src/main/java/groovy/lang/GrabConfig.java

/*
 *  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
 *
 *    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 groovy.lang;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * Used to modify the grape configuration for grab requests.
 * <p>
 * An example involving databases:
 * <pre>
 * {@code @Grab}('mysql:mysql-connector-java:5.1.6')
 * {@code @GrabConfig}(systemClassLoader=true)
 * import groovy.sql.Sql
 *
 * def sql=Sql.newInstance("jdbc:mysql://localhost/test", "user", "password", "com.mysql.jdbc.Driver")
 * println sql.firstRow('SELECT * FROM INFORMATION_SCHEMA.COLUMNS')
 * </pre>
 * Another example involving XStream:
 * <pre>
 * {@code @Grab}('com.thoughtworks.xstream:xstream:1.4.9')
 * {@code @Grab}('xpp3:xpp3_min:1.1.4c')
 * {@code @GrabConfig}(systemClassLoader=true, initContextClassLoader=true)
 * {@code
 * import com.thoughtworks.xstream.*
 *
 * class Staff {
 *     String firstname, lastname, position
 * }
 *
 * def xstream = new XStream()
 * def john1 = new Staff(firstname:'John',
 *                      lastname:'Connor',
 *                      position:'Resistance Leader')
 *
 * // write out to XML file
 * new File("john.xml").withOutputStream { out ->
 *     xstream.toXML(john1, out)
 * }
 *
 * // now read back in
 * def john2
 * new File("john.xml").withInputStream { ins ->
 *     john2 = xstream.fromXML(ins)
 * }
 *
 * println john2.dump()
 * }
 * </pre>
 * <p>
 * Further information about customising grape behavior can be found on the Grape documentation page:
 * <a href="http://groovy-lang.org/grape.html">http://groovy-lang.org/grape.html</a>.
 */
@Retention(RetentionPolicy.SOURCE)
@Target({
        ElementType.CONSTRUCTOR,
        ElementType.FIELD,
        ElementType.LOCAL_VARIABLE,
        ElementType.METHOD,
        ElementType.PARAMETER,
        ElementType.TYPE})
public @interface GrabConfig {
    /**
     * Set to true if you want to use the system classloader when loading the grape.
     * This is normally only required when a core Java class needs to reference the grabbed
     * classes, e.g. for a database driver accessed using DriverManager.
     */
    boolean systemClassLoader() default false;

    /**
     * Define any system properties which must be set before invoking the grab - useful for
     * declaring SSL certificates or proxy settings. Currently, this only affects the generated
     * class or script. You may need to also set those same properties for the Groovy compiler.
     * For convenience, a String with comma separated name=value pairs
     * can be used in addition to an array (using Groovy's literal list notation) of String name=value items.
     * The single String shorthand form can't be used if value part of a property contains a comma.
     *
     * @since 2.4.5
     */
    String[] systemProperties() default "";

    /**
     * Set to true if you want the context classloader to be initialised to the classloader
     * of the current class or script. This is useful for libraries or frameworks that assume
     * that the context classloader has been set. But be careful when using this flag as your
     * script or class might behave differently when called directly (from the command line or
     * from an IDE) versus when called from within a container, e.g. a web container or a JEE container.
     */
    boolean initContextClassLoader() default false;

    /**
     * Set to false if you want to disable automatic downloading of locally missing jars.
     */
    boolean autoDownload() default true;

    /**
     * Set to true if you want to disable checksum checking.
     */
    boolean disableChecksums() default false;
}