ClassLoader.java revision 1957
1042N/A * Copyright 1994-2009 Sun Microsystems, Inc. All Rights Reserved. 0N/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 0N/A * This code is free software; you can redistribute it and/or modify it 0N/A * under the terms of the GNU General Public License version 2 only, as 0N/A * published by the Free Software Foundation. Sun designates this 0N/A * particular file as subject to the "Classpath" exception as provided 0N/A * by Sun in the LICENSE file that accompanied this code. 0N/A * This code is distributed in the hope that it will be useful, but WITHOUT 0N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 0N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 0N/A * version 2 for more details (a copy is included in the LICENSE file that 0N/A * accompanied this code). 0N/A * You should have received a copy of the GNU General Public License version 0N/A * 2 along with this work; if not, write to the Free Software Foundation, 0N/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 0N/A * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, 0N/A * CA 95054 USA or visit www.sun.com if you need additional information or 0N/A * have any questions. 0N/A * A class loader is an object that is responsible for loading classes. The 0N/A * class <tt>ClassLoader</tt> is an abstract class. Given the <a 0N/A * href="#name">binary name</a> of a class, a class loader should attempt to 0N/A * locate or generate data that constitutes a definition for the class. A 0N/A * typical strategy is to transform the name into a file name and then read a 0N/A * "class file" of that name from a file system. 0N/A * <p> Every {@link Class <tt>Class</tt>} object contains a {@link 0N/A * Class#getClassLoader() reference} to the <tt>ClassLoader</tt> that defined 0N/A * <p> <tt>Class</tt> objects for array classes are not created by class 0N/A * loaders, but are created automatically as required by the Java runtime. 0N/A * The class loader for an array class, as returned by {@link 0N/A * Class#getClassLoader()} is the same as the class loader for its element 0N/A * type; if the element type is a primitive type, then the array class has no 0N/A * <p> Applications implement subclasses of <tt>ClassLoader</tt> in order to 0N/A * extend the manner in which the Java virtual machine dynamically loads 0N/A * <p> Class loaders may typically be used by security managers to indicate 0N/A * <p> The <tt>ClassLoader</tt> class uses a delegation model to search for 0N/A * classes and resources. Each instance of <tt>ClassLoader</tt> has an 0N/A * associated parent class loader. When requested to find a class or 0N/A * resource, a <tt>ClassLoader</tt> instance will delegate the search for the 0N/A * class or resource to its parent class loader before attempting to find the 0N/A * class or resource itself. The virtual machine's built-in class loader, 0N/A * called the "bootstrap class loader", does not itself have a parent but may 0N/A * serve as the parent of a <tt>ClassLoader</tt> instance. 1042N/A * <p> Class loaders that support concurrent loading of classes are known as 1042N/A * <em>parallel capable</em> class loaders and are required to register 1042N/A * themselves at their class initialization time by invoking the 1042N/A * #registerAsParallelCapable <tt>ClassLoader.registerAsParallelCapable</tt>} 1042N/A * method. In environments in which the delegation model is not strictly 1042N/A * hierarchical, class loaders need to be parallel capable, otherise class 1042N/A * loading can lead to deadlocks because the loader lock is held for the 1042N/A * duration of the class loading process (see {@link #loadClass 1042N/A * <tt>loadClass</tt>} methods). 0N/A * <p> Normally, the Java virtual machine loads classes from the local file 0N/A * system in a platform-dependent manner. For example, on UNIX systems, the 0N/A * virtual machine loads classes from the directory defined by the 0N/A * <tt>CLASSPATH</tt> environment variable. 0N/A * <p> However, some classes may not originate from a file; they may originate 0N/A * from other sources, such as the network, or they could be constructed by an 0N/A * application. The method {@link #defineClass(String, byte[], int, int) 0N/A * <tt>defineClass</tt>} converts an array of bytes into an instance of class 0N/A * <tt>Class</tt>. Instances of this newly defined class can be created using 0N/A * {@link Class#newInstance <tt>Class.newInstance</tt>}. 0N/A * <p> The methods and constructors of objects created by a class loader may 0N/A * reference other classes. To determine the class(es) referred to, the Java 0N/A * virtual machine invokes the {@link #loadClass <tt>loadClass</tt>} method of 0N/A * the class loader that originally created the class. 0N/A * <p> For example, an application could create a network class loader to 0N/A * download class files from a server. Sample code might look like: 0N/A * ClassLoader loader = new NetworkClassLoader(host, port); 0N/A * Object main = loader.loadClass("Main", true).newInstance(); 0N/A * . . . 0N/A * </pre></blockquote> 0N/A * <p> The network class loader subclass must define the methods {@link 0N/A * #findClass <tt>findClass</tt>} and <tt>loadClassData</tt> to load a class 0N/A * from the network. Once it has downloaded the bytes that make up the class, 0N/A * it should use the method {@link #defineClass <tt>defineClass</tt>} to 0N/A * create a class instance. A sample implementation is: 0N/A * class NetworkClassLoader extends ClassLoader { 0N/A * public Class findClass(String name) { 0N/A * byte[] b = loadClassData(name); 0N/A * return defineClass(name, b, 0, b.length); 0N/A * private byte[] loadClassData(String name) { 0N/A * // load the class data from the connection 0N/A * . . . 0N/A * </pre></blockquote> 0N/A * <h4> <a name="name">Binary names</a> </h4> 0N/A * <p> Any class name provided as a {@link String} parameter to methods in 0N/A * <tt>ClassLoader</tt> must be a binary name as defined by the <a 0N/A * <p> Examples of valid class names include: 0N/A * "java.lang.String" 0N/A * "javax.swing.JSpinner$DefaultEditor" 0N/A * "java.security.KeyStore$Builder$FileBuilder$1" 0N/A * "java.net.URLClassLoader$3$1" 0N/A * </pre></blockquote> 0N/A * @see #resolveClass(Class) 0N/A // The parent class loader for delegation 1042N/A // Note: VM hardcoded the offset of this field, thus all new fields 1042N/A // must be added *after* it. 1957N/A * Encapsulates the set of parallel capable loader types. 1957N/A // the set of parallel capable loader types 1957N/A * Registers the given class loader type as parallel capabale. 1957N/A * Returns {@code true} is successfully registered; {@code false} if 1957N/A * loader's super class is not registered. 1957N/A // register the class loader as parallel capable 1957N/A // if and only if all of its super classes are. 1957N/A // Note: given current classloading sequence, if 1957N/A // the immediate super class is parallel capable, 1957N/A // all the super classes higher up must be too. 1957N/A * Returns {@code true} if the given class loader type is 1957N/A * registered as parallel capable. 1042N/A // Maps class name to the corresponding lock object when the current 1042N/A // class loader is parallel capable. 1042N/A // Note: VM also uses this field to decide if the current class loader 1042N/A // is parallel capable and the appropriate lock object for class loading. 0N/A // Hashtable that maps packages to certs 0N/A // Shared among all packages with unsigned classes 1042N/A // The classes loaded by this class loader. The only purpose of this table 1042N/A // is to keep the classes from being GC'ed until the loader is GC'ed. 1042N/A // The "default" domain. Set as the default ProtectionDomain on newly 0N/A // The initiating protection domains for all classes loaded by this loader 0N/A // Invoked by the VM to record every loaded class with this loader. 0N/A // The packages defined in this class loader. Each package name is mapped 0N/A // to its corresponding Package object. 1826N/A // no finer-grained lock; lock on the classloader instance 0N/A * Creates a new class loader using the specified parent class loader for 0N/A * <p> If there is a security manager, its {@link 0N/A * SecurityManager#checkCreateClassLoader() 0N/A * <tt>checkCreateClassLoader</tt>} method is invoked. This may result in 0N/A * a security exception. </p> 0N/A * The parent class loader 0N/A * @throws SecurityException 0N/A * If a security manager exists and its 0N/A * <tt>checkCreateClassLoader</tt> method doesn't allow creation 0N/A * of a new class loader. 0N/A * Creates a new class loader using the <tt>ClassLoader</tt> returned by 0N/A * the method {@link #getSystemClassLoader() 0N/A * <tt>getSystemClassLoader()</tt>} as the parent class loader. 0N/A * <p> If there is a security manager, its {@link 0N/A * SecurityManager#checkCreateClassLoader() 0N/A * <tt>checkCreateClassLoader</tt>} method is invoked. This may result in 0N/A * a security exception. </p> 0N/A * @throws SecurityException 0N/A * If a security manager exists and its 0N/A * <tt>checkCreateClassLoader</tt> method doesn't allow creation 0N/A * of a new class loader. 0N/A * Loads the class with the specified <a href="#name">binary name</a>. 0N/A * This method searches for classes in the same manner as the {@link 0N/A * #loadClass(String, boolean)} method. It is invoked by the Java virtual 0N/A * machine to resolve class references. Invoking this method is equivalent 0N/A * to invoking {@link #loadClass(String, boolean) <tt>loadClass(name, 0N/A * false)</tt>}. </p> 0N/A * The <a href="#name">binary name</a> of the class 0N/A * @return The resulting <tt>Class</tt> object 0N/A * @throws ClassNotFoundException 0N/A * If the class was not found 0N/A * Loads the class with the specified <a href="#name">binary name</a>. The 0N/A * default implementation of this method searches for classes in the 0N/A * <li><p> Invoke {@link #findLoadedClass(String)} to check if the class 0N/A * has already been loaded. </p></li> 0N/A * <li><p> Invoke the {@link #loadClass(String) <tt>loadClass</tt>} method 0N/A * on the parent class loader. If the parent is <tt>null</tt> the class 0N/A * loader built-in to the virtual machine is used, instead. </p></li> 0N/A * <li><p> Invoke the {@link #findClass(String)} method to find the 0N/A * <p> If the class was found using the above steps, and the 0N/A * <tt>resolve</tt> flag is true, this method will then invoke the {@link 0N/A * #resolveClass(Class)} method on the resulting <tt>Class</tt> object. 0N/A * <p> Subclasses of <tt>ClassLoader</tt> are encouraged to override {@link 0N/A * #findClass(String)}, rather than this method. </p> 1042N/A * <p> Unless overridden, this method synchronizes on the result of 1042N/A * {@link #getClassLoadingLock <tt>getClassLoadingLock</tt>} method 1042N/A * during the entire class loading process. 0N/A * The <a href="#name">binary name</a> of the class 0N/A * If <tt>true</tt> then resolve the class 0N/A * @return The resulting <tt>Class</tt> object 0N/A * @throws ClassNotFoundException 0N/A * If the class could not be found 1042N/A // First, check if the class has already been loaded 1644N/A // ClassNotFoundException thrown if class not found 1644N/A // from the non-null parent class loader 1042N/A // If still not found, then invoke findClass in order 1660N/A // this is the defining class loader; record the stats 1042N/A * Returns the lock object for class loading operations. 1042N/A * For backward compatibility, the default implementation of this method 1042N/A * behaves as follows. If this ClassLoader object is registered as 1042N/A * parallel capable, the method returns a dedicated object associated 1042N/A * with the specified class name. Otherwise, the method returns this 1042N/A * The name of the to-be-loaded class 1042N/A * @return the lock for class loading operations 1042N/A * @throws NullPointerException 1042N/A * If registered as parallel capable and <tt>className</tt> is null 1042N/A * @see #loadClass(String, boolean) 0N/A // This method is invoked by the virtual machine to load a class. 1042N/A // For backward compatibility, explicitly lock on 'this' when 1042N/A // the current class loader is not parallel capable. 1042N/A // Invoked by the VM after loading class with this loader. 0N/A * Finds the class with the specified <a href="#name">binary name</a>. 0N/A * This method should be overridden by class loader implementations that 0N/A * follow the delegation model for loading classes, and will be invoked by 0N/A * the {@link #loadClass <tt>loadClass</tt>} method after checking the 0N/A * parent class loader for the requested class. The default implementation 0N/A * throws a <tt>ClassNotFoundException</tt>. </p> 0N/A * The <a href="#name">binary name</a> of the class 0N/A * @return The resulting <tt>Class</tt> object 0N/A * @throws ClassNotFoundException 0N/A * If the class could not be found 0N/A * Converts an array of bytes into an instance of class <tt>Class</tt>. 0N/A * Before the <tt>Class</tt> can be used it must be resolved. This method 0N/A * is deprecated in favor of the version that takes a <a 0N/A * href="#name">binary name</a> as its first argument, and is more secure. 0N/A * The bytes that make up the class data. The bytes in positions 0N/A * <tt>off</tt> through <tt>off+len-1</tt> should have the format 0N/A * of a valid class file as defined by the <a 0N/A * Machine Specification</a>. 0N/A * The start offset in <tt>b</tt> of the class data 0N/A * The length of the class data 0N/A * @return The <tt>Class</tt> object that was created from the specified 0N/A * @throws ClassFormatError 0N/A * If the data did not contain a valid class 0N/A * @throws IndexOutOfBoundsException 0N/A * If either <tt>off</tt> or <tt>len</tt> is negative, or if 0N/A * <tt>off+len</tt> is greater than <tt>b.length</tt>. 0N/A * @see #loadClass(String, boolean) 0N/A * @see #resolveClass(Class) 0N/A * @deprecated Replaced by {@link #defineClass(String, byte[], int, int) 0N/A * defineClass(String, byte[], int, int)} 0N/A * Converts an array of bytes into an instance of class <tt>Class</tt>. 0N/A * Before the <tt>Class</tt> can be used it must be resolved. 0N/A * <p> This method assigns a default {@link java.security.ProtectionDomain 0N/A * <tt>ProtectionDomain</tt>} to the newly defined class. The 0N/A * <tt>ProtectionDomain</tt> is effectively granted the same set of 0N/A * permissions returned when {@link 0N/A * java.security.Policy#getPermissions(java.security.CodeSource) 0N/A * <tt>Policy.getPolicy().getPermissions(new CodeSource(null, null))</tt>} 0N/A * is invoked. The default domain is created on the first invocation of 0N/A * {@link #defineClass(String, byte[], int, int) <tt>defineClass</tt>}, 0N/A * and re-used on subsequent invocations. 0N/A * <p> To assign a specific <tt>ProtectionDomain</tt> to the class, use 0N/A * the {@link #defineClass(String, byte[], int, int, 0N/A * java.security.ProtectionDomain) <tt>defineClass</tt>} method that takes a 0N/A * <tt>ProtectionDomain</tt> as one of its arguments. </p> 0N/A * The expected <a href="#name">binary name</a> of the class, or 0N/A * <tt>null</tt> if not known 0N/A * The bytes that make up the class data. The bytes in positions 0N/A * <tt>off</tt> through <tt>off+len-1</tt> should have the format 0N/A * of a valid class file as defined by the <a 0N/A * Machine Specification</a>. 0N/A * The start offset in <tt>b</tt> of the class data 0N/A * The length of the class data 0N/A * @return The <tt>Class</tt> object that was created from the specified 0N/A * @throws ClassFormatError 0N/A * If the data did not contain a valid class 0N/A * @throws IndexOutOfBoundsException 0N/A * If either <tt>off</tt> or <tt>len</tt> is negative, or if 0N/A * <tt>off+len</tt> is greater than <tt>b.length</tt>. 0N/A * @throws SecurityException 0N/A * If an attempt is made to add this class to a package that 0N/A * contains classes that were signed by a different set of 0N/A * certificates than this class (which is unsigned), or if 0N/A * <tt>name</tt> begins with "<tt>java.</tt>". 0N/A * @see #loadClass(String, boolean) 0N/A * @see #resolveClass(Class) 0N/A * @see java.security.CodeSource 0N/A * @see java.security.SecureClassLoader 0N/A /* Determine protection domain, and check that: 0N/A - not define java.* class, 1042N/A - signer of this class matches signers for the rest of the classes in 1042N/A (
"Prohibited package name: " +
0N/A // Class format error - try to transform the bytecode and 0N/A // define the class again 28N/A // Transform byte code using transformer 28N/A // If ClassFormatError occurs, try next transformer 0N/A // Rethrow original ClassFormatError if unable to transform 0N/A // bytecode to well-formed 0N/A * Converts an array of bytes into an instance of class <tt>Class</tt>, 0N/A * with an optional <tt>ProtectionDomain</tt>. If the domain is 0N/A * <tt>null</tt>, then a default domain will be assigned to the class as 0N/A * specified in the documentation for {@link #defineClass(String, byte[], 0N/A * int, int)}. Before the class can be used it must be resolved. 0N/A * <p> The first class defined in a package determines the exact set of 0N/A * certificates that all subsequent classes defined in that package must 0N/A * contain. The set of certificates for a class is obtained from the 0N/A * {@link java.security.CodeSource <tt>CodeSource</tt>} within the 0N/A * <tt>ProtectionDomain</tt> of the class. Any classes added to that 0N/A * package must contain the same set of certificates or a 0N/A * <tt>SecurityException</tt> will be thrown. Note that if 0N/A * <tt>name</tt> is <tt>null</tt>, this check is not performed. 0N/A * You should always pass in the <a href="#name">binary name</a> of the 0N/A * class you are defining as well as the bytes. This ensures that the 0N/A * class you are defining is indeed the class you think it is. 0N/A * <p> The specified <tt>name</tt> cannot begin with "<tt>java.</tt>", since 0N/A * all classes in the "<tt>java.*</tt> packages can only be defined by the 0N/A * bootstrap class loader. If <tt>name</tt> is not <tt>null</tt>, it 0N/A * must be equal to the <a href="#name">binary name</a> of the class 0N/A * specified by the byte array "<tt>b</tt>", otherwise a {@link 0N/A * <tt>NoClassDefFoundError</tt>} will be thrown. </p> 0N/A * The expected <a href="#name">binary name</a> of the class, or 0N/A * <tt>null</tt> if not known 0N/A * The bytes that make up the class data. The bytes in positions 0N/A * <tt>off</tt> through <tt>off+len-1</tt> should have the format 0N/A * of a valid class file as defined by the <a 0N/A * Machine Specification</a>. 0N/A * The start offset in <tt>b</tt> of the class data 0N/A * The length of the class data 0N/A * @param protectionDomain 0N/A * The ProtectionDomain of the class 0N/A * @return The <tt>Class</tt> object created from the data, 0N/A * and optional <tt>ProtectionDomain</tt>. 0N/A * @throws ClassFormatError 0N/A * If the data did not contain a valid class 0N/A * @throws NoClassDefFoundError 0N/A * If <tt>name</tt> is not equal to the <a href="#name">binary 0N/A * name</a> of the class specified by <tt>b</tt> 0N/A * @throws IndexOutOfBoundsException 0N/A * If either <tt>off</tt> or <tt>len</tt> is negative, or if 0N/A * <tt>off+len</tt> is greater than <tt>b.length</tt>. 0N/A * @throws SecurityException 0N/A * If an attempt is made to add this class to a package that 0N/A * contains classes that were signed by a different set of 0N/A * certificates than this class, or if <tt>name</tt> begins with 0N/A * Converts a {@link java.nio.ByteBuffer <tt>ByteBuffer</tt>} 0N/A * into an instance of class <tt>Class</tt>, 0N/A * with an optional <tt>ProtectionDomain</tt>. If the domain is 0N/A * <tt>null</tt>, then a default domain will be assigned to the class as 0N/A * specified in the documentation for {@link #defineClass(String, byte[], 0N/A * int, int)}. Before the class can be used it must be resolved. 1042N/A * <p>The rules about the first class defined in a package determining the 1042N/A * set of certificates for the package, and the restrictions on class names 1042N/A * are identical to those specified in the documentation for {@link 1042N/A * #defineClass(String, byte[], int, int, ProtectionDomain)}. 0N/A * <p> An invocation of this method of the form 0N/A * <i>cl</i><tt>.defineClass(</tt><i>name</i><tt>,</tt> 0N/A * <i>bBuffer</i><tt>,</tt> <i>pd</i><tt>)</tt> yields exactly the same 0N/A * result as the statements 1042N/A * byte[] temp = new byte[</tt><i>bBuffer</i><tt>.{@link 1042N/A * java.nio.ByteBuffer#remaining remaining}()];<br> 0N/A * </tt><i>bBuffer</i><tt>.{@link java.nio.ByteBuffer#get(byte[]) 0N/A * return {@link #defineClass(String, byte[], int, int, ProtectionDomain) 1042N/A * </tt><i>cl</i><tt>.defineClass}(</tt><i>name</i><tt>, temp, 0, 1042N/A * temp.length, </tt><i>pd</i><tt>);<br> 0N/A * </tt></blockquote> 0N/A * The expected <a href="#name">binary name</a. of the class, or 0N/A * <tt>null</tt> if not known 0N/A * The bytes that make up the class data. The bytes from positions 1042N/A * <tt>b.position()</tt> through <tt>b.position() + b.limit() -1 1042N/A * </tt> should have the format of a valid class file as defined by 0N/A * Machine Specification</a>. 0N/A * @param protectionDomain 0N/A * The ProtectionDomain of the class, or <tt>null</tt>. 0N/A * @return The <tt>Class</tt> object created from the data, 0N/A * and optional <tt>ProtectionDomain</tt>. 0N/A * @throws ClassFormatError 0N/A * If the data did not contain a valid class. 0N/A * @throws NoClassDefFoundError 0N/A * If <tt>name</tt> is not equal to the <a href="#name">binary 0N/A * name</a> of the class specified by <tt>b</tt> 0N/A * @throws SecurityException 0N/A * If an attempt is made to add this class to a package that 0N/A * contains classes that were signed by a different set of 0N/A * certificates than this class, or if <tt>name</tt> begins with 0N/A * @see #defineClass(String, byte[], int, int, ProtectionDomain) 0N/A // Use byte[] if not a direct ByteBufer: 0N/A // no array, or read-only array 0N/A b.
get(
tb);
// get bytes out of byte buffer. 0N/A b.
get(
tb);
// get bytes out of byte buffer. 0N/A // true if the name is null or has the potential to be a valid binary name 1042N/A "\"'s signer information does not match signer information of other classes in the same package");
0N/A * check to make sure the certs for the new class (certs) are the same as 0N/A * the certs for the first class inserted in the package (pcerts) 0N/A // certs can be null, indicating no certs. 0N/A // the length must be the same at this point 0N/A // go through and make sure all the certs in one array 0N/A // are in the other and vice-versa. 0N/A // now do the same for pcerts 0N/A * Links the specified class. This (misleadingly named) method may be 0N/A * used by a class loader to link a class. If the class <tt>c</tt> has 0N/A * already been linked, then this method simply returns. Otherwise, the 0N/A * class is linked as described in the "Execution" chapter of the <a 0N/A * Specification</a>. 0N/A * @throws NullPointerException 0N/A * If <tt>c</tt> is <tt>null</tt>. 0N/A * @see #defineClass(String, byte[], int, int) 0N/A * Finds a class with the specified <a href="#name">binary name</a>, 0N/A * loading it if necessary. 0N/A * <p> This method loads the class through the system class loader (see 0N/A * {@link #getSystemClassLoader()}). The <tt>Class</tt> object returned 0N/A * might have more than one <tt>ClassLoader</tt> associated with it. 0N/A * Subclasses of <tt>ClassLoader</tt> need not usually invoke this method, 0N/A * because most class loaders need to override just {@link 0N/A * #findClass(String)}. </p> 0N/A * The <a href="#name">binary name</a> of the class 0N/A * @return The <tt>Class</tt> object for the specified <tt>name</tt> 0N/A * @throws ClassNotFoundException 0N/A * If the class could not be found 0N/A * @see #ClassLoader(ClassLoader) 1644N/A * Returns a class loaded by the bootstrap class loader; 1644N/A * or return null if not found. 1644N/A // return null if not found 0N/A * Returns the class with the given <a href="#name">binary name</a> if this 0N/A * loader has been recorded by the Java virtual machine as an initiating 0N/A * loader of a class with that <a href="#name">binary name</a>. Otherwise 0N/A * <tt>null</tt> is returned. </p> 0N/A * The <a href="#name">binary name</a> of the class 0N/A * @return The <tt>Class</tt> object, or <tt>null</tt> if the class has 0N/A * Sets the signers of a class. This should be invoked after defining a 0N/A * The <tt>Class</tt> object 0N/A * The signers for the class 0N/A * Finds the resource with the given name. A resource is some data 0N/A * (images, audio, text, etc) that can be accessed by class code in a way 0N/A * that is independent of the location of the code. 0N/A * <p> The name of a resource is a '<tt>/</tt>'-separated path name that 0N/A * identifies the resource. 0N/A * <p> This method will first search the parent class loader for the 0N/A * resource; if the parent is <tt>null</tt> the path of the class loader 0N/A * built-in to the virtual machine is searched. That failing, this method 0N/A * will invoke {@link #findResource(String)} to find the resource. </p> 0N/A * @return A <tt>URL</tt> object for reading the resource, or 0N/A * <tt>null</tt> if the resource could not be found or the invoker 0N/A * doesn't have adequate privileges to get the resource. 0N/A * Finds all the resources with the given name. A resource is some data 0N/A * (images, audio, text, etc) that can be accessed by class code in a way 0N/A * that is independent of the location of the code. 0N/A * <p>The name of a resource is a <tt>/</tt>-separated path name that 0N/A * identifies the resource. 0N/A * <p> The search order is described in the documentation for {@link 0N/A * #getResource(String)}. </p> 0N/A * @return An enumeration of {@link java.net.URL <tt>URL</tt>} objects for 0N/A * the resource. If no resources could be found, the enumeration 0N/A * will be empty. Resources that the class loader doesn't have 0N/A * access to will not be in the enumeration. 0N/A * @throws IOException 0N/A * If I/O errors occur 0N/A * @see #findResources(String) 0N/A * Finds the resource with the given name. Class loader implementations 0N/A * should override this method to specify where to find resources. </p> 0N/A * @return A <tt>URL</tt> object for reading the resource, or 0N/A * <tt>null</tt> if the resource could not be found 0N/A * Returns an enumeration of {@link java.net.URL <tt>URL</tt>} objects 0N/A * representing all the resources with the given name. Class loader 0N/A * implementations should override this method to specify where to load 0N/A * resources from. </p> 0N/A * @return An enumeration of {@link java.net.URL <tt>URL</tt>} objects for 0N/A * @throws IOException 0N/A * If I/O errors occur 1042N/A // index 0: java.lang.ClassLoader.class 1042N/A // index 1: the immediate caller of index 0. 1042N/A // index 2: the immediate caller of index 1. 1042N/A * Registers the caller class loader as parallel capable. 1042N/A * In order for the registration to succeed, all super classes 1042N/A * of the caller class loader must also be registered as 1042N/A * parallel capable when this method is called. </p> 1042N/A * Note that once a class loader is registered as 1042N/A * parallel capable, there is no way to change it back. 1042N/A * In addition, registration should be done statically before 1042N/A * any instance of the caller classloader being constructed. </p> 1042N/A * @return true if the caller is successfully registered as 1042N/A * parallel capable and false if otherwise. 0N/A * Find a resource of the specified name from the search path used to load 0N/A * classes. This method locates the resource through the system class 0N/A * loader (see {@link #getSystemClassLoader()}). </p> 0N/A * @return A {@link java.net.URL <tt>URL</tt>} object for reading the 0N/A * resource, or <tt>null</tt> if the resource could not be found 0N/A * Finds all resources of the specified name from the search path used to 0N/A * load classes. The resources thus found are returned as an 0N/A * {@link java.util.Enumeration <tt>Enumeration</tt>} of {@link 0N/A * java.net.URL <tt>URL</tt>} objects. 0N/A * <p> The search order is described in the documentation for {@link 0N/A * #getSystemResource(String)}. </p> 0N/A * @return An enumeration of resource {@link java.net.URL <tt>URL</tt>} 0N/A * @throws IOException 0N/A * If I/O errors occur 0N/A * Find resources from the VM's built-in classloader. 0N/A * Find resources from the VM's built-in classloader. 0N/A // Returns the URLClassPath that is used for finding system resources. 0N/A * Returns an input stream for reading the specified resource. 0N/A * <p> The search order is described in the documentation for {@link 0N/A * #getResource(String)}. </p> 0N/A * @return An input stream for reading the resource, or <tt>null</tt> 0N/A * if the resource could not be found 0N/A * Open for reading, a resource of the specified name from the search path 0N/A * used to load classes. This method locates the resource through the 0N/A * system class loader (see {@link #getSystemClassLoader()}). </p> 0N/A * @return An input stream for reading the resource, or <tt>null</tt> 0N/A * if the resource could not be found 0N/A * Returns the parent class loader for delegation. Some implementations may 0N/A * use <tt>null</tt> to represent the bootstrap class loader. This method 0N/A * will return <tt>null</tt> in such implementations if this class loader's 0N/A * parent is the bootstrap class loader. 0N/A * <p> If a security manager is present, and the invoker's class loader is 0N/A * not <tt>null</tt> and is not an ancestor of this class loader, then this 0N/A * method invokes the security manager's {@link 0N/A * SecurityManager#checkPermission(java.security.Permission) 0N/A * <tt>checkPermission</tt>} method with a {@link 0N/A * RuntimePermission#RuntimePermission(String) 0N/A * <tt>RuntimePermission("getClassLoader")</tt>} permission to verify 0N/A * access to the parent class loader is permitted. If not, a 0N/A * <tt>SecurityException</tt> will be thrown. </p> 0N/A * @return The parent <tt>ClassLoader</tt> 0N/A * @throws SecurityException 0N/A * If a security manager exists and its <tt>checkPermission</tt> 0N/A * method doesn't allow access to this class loader's parent class 0N/A * Returns the system class loader for delegation. This is the default 0N/A * delegation parent for new <tt>ClassLoader</tt> instances, and is 0N/A * typically the class loader used to start the application. 0N/A * <p> This method is first invoked early in the runtime's startup 0N/A * sequence, at which point it creates the system class loader and sets it 0N/A * as the context class loader of the invoking <tt>Thread</tt>. 0N/A * <p> The default system class loader is an implementation-dependent 0N/A * instance of this class. 0N/A * <p> If the system property "<tt>java.system.class.loader</tt>" is defined 0N/A * when this method is first invoked then the value of that property is 0N/A * taken to be the name of a class that will be returned as the system 0N/A * class loader. The class is loaded using the default system class loader 0N/A * and must define a public constructor that takes a single parameter of 0N/A * type <tt>ClassLoader</tt> which is used as the delegation parent. An 0N/A * instance is then created using this constructor with the default system 0N/A * class loader as the parameter. The resulting class loader is defined 0N/A * to be the system class loader. 0N/A * <p> If a security manager is present, and the invoker's class loader is 0N/A * not <tt>null</tt> and the invoker's class loader is not the same as or 0N/A * an ancestor of the system class loader, then this method invokes the 0N/A * security manager's {@link 0N/A * SecurityManager#checkPermission(java.security.Permission) 0N/A * <tt>checkPermission</tt>} method with a {@link 0N/A * RuntimePermission#RuntimePermission(String) 0N/A * <tt>RuntimePermission("getClassLoader")</tt>} permission to verify 0N/A * access to the system class loader. If not, a 0N/A * <tt>SecurityException</tt> will be thrown. </p> 0N/A * @return The system <tt>ClassLoader</tt> for delegation, or 0N/A * <tt>null</tt> if none 0N/A * @throws SecurityException 0N/A * If a security manager exists and its <tt>checkPermission</tt> 0N/A * method doesn't allow access to the system class loader. 0N/A * @throws IllegalStateException 0N/A * If invoked recursively during the construction of the class 0N/A * loader specified by the "<tt>java.system.class.loader</tt>" 0N/A * If the system property "<tt>java.system.class.loader</tt>" 0N/A * is defined but the named class could not be loaded, the 0N/A * provider class does not define the required constructor, or an 0N/A * exception is thrown by that constructor when it is invoked. The 0N/A * underlying cause of the error can be retrieved via the 0N/A * {@link Throwable#getCause()} method. 0N/A // wrap the exception 0N/A // Returns true if the specified class loader can be found in this class 0N/A // loader's delegation chain. 0N/A // Returns the invoker's class loader, or null if none. 0N/A // NOTE: This must always be invoked when there is exactly one intervening 0N/A // frame from the core libraries on the stack between this method's 0N/A // invocation and the desired invoker. 0N/A // NOTE use of more generic Reflection.getCallerClass() 0N/A // This can be null if the VM is requesting it 0N/A // Circumvent security check since this is package-private 0N/A // The class loader for the system 1042N/A // @GuardedBy("ClassLoader.class") 0N/A // Set to true once the system class loader has been set 1042N/A // @GuardedBy("ClassLoader.class") 0N/A * Defines a package by name in this <tt>ClassLoader</tt>. This allows 0N/A * class loaders to define the packages for their classes. Packages must 0N/A * be created before the class is defined, and package names must be 0N/A * unique within a class loader and cannot be redefined or changed once 0N/A * The specification title 0N/A * @param specVersion 0N/A * The specification version 0N/A * The specification vendor 0N/A * The implementation title 0N/A * @param implVersion 0N/A * The implementation version 0N/A * The implementation vendor 0N/A * If not <tt>null</tt>, then this package is sealed with 0N/A * respect to the given code source {@link java.net.URL 0N/A * <tt>URL</tt>} object. Otherwise, the package is not sealed. 0N/A * @return The newly defined <tt>Package</tt> object 0N/A * @throws IllegalArgumentException 0N/A * If package name duplicates an existing package either in this 0N/A * class loader or one of its ancestors 0N/A * Returns a <tt>Package</tt> that has been defined by this class loader 0N/A * or any of its ancestors. </p> 0N/A * @return The <tt>Package</tt> corresponding to the given name, or 0N/A * <tt>null</tt> if not found 0N/A * Returns all of the <tt>Packages</tt> defined by this class loader and 0N/A * its ancestors. </p> 0N/A * @return The array of <tt>Package</tt> objects defined by this 0N/A * <tt>ClassLoader</tt> 0N/A // -- Native library access -- 0N/A * Returns the absolute path name of a native library. The VM invokes this 0N/A * method to locate the native libraries that belong to classes loaded with 0N/A * this class loader. If this method returns <tt>null</tt>, the VM 0N/A * searches the library along the path specified as the 0N/A * "<tt>java.library.path</tt>" property. </p> 0N/A * @return The absolute path of the native library 0N/A * @see System#loadLibrary(String) 0N/A * @see System#mapLibraryName(String) 0N/A * The inner class NativeLibrary denotes a loaded native library instance. 0N/A * Every classloader contains a vector of loaded native libraries in the 0N/A * private field <tt>nativeLibraries</tt>. The native libraries loaded 0N/A * into the system are entered into the <tt>systemNativeLibraries</tt> 0N/A * <p> Every native library requires a particular version of JNI. This is 0N/A * denoted by the private <tt>jniVersion</tt> field. This field is set by 0N/A * the VM when it loads the library, and used by the VM to pass the correct 0N/A * version of JNI to the native methods. </p> 0N/A // opaque handle to native library, used in native code. 0N/A // the version of JNI environment the native library requires. 0N/A // the class from which the library is loaded, also indicates 0N/A // the loader this native library belongs. 0N/A // the canonicalized name of the native library. 0N/A /* remove the native library name */ 0N/A /* unload the library. */ 0N/A // Invoked in the VM to determine the context class in 0N/A // All native library names we've loaded. 0N/A // Native libraries belonging to system classes. 0N/A // Native libraries associated with the class loader. 0N/A // The paths searched for libraries 0N/A // Count the separators in the path 0N/A // allocate the array of paths - n :'s = n + 1 path elements 0N/A // Fill the array with paths from the ldpath 0N/A }
else if (j - i ==
0) {
0N/A // Invoked in the java.lang.Runtime class to implement load and loadLibrary. 0N/A "ClassLoader.findLibrary failed to return an absolute path: " +
libfilename);
0N/A (
"Native Library " +
0N/A " already loaded in another classloader");
0N/A /* If the library is being loaded (must be by the same thread, 0N/A * because Runtime.load and Runtime.loadLibrary are 0N/A * synchronous). The reason is can occur is that the JNI_OnLoad 0N/A * function can cause another loadLibrary invocation. 0N/A * Thus we can use a static stack to hold the list of libraries 0N/A * If there is a pending load operation for the library, we 0N/A * immediately return success; otherwise, we raise 0N/A * UnsatisfiedLinkError. 0N/A for (
int i =
0; i < n; i++) {
0N/A (
"Native Library " +
0N/A " is being loaded in another classloader");
0N/A // Invoked in the VM class linking code. 0N/A // -- Assertion management -- 0N/A // The default toggle for assertion checking. 1042N/A // @GuardedBy("assertionLock") 0N/A // Maps String packageName to Boolean package default assertion status Note 0N/A // that the default package is placed under a null map key. If this field 0N/A // is null then we are delegating assertion status queries to the VM, i.e., 0N/A // none of this ClassLoader's assertion status modification methods have 1042N/A // @GuardedBy("assertionLock") 0N/A // Maps String fullyQualifiedClassName to Boolean assertionStatus If this 0N/A // field is null then we are delegating assertion status queries to the VM, 0N/A // i.e., none of this ClassLoader's assertion status modification methods 0N/A // have been invoked. 1042N/A // @GuardedBy("assertionLock") 0N/A * Sets the default assertion status for this class loader. This setting 0N/A * determines whether classes loaded by this class loader and initialized 0N/A * in the future will have assertions enabled or disabled by default. 0N/A * This setting may be overridden on a per-package or per-class basis by 0N/A * invoking {@link #setPackageAssertionStatus(String, boolean)} or {@link 0N/A * #setClassAssertionStatus(String, boolean)}. </p> 0N/A * <tt>true</tt> if classes loaded by this class loader will 0N/A * henceforth have assertions enabled by default, <tt>false</tt> 0N/A * if they will have assertions disabled by default. 0N/A * Sets the package default assertion status for the named package. The 0N/A * package default assertion status determines the assertion status for 0N/A * classes initialized in the future that belong to the named package or 0N/A * any of its "subpackages". 0N/A * <p> A subpackage of a package named p is any package whose name begins 0N/A * with "<tt>p.</tt>". For example, <tt>javax.swing.text</tt> is a 0N/A * subpackage of <tt>javax.swing</tt>, and both <tt>java.util</tt> and 0N/A * <tt>java.lang.reflect</tt> are subpackages of <tt>java</tt>. 0N/A * <p> In the event that multiple package defaults apply to a given class, 0N/A * the package default pertaining to the most specific package takes 0N/A * precedence over the others. For example, if <tt>javax.lang</tt> and 0N/A * <tt>javax.lang.reflect</tt> both have package defaults associated with 0N/A * them, the latter package default applies to classes in 0N/A * <tt>javax.lang.reflect</tt>. 0N/A * <p> Package defaults take precedence over the class loader's default 0N/A * assertion status, and may be overridden on a per-class basis by invoking 0N/A * {@link #setClassAssertionStatus(String, boolean)}. </p> 0N/A * @param packageName 0N/A * The name of the package whose package default assertion status 0N/A * is to be set. A <tt>null</tt> value indicates the unnamed 0N/A * package that is "current" 0N/A * Specification</a>, section 7.4.2). 0N/A * <tt>true</tt> if classes loaded by this classloader and 0N/A * belonging to the named package or any of its subpackages will 0N/A * have assertions enabled by default, <tt>false</tt> if they will 0N/A * have assertions disabled by default. 0N/A * Sets the desired assertion status for the named top-level class in this 0N/A * class loader and any nested classes contained therein. This setting 0N/A * takes precedence over the class loader's default assertion status, and 0N/A * over any applicable per-package default. This method has no effect if 0N/A * the named class has already been initialized. (Once a class is 0N/A * initialized, its assertion status cannot change.) 0N/A * <p> If the named class is not a top-level class, this invocation will 0N/A * have no effect on the actual assertion status of any class. </p> 0N/A * The fully qualified class name of the top-level class whose 0N/A * assertion status is to be set. 0N/A * <tt>true</tt> if the named class is to have assertions 0N/A * enabled when (and if) it is initialized, <tt>false</tt> if the 0N/A * class is to have assertions disabled. 0N/A * Sets the default assertion status for this class loader to 0N/A * <tt>false</tt> and discards any package defaults or class assertion 0N/A * status settings associated with the class loader. This method is 0N/A * provided so that class loaders can be made to ignore any command line or 0N/A * persistent assertion status settings and "start with a clean slate." 0N/A * Whether or not "Java assertion maps" are initialized, set 0N/A * them to empty maps, effectively ignoring any present settings. 0N/A * Returns the assertion status that would be assigned to the specified 0N/A * class if it were to be initialized at the time this method is invoked. 0N/A * If the named class has had its assertion status set, the most recent 0N/A * setting will be returned; otherwise, if any package default assertion 0N/A * status pertains to this class, the most recent setting for the most 0N/A * specific pertinent package default assertion status is returned; 0N/A * otherwise, this class loader's default assertion status is returned. 0N/A * The fully qualified class name of the class whose desired 0N/A * assertion status is being queried. 0N/A * @return The desired assertion status of the specified class. 0N/A * @see #setClassAssertionStatus(String, boolean) 0N/A * @see #setPackageAssertionStatus(String, boolean) 0N/A * @see #setDefaultAssertionStatus(boolean) 1042N/A // assert classAssertionStatus != null; 1042N/A // assert packageAssertionStatus != null; 1042N/A // Check for most specific package entry 1042N/A // Return the classloader default 0N/A // Set up the assertions with information provided by the VM. 1042N/A // Note: Should only be called inside a synchronized block 1042N/A // assert Thread.holdsLock(assertionLock); 0N/A // Retrieves the assertion directives from the VM.