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/*
* Copyright 2007-2008 Sun Microsystems, Inc. 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. Sun designates this
* particular file as subject to the "Classpath" exception as provided
* by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
package sun.launcher;
/*
*
* <p><b>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.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ResourceBundle;
import java.text.MessageFormat;
import java.util.jar.Attributes;
import java.util.jar.JarFile;
import java.util.jar.Manifest;
public enum LauncherHelper {
INSTANCE;
private static final String defaultBundleName =
"sun.launcher.resources.launcher";
private static ResourceBundle javarb =
ResourceBundle.getBundle(defaultBundleName);
private static final String MAIN_CLASS = "Main-Class";
private static StringBuilder outBuf = new StringBuilder();
/**
* 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 = javarb.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) {
PrintStream ostream = (printToStderr) ? System.err : System.out;
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) {
PrintStream ostream = (printToStderr) ? System.err : System.out;
ostream.println(getLocalizedMessage("java.launcher.X.usage",
File.pathSeparator));
}
static String getMainClassFromJar(String jarname) throws IOException {
JarFile jarFile = null;
try {
jarFile = new JarFile(jarname);
Manifest manifest = jarFile.getManifest();
if (manifest == null) {
throw new IOException("manifest not found in " + jarname);
}
Attributes mainAttrs = manifest.getMainAttributes();
if (mainAttrs == null) {
throw new IOException("no main mainifest attributes, in " +
jarname);
}
return mainAttrs.getValue(MAIN_CLASS);
} finally {
if (jarFile != null) {
jarFile.close();
}
}
}
/**
* 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
* c. does the main take a String array for args
* 4. and off we go......
*
* @param printToStderr
* @param isJar
* @param name
* @return
* @throws java.lang.Exception
*/
public static Object checkAndLoadMain(boolean printToStderr,
boolean isJar, String name) throws Exception {
// get the class name
String classname = (isJar) ? getMainClassFromJar(name) : name;
classname = classname.replace('/', '.');
ClassLoader loader = ClassLoader.getSystemClassLoader();
Class<?> clazz = null;
PrintStream ostream = (printToStderr) ? System.err : System.out;
try {
clazz = loader.loadClass(classname);
} catch (ClassNotFoundException cnfe) {
ostream.println(getLocalizedMessage("java.launcher.cls.error1", classname));
throw new RuntimeException("Could not find the main class " + classname);
}
signatureDiagnostic(ostream, clazz);
return clazz;
}
static void signatureDiagnostic(PrintStream ostream, Class<?> clazz) {
String classname = clazz.getName();
Method method = null;
try {
method = clazz.getMethod("main", String[].class);
} catch (Exception e) {
ostream.println(getLocalizedMessage("java.launcher.cls.error4",
classname));
throw new RuntimeException("Main method not found in " + classname);
}
/*
* Usually the getMethod (above) will choose the correct method, based
* on its modifiers and parameter types, the only check required is the
* getReturnType check as getMethod does not check for this, all the
* other modifier tests are redundant, and are simply here for safety.
*/
int mod = method.getModifiers();
if (!Modifier.isStatic(mod)) {
ostream.println(getLocalizedMessage("java.launcher.cls.error2",
"static", classname));
throw new RuntimeException("Main method is not static in class " +
classname);
}
if (!Modifier.isPublic(mod)) {
ostream.println(getLocalizedMessage("java.launcher.cls.error2",
"public", classname));
throw new RuntimeException("Main method is not public in class " +
classname);
}
Class<?> rType = method.getReturnType();
if (!rType.isPrimitive() || !rType.getName().equals("void")) {
ostream.println(getLocalizedMessage("java.launcher.cls.error3",
classname));
throw new RuntimeException("Main method must return a value" +
" of type void in class " +
classname);
}
return;
}
}
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