| /* |
| * 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. |
| */ |
| /* |
| * Copyright (C) 2008 The Android Open Source Project |
| * |
| * 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 java.lang; |
| |
| import dalvik.system.VMStack; |
| import java.io.Console; |
| import java.io.FileDescriptor; |
| import java.io.FileInputStream; |
| import java.io.FileOutputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.PrintStream; |
| import java.nio.channels.Channel; |
| import java.nio.channels.spi.SelectorProvider; |
| import java.util.AbstractMap; |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.Map; |
| import java.util.Properties; |
| import java.util.PropertyPermission; |
| import java.util.Set; |
| |
| /** |
| * Provides access to system-related information and resources including |
| * standard input and output. Enables clients to dynamically load native |
| * libraries. All methods of this class are accessed in a static way and the |
| * class itself can not be instantiated. |
| * |
| * @see Runtime |
| */ |
| public final class System { |
| |
| /** |
| * Default input stream. |
| */ |
| public static final InputStream in; |
| |
| /** |
| * Default output stream. |
| */ |
| public static final PrintStream out; |
| |
| /** |
| * Default error output stream. |
| */ |
| public static final PrintStream err; |
| |
| /** |
| * The System Properties table. |
| */ |
| private static Properties systemProperties; |
| |
| /** |
| * Initialize all the slots in System on first use. |
| */ |
| static { |
| /* |
| * Set up standard in, out, and err. TODO err and out are |
| * String.ConsolePrintStream. All three are buffered in Harmony. Check |
| * and possibly change this later. |
| */ |
| err = new PrintStream(new FileOutputStream(FileDescriptor.err)); |
| out = new PrintStream(new FileOutputStream(FileDescriptor.out)); |
| in = new FileInputStream(FileDescriptor.in); |
| } |
| |
| /** |
| * Sets the standard input stream to the given user defined input stream. |
| * |
| * @param newIn |
| * the user defined input stream to set as the standard input |
| * stream. |
| * @throws SecurityException |
| * if a {@link SecurityManager} is installed and its {@code |
| * checkPermission()} method does not allow the change of the |
| * stream. |
| */ |
| public static void setIn(InputStream newIn) { |
| SecurityManager secMgr = System.getSecurityManager(); |
| if(secMgr != null) { |
| secMgr.checkPermission(RuntimePermission.permissionToSetIO); |
| } |
| setFieldImpl("in", "Ljava/io/InputStream;", newIn); |
| } |
| |
| /** |
| * Sets the standard output stream to the given user defined output stream. |
| * |
| * @param newOut |
| * the user defined output stream to set as the standard output |
| * stream. |
| * @throws SecurityException |
| * if a {@link SecurityManager} is installed and its {@code |
| * checkPermission()} method does not allow the change of the |
| * stream. |
| */ |
| public static void setOut(java.io.PrintStream newOut) { |
| SecurityManager secMgr = System.getSecurityManager(); |
| if(secMgr != null) { |
| secMgr.checkPermission(RuntimePermission.permissionToSetIO); |
| } |
| setFieldImpl("out", "Ljava/io/PrintStream;", newOut); |
| } |
| |
| /** |
| * Sets the standard error output stream to the given user defined output |
| * stream. |
| * |
| * @param newErr |
| * the user defined output stream to set as the standard error |
| * output stream. |
| * @throws SecurityException |
| * if a {@link SecurityManager} is installed and its {@code |
| * checkPermission()} method does not allow the change of the |
| * stream. |
| */ |
| public static void setErr(java.io.PrintStream newErr) { |
| SecurityManager secMgr = System.getSecurityManager(); |
| if(secMgr != null) { |
| secMgr.checkPermission(RuntimePermission.permissionToSetIO); |
| } |
| setFieldImpl("err", "Ljava/io/PrintStream;", newErr); |
| } |
| |
| /** |
| * Prevents this class from being instantiated. |
| */ |
| private System() { |
| } |
| |
| /** |
| * Copies {@code length} elements from the array {@code src}, |
| * starting at offset {@code srcPos}, into the array {@code dst}, |
| * starting at offset {@code dstPos}. |
| * |
| * @param src |
| * the source array to copy the content. |
| * @param srcPos |
| * the starting index of the content in {@code src}. |
| * @param dst |
| * the destination array to copy the data into. |
| * @param dstPos |
| * the starting index for the copied content in {@code dst}. |
| * @param length |
| * the number of elements to be copied. |
| */ |
| public static native void arraycopy(Object src, int srcPos, Object dst, int dstPos, int length); |
| |
| /** |
| * Returns the current system time in milliseconds since January 1, 1970 |
| * 00:00:00 UTC. This method shouldn't be used for measuring timeouts or |
| * other elapsed time measurements, as changing the system time can affect |
| * the results. |
| * |
| * @return the local system time in milliseconds. |
| */ |
| public static native long currentTimeMillis(); |
| |
| /** |
| * Returns the current timestamp of the most precise timer available on the |
| * local system. This timestamp can only be used to measure an elapsed |
| * period by comparing it against another timestamp. It cannot be used as a |
| * very exact system time expression. |
| * |
| * @return the current timestamp in nanoseconds. |
| */ |
| public static native long nanoTime(); |
| |
| /** |
| * Causes the virtual machine to stop running and the program to exit. If |
| * {@link #runFinalizersOnExit(boolean)} has been previously invoked with a |
| * {@code true} argument, then all objects will be properly |
| * garbage-collected and finalized first. |
| * |
| * @param code |
| * the return code. |
| * @throws SecurityException |
| * if the running thread has not enough permission to exit the |
| * virtual machine. |
| * @see SecurityManager#checkExit |
| */ |
| public static void exit(int code) { |
| Runtime.getRuntime().exit(code); |
| } |
| |
| /** |
| * Indicates to the virtual machine that it would be a good time to run the |
| * garbage collector. Note that this is a hint only. There is no guarantee |
| * that the garbage collector will actually be run. |
| */ |
| public static void gc() { |
| Runtime.getRuntime().gc(); |
| } |
| |
| /** |
| * Returns the value of the environment variable with the given name {@code |
| * var}. |
| * |
| * @param name |
| * the name of the environment variable. |
| * @return the value of the specified environment variable or {@code null} |
| * if no variable exists with the given name. |
| * @throws SecurityException |
| * if a {@link SecurityManager} is installed and its {@code |
| * checkPermission()} method does not allow the querying of |
| * single environment variables. |
| */ |
| public static String getenv(String name) { |
| if (name == null) { |
| throw new NullPointerException(); |
| } |
| SecurityManager secMgr = System.getSecurityManager(); |
| if (secMgr != null) { |
| secMgr.checkPermission(new RuntimePermission("getenv." + name)); |
| } |
| |
| return getEnvByName(name); |
| } |
| |
| /* |
| * Returns an environment variable. No security checks are performed. |
| * @param var the name of the environment variable |
| * @return the value of the specified environment variable |
| */ |
| private static native String getEnvByName(String name); |
| |
| /** |
| * Returns an unmodifiable map of all available environment variables. |
| * |
| * @return the map representing all environment variables. |
| * @throws SecurityException |
| * if a {@link SecurityManager} is installed and its {@code |
| * checkPermission()} method does not allow the querying of |
| * all environment variables. |
| */ |
| public static Map<String, String> getenv() { |
| SecurityManager secMgr = System.getSecurityManager(); |
| if (secMgr != null) { |
| secMgr.checkPermission(new RuntimePermission("getenv.*")); |
| } |
| |
| Map<String, String> map = new HashMap<String, String>(); |
| |
| int index = 0; |
| String entry = getEnvByIndex(index++); |
| while (entry != null) { |
| int pos = entry.indexOf('='); |
| if (pos != -1) { |
| map.put(entry.substring(0, pos), entry.substring(pos + 1)); |
| } |
| |
| entry = getEnvByIndex(index++); |
| } |
| |
| return new SystemEnvironment(map); |
| } |
| |
| /* |
| * Returns an environment variable. No security checks are performed. The |
| * safe way of traversing the environment is to start at index zero and |
| * count upwards until a null pointer is encountered. This marks the end of |
| * the Unix environment. |
| * @param index the index of the environment variable |
| * @return the value of the specified environment variable |
| */ |
| private static native String getEnvByIndex(int index); |
| |
| /** |
| * Returns the inherited channel from the creator of the current virtual |
| * machine. |
| * |
| * @return the inherited {@link Channel} or {@code null} if none exists. |
| * @throws IOException |
| * if an I/O error occurred. |
| * @see SelectorProvider |
| * @see SelectorProvider#inheritedChannel() |
| */ |
| public static Channel inheritedChannel() throws IOException { |
| return SelectorProvider.provider().inheritedChannel(); |
| } |
| |
| /** |
| * Returns the system properties. Note that this is not a copy, so that |
| * changes made to the returned Properties object will be reflected in |
| * subsequent calls to getProperty and getProperties. |
| * |
| * @return the system properties. |
| * @throws SecurityException |
| * if a {@link SecurityManager} is installed and its {@code |
| * checkPropertiesAccess()} method does not allow the operation. |
| */ |
| public static Properties getProperties() { |
| SecurityManager secMgr = System.getSecurityManager(); |
| if (secMgr != null) { |
| secMgr.checkPropertiesAccess(); |
| } |
| |
| return internalGetProperties(); |
| } |
| |
| /** |
| * Returns the system properties without any security checks. This is used |
| * for access from within java.lang. |
| * |
| * @return the system properties |
| */ |
| static Properties internalGetProperties() { |
| if (System.systemProperties == null) { |
| SystemProperties props = new SystemProperties(); |
| props.preInit(); |
| props.postInit(); |
| System.systemProperties = props; |
| } |
| |
| return systemProperties; |
| } |
| |
| /** |
| * Returns the value of a particular system property or {@code null} if no |
| * such property exists. |
| * |
| * <p>The following properties are always provided by the virtual machine: |
| * <p><table BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY=""> |
| * <tr BGCOLOR="#CCCCFF" CLASS="TableHeadingColor"> |
| * <td><b>Name</b></td> <td><b>Meaning</b></td> <td><b>Example</b></td></tr> |
| * <tr><td>file.separator</td> <td>{@link java.io.File#separator}</td> <td>{@code /}</td></tr> |
| * |
| * <tr><td>java.class.path</td> <td>System class path</td> <td>{@code .}</td></tr> |
| * <tr><td>java.class.version</td> <td>Maximum supported .class file version</td> <td>{@code 46.0}</td></tr> |
| * <tr><td>java.compiler</td> <td>(Not useful on Android)</td> <td>Empty</td></tr> |
| * <tr><td>java.ext.dirs</td> <td>(Not useful on Android)</td> <td>Empty</td></tr> |
| * <tr><td>java.home</td> <td>Location of the VM on the file system</td> <td>{@code /system}</td></tr> |
| * <tr><td>java.io.tmpdir</td> <td>See {@link java.io.File#createTempFile}</td> <td>{@code /sdcard}</td></tr> |
| * <tr><td>java.library.path</td> <td>Search path for JNI libraries</td> <td>{@code /system/lib}</td></tr> |
| * <tr><td>java.vendor</td> <td>Human-readable VM vendor</td> <td>{@code The Android Project}</td></tr> |
| * <tr><td>java.vendor.url</td> <td>URL for VM vendor's web site</td> <td>{@code http://www.android.com/}</td></tr> |
| * <tr><td>java.version</td> <td>(Not useful on Android)</td> <td>{@code 0}</td></tr> |
| * |
| * <tr><td>java.specification.version</td> <td>VM libraries version</td> <td>{@code 0.9}</td></tr> |
| * <tr><td>java.specification.vendor</td> <td>VM libraries vendor</td> <td>{@code The Android Project}</td></tr> |
| * <tr><td>java.specification.name</td> <td>VM libraries name</td> <td>{@code Dalvik Core Library}</td></tr> |
| * <tr><td>java.vm.version</td> <td>VM implementation version</td> <td>{@code 1.2.0}</td></tr> |
| * <tr><td>java.vm.vendor</td> <td>VM implementation vendor</td> <td>{@code The Android Project}</td></tr> |
| * <tr><td>java.vm.name</td> <td>VM implementation name</td> <td>{@code Dalvik}</td></tr> |
| * <tr><td>java.vm.specification.version</td> <td>VM specification version</td> <td>{@code 0.9}</td></tr> |
| * <tr><td>java.vm.specification.vendor</td> <td>VM specification vendor</td> <td>{@code The Android Project}</td></tr> |
| * <tr><td>java.vm.specification.name</td> <td>VM specification name</td> <td>{@code Dalvik Virtual Machine Specification}</td></tr> |
| * |
| * <tr><td>line.separator</td> <td>Default line separator</td> <td>{@code \n}</td></tr> |
| * |
| * <tr><td>os.arch</td> <td>OS architecture</td> <td>{@code armv7l}</td></tr> |
| * <tr><td>os.name</td> <td>OS (kernel) name</td> <td>{@code Linux}</td></tr> |
| * <tr><td>os.version</td> <td>OS (kernel) version</td> <td>{@code 2.6.32.9-g103d848}</td></tr> |
| * |
| * <tr><td>path.separator</td> <td>{@link java.io.File#pathSeparator}</td> <td>{@code :}</td></tr> |
| * |
| * <tr><td>user.dir</td> <td>Base of non-absolute paths</td> <td>{@code /}</td></tr> |
| * <tr><td>user.home</td> <td>(Not useful on Android)</td> <td>Empty</td></tr> |
| * <tr><td>user.name</td> <td>(Not useful on Android)</td> <td>Empty</td></tr> |
| * |
| * </table> |
| * |
| * @param propertyName |
| * the name of the system property to look up. |
| * @return the value of the specified system property or {@code null} if the |
| * property doesn't exist. |
| * @throws SecurityException |
| * if a {@link SecurityManager} is installed and its {@code |
| * checkPropertyAccess()} method does not allow the operation. |
| */ |
| public static String getProperty(String propertyName) { |
| return getProperty(propertyName, null); |
| } |
| |
| /** |
| * Returns the value of a particular system property. The {@code |
| * defaultValue} will be returned if no such property has been found. |
| * |
| * @param prop |
| * the name of the system property to look up. |
| * @param defaultValue |
| * the return value if the system property with the given name |
| * does not exist. |
| * @return the value of the specified system property or the {@code |
| * defaultValue} if the property does not exist. |
| * @throws SecurityException |
| * if a {@link SecurityManager} is installed and its {@code |
| * checkPropertyAccess()} method does not allow the operation. |
| */ |
| public static String getProperty(String prop, String defaultValue) { |
| if (prop.length() == 0) { |
| throw new IllegalArgumentException(); |
| } |
| SecurityManager secMgr = System.getSecurityManager(); |
| if (secMgr != null) { |
| secMgr.checkPropertyAccess(prop); |
| } |
| |
| return internalGetProperties().getProperty(prop, defaultValue); |
| } |
| |
| /** |
| * Sets the value of a particular system property. |
| * |
| * @param prop |
| * the name of the system property to be changed. |
| * @param value |
| * the value to associate with the given property {@code prop}. |
| * @return the old value of the property or {@code null} if the property |
| * didn't exist. |
| * @throws SecurityException |
| * if a security manager exists and write access to the |
| * specified property is not allowed. |
| */ |
| public static String setProperty(String prop, String value) { |
| if (prop.length() == 0) { |
| throw new IllegalArgumentException(); |
| } |
| SecurityManager secMgr = System.getSecurityManager(); |
| if (secMgr != null) { |
| secMgr.checkPermission(new PropertyPermission(prop, "write")); |
| } |
| return (String)internalGetProperties().setProperty(prop, value); |
| } |
| |
| /** |
| * Removes a specific system property. |
| * |
| * @param key |
| * the name of the system property to be removed. |
| * @return the property value or {@code null} if the property didn't exist. |
| * @throws NullPointerException |
| * if the argument {@code key} is {@code null}. |
| * @throws IllegalArgumentException |
| * if the argument {@code key} is empty. |
| * @throws SecurityException |
| * if a security manager exists and write access to the |
| * specified property is not allowed. |
| */ |
| public static String clearProperty(String key) { |
| if (key == null) { |
| throw new NullPointerException(); |
| } |
| if (key.length() == 0) { |
| throw new IllegalArgumentException(); |
| } |
| |
| SecurityManager secMgr = System.getSecurityManager(); |
| if (secMgr != null) { |
| secMgr.checkPermission(new PropertyPermission(key, "write")); |
| } |
| return (String)internalGetProperties().remove(key); |
| } |
| |
| /** |
| * Returns the {@link java.io.Console} associated with this VM, or null. |
| * Not all VMs will have an associated console. A console is typically only |
| * available for programs run from the command line. |
| * @since 1.6 |
| */ |
| public static Console console() { |
| return Console.getConsole(); |
| } |
| |
| /** |
| * Returns null. Android does not use {@code SecurityManager}. This method |
| * is only provided for source compatibility. |
| * |
| * @return null |
| */ |
| public static SecurityManager getSecurityManager() { |
| return null; |
| } |
| |
| /** |
| * Returns an integer hash code for the parameter. The hash code returned is |
| * the same one that would be returned by the method {@code |
| * java.lang.Object.hashCode()}, whether or not the object's class has |
| * overridden hashCode(). The hash code for {@code null} is {@code 0}. |
| * |
| * @param anObject |
| * the object to calculate the hash code. |
| * @return the hash code for the given object. |
| * @see java.lang.Object#hashCode |
| */ |
| public static native int identityHashCode(Object anObject); |
| |
| /** |
| * Loads and links the dynamic library that is identified through the |
| * specified path. This method is similar to {@link #loadLibrary(String)}, |
| * but it accepts a full path specification whereas {@code loadLibrary} just |
| * accepts the name of the library to load. |
| * |
| * @param pathName |
| * the path of the file to be loaded. |
| * @throws SecurityException |
| * if the library was not allowed to be loaded. |
| */ |
| public static void load(String pathName) { |
| SecurityManager smngr = System.getSecurityManager(); |
| if (smngr != null) { |
| smngr.checkLink(pathName); |
| } |
| Runtime.getRuntime().load(pathName, VMStack.getCallingClassLoader()); |
| } |
| |
| /** |
| * Loads and links the library with the specified name. The mapping of the |
| * specified library name to the full path for loading the library is |
| * implementation-dependent. |
| * |
| * @param libName |
| * the name of the library to load. |
| * @throws UnsatisfiedLinkError |
| * if the library could not be loaded. |
| * @throws SecurityException |
| * if the library was not allowed to be loaded. |
| */ |
| public static void loadLibrary(String libName) { |
| SecurityManager smngr = System.getSecurityManager(); |
| if (smngr != null) { |
| smngr.checkLink(libName); |
| } |
| Runtime.getRuntime().loadLibrary(libName, VMStack.getCallingClassLoader()); |
| } |
| |
| /** |
| * Provides a hint to the virtual machine that it would be useful to attempt |
| * to perform any outstanding object finalization. |
| */ |
| public static void runFinalization() { |
| Runtime.getRuntime().runFinalization(); |
| } |
| |
| /** |
| * Ensures that, when the virtual machine is about to exit, all objects are |
| * finalized. Note that all finalization which occurs when the system is |
| * exiting is performed after all running threads have been terminated. |
| * |
| * @param flag |
| * the flag determines if finalization on exit is enabled. |
| * @deprecated this method is unsafe. |
| */ |
| @SuppressWarnings("deprecation") |
| @Deprecated |
| public static void runFinalizersOnExit(boolean flag) { |
| Runtime.runFinalizersOnExit(flag); |
| } |
| |
| /** |
| * Sets all system properties. |
| * |
| * @param p |
| * the new system property. |
| * @throws SecurityException |
| * if a {@link SecurityManager} is installed and its {@code |
| * checkPropertiesAccess()} method does not allow the operation. |
| */ |
| public static void setProperties(Properties p) { |
| SecurityManager secMgr = System.getSecurityManager(); |
| if (secMgr != null) { |
| secMgr.checkPropertiesAccess(); |
| } |
| |
| systemProperties = p; |
| } |
| |
| /** |
| * Throws {@code SecurityException}. |
| * |
| * <p>Security managers do <i>not</i> provide a secure environment for |
| * executing untrusted code and are unsupported on Android. Untrusted code |
| * cannot be safely isolated within a single VM on Android. |
| * |
| * @param sm a security manager |
| * @throws SecurityException always |
| */ |
| public static void setSecurityManager(SecurityManager sm) { |
| if (sm != null) { |
| throw new SecurityException(); |
| } |
| } |
| |
| /** |
| * Returns the platform specific file name format for the shared library |
| * named by the argument. |
| * |
| * @param userLibName |
| * the name of the library to look up. |
| * @return the platform specific filename for the library. |
| */ |
| public static native String mapLibraryName(String userLibName); |
| |
| /** |
| * Sets the value of the named static field in the receiver to the passed in |
| * argument. |
| * |
| * @param fieldName |
| * the name of the field to set, one of in, out, or err |
| * @param stream |
| * the new value of the field |
| */ |
| private static native void setFieldImpl(String fieldName, String signature, Object stream); |
| |
| |
| /** |
| * The unmodifiable environment variables map. The System.getenv() specifies |
| * that this map must throw when queried with non-String keys values. |
| */ |
| static class SystemEnvironment extends AbstractMap<String, String> { |
| private final Map<String, String> map; |
| |
| public SystemEnvironment(Map<String, String> map) { |
| this.map = Collections.unmodifiableMap(map); |
| } |
| |
| @Override public Set<Entry<String, String>> entrySet() { |
| return map.entrySet(); |
| } |
| |
| @Override public String get(Object key) { |
| return map.get(toNonNullString(key)); |
| } |
| |
| @Override public boolean containsKey(Object key) { |
| return map.containsKey(toNonNullString(key)); |
| } |
| |
| @Override public boolean containsValue(Object value) { |
| return map.containsValue(toNonNullString(value)); |
| } |
| |
| private String toNonNullString(Object o) { |
| if (o == null) { |
| throw new NullPointerException(); |
| } |
| return (String) o; |
| } |
| } |
| } |
| |
| /** |
| * Internal class holding the System properties. Needed by the Dalvik VM for the |
| * two native methods. Must not be a local class, since we don't have a System |
| * instance. |
| */ |
| class SystemProperties extends Properties { |
| // Dummy, just to make the compiler happy. |
| |
| native void preInit(); |
| |
| native void postInit(); |
| } |
