总结4

顶层Number类

public abstract class Number implements java.io.Serializable {
    /**
     * Returns the value of the specified number as an {@code int},
     * which may involve rounding or truncation.
     *
     * @return  the numeric value represented by this object after conversion
     *          to type {@code int}.
     */
    public abstract int intValue();

    /**
     * Returns the value of the specified number as a {@code long},
     * which may involve rounding or truncation.
     *
     * @return  the numeric value represented by this object after conversion
     *          to type {@code long}.
     */
    public abstract long longValue();

    /**
     * Returns the value of the specified number as a {@code float},
     * which may involve rounding.
     *
     * @return  the numeric value represented by this object after conversion
     *          to type {@code float}.
     */
    public abstract float floatValue();

    /**
     * Returns the value of the specified number as a {@code double},
     * which may involve rounding.
     *
     * @return  the numeric value represented by this object after conversion
     *          to type {@code double}.
     */
    public abstract double doubleValue();

    /**
     * Returns the value of the specified number as a {@code byte},
     * which may involve rounding or truncation.
     *
     * <p>This implementation returns the result of {@link #intValue} cast
     * to a {@code byte}.
     *
     * @return  the numeric value represented by this object after conversion
     *          to type {@code byte}.
     * @since   JDK1.1
     */
    public byte byteValue() {
        return (byte)intValue();
    }

    /**
     * Returns the value of the specified number as a {@code short},
     * which may involve rounding or truncation.
     *
     * <p>This implementation returns the result of {@link #intValue} cast
     * to a {@code short}.
     *
     * @return  the numeric value represented by this object after conversion
     *          to type {@code short}.
     * @since   JDK1.1
     */
    public short shortValue() {
        return (short)intValue();
    }

    /** use serialVersionUID from JDK 1.0.2 for interoperability */
    private static final long serialVersionUID = -8742448824652078965L;
}

AtomicInteger原子类

public class AtomicInteger extends Number implements java.io.Serializable {
    private static final long serialVersionUID = 6214790243416807050L;

    // setup to use Unsafe.compareAndSwapInt for updates
    private static final Unsafe unsafe = Unsafe.getUnsafe();
    private static final long valueOffset;

    static {
        try {
            valueOffset = unsafe.objectFieldOffset
                (AtomicInteger.class.getDeclaredField("value"));
        } catch (Exception ex) { throw new Error(ex); }
    }

    private volatile int value;

    /**
     * Creates a new AtomicInteger with the given initial value.
     *
     * @param initialValue the initial value
     */
    public AtomicInteger(int initialValue) {
        value = initialValue;
    }

    /**
     * Creates a new AtomicInteger with initial value {@code 0}.
     */
    public AtomicInteger() {
    }

    /**
     * Gets the current value.
     *
     * @return the current value
     */
    public final int get() {
        return value;
    }

Math有正弦余弦等方法

public final class Math {

    /**
     * Don't let anyone instantiate this class.
     */
    private Math() {}

    /**
     * The {@code double} value that is closer than any other to
     * <i>e</i>, the base of the natural logarithms.
     */
    public static final double E = 2.7182818284590452354;

    /**
     * The {@code double} value that is closer than any other to
     * <i>pi</i>, the ratio of the circumference of a circle to its
     * diameter.
     */
    public static final double PI = 3.14159265358979323846;

    /**
     * Returns the trigonometric sine of an angle.  Special cases:
     * <ul><li>If the argument is NaN or an infinity, then the
     * result is NaN.
     * <li>If the argument is zero, then the result is a zero with the
     * same sign as the argument.</ul>
     *
     * <p>The computed result must be within 1 ulp of the exact result.
     * Results must be semi-monotonic.
     *
     * @param   a   an angle, in radians.
     * @return  the sine of the argument.
     */
    public static double sin(double a) {
        return StrictMath.sin(a); // default impl. delegates to StrictMath
    }

    /**
     * Returns the trigonometric cosine of an angle. Special cases:
     * <ul><li>If the argument is NaN or an infinity, then the
     * result is NaN.</ul>
     *
     * <p>The computed result must be within 1 ulp of the exact result.
     * Results must be semi-monotonic.
     *
     * @param   a   an angle, in radians.
     * @return  the cosine of the argument.
     */
    public static double cos(double a) {
        return StrictMath.cos(a); // default impl. delegates to StrictMath
    }

    /**
     * Returns the trigonometric tangent of an angle.  Special cases:
     * <ul><li>If the argument is NaN or an infinity, then the result
     * is NaN.
     * <li>If the argument is zero, then the result is a zero with the
     * same sign as the argument.</ul>
     *
     * <p>The computed result must be within 1 ulp of the exact result.
     * Results must be semi-monotonic.
     *
     * @param   a   an angle, in radians.
     * @return  the tangent of the argument.
     */
    public static double tan(double a) {
        return StrictMath.tan(a); // default impl. delegates to StrictMath
    }

SocketFactory抽象类

顶级抽象类

public abstract class SocketFactory {
    private static SocketFactory theFactory;

    protected SocketFactory() {
    }

    public static SocketFactory getDefault() {
        Class var0 = SocketFactory.class;
        synchronized(SocketFactory.class) {
            if (theFactory == null) {
                theFactory = new DefaultSocketFactory();
            }
        }

        return theFactory;
    }

    public Socket createSocket() throws IOException {
        UnsupportedOperationException var1 = new UnsupportedOperationException();
        SocketException var2 = new SocketException("Unconnected sockets not implemented");
        var2.initCause(var1);
        throw var2;
    }

    public abstract Socket createSocket(String var1, int var2) throws IOException, UnknownHostException;

    public abstract Socket createSocket(String var1, int var2, InetAddress var3, int var4) throws IOException, UnknownHostException;

    public abstract Socket createSocket(InetAddress var1, int var2) throws IOException;

    public abstract Socket createSocket(InetAddress var1, int var2, InetAddress var3, int var4) throws IOException;
}

脚本工厂

public interface ScriptEngineFactory {
    /**
     * Returns the full  name of the <code>ScriptEngine</code>.  For
     * instance an implementation based on the Mozilla Rhino Javascript engine
     * might return <i>Rhino Mozilla Javascript Engine</i>.
     * @return The name of the engine implementation.
     */
    public String getEngineName();

    /**
     * Returns the version of the <code>ScriptEngine</code>.
     * @return The <code>ScriptEngine</code> implementation version.
     */
    public String getEngineVersion();


    /**
     * Returns an immutable list of filename extensions, which generally identify scripts
     * written in the language supported by this <code>ScriptEngine</code>.
     * The array is used by the <code>ScriptEngineManager</code> to implement its
     * <code>getEngineByExtension</code> method.
     * @return The list of extensions.
     */
    public List<String> getExtensions();


    /**
     * Returns an immutable list of mimetypes, associated with scripts that
     * can be executed by the engine.  The list is used by the
     * <code>ScriptEngineManager</code> class to implement its
     * <code>getEngineByMimetype</code> method.
     * @return The list of mime types.
     */
    public List<String> getMimeTypes();

    /**
     * Returns an immutable list of  short names for the <code>ScriptEngine</code>, which may be used to
     * identify the <code>ScriptEngine</code> by the <code>ScriptEngineManager</code>.
     * For instance, an implementation based on the Mozilla Rhino Javascript engine might
     * return list containing {&quot;javascript&quot;, &quot;rhino&quot;}.
     * @return an immutable list of short names
     */
    public List<String> getNames();

    /**
     * Returns the name of the scripting language supported by this
     * <code>ScriptEngine</code>.
     * @return The name of the supported language.
     */
    public String getLanguageName();

    /**
     * Returns the version of the scripting language supported by this
     * <code>ScriptEngine</code>.
     * @return The version of the supported language.
     */
    public String getLanguageVersion();

    /**
     * Returns the value of an attribute whose meaning may be implementation-specific.
     * Keys for which the value is defined in all implementations are:
     * <ul>
     * <li>ScriptEngine.ENGINE</li>
     * <li>ScriptEngine.ENGINE_VERSION</li>
     * <li>ScriptEngine.LANGUAGE</li>
     * <li>ScriptEngine.LANGUAGE_VERSION</li>
     * <li>ScriptEngine.NAME</li>
     * </ul>
     * <p>
     * The values for these keys are the Strings returned by <code>getEngineName</code>,
     * <code>getEngineVersion</code>, <code>getLanguageName</code>,
     * <code>getLanguageVersion</code> for the first four keys respectively. For NAME, one of the Strings
     * returned by <code>getNames</code> is returned.<br><br>
     * A reserved key, <code><b>THREADING</b></code>, whose value describes the behavior of the engine
     * with respect to concurrent execution of scripts and maintenance of state is also defined.
     * These values for the <code><b>THREADING</b></code> key are:<br><br>
     * <ul>
     * <li><code>null</code> - The engine implementation is not thread safe, and cannot
     * be used to execute scripts concurrently on multiple threads.
     * <li><code>&quot;MULTITHREADED&quot;</code> - The engine implementation is internally
     * thread-safe and scripts may execute concurrently although effects of script execution
     * on one thread may be visible to scripts on other threads.
     * <li><code>&quot;THREAD-ISOLATED&quot;</code> - The implementation satisfies the requirements
     * of &quot;MULTITHREADED&quot;, and also, the engine maintains independent values
     * for symbols in scripts executing on different threads.
     * <li><code>&quot;STATELESS&quot;</code> - The implementation satisfies the requirements of
     * <li><code>&quot;THREAD-ISOLATED&quot;</code>.  In addition, script executions do not alter the
     * mappings in the <code>Bindings</code> which is the engine scope of the
     * <code>ScriptEngine</code>.  In particular, the keys in the <code>Bindings</code>
     * and their associated values are the same before and after the execution of the script.
     * </ul>
     * <br><br>
     * Implementations may define implementation-specific keys.
     *
     * @param key The name of the parameter
     * @return The value for the given parameter. Returns <code>null</code> if no
     * value is assigned to the key.
     *
     */
    public Object getParameter(String key);

    /**
     * Returns a String which can be used to invoke a method of a  Java object using the syntax
     * of the supported scripting language.  For instance, an implementation for a Javascript
     * engine might be;
     *
     * <pre>{@code
     * public String getMethodCallSyntax(String obj,
     *                                   String m, String... args) {
     *      String ret = obj;
     *      ret += "." + m + "(";
     *      for (int i = 0; i < args.length; i++) {
     *          ret += args[i];
     *          if (i < args.length - 1) {
     *              ret += ",";
     *          }
     *      }
     *      ret += ")";
     *      return ret;
     * }
     * } </pre>
     * <p>
     *
     * @param obj The name representing the object whose method is to be invoked. The
     * name is the one used to create bindings using the <code>put</code> method of
     * <code>ScriptEngine</code>, the <code>put</code> method of an <code>ENGINE_SCOPE</code>
     * <code>Bindings</code>,or the <code>setAttribute</code> method
     * of <code>ScriptContext</code>.  The identifier used in scripts may be a decorated form of the
     * specified one.
     *
     * @param m The name of the method to invoke.
     * @param args names of the arguments in the method call.
     *
     * @return The String used to invoke the method in the syntax of the scripting language.
     */
    public String getMethodCallSyntax(String obj, String m, String... args);

    /**
     * Returns a String that can be used as a statement to display the specified String  using
     * the syntax of the supported scripting language.  For instance, the implementation for a Perl
     * engine might be;
     *
     * <pre><code>
     * public String getOutputStatement(String toDisplay) {
     *      return "print(" + toDisplay + ")";
     * }
     * </code></pre>
     *
     * @param toDisplay The String to be displayed by the returned statement.
     * @return The string used to display the String in the syntax of the scripting language.
     *
     *
     */
    public String getOutputStatement(String toDisplay);


    /**
     * Returns a valid scripting language executable program with given statements.
     * For instance an implementation for a PHP engine might be:
     *
     * <pre>{@code
     * public String getProgram(String... statements) {
     *      String retval = "<?\n";
     *      int len = statements.length;
     *      for (int i = 0; i < len; i++) {
     *          retval += statements[i] + ";\n";
     *      }
     *      return retval += "?>";
     * }
     * }</pre>
     *
     *  @param statements The statements to be executed.  May be return values of
     *  calls to the <code>getMethodCallSyntax</code> and <code>getOutputStatement</code> methods.
     *  @return The Program
     */

    public String getProgram(String... statements);

    /**
     * Returns an instance of the <code>ScriptEngine</code> associated with this
     * <code>ScriptEngineFactory</code>. A new ScriptEngine is generally
     * returned, but implementations may pool, share or reuse engines.
     *
     * @return A new <code>ScriptEngine</code> instance.
     */
    public  ScriptEngine getScriptEngine();
}

自定义注解

package jdk;

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

@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE, ElementType.PACKAGE})
@Exported
public @interface Exported {
    boolean value() default true;
}

底层用Map

public class SimpleBindings implements Bindings {

    /**
     * The <code>Map</code> field stores the attributes.
     */
    private Map<String,Object> map;

    /**
     * Constructor uses an existing <code>Map</code> to store the values.
     * @param m The <code>Map</code> backing this <code>SimpleBindings</code>.
     * @throws NullPointerException if m is null
     */
    public SimpleBindings(Map<String,Object> m) {
        if (m == null) {
            throw new NullPointerException();
        }
        this.map = m;
    }

    /**
     * Default constructor uses a <code>HashMap</code>.
     */
    public SimpleBindings() {
        this(new HashMap<String,Object>());
    }

    /**
     * Sets the specified key/value in the underlying <code>map</code> field.
     *
     * @param name Name of value
     * @param value Value to set.
     *
     * @return Previous value for the specified key.  Returns null if key was previously
     * unset.
     *
     * @throws NullPointerException if the name is null.
     * @throws IllegalArgumentException if the name is empty.
     */
    public Object put(String name, Object value) {
        checkKey(name);
        return map.put(name,value);
    }

    /**
     * <code>putAll</code> is implemented using <code>Map.putAll</code>.
     *
     * @param toMerge The <code>Map</code> of values to add.
     *
     * @throws NullPointerException
     *         if toMerge map is null or if some key in the map is null.
     * @throws IllegalArgumentException
     *         if some key in the map is an empty String.
     */
    public void putAll(Map<? extends String, ? extends Object> toMerge) {
        if (toMerge == null) {
            throw new NullPointerException("toMerge map is null");
        }
        for (Map.Entry<? extends String, ? extends Object> entry : toMerge.entrySet()) {
            String key = entry.getKey();
            checkKey(key);
            put(key, entry.getValue());
        }
    }

    /** {@inheritDoc} */
    public void clear() {
        map.clear();
    }

    /**
     * Returns <tt>true</tt> if this map contains a mapping for the specified
     * key.  More formally, returns <tt>true</tt> if and only if
     * this map contains a mapping for a key <tt>k</tt> such that
     * <tt>(key==null ? k==null : key.equals(k))</tt>.  (There can be
     * at most one such mapping.)
     *
     * @param key key whose presence in this map is to be tested.
     * @return <tt>true</tt> if this map contains a mapping for the specified
     *         key.
     *
     * @throws NullPointerException if key is null
     * @throws ClassCastException if key is not String
     * @throws IllegalArgumentException if key is empty String
     */
    public boolean containsKey(Object key) {
        checkKey(key);
        return map.containsKey(key);
    }

    /** {@inheritDoc} */
    public boolean containsValue(Object value) {
        return map.containsValue(value);
    }

    /** {@inheritDoc} */
    public Set<Map.Entry<String, Object>> entrySet() {
        return map.entrySet();
    }

    /**
     * Returns the value to which this map maps the specified key.  Returns
     * <tt>null</tt> if the map contains no mapping for this key.  A return
     * value of <tt>null</tt> does not <i>necessarily</i> indicate that the
     * map contains no mapping for the key; it's also possible that the map
     * explicitly maps the key to <tt>null</tt>.  The <tt>containsKey</tt>
     * operation may be used to distinguish these two cases.
     *
     * <p>More formally, if this map contains a mapping from a key
     * <tt>k</tt> to a value <tt>v</tt> such that <tt>(key==null ? k==null :
     * key.equals(k))</tt>, then this method returns <tt>v</tt>; otherwise
     * it returns <tt>null</tt>.  (There can be at most one such mapping.)
     *
     * @param key key whose associated value is to be returned.
     * @return the value to which this map maps the specified key, or
     *         <tt>null</tt> if the map contains no mapping for this key.
     *
     * @throws NullPointerException if key is null
     * @throws ClassCastException if key is not String
     * @throws IllegalArgumentException if key is empty String
     */
    public Object get(Object key) {
        checkKey(key);
        return map.get(key);
    }

    /** {@inheritDoc} */
    public boolean isEmpty() {
        return map.isEmpty();
    }

    /** {@inheritDoc} */
    public Set<String> keySet() {
        return map.keySet();
    }

    /**
     * Removes the mapping for this key from this map if it is present
     * (optional operation).   More formally, if this map contains a mapping
     * from key <tt>k</tt> to value <tt>v</tt> such that
     * <code>(key==null ?  k==null : key.equals(k))</code>, that mapping
     * is removed.  (The map can contain at most one such mapping.)
     *
     * <p>Returns the value to which the map previously associated the key, or
     * <tt>null</tt> if the map contained no mapping for this key.  (A
     * <tt>null</tt> return can also indicate that the map previously
     * associated <tt>null</tt> with the specified key if the implementation
     * supports <tt>null</tt> values.)  The map will not contain a mapping for
     * the specified  key once the call returns.
     *
     * @param key key whose mapping is to be removed from the map.
     * @return previous value associated with specified key, or <tt>null</tt>
     *         if there was no mapping for key.
     *
     * @throws NullPointerException if key is null
     * @throws ClassCastException if key is not String
     * @throws IllegalArgumentException if key is empty String
     */
    public Object remove(Object key) {
        checkKey(key);
        return map.remove(key);
    }

    /** {@inheritDoc} */
    public int size() {
        return map.size();
    }

    /** {@inheritDoc} */
    public Collection<Object> values() {
        return map.values();
    }

    private void checkKey(Object key) {
        if (key == null) {
            throw new NullPointerException("key can not be null");
        }
        if (!(key instanceof String)) {
            throw new ClassCastException("key should be a String");
        }
        if (key.equals("")) {
            throw new IllegalArgumentException("key can not be empty");
        }
    }
}

多级注解使用

@Exported
public interface JConsoleContext {
    String CONNECTION_STATE_PROPERTY = "connectionState";

    MBeanServerConnection getMBeanServerConnection();

    JConsoleContext.ConnectionState getConnectionState();

    void addPropertyChangeListener(PropertyChangeListener var1);

    void removePropertyChangeListener(PropertyChangeListener var1);

    @Exported
    public static enum ConnectionState {
        CONNECTED,
        DISCONNECTED,
        CONNECTING;

        private ConnectionState() {
        }
    }
}

适配器类中增加Cache

public class JUnit4TestAdapter implements Test, Filterable, Orderable, Describable {
    private final Class<?> fNewTestClass;
    private final Runner fRunner;
    private final JUnit4TestAdapterCache fCache;

    public JUnit4TestAdapter(Class<?> newTestClass) {
        this(newTestClass, JUnit4TestAdapterCache.getDefault());
    }

    public JUnit4TestAdapter(Class<?> newTestClass, JUnit4TestAdapterCache cache) {
        this.fCache = cache;
        this.fNewTestClass = newTestClass;
        this.fRunner = Request.classWithoutSuiteMethod(newTestClass).getRunner();
    }

    public int countTestCases() {
        return this.fRunner.testCount();
    }

    public void run(TestResult result) {
        this.fRunner.run(this.fCache.getNotifier(result, this));
    }

    public List<Test> getTests() {
        return this.fCache.asTestList(this.getDescription());
    }

    public Class<?> getTestClass() {
        return this.fNewTestClass;
    }

    public Description getDescription() {
        Description description = this.fRunner.getDescription();
        return this.removeIgnored(description);
    }

门面类

public class JUnit4TestCaseFacade implements Test, Describable {
    private final Description fDescription;

    JUnit4TestCaseFacade(Description description) {
        this.fDescription = description;
    }

    public String toString() {
        return this.getDescription().toString();
    }

    public int countTestCases() {
        return 1;
    }

    public void run(TestResult result) {
        throw new RuntimeException("This test stub created only for informational purposes.");
    }

    public Description getDescription() {
        return this.fDescription;
    }
}