Java example source code file (LauncherHelper.java)
The LauncherHelper.java Java example source code
/*
* Copyright (c) 2007, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package sun.launcher;
/*
*
* <p>This is NOT part of any API supported by Sun Microsystems.
* If you write code that depends on this, you do so at your own
* risk. This code and its internal interfaces are subject to change
* or deletion without notice.</b>
*
*/
/**
* A utility package for the java(1), javaw(1) launchers.
* The following are helper methods that the native launcher uses
* to perform checks etc. using JNI, see src/share/bin/java.c
*/
import java.io.File;
import java.io.IOException;
import java.io.PrintStream;
import java.io.UnsupportedEncodingException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.nio.charset.Charset;
import java.nio.file.DirectoryStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.text.Normalizer;
import java.util.ResourceBundle;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
import java.util.Locale.Category;
import java.util.Properties;
import java.util.Set;
import java.util.TreeSet;
import java.util.jar.Attributes;
import java.util.jar.JarFile;
import java.util.jar.Manifest;
public enum LauncherHelper {
INSTANCE;
private static final String MAIN_CLASS = "Main-Class";
private static StringBuilder outBuf = new StringBuilder();
private static final String INDENT = " ";
private static final String VM_SETTINGS = "VM settings:";
private static final String PROP_SETTINGS = "Property settings:";
private static final String LOCALE_SETTINGS = "Locale settings:";
// sync with java.c and sun.misc.VM
private static final String diagprop = "sun.java.launcher.diag";
final static boolean trace = sun.misc.VM.getSavedProperty(diagprop) != null;
private static final String defaultBundleName =
"sun.launcher.resources.launcher";
private static class ResourceBundleHolder {
private static final ResourceBundle RB =
ResourceBundle.getBundle(defaultBundleName);
}
private static PrintStream ostream;
private static final ClassLoader scloader = ClassLoader.getSystemClassLoader();
private static Class<?> appClass; // application class, for GUI/reporting purposes
/*
* A method called by the launcher to print out the standard settings,
* by default -XshowSettings is equivalent to -XshowSettings:all,
* Specific information may be gotten by using suboptions with possible
* values vm, properties and locale.
*
* printToStderr: choose between stdout and stderr
*
* optionFlag: specifies which options to print default is all other
* possible values are vm, properties, locale.
*
* initialHeapSize: in bytes, as set by the launcher, a zero-value indicates
* this code should determine this value, using a suitable method or
* the line could be omitted.
*
* maxHeapSize: in bytes, as set by the launcher, a zero-value indicates
* this code should determine this value, using a suitable method.
*
* stackSize: in bytes, as set by the launcher, a zero-value indicates
* this code determine this value, using a suitable method or omit the
* line entirely.
*/
static void showSettings(boolean printToStderr, String optionFlag,
long initialHeapSize, long maxHeapSize, long stackSize,
boolean isServer) {
initOutput(printToStderr);
String opts[] = optionFlag.split(":");
String optStr = (opts.length > 1 && opts[1] != null)
? opts[1].trim()
: "all";
switch (optStr) {
case "vm":
printVmSettings(initialHeapSize, maxHeapSize,
stackSize, isServer);
break;
case "properties":
printProperties();
break;
case "locale":
printLocale();
break;
default:
printVmSettings(initialHeapSize, maxHeapSize, stackSize,
isServer);
printProperties();
printLocale();
break;
}
}
/*
* prints the main vm settings subopt/section
*/
private static void printVmSettings(
long initialHeapSize, long maxHeapSize,
long stackSize, boolean isServer) {
ostream.println(VM_SETTINGS);
if (stackSize != 0L) {
ostream.println(INDENT + "Stack Size: " +
SizePrefix.scaleValue(stackSize));
}
if (initialHeapSize != 0L) {
ostream.println(INDENT + "Min. Heap Size: " +
SizePrefix.scaleValue(initialHeapSize));
}
if (maxHeapSize != 0L) {
ostream.println(INDENT + "Max. Heap Size: " +
SizePrefix.scaleValue(maxHeapSize));
} else {
ostream.println(INDENT + "Max. Heap Size (Estimated): "
+ SizePrefix.scaleValue(Runtime.getRuntime().maxMemory()));
}
ostream.println(INDENT + "Ergonomics Machine Class: "
+ ((isServer) ? "server" : "client"));
ostream.println(INDENT + "Using VM: "
+ System.getProperty("java.vm.name"));
ostream.println();
}
/*
* prints the properties subopt/section
*/
private static void printProperties() {
Properties p = System.getProperties();
ostream.println(PROP_SETTINGS);
List<String> sortedPropertyKeys = new ArrayList<>();
sortedPropertyKeys.addAll(p.stringPropertyNames());
Collections.sort(sortedPropertyKeys);
for (String x : sortedPropertyKeys) {
printPropertyValue(x, p.getProperty(x));
}
ostream.println();
}
private static boolean isPath(String key) {
return key.endsWith(".dirs") || key.endsWith(".path");
}
private static void printPropertyValue(String key, String value) {
ostream.print(INDENT + key + " = ");
if (key.equals("line.separator")) {
for (byte b : value.getBytes()) {
switch (b) {
case 0xd:
ostream.print("\\r ");
break;
case 0xa:
ostream.print("\\n ");
break;
default:
// print any bizzare line separators in hex, but really
// shouldn't happen.
ostream.printf("0x%02X", b & 0xff);
break;
}
}
ostream.println();
return;
}
if (!isPath(key)) {
ostream.println(value);
return;
}
String[] values = value.split(System.getProperty("path.separator"));
boolean first = true;
for (String s : values) {
if (first) { // first line treated specially
ostream.println(s);
first = false;
} else { // following lines prefix with indents
ostream.println(INDENT + INDENT + s);
}
}
}
/*
* prints the locale subopt/section
*/
private static void printLocale() {
Locale locale = Locale.getDefault();
ostream.println(LOCALE_SETTINGS);
ostream.println(INDENT + "default locale = " +
locale.getDisplayLanguage());
ostream.println(INDENT + "default display locale = " +
Locale.getDefault(Category.DISPLAY).getDisplayName());
ostream.println(INDENT + "default format locale = " +
Locale.getDefault(Category.FORMAT).getDisplayName());
printLocales();
ostream.println();
}
private static void printLocales() {
Locale[] tlocales = Locale.getAvailableLocales();
final int len = tlocales == null ? 0 : tlocales.length;
if (len < 1 ) {
return;
}
// Locale does not implement Comparable so we convert it to String
// and sort it for pretty printing.
Set<String> sortedSet = new TreeSet<>();
for (Locale l : tlocales) {
sortedSet.add(l.toString());
}
ostream.print(INDENT + "available locales = ");
Iterator<String> iter = sortedSet.iterator();
final int last = len - 1;
for (int i = 0 ; iter.hasNext() ; i++) {
String s = iter.next();
ostream.print(s);
if (i != last) {
ostream.print(", ");
}
// print columns of 8
if ((i + 1) % 8 == 0) {
ostream.println();
ostream.print(INDENT + INDENT);
}
}
}
private enum SizePrefix {
KILO(1024, "K"),
MEGA(1024 * 1024, "M"),
GIGA(1024 * 1024 * 1024, "G"),
TERA(1024L * 1024L * 1024L * 1024L, "T");
long size;
String abbrev;
SizePrefix(long size, String abbrev) {
this.size = size;
this.abbrev = abbrev;
}
private static String scale(long v, SizePrefix prefix) {
return BigDecimal.valueOf(v).divide(BigDecimal.valueOf(prefix.size),
2, RoundingMode.HALF_EVEN).toPlainString() + prefix.abbrev;
}
/*
* scale the incoming values to a human readable form, represented as
* K, M, G and T, see java.c parse_size for the scaled values and
* suffixes. The lowest possible scaled value is Kilo.
*/
static String scaleValue(long v) {
if (v < MEGA.size) {
return scale(v, KILO);
} else if (v < GIGA.size) {
return scale(v, MEGA);
} else if (v < TERA.size) {
return scale(v, GIGA);
} else {
return scale(v, TERA);
}
}
}
/**
* A private helper method to get a localized message and also
* apply any arguments that we might pass.
*/
private static String getLocalizedMessage(String key, Object... args) {
String msg = ResourceBundleHolder.RB.getString(key);
return (args != null) ? MessageFormat.format(msg, args) : msg;
}
/**
* The java -help message is split into 3 parts, an invariant, followed
* by a set of platform dependent variant messages, finally an invariant
* set of lines.
* This method initializes the help message for the first time, and also
* assembles the invariant header part of the message.
*/
static void initHelpMessage(String progname) {
outBuf = outBuf.append(getLocalizedMessage("java.launcher.opt.header",
(progname == null) ? "java" : progname ));
outBuf = outBuf.append(getLocalizedMessage("java.launcher.opt.datamodel",
32));
outBuf = outBuf.append(getLocalizedMessage("java.launcher.opt.datamodel",
64));
}
/**
* Appends the vm selection messages to the header, already created.
* initHelpSystem must already be called.
*/
static void appendVmSelectMessage(String vm1, String vm2) {
outBuf = outBuf.append(getLocalizedMessage("java.launcher.opt.vmselect",
vm1, vm2));
}
/**
* Appends the vm synoym message to the header, already created.
* initHelpSystem must be called before using this method.
*/
static void appendVmSynonymMessage(String vm1, String vm2) {
outBuf = outBuf.append(getLocalizedMessage("java.launcher.opt.hotspot",
vm1, vm2));
}
/**
* Appends the vm Ergo message to the header, already created.
* initHelpSystem must be called before using this method.
*/
static void appendVmErgoMessage(boolean isServerClass, String vm) {
outBuf = outBuf.append(getLocalizedMessage("java.launcher.ergo.message1",
vm));
outBuf = (isServerClass)
? outBuf.append(",\n" +
getLocalizedMessage("java.launcher.ergo.message2") + "\n\n")
: outBuf.append(".\n\n");
}
/**
* Appends the last invariant part to the previously created messages,
* and finishes up the printing to the desired output stream.
* initHelpSystem must be called before using this method.
*/
static void printHelpMessage(boolean printToStderr) {
initOutput(printToStderr);
outBuf = outBuf.append(getLocalizedMessage("java.launcher.opt.footer",
File.pathSeparator));
ostream.println(outBuf.toString());
}
/**
* Prints the Xusage text to the desired output stream.
*/
static void printXUsageMessage(boolean printToStderr) {
initOutput(printToStderr);
ostream.println(getLocalizedMessage("java.launcher.X.usage",
File.pathSeparator));
if (System.getProperty("os.name").contains("OS X")) {
ostream.println(getLocalizedMessage("java.launcher.X.macosx.usage",
File.pathSeparator));
}
}
static void initOutput(boolean printToStderr) {
ostream = (printToStderr) ? System.err : System.out;
}
static String getMainClassFromJar(String jarname) {
String mainValue = null;
try (JarFile jarFile = new JarFile(jarname)) {
Manifest manifest = jarFile.getManifest();
if (manifest == null) {
abort(null, "java.launcher.jar.error2", jarname);
}
Attributes mainAttrs = manifest.getMainAttributes();
if (mainAttrs == null) {
abort(null, "java.launcher.jar.error3", jarname);
}
mainValue = mainAttrs.getValue(MAIN_CLASS);
if (mainValue == null) {
abort(null, "java.launcher.jar.error3", jarname);
}
/*
* Hand off to FXHelper if it detects a JavaFX application
* This must be done after ensuring a Main-Class entry
* exists to enforce compliance with the jar specification
*/
if (mainAttrs.containsKey(
new Attributes.Name(FXHelper.JAVAFX_APPLICATION_MARKER))) {
return FXHelper.class.getName();
}
return mainValue.trim();
} catch (IOException ioe) {
abort(ioe, "java.launcher.jar.error1", jarname);
}
return null;
}
// From src/share/bin/java.c:
// enum LaunchMode { LM_UNKNOWN = 0, LM_CLASS, LM_JAR };
private static final int LM_UNKNOWN = 0;
private static final int LM_CLASS = 1;
private static final int LM_JAR = 2;
static void abort(Throwable t, String msgKey, Object... args) {
if (msgKey != null) {
ostream.println(getLocalizedMessage(msgKey, args));
}
if (trace) {
if (t != null) {
t.printStackTrace();
} else {
Thread.dumpStack();
}
}
System.exit(1);
}
/**
* This method does the following:
* 1. gets the classname from a Jar's manifest, if necessary
* 2. loads the class using the System ClassLoader
* 3. ensures the availability and accessibility of the main method,
* using signatureDiagnostic method.
* a. does the class exist
* b. is there a main
* c. is the main public
* d. is the main static
* e. does the main take a String array for args
* 4. if no main method and if the class extends FX Application, then call
* on FXHelper to determine the main class to launch
* 5. and off we go......
*
* @param printToStderr if set, all output will be routed to stderr
* @param mode LaunchMode as determined by the arguments passed on the
* command line
* @param what either the jar file to launch or the main class when using
* LM_CLASS mode
* @return the application's main class
*/
public static Class<?> checkAndLoadMain(boolean printToStderr,
int mode,
String what) {
initOutput(printToStderr);
// get the class name
String cn = null;
switch (mode) {
case LM_CLASS:
cn = what;
break;
case LM_JAR:
cn = getMainClassFromJar(what);
break;
default:
// should never happen
throw new InternalError("" + mode + ": Unknown launch mode");
}
cn = cn.replace('/', '.');
Class<?> mainClass = null;
try {
mainClass = scloader.loadClass(cn);
} catch (NoClassDefFoundError | ClassNotFoundException cnfe) {
if (System.getProperty("os.name", "").contains("OS X")
&& Normalizer.isNormalized(cn, Normalizer.Form.NFD)) {
try {
// On Mac OS X since all names with diacretic symbols are given as decomposed it
// is possible that main class name comes incorrectly from the command line
// and we have to re-compose it
mainClass = scloader.loadClass(Normalizer.normalize(cn, Normalizer.Form.NFC));
} catch (NoClassDefFoundError | ClassNotFoundException cnfe1) {
abort(cnfe, "java.launcher.cls.error1", cn);
}
} else {
abort(cnfe, "java.launcher.cls.error1", cn);
}
}
// set to mainClass
appClass = mainClass;
/*
* Check if FXHelper can launch it using the FX launcher. In an FX app,
* the main class may or may not have a main method, so do this before
* validating the main class.
*/
if (mainClass.equals(FXHelper.class) ||
FXHelper.doesExtendFXApplication(mainClass)) {
// Will abort() if there are problems with the FX runtime
FXHelper.setFXLaunchParameters(what, mode);
return FXHelper.class;
}
validateMainClass(mainClass);
return mainClass;
}
/*
* Accessor method called by the launcher after getting the main class via
* checkAndLoadMain(). The "application class" is the class that is finally
* executed to start the application and in this case is used to report
* the correct application name, typically for UI purposes.
*/
public static Class<?> getApplicationClass() {
return appClass;
}
// Check the existence and signature of main and abort if incorrect
static void validateMainClass(Class<?> mainClass) {
Method mainMethod;
try {
mainMethod = mainClass.getMethod("main", String[].class);
} catch (NoSuchMethodException nsme) {
// invalid main or not FX application, abort with an error
abort(null, "java.launcher.cls.error4", mainClass.getName(),
FXHelper.JAVAFX_APPLICATION_CLASS_NAME);
return; // Avoid compiler issues
}
/*
* getMethod (above) will choose the correct method, based
* on its name and parameter type, however, we still have to
* ensure that the method is static and returns a void.
*/
int mod = mainMethod.getModifiers();
if (!Modifier.isStatic(mod)) {
abort(null, "java.launcher.cls.error2", "static",
mainMethod.getDeclaringClass().getName());
}
if (mainMethod.getReturnType() != java.lang.Void.TYPE) {
abort(null, "java.launcher.cls.error3",
mainMethod.getDeclaringClass().getName());
}
}
private static final String encprop = "sun.jnu.encoding";
private static String encoding = null;
private static boolean isCharsetSupported = false;
/*
* converts a c or a byte array to a platform specific string,
* previously implemented as a native method in the launcher.
*/
static String makePlatformString(boolean printToStderr, byte[] inArray) {
initOutput(printToStderr);
if (encoding == null) {
encoding = System.getProperty(encprop);
isCharsetSupported = Charset.isSupported(encoding);
}
try {
String out = isCharsetSupported
? new String(inArray, encoding)
: new String(inArray);
return out;
} catch (UnsupportedEncodingException uee) {
abort(uee, null);
}
return null; // keep the compiler happy
}
static String[] expandArgs(String[] argArray) {
List<StdArg> aList = new ArrayList<>();
for (String x : argArray) {
aList.add(new StdArg(x));
}
return expandArgs(aList);
}
static String[] expandArgs(List<StdArg> argList) {
ArrayList<String> out = new ArrayList<>();
if (trace) {
System.err.println("Incoming arguments:");
}
for (StdArg a : argList) {
if (trace) {
System.err.println(a);
}
if (a.needsExpansion) {
File x = new File(a.arg);
File parent = x.getParentFile();
String glob = x.getName();
if (parent == null) {
parent = new File(".");
}
try (DirectoryStream<Path> dstream =
Files.newDirectoryStream(parent.toPath(), glob)) {
int entries = 0;
for (Path p : dstream) {
out.add(p.normalize().toString());
entries++;
}
if (entries == 0) {
out.add(a.arg);
}
} catch (Exception e) {
out.add(a.arg);
if (trace) {
System.err.println("Warning: passing argument as-is " + a);
System.err.print(e);
}
}
} else {
out.add(a.arg);
}
}
String[] oarray = new String[out.size()];
out.toArray(oarray);
if (trace) {
System.err.println("Expanded arguments:");
for (String x : oarray) {
System.err.println(x);
}
}
return oarray;
}
/* duplicate of the native StdArg struct */
private static class StdArg {
final String arg;
final boolean needsExpansion;
StdArg(String arg, boolean expand) {
this.arg = arg;
this.needsExpansion = expand;
}
// protocol: first char indicates whether expansion is required
// 'T' = true ; needs expansion
// 'F' = false; needs no expansion
StdArg(String in) {
this.arg = in.substring(1);
needsExpansion = in.charAt(0) == 'T';
}
public String toString() {
return "StdArg{" + "arg=" + arg + ", needsExpansion=" + needsExpansion + '}';
}
}
static final class FXHelper {
// Marker entry in jar manifest that designates a JavaFX application jar
private static final String JAVAFX_APPLICATION_MARKER =
"JavaFX-Application-Class";
private static final String JAVAFX_APPLICATION_CLASS_NAME =
"javafx.application.Application";
private static final String JAVAFX_LAUNCHER_CLASS_NAME =
"com.sun.javafx.application.LauncherImpl";
/*
* The launch method used to invoke the JavaFX launcher. These must
* match the strings used in the launchApplication method.
*
* Command line JavaFX-App-Class Launch mode FX Launch mode
* java -cp fxapp.jar FXClass N/A LM_CLASS "LM_CLASS"
* java -cp somedir FXClass N/A LM_CLASS "LM_CLASS"
* java -jar fxapp.jar Present LM_JAR "LM_JAR"
* java -jar fxapp.jar Not Present LM_JAR "LM_JAR"
*/
private static final String JAVAFX_LAUNCH_MODE_CLASS = "LM_CLASS";
private static final String JAVAFX_LAUNCH_MODE_JAR = "LM_JAR";
/*
* FX application launcher and launch method, so we can launch
* applications with no main method.
*/
private static String fxLaunchName = null;
private static String fxLaunchMode = null;
private static Class<?> fxLauncherClass = null;
private static Method fxLauncherMethod = null;
/*
* Set the launch params according to what was passed to LauncherHelper
* so we can use the same launch mode for FX. Abort if there is any
* issue with loading the FX runtime or with the launcher method.
*/
private static void setFXLaunchParameters(String what, int mode) {
// Check for the FX launcher classes
try {
fxLauncherClass = scloader.loadClass(JAVAFX_LAUNCHER_CLASS_NAME);
/*
* signature must be:
* public static void launchApplication(String launchName,
* String launchMode, String[] args);
*/
fxLauncherMethod = fxLauncherClass.getMethod("launchApplication",
String.class, String.class, String[].class);
// verify launcher signature as we do when validating the main method
int mod = fxLauncherMethod.getModifiers();
if (!Modifier.isStatic(mod)) {
abort(null, "java.launcher.javafx.error1");
}
if (fxLauncherMethod.getReturnType() != java.lang.Void.TYPE) {
abort(null, "java.launcher.javafx.error1");
}
} catch (ClassNotFoundException | NoSuchMethodException ex) {
abort(ex, "java.launcher.cls.error5", ex);
}
fxLaunchName = what;
switch (mode) {
case LM_CLASS:
fxLaunchMode = JAVAFX_LAUNCH_MODE_CLASS;
break;
case LM_JAR:
fxLaunchMode = JAVAFX_LAUNCH_MODE_JAR;
break;
default:
// should not have gotten this far...
throw new InternalError(mode + ": Unknown launch mode");
}
}
/*
* Check if the given class is a JavaFX Application class. This is done
* in a way that does not cause the Application class to load or throw
* ClassNotFoundException if the JavaFX runtime is not available.
*/
private static boolean doesExtendFXApplication(Class<?> mainClass) {
for (Class<?> sc = mainClass.getSuperclass(); sc != null;
sc = sc.getSuperclass()) {
if (sc.getName().equals(JAVAFX_APPLICATION_CLASS_NAME)) {
return true;
}
}
return false;
}
public static void main(String... args) throws Exception {
if (fxLauncherMethod == null
|| fxLaunchMode == null
|| fxLaunchName == null) {
throw new RuntimeException("Invalid JavaFX launch parameters");
}
// launch appClass via fxLauncherMethod
fxLauncherMethod.invoke(null,
new Object[] {fxLaunchName, fxLaunchMode, args});
}
}
}
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