com.google.gwt.util.tools.ToolBase Maven / Gradle / Ivy
/*
* Copyright 2006 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.gwt.util.tools;
import com.google.gwt.dev.About;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Set;
/**
* A base class for a GWT related command-line application. To use this:
*
* - Derive a class for this class.
* - In your constructor, call {@link #registerHandler(ArgHandler)}
* repeatedly to register particular command line arguments and options.
* - Write a main that looks like this:
*
*
* public static void main(String[] args) {
* MyShell myShell = new MyShell();
* if (myShell.processArgs(args)) {
* // main program operation
* }
* System.exit(1);
* }
*
*
*
* - Create launch config whose main class is MyShell.
*
*/
public abstract class ToolBase {
private static final String PROPERTY_NOWARN_LEGACY_TOOLS = "gwt.nowarn.legacy.tools";
public static void legacyWarn(Class legacy, Class replacement) {
if (System.getProperty(PROPERTY_NOWARN_LEGACY_TOOLS) == null) {
System.err.println("WARNING: '" + legacy.getName()
+ "' is deprecated and will be removed in a future release.");
System.err.println("Use '" + replacement.getName() + "' instead.");
System.err.println("(To disable this warning, pass -D"
+ PROPERTY_NOWARN_LEGACY_TOOLS + " as a JVM arg.)");
}
}
/**
* Use a linked hash map to preserve the declaration order.
*/
private final Map argHandlers = new LinkedHashMap();
/**
* Log deprecation warning on old JREs.
*/
protected void checkJdkVersion() {
// JDK 1.6 is 50
double classVersion = Double.valueOf(System.getProperty("java.class.version","0.0"));
if (classVersion < 50) {
System.err.println("WARNING: Use on a JRE prior to version 1.6 is deprecated");
}
}
protected String getDescription() {
return null;
}
protected String getName() {
return getClass().getName();
}
protected void printHelp() {
System.err.println(About.getGwtVersion());
ArgHandler nullHandler = null;
int widest = 0;
for (ArgHandler handler : argHandlers.values()) {
if (handler.isUndocumented()) {
continue;
}
String tag = handler.getTag();
if (tag != null) {
if (tag.length() > widest) {
widest = tag.length();
}
} else {
nullHandler = handler;
int len = nullHandler.getTagArgs()[0].length();
if (len > widest) {
widest = len;
}
}
}
// Print the name.
//
String name = getName();
int i = name.lastIndexOf('.');
if (i != -1) {
name = name.substring(i + 1);
}
System.err.print(name);
// Print the command-line template.
//
for (ArgHandler handler : argHandlers.values()) {
if (handler.isUndocumented()) {
continue;
}
String tag = handler.getTag();
if (tag != null) {
System.err.print(handler.isRequired() ? " " : " [");
System.err.print(tag);
String[] tagArgs = handler.getTagArgs();
for (String tagArg : tagArgs) {
System.err.print(" " + tagArg);
}
System.err.print(handler.isRequired() ? "" : "]");
}
}
// Print the flagless args.
//
if (nullHandler != null && !nullHandler.isUndocumented()) {
String[] tagArgs = nullHandler.getTagArgs();
for (String element : tagArgs) {
System.err.print(nullHandler.isRequired() ? " " : " [");
System.err.print(element);
System.err.print(nullHandler.isRequired() ? " " : "]");
}
System.err.println();
}
System.err.println();
String description = getDescription();
if (description != null) {
System.err.println(description);
System.err.println();
}
System.err.println("where ");
// Print the details.
//
for (ArgHandler handler : argHandlers.values()) {
if (handler.isUndocumented()) {
continue;
}
String tag = handler.getTag();
if (tag != null) {
int len = tag.length();
System.err.print(" ");
System.err.print(tag);
for (i = len; i < widest; ++i) {
System.err.print(' ');
}
System.err.print(" ");
System.err.print(handler.getPurpose());
System.err.println();
}
}
// And details for the "extra" args, if any.
//
if (nullHandler != null && !nullHandler.isUndocumented()) {
System.err.println("and ");
String tagArg = nullHandler.getTagArgs()[0];
int len = tagArg.length();
System.err.print(" ");
System.err.print(tagArg);
for (i = len; i < widest; ++i) {
System.err.print(' ');
}
System.err.print(" ");
System.err.print(nullHandler.getPurpose());
System.err.println();
}
}
protected boolean processArgs(String... args) {
checkJdkVersion();
if (args.length > 0) {
boolean help = false;
if ("-help".equalsIgnoreCase(args[0])) {
help = true;
} else if ("-?".equals(args[0])) {
help = true;
}
if (help) {
printHelp();
return false;
}
}
Set defs = new HashSet(argHandlers.values());
int extraArgCount = 0;
Set receivedArg = new HashSet();
// Let the args drive the handlers.
//
ArgHandler nullHandler = argHandlers.get("");
for (int i = 0; i < args.length; i++) {
String arg = args[i];
ArgHandler handler;
if (arg.startsWith("-")) {
// Use the handler registered for this flag.
//
handler = argHandlers.get(arg);
} else {
// Use the handler that doesn't have a leading flag.
//
handler = nullHandler;
++extraArgCount;
}
if (handler == null) {
System.err.println("Unknown argument: " + arg);
printHelp();
return false;
}
int addtlConsumed = handler.handle(args, i);
if (addtlConsumed == -1) {
printHelp();
return false;
}
i += addtlConsumed;
// We don't need to use this as a default handler.
//
defs.remove(handler);
// Record that this handler saw a value
//
receivedArg.add(handler);
}
// See if any handler didn't get its required argument(s).
//
for (ArgHandler argHandler : argHandlers.values()) {
if (argHandler.isRequired() && !receivedArg.contains(argHandler)) {
System.err.print("Missing required argument '");
String tag = argHandler.getTag();
if (tag != null) {
System.err.print(tag);
System.err.print(" ");
}
String tagArg = argHandler.getTagArgs()[0];
System.err.print(tagArg);
System.err.println("'");
printHelp();
return false;
}
}
if (extraArgCount == 0 && nullHandler != null && nullHandler.isRequired()) {
System.err.print("Missing required argument '");
String tagArg = nullHandler.getTagArgs()[0];
System.err.print(tagArg);
System.err.println("'");
printHelp();
return false;
}
// Set if there are any remaining unused handlers with default arguments.
// Allow the default handlers to pretend there were other arguments.
//
for (ArgHandler def : defs) {
String[] defArgs = def.getDefaultArgs();
if (defArgs != null) {
if (def.handle(defArgs, 0) == -1) {
return false;
}
}
}
return true;
}
protected void registerHandler(ArgHandler handler) {
String tag = handler.getTag();
argHandlers.put(tag != null ? tag : "", handler);
}
}