# HG changeset patch
# User Jaroslav Tulach <jtulach@netbeans.org>
# Date 1213430283 -7200
# Node ID 8a1e5fd8e077347e857b683618a13ae0d3971410
# Parent  7bb92c7ec747fcc0de3acb81e8c9087f2f74757a
Adding example with factory method for unsynchronized StringBuffer

diff -r 7bb92c7ec747 -r 8a1e5fd8e077 samples/composition/src-api2.0-enum/api/Arithmetica.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/samples/composition/src-api2.0-enum/api/Arithmetica.java	Sat Jun 14 09:58:03 2008 +0200
@@ -0,0 +1,59 @@
+package api;
+
+/** Class to simplify arithmetical operations, improved version to compute
+ * the sum for ranges, but only if one uses the new constructor to indicate
+ * need for new version.
+ *
+ * @author Jaroslav Tulach <jtulach@netbeans.org>
+ * @version 2.0
+ */
+// BEGIN: design.composition.arith2.0.enum
+public class Arithmetica {
+    private final Version version;
+    public enum Version { VERSION_1_0, VERSION_2_0 }
+    
+    public Arithmetica() {
+        this(Version.VERSION_1_0);
+    }
+    public Arithmetica(Version version) {
+        this.version = version;
+    }
+
+    public int sumRange(int from, int to) {
+        switch (version) {
+            case VERSION_1_0:
+                return sumRange1(from, to);
+            case VERSION_2_0:
+                return sumRange2(from, to);
+            default:
+                throw new IllegalStateException();
+        }
+    }
+// END: design.composition.arith2.0.enum
+    
+    public int sumTwo(int one, int second) {
+        return one + second;
+    }
+    
+    public int sumAll(int... numbers) {
+        int sum = numbers[0];
+        for (int i = 1; i < numbers.length; i++) {
+            sum = sumTwo(sum, numbers[i]);
+        }
+        return sum;
+    }
+    
+
+    private int sumRange1(int from, int to) {
+        int len = to - from;
+        int[] array = new int[len + 1];
+        for (int i = 0; i <= len; i++) {
+            array[i] = from + i;
+        }
+        return sumAll(array);
+    }
+    
+    private int sumRange2(int from, int to) {
+        return (from + to) * (to - from + 1) / 2;
+    }
+}
diff -r 7bb92c7ec747 -r 8a1e5fd8e077 samples/individualsamples/src/org/apidesign/samples/StringBuffer.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/samples/individualsamples/src/org/apidesign/samples/StringBuffer.java	Sat Jun 14 09:58:03 2008 +0200
@@ -0,0 +1,56 @@
+package org.apidesign.samples;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class StringBuffer {
+    private List<String> all = new ArrayList<String>();
+    
+    public StringBuffer() {
+        // prevent subclassing from 3rd party code
+        if (getClass() != StringBuffer.class && getClass() != StringBufferUnsynch.class) {
+            throw new IllegalStateException();
+        }
+    }
+    
+    // BEGIN: string.buffer.factory
+    public static StringBuffer createUnsynchronized() {
+        return new StringBufferUnsynch();
+    }
+    // END: string.buffer.factory
+    
+    public synchronized StringBuffer append(String s) {
+        return appendImpl(s);
+    }
+    
+    @Override
+    public synchronized String toString() {
+        return toStringImpl();
+    }
+    
+    final String toStringImpl() {
+        String ret = "";
+        for (String s : all) {
+            ret += s;
+        }
+        return ret;
+    }
+    
+    
+    final StringBuffer appendImpl(String s) {
+        all.add(s);
+        return this;
+    }
+    
+    
+    private static final class StringBufferUnsynch extends StringBuffer {
+        @Override
+        public StringBuffer append(String s) {
+            return appendImpl(s);
+        }
+        @Override
+        public String toString() {
+            return toStringImpl();
+        }
+    }
+}
diff -r 7bb92c7ec747 -r 8a1e5fd8e077 samples/individualsamples/test/org/apidesign/samples/StringBufferTest.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/samples/individualsamples/test/org/apidesign/samples/StringBufferTest.java	Sat Jun 14 09:58:03 2008 +0200
@@ -0,0 +1,69 @@
+package org.apidesign.samples;
+
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+public class StringBufferTest {
+    @Test
+    public void createRegular() {
+        StringBuffer sb = new StringBuffer();
+        assertAddAndToString(sb);
+    }
+
+    @Test
+    public void createUnsynchronized() throws InterruptedException {
+        final StringBuffer sb = StringBuffer.createUnsynchronized();
+        
+        class Lock extends Thread {
+            int state;
+            
+            @Override
+            public void run() {
+                synchronized (sb) {
+                    try {
+                        state = 1;
+                        sb.notifyAll();
+                        sb.wait();
+                        state = 2;
+                    } catch (InterruptedException ex) {
+                        Logger.getLogger(StringBufferTest.class.getName()).log(Level.SEVERE, null, ex);
+                    }
+                }
+            }
+            
+            public void waitLocked() throws InterruptedException {
+                synchronized (sb) {
+                    for (;;) {
+                        if (state == 1) {
+                            return;
+                        }
+                        sb.wait();
+                    }
+                }
+            }
+        }
+        Lock lock = new Lock();
+        lock.start();
+        lock.waitLocked();
+        
+        assertEquals("result is really locked", 1, lock.state);
+        
+        assertAddAndToString(sb);
+        
+        assertEquals("result is still locked", 1, lock.state);
+    }
+
+    private void assertAddAndToString(StringBuffer sb) {
+        sb.append("Hello").append(" ");
+        sb.append("API").append(" Design!");
+        
+        assertEquals("Hello API Design!", sb.toString());
+    }
+
+}
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