Class System

classpath/java/lang/System.java:24–166

import java.util.Properties;

public abstract class System {
  private static final long NanoTimeBaseInMillis = currentTimeMillis();
  
  private static class Static {
    public static Properties properties = makeProperties();
  }

  private static Map<String, String> environment;
  
  private static SecurityManager securityManager;
  //   static {
  //     loadLibrary("natives");
  //   }

  public static final PrintStream out = new PrintStream
    (new BufferedOutputStream(new FileOutputStream(FileDescriptor.out)), true);

  public static final PrintStream err = new PrintStream
    (new BufferedOutputStream(new FileOutputStream(FileDescriptor.err)), true);

  public static final InputStream in
    = new BufferedInputStream(new FileInputStream(FileDescriptor.in));

  public static native void arraycopy(Object src, int srcOffset, Object dst,
                                      int dstOffset, int length);

  public static String getProperty(String name) {
    return (String) Static.properties.get(name);
  }
  
  public static String getProperty(String name, String defaultValue) {
    String result = getProperty(name);
    if (result==null) {
      return defaultValue;
    }
    return result;
  }
  
  public static String setProperty(String name, String value) {
    return (String) Static.properties.put(name, value);
  }

  public static Properties getProperties() {
    return Static.properties;
  }

  private static Properties makeProperties() {
    Properties properties = new Properties();

    for (String p: getNativeProperties()) {
      if (p == null) break;
      int index = p.indexOf('=');
      properties.put(p.substring(0, index), p.substring(index + 1));
    }

    for (String p: getVMProperties()) {
      if (p == null) break;
      int index = p.indexOf('=');