stai installando la tua applicazione usando Java Web Start in esecuzione all'interno di uno di questi browser.

Ho avuto lo stesso identico problema e ho implementato una ricerca a livello di sistema per javas installati, in modo da poter creare un file batch che chiama l'esatto java.exe con la giusta bitness.

Questo è quello che bisogno:

/**
 * Java Finder by petrucio@stackoverflow(828681) is licensed under a Creative Commons Attribution 3.0 Unported License.
 * Needs WinRegistry.java. Get it at: https://stackoverflow.com/questions/62289/read-write-to-windows-registry-using-java
 *
 * JavaFinder - Windows-specific classes to search for all installed versions of java on this system
 * Author: petrucio@stackoverflow (828681)
 *****************************************************************************/

import java.util.*;
import java.io.*;

/**
 * Helper class to fetch the stdout and stderr outputs from started Runtime execs
 * Modified from http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps.html?page=4
 *****************************************************************************/
class RuntimeStreamer extends Thread {
    InputStream is;
    String lines;

    RuntimeStreamer(InputStream is) {
        this.is = is;
        this.lines = "";
    }
    public String contents() {
        return this.lines;
    }

    public void run() {
        try {
            InputStreamReader isr = new InputStreamReader(is);
            BufferedReader    br  = new BufferedReader(isr);
            String line = null;
            while ( (line = br.readLine()) != null) {
                this.lines += line + "\n";
            }
        } catch (IOException ioe) {
            ioe.printStackTrace();  
        }
    }

    /**
     * Execute a command and wait for it to finish
     * @return The resulting stdout and stderr outputs concatenated
     ****************************************************************************/
    public static String execute(String[] cmdArray) {
        try {
            Runtime runtime = Runtime.getRuntime();
            Process proc = runtime.exec(cmdArray);
            RuntimeStreamer outputStreamer = new RuntimeStreamer(proc.getInputStream());
            RuntimeStreamer errorStreamer  = new RuntimeStreamer(proc.getErrorStream());
            outputStreamer.start();
            errorStreamer.start();
            proc.waitFor();
            return outputStreamer.contents() + errorStreamer.contents();
        } catch (Throwable t) {
            t.printStackTrace();
        }
        return null;
    }
    public static String execute(String cmd) {
        String[] cmdArray = { cmd };
        return RuntimeStreamer.execute(cmdArray);
    }
}

/**
 * Helper struct to hold information about one installed java version
 ****************************************************************************/
class JavaInfo {
    public String  path;        //! Full path to java.exe executable file
    public String  version;     //! Version string. "Unkown" if the java process returned non-standard version string
    public boolean is64bits;    //! true for 64-bit javas, false for 32

    /**
     * Calls 'javaPath -version' and parses the results
     * @param javaPath: path to a java.exe executable
     ****************************************************************************/
    public JavaInfo(String javaPath) {
        String versionInfo = RuntimeStreamer.execute( new String[] { javaPath, "-version" } );
        String[] tokens = versionInfo.split("\"");

        if (tokens.length < 2) this.version = "Unkown";
        else this.version = tokens[1];
        this.is64bits = versionInfo.toUpperCase().contains("64-BIT");
        this.path     = javaPath;
    }

    /**
     * @return Human-readable contents of this JavaInfo instance
     ****************************************************************************/
    public String toString() {
        return this.path + ":\n  Version: " + this.version + "\n  Bitness: " + (this.is64bits ? "64-bits" : "32-bits");
    }
}

/**
 * Windows-specific java versions finder
 *****************************************************************************/
public class JavaFinder {

    /**
     * @return: A list of javaExec paths found under this registry key (rooted at HKEY_LOCAL_MACHINE)
     * @param wow64  0 for standard registry access (32-bits for 32-bit app, 64-bits for 64-bits app)
     *               or WinRegistry.KEY_WOW64_32KEY to force access to 32-bit registry view,
     *               or WinRegistry.KEY_WOW64_64KEY to force access to 64-bit registry view
     * @param previous: Insert all entries from this list at the beggining of the results
     *************************************************************************/
    private static List<String> searchRegistry(String key, int wow64, List<String> previous) {
        List<String> result = previous;
        try {
            List<String> entries = WinRegistry.readStringSubKeys(WinRegistry.HKEY_LOCAL_MACHINE, key, wow64);
            for (int i = 0; entries != null && i < entries.size(); i++) {
                String val = WinRegistry.readString(WinRegistry.HKEY_LOCAL_MACHINE, key + "\\" + entries.get(i), "JavaHome", wow64);
                if (!result.contains(val + "\\bin\\java.exe")) {
                    result.add(val + "\\bin\\java.exe");
                }
            }
        } catch (Throwable t) {
            t.printStackTrace();
        }
        return result;
    }

    /**
     * @return: A list of JavaInfo with informations about all javas installed on this machine
     * Searches and returns results in this order:
     *   HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Runtime Environment (32-bits view)
     *   HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Runtime Environment (64-bits view)
     *   HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Development Kit     (32-bits view)
     *   HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Development Kit     (64-bits view)
     *   WINDIR\system32
     *   WINDIR\SysWOW64
     ****************************************************************************/
    public static List<JavaInfo> findJavas() {
        List<String> javaExecs = new ArrayList<String>();

        javaExecs = JavaFinder.searchRegistry("SOFTWARE\\JavaSoft\\Java Runtime Environment", WinRegistry.KEY_WOW64_32KEY, javaExecs);
        javaExecs = JavaFinder.searchRegistry("SOFTWARE\\JavaSoft\\Java Runtime Environment", WinRegistry.KEY_WOW64_64KEY, javaExecs);
        javaExecs = JavaFinder.searchRegistry("SOFTWARE\\JavaSoft\\Java Development Kit",     WinRegistry.KEY_WOW64_32KEY, javaExecs);
        javaExecs = JavaFinder.searchRegistry("SOFTWARE\\JavaSoft\\Java Development Kit",     WinRegistry.KEY_WOW64_64KEY, javaExecs);

        javaExecs.add(System.getenv("WINDIR") + "\\system32\\java.exe");
        javaExecs.add(System.getenv("WINDIR") + "\\SysWOW64\\java.exe");

        List<JavaInfo> result = new ArrayList<JavaInfo>();
        for (String javaPath: javaExecs) {
            if (!(new File(javaPath).exists())) continue;
            result.add(new JavaInfo(javaPath));
        }
        return result;
    }

    /**
     * @return: The path to a java.exe that has the same bitness as the OS
     * (or null if no matching java is found)
     ****************************************************************************/
    public static String getOSBitnessJava() {
        String arch      = System.getenv("PROCESSOR_ARCHITECTURE");
        String wow64Arch = System.getenv("PROCESSOR_ARCHITEW6432");
        boolean isOS64 = arch.endsWith("64") || (wow64Arch != null && wow64Arch.endsWith("64"));

        List<JavaInfo> javas = JavaFinder.findJavas();
        for (int i = 0; i < javas.size(); i++) {
            if (javas.get(i).is64bits == isOS64) return javas.get(i).path;
        }
        return null;
    }

    /**
     * Standalone testing - lists all Javas in the system
     ****************************************************************************/
    public static void main(String [] args) {
        List<JavaInfo> javas = JavaFinder.findJavas();
        for (int i = 0; i < javas.size(); i++) {
            System.out.println("\n" + javas.get(i));
        }
    }
}

Avrai anche bisogno del WinRegistry aggiornato.java per leggere i valori da entrambe le sezioni da 32 bit e 64 bit del registro di Windows: https://stackoverflow.com/a/11854901/828681

Di solito non sono un programmatore java, quindi il mio codice probabilmente non segue le convenzioni java. Fammi causa.

Ecco i risultati di JavaFinder.findJavas () sulla mia vittoria 7 macchina a 64 bit:

>java JavaFinder

C:\Program Files (x86)\Java\jre6\bin\java.exe:
  Version: 1.6.0_31
  Bitness: 32-bits

C:\Program Files\Java\jre6\bin\java.exe:
  Version: 1.6.0_31
  Bitness: 64-bits

D:\Dev\Java\jdk1.6.0_31\bin\java.exe:
  Version: 1.6.0_31
  Bitness: 64-bits

C:\Windows\system32\java.exe:
  Version: 1.6.0_31
  Bitness: 64-bits

C:\Windows\SysWOW64\java.exe:
  Version: 1.6.0_31
  Bitness: 32-bits

Nota c'è un java a 32 bit.exe sotto SysWOW64 - e verrà chiamato dal web starter quando si esegue all'interno di Chrome o Firefox poiché sono applicazioni a 32 bit, a meno che non si utilizzi JavaFinder per trovare un java correttamente bit.exe e usa il suo percorso completo.

 1
Author: Petrucio, 2017-05-23 12:04:44