org.apache.tools.ant.taskdefs.Available Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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
*
* https://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 org.apache.tools.ant.taskdefs;
import java.io.File;
import java.io.InputStream;
import org.apache.tools.ant.AntClassLoader;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.PropertyHelper;
import org.apache.tools.ant.Task;
import org.apache.tools.ant.taskdefs.condition.Condition;
import org.apache.tools.ant.types.EnumeratedAttribute;
import org.apache.tools.ant.types.Path;
import org.apache.tools.ant.types.Reference;
import org.apache.tools.ant.util.FileUtils;
/**
* Will set the given property if the requested resource is available at
* runtime. This task may also be used as a condition by the condition task.
*
* @since Ant 1.1
*
* @ant.task category="control"
*/
public class Available extends Task implements Condition {
private static final FileUtils FILE_UTILS = FileUtils.getFileUtils();
private String property;
private String classname;
private String filename;
private File file;
private Path filepath;
private String resource;
private FileDir type;
private Path classpath;
private AntClassLoader loader;
private Object value = "true";
private boolean isTask = false;
private boolean ignoreSystemclasses = false;
private boolean searchParents = false;
/**
* Set the searchParents attribute.
* This controls the behaviour of the the "file" type.
* If true, the path, parent path and grandparent path are
* searched for the file. If false, only the path is searched.
* The default value is false.
* @param searchParents the value to set.
*/
public void setSearchParents(boolean searchParents) {
this.searchParents = searchParents;
}
/**
* Set the classpath to be used when searching for classes and resources.
*
* @param classpath an Ant Path object containing the search path.
*/
public void setClasspath(Path classpath) {
createClasspath().append(classpath);
}
/**
* Classpath to be used when searching for classes and resources.
*
* @return an empty Path instance to be configured by Ant.
*/
public Path createClasspath() {
if (this.classpath == null) {
this.classpath = new Path(getProject());
}
return this.classpath.createPath();
}
/**
* Set the classpath by reference.
*
* @param r a Reference to a Path instance to be used as the classpath
* value.
*/
public void setClasspathRef(Reference r) {
createClasspath().setRefid(r);
}
/**
* Set the path to use when looking for a file.
*
* @param filepath a Path instance containing the search path for files.
*/
public void setFilepath(Path filepath) {
createFilepath().append(filepath);
}
/**
* Path to search for file resources.
*
* @return a new Path instance which Ant will configure with a file search
* path.
*/
public Path createFilepath() {
if (this.filepath == null) {
this.filepath = new Path(getProject());
}
return this.filepath.createPath();
}
/**
* Set the name of the property which will be set if the particular resource
* is available.
*
* @param property the name of the property to set.
*/
public void setProperty(String property) {
this.property = property;
}
/**
* Set the value to be given to the property if the desired resource is
* available.
*
* @param value the value to be given.
*/
public void setValue(Object value) {
this.value = value;
}
/**
* Set the value to be given to the property if the desired resource is
* available.
*
* @param value the value to be given.
*/
public void setValue(String value) {
setValue((Object) value);
}
/**
* Set a classname of a class which must be available to set the given
* property.
*
* @param classname the name of the class required.
*/
public void setClassname(String classname) {
if (!classname.isEmpty()) {
this.classname = classname;
}
}
/**
* Set the file which must be present in the file system to set the given
* property.
*
* @param file the name of the file which is required.
*/
public void setFile(File file) {
this.file = file;
this.filename = FILE_UTILS.removeLeadingPath(getProject().getBaseDir(), file);
}
/**
* Set the name of a Java resource which is required to set the property.
*
* @param resource the name of a resource which is required to be available.
*/
public void setResource(String resource) {
this.resource = resource;
}
/**
* @deprecated since 1.5.x.
* setType(String) is deprecated and is replaced with
* setType(Available.FileDir) to make Ant's Introspection
* mechanism do the work and also to encapsulate operations on
* the type in its own class.
* @param type the type of resource
*/
@Deprecated
public void setType(String type) {
log("DEPRECATED - The setType(String) method has been deprecated. Use setType(Available.FileDir) instead.",
Project.MSG_WARN);
this.type = new FileDir();
this.type.setValue(type);
}
/**
* Set what type of file is required - either directory or file.
*
* @param type an instance of the FileDir enumeratedAttribute indicating
* whether the file required is to be a directory or a plain
* file.
*/
public void setType(FileDir type) {
this.type = type;
}
/**
* Set whether the search for classes should ignore the runtime classes and
* just use the given classpath.
*
* @param ignore true if system classes are to be ignored.
*/
public void setIgnoresystemclasses(boolean ignore) {
this.ignoreSystemclasses = ignore;
}
/**
* Entry point when operating as a task.
*
* @exception BuildException if the task is not configured correctly.
*/
@Override
public void execute() throws BuildException {
if (property == null) {
throw new BuildException("property attribute is required",
getLocation());
}
isTask = true;
try {
if (eval()) {
PropertyHelper ph = PropertyHelper.getPropertyHelper(getProject());
Object oldvalue = ph.getProperty(property);
if (null != oldvalue && !oldvalue.equals(value)) {
log(String.format("DEPRECATED - used to override an existing property.%n"
+ " Build file should not reuse the same property name for different values."),
Project.MSG_WARN);
}
// NB: this makes use of Project#setProperty rather than Project#setNewProperty
// due to backwards compatibility reasons
ph.setProperty(property, value, true);
}
} finally {
isTask = false;
}
}
/**
* Evaluate the availability of a resource.
*
* @return boolean is the resource is available.
* @exception BuildException if the condition is not configured correctly
*/
@Override
public boolean eval() throws BuildException {
try {
if (classname == null && file == null && resource == null) {
throw new BuildException(
"At least one of (classname|file|resource) is required",
getLocation());
}
if (type != null) {
if (file == null) {
throw new BuildException(
"The type attribute is only valid when specifying the file attribute.",
getLocation());
}
}
if (classpath != null) {
classpath.setProject(getProject());
this.loader = getProject().createClassLoader(classpath);
}
String appendix = "";
if (isTask) {
appendix = " to set property " + property;
} else {
setTaskName("available");
}
if (classname != null && !checkClass(classname)) {
log("Unable to load class " + classname + appendix,
Project.MSG_VERBOSE);
return false;
}
if (file != null && !checkFile()) {
StringBuilder buf = new StringBuilder("Unable to find ");
if (type != null) {
buf.append(type).append(' ');
}
buf.append(filename).append(appendix);
log(buf.toString(), Project.MSG_VERBOSE);
return false;
}
if (resource != null && !checkResource(resource)) {
log("Unable to load resource " + resource + appendix,
Project.MSG_VERBOSE);
return false;
}
} finally {
if (loader != null) {
loader.cleanup();
loader = null;
}
if (!isTask) {
setTaskName(null);
}
}
return true;
}
/**
* Search for file/directory either relative to project's
* basedir or in the path given as filepath.
*
* filepath can be a list of directory and/or file names (gen'd
* via )
*
* look for:
* - full-pathname specified == path in list
* - full-pathname specified == parent dir of path in list
* - simple name specified == path in list
* - simple name specified == path in list + name
* - simple name specified == parent dir + name
* - simple name specified == parent of parent dir + name
*
*/
private boolean checkFile() {
if (filepath == null) {
return checkFile(file, filename);
}
String[] paths = filepath.list();
for (String p : paths) {
log("Searching " + p, Project.MSG_VERBOSE);
File path = new File(p);
// ** full-pathname specified == path in list
// ** simple name specified == path in list
if (path.exists()
&& (filename.equals(p)
|| filename.equals(path.getName()))) {
if (type == null) {
log("Found: " + path, Project.MSG_VERBOSE);
return true;
}
if (type.isDir()
&& path.isDirectory()) {
log("Found directory: " + path, Project.MSG_VERBOSE);
return true;
}
if (type.isFile()
&& path.isFile()) {
log("Found file: " + path, Project.MSG_VERBOSE);
return true;
}
// not the requested type
return false;
}
File parent = path.getParentFile();
// ** full-pathname specified == parent dir of path in list
if (parent != null && parent.exists()
&& filename.equals(parent.getAbsolutePath())) {
if (type == null) {
log("Found: " + parent, Project.MSG_VERBOSE);
return true;
}
if (type.isDir()) {
log("Found directory: " + parent, Project.MSG_VERBOSE);
return true;
}
// not the requested type
return false;
}
// ** simple name specified == path in list + name
if (path.exists() && path.isDirectory()) {
if (checkFile(new File(path, filename),
filename + " in " + path)) {
return true;
}
}
// ** simple name specified == parent dir + name
while (searchParents && parent != null && parent.exists()) {
if (checkFile(new File(parent, filename),
filename + " in " + parent)) {
return true;
}
parent = parent.getParentFile();
}
}
return false;
}
/**
* Check if a given file exists and matches the required type.
*/
private boolean checkFile(File f, String text) {
if (type != null) {
if (type.isDir()) {
if (f.isDirectory()) {
log("Found directory: " + text, Project.MSG_VERBOSE);
}
return f.isDirectory();
}
if (type.isFile()) {
if (f.isFile()) {
log("Found file: " + text, Project.MSG_VERBOSE);
}
return f.isFile();
}
}
if (f.exists()) {
log("Found: " + text, Project.MSG_VERBOSE);
}
return f.exists();
}
/**
* Check if a given resource can be loaded.
*/
private boolean checkResource(String resource) {
InputStream is = null;
try {
if (loader != null) {
is = loader.getResourceAsStream(resource);
} else {
ClassLoader cL = this.getClass().getClassLoader();
if (cL != null) {
is = cL.getResourceAsStream(resource);
} else {
is = ClassLoader.getSystemResourceAsStream(resource);
}
}
return is != null;
} finally {
FileUtils.close(is);
}
}
/**
* Check if a given class can be loaded.
*/
private boolean checkClass(String classname) {
try {
if (ignoreSystemclasses) {
loader = getProject().createClassLoader(classpath);
loader.setParentFirst(false);
loader.addJavaLibraries();
try {
loader.findClass(classname);
} catch (SecurityException se) {
// class found but restricted name; this is
// actually the case we're looking for in JDK 1.3+,
// so catch the exception and return
return true;
}
} else if (loader != null) {
loader.loadClass(classname);
} else {
ClassLoader l = this.getClass().getClassLoader();
// Can return null to represent the bootstrap class loader.
// see API docs of Class.getClassLoader.
if (l != null) {
Class.forName(classname, true, l);
} else {
Class.forName(classname);
}
}
return true;
} catch (ClassNotFoundException e) {
log("class \"" + classname + "\" was not found",
Project.MSG_DEBUG);
return false;
} catch (NoClassDefFoundError e) {
log("Could not load dependent class \"" + e.getMessage()
+ "\" for class \"" + classname + "\"",
Project.MSG_DEBUG);
return false;
}
}
/**
* EnumeratedAttribute covering the file types to be checked for, either
* file or dir.
*/
public static class FileDir extends EnumeratedAttribute {
private static final String[] VALUES = {"file", "dir"};
/**
* @see EnumeratedAttribute#getValues
* {@inheritDoc}.
*/
@Override
public String[] getValues() {
return VALUES;
}
/**
* Indicate if the value specifies a directory.
*
* @return true if the value specifies a directory.
*/
public boolean isDir() {
return "dir".equalsIgnoreCase(getValue());
}
/**
* Indicate if the value specifies a file.
*
* @return true if the value specifies a file.
*/
public boolean isFile() {
return "file".equalsIgnoreCase(getValue());
}
}
}