19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package jdk.internal.loader;
27
28 import java.io.IOException;
29 import java.net.URL;
30 import java.nio.file.InvalidPathException;
31 import java.nio.file.Path;
32 import java.security.CodeSource;
33 import java.security.PermissionCollection;
34 import java.util.jar.Manifest;
35
36 import jdk.internal.access.JavaLangAccess;
37 import jdk.internal.access.SharedSecrets;
38 import jdk.internal.misc.VM;
39
40 /**
41 * Creates and provides access to the built-in platform and application class
42 * loaders. It also creates the class loader that is used to locate resources
43 * in modules defined to the boot class loader.
44 */
45
46 public class ClassLoaders {
47
48 private ClassLoaders() { }
49
50 private static final JavaLangAccess JLA = SharedSecrets.getJavaLangAccess();
51
52 // the built-in class loaders
53 private static final BootClassLoader BOOT_LOADER;
54 private static final PlatformClassLoader PLATFORM_LOADER;
55 private static final AppClassLoader APP_LOADER;
56
57 // Creates the built-in class loaders.
58 static {
59 // -Xbootclasspath/a or -javaagent with Boot-Class-Path attribute
60 String append = VM.getSavedProperty("jdk.boot.class.path.append");
61 BOOT_LOADER =
62 new BootClassLoader((append != null && !append.isEmpty())
63 ? new URLClassPath(append, true)
64 : null);
65 PLATFORM_LOADER = new PlatformClassLoader(BOOT_LOADER);
66
67 // A class path is required when no initial module is specified.
68 // In this case the class path defaults to "", meaning the current
69 // working directory. When an initial module is specified, on the
70 // contrary, we drop this historic interpretation of the empty
71 // string and instead treat it as unspecified.
72 String cp = System.getProperty("java.class.path");
73 if (cp == null || cp.isEmpty()) {
74 String initialModuleName = System.getProperty("jdk.module.main");
75 cp = (initialModuleName == null) ? "" : null;
76 }
77 URLClassPath ucp = new URLClassPath(cp, false);
78 APP_LOADER = new AppClassLoader(PLATFORM_LOADER, ucp);
79 }
80
81 /**
82 * Returns the class loader that is used to find resources in modules
83 * defined to the boot class loader.
84 *
85 * @apiNote This method is not public, it should instead be used via
86 * the BootLoader class that provides a restricted API to this class
87 * loader.
88 */
89 static BuiltinClassLoader bootLoader() {
90 return BOOT_LOADER;
91 }
92
93 /**
94 * Returns the platform class loader.
95 */
96 public static ClassLoader platformClassLoader() {
97 return PLATFORM_LOADER;
98 }
127 static {
128 if (!ClassLoader.registerAsParallelCapable())
129 throw new InternalError();
130 }
131
132 PlatformClassLoader(BootClassLoader parent) {
133 super("platform", parent, null);
134 }
135 }
136
137 /**
138 * The application class loader that is a {@code BuiltinClassLoader} with
139 * customizations to be compatible with long standing behavior.
140 */
141 private static class AppClassLoader extends BuiltinClassLoader {
142 static {
143 if (!ClassLoader.registerAsParallelCapable())
144 throw new InternalError();
145 }
146
147 final URLClassPath ucp;
148
149 AppClassLoader(PlatformClassLoader parent, URLClassPath ucp) {
150 super("app", parent, ucp);
151 this.ucp = ucp;
152 }
153
154 @Override
155 protected Class<?> loadClass(String cn, boolean resolve)
156 throws ClassNotFoundException
157 {
158 // for compatibility reasons, say where restricted package list has
159 // been updated to list API packages in the unnamed module.
160 SecurityManager sm = System.getSecurityManager();
161 if (sm != null) {
162 int i = cn.lastIndexOf('.');
163 if (i != -1) {
164 sm.checkPackageAccess(cn.substring(0, i));
165 }
166 }
167
168 return super.loadClass(cn, resolve);
169 }
170
171 @Override
172 protected PermissionCollection getPermissions(CodeSource cs) {
173 PermissionCollection perms = super.getPermissions(cs);
174 perms.add(new RuntimePermission("exitVM"));
175 return perms;
176 }
177
178 /**
179 * Called by the VM to support dynamic additions to the class path
180 *
181 * @see java.lang.instrument.Instrumentation#appendToSystemClassLoaderSearch
182 */
183 void appendToClassPathForInstrumentation(String path) {
184 ucp.addFile(path);
185 }
186
187 /**
188 * Called by the VM to support define package for AppCDS
189 */
190 protected Package defineOrCheckPackage(String pn, Manifest man, URL url) {
191 return super.defineOrCheckPackage(pn, man, url);
192 }
193 }
194
195 /**
196 * Attempts to convert the given string to a file URL.
197 *
198 * @apiNote This is called by the VM
199 */
200 @Deprecated
201 private static URL toFileURL(String s) {
202 try {
203 // Use an intermediate File object to construct a URI/URL without
204 // authority component as URLClassPath can't handle URLs with a UNC
205 // server name in the authority component.
206 return Path.of(s).toRealPath().toFile().toURI().toURL();
207 } catch (InvalidPathException | IOException ignore) {
208 // malformed path string or class path element does not exist
209 return null;
210 }
211 }
|
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package jdk.internal.loader;
27
28 import java.io.IOException;
29 import java.net.URL;
30 import java.nio.file.InvalidPathException;
31 import java.nio.file.Path;
32 import java.security.CodeSource;
33 import java.security.PermissionCollection;
34 import java.util.jar.Manifest;
35
36 import jdk.internal.access.JavaLangAccess;
37 import jdk.internal.access.SharedSecrets;
38 import jdk.internal.misc.VM;
39 import jdk.internal.module.ServicesCatalog;
40
41 /**
42 * Creates and provides access to the built-in platform and application class
43 * loaders. It also creates the class loader that is used to locate resources
44 * in modules defined to the boot class loader.
45 */
46
47 public class ClassLoaders {
48
49 private ClassLoaders() { }
50
51 private static final JavaLangAccess JLA = SharedSecrets.getJavaLangAccess();
52
53 // the built-in class loaders
54 private static final BootClassLoader BOOT_LOADER;
55 private static final PlatformClassLoader PLATFORM_LOADER;
56 private static final AppClassLoader APP_LOADER;
57
58 // Creates the built-in class loaders.
59 static {
60 ArchivedClassLoaders archivedClassLoaders = ArchivedClassLoaders.get();
61 if (archivedClassLoaders != null) {
62 // assert VM.getSavedProperty("jdk.boot.class.path.append") == null
63 BOOT_LOADER = (BootClassLoader) archivedClassLoaders.bootLoader();
64 PLATFORM_LOADER = (PlatformClassLoader) archivedClassLoaders.platformLoader();
65 ServicesCatalog catalog = archivedClassLoaders.servicesCatalog(PLATFORM_LOADER);
66 ServicesCatalog.putServicesCatalog(PLATFORM_LOADER, catalog);
67 } else {
68 // -Xbootclasspath/a or -javaagent with Boot-Class-Path attribute
69 String append = VM.getSavedProperty("jdk.boot.class.path.append");
70 URLClassPath ucp = (append != null && !append.isEmpty())
71 ? new URLClassPath(append, true)
72 : null;
73 BOOT_LOADER = new BootClassLoader(ucp);
74 PLATFORM_LOADER = new PlatformClassLoader(BOOT_LOADER);
75 }
76 // A class path is required when no initial module is specified.
77 // In this case the class path defaults to "", meaning the current
78 // working directory. When an initial module is specified, on the
79 // contrary, we drop this historic interpretation of the empty
80 // string and instead treat it as unspecified.
81 String cp = System.getProperty("java.class.path");
82 if (cp == null || cp.isEmpty()) {
83 String initialModuleName = System.getProperty("jdk.module.main");
84 cp = (initialModuleName == null) ? "" : null;
85 }
86 URLClassPath ucp = new URLClassPath(cp, false);
87 if (archivedClassLoaders != null) {
88 APP_LOADER = (AppClassLoader) archivedClassLoaders.appLoader();
89 ServicesCatalog catalog = archivedClassLoaders.servicesCatalog(APP_LOADER);
90 ServicesCatalog.putServicesCatalog(APP_LOADER, catalog);
91 APP_LOADER.setClassPath(ucp);
92 } else {
93 APP_LOADER = new AppClassLoader(PLATFORM_LOADER, ucp);
94 ArchivedClassLoaders.archive();
95 }
96 }
97
98 /**
99 * Returns the class loader that is used to find resources in modules
100 * defined to the boot class loader.
101 *
102 * @apiNote This method is not public, it should instead be used via
103 * the BootLoader class that provides a restricted API to this class
104 * loader.
105 */
106 static BuiltinClassLoader bootLoader() {
107 return BOOT_LOADER;
108 }
109
110 /**
111 * Returns the platform class loader.
112 */
113 public static ClassLoader platformClassLoader() {
114 return PLATFORM_LOADER;
115 }
144 static {
145 if (!ClassLoader.registerAsParallelCapable())
146 throw new InternalError();
147 }
148
149 PlatformClassLoader(BootClassLoader parent) {
150 super("platform", parent, null);
151 }
152 }
153
154 /**
155 * The application class loader that is a {@code BuiltinClassLoader} with
156 * customizations to be compatible with long standing behavior.
157 */
158 private static class AppClassLoader extends BuiltinClassLoader {
159 static {
160 if (!ClassLoader.registerAsParallelCapable())
161 throw new InternalError();
162 }
163
164 AppClassLoader(BuiltinClassLoader parent, URLClassPath ucp) {
165 super("app", parent, ucp);
166 }
167
168 @Override
169 protected Class<?> loadClass(String cn, boolean resolve)
170 throws ClassNotFoundException
171 {
172 // for compatibility reasons, say where restricted package list has
173 // been updated to list API packages in the unnamed module.
174 SecurityManager sm = System.getSecurityManager();
175 if (sm != null) {
176 int i = cn.lastIndexOf('.');
177 if (i != -1) {
178 sm.checkPackageAccess(cn.substring(0, i));
179 }
180 }
181
182 return super.loadClass(cn, resolve);
183 }
184
185 @Override
186 protected PermissionCollection getPermissions(CodeSource cs) {
187 PermissionCollection perms = super.getPermissions(cs);
188 perms.add(new RuntimePermission("exitVM"));
189 return perms;
190 }
191
192 /**
193 * Called by the VM to support dynamic additions to the class path
194 *
195 * @see java.lang.instrument.Instrumentation#appendToSystemClassLoaderSearch
196 */
197 void appendToClassPathForInstrumentation(String path) {
198 appendClassPath(path);
199 }
200
201 /**
202 * Called by the VM to support define package for AppCDS
203 */
204 protected Package defineOrCheckPackage(String pn, Manifest man, URL url) {
205 return super.defineOrCheckPackage(pn, man, url);
206 }
207
208 /**
209 * Called by the VM, during -Xshare:dump
210 */
211 private void resetArchivedStates() {
212 setClassPath(null);
213 }
214 }
215
216 /**
217 * Attempts to convert the given string to a file URL.
218 *
219 * @apiNote This is called by the VM
220 */
221 @Deprecated
222 private static URL toFileURL(String s) {
223 try {
224 // Use an intermediate File object to construct a URI/URL without
225 // authority component as URLClassPath can't handle URLs with a UNC
226 // server name in the authority component.
227 return Path.of(s).toRealPath().toFile().toURI().toURL();
228 } catch (InvalidPathException | IOException ignore) {
229 // malformed path string or class path element does not exist
230 return null;
231 }
232 }
|