增加同步

2.javaThreadDemo/READEME.md

@@ -1,2 +1,3 @@
 本文件用于说明包用途：
-- base: 创建线程的两种方式
+- base: 创建线程的两种方式,设置异常处理器
+- synchronization:同步机制。Lock/condition,synchronized

2.javaThreadDemo/src/synchronization/Demo1.java

@@ -0,0 +1,77 @@
+package synchronization;
+
+import sun.util.locale.provider.FallbackLocaleProviderAdapter;
+
+import java.util.Arrays;
+import java.util.Map;
+import java.util.concurrent.locks.Condition;
+import java.util.concurrent.locks.ReentrantLock;
+
+/**
+ * 类功能简述：测试不使用同步的后果
+ * 类功能详述：
+ *
+ * @author fanxb
+ * @date 2019/4/10 10:28
+ */
+public class Demo1 {
+    public static void main(String[] args) {
+        Bank bank = new Bank();
+        //创建10个线程，不停的将一个账号资金转移到另一个账号上
+        for (int i = 0; i < 100; i++) {
+            new Thread(() -> {
+                while (true) {
+                    int account1 = ((Double) Math.floor(Math.random() * 10)).intValue();
+                    int account2 = ((Double) Math.floor(Math.random() * 10)).intValue();
+                    int num = ((Long) Math.round(Math.random() * 100)).intValue();
+                    bank.transfer(account1, account2, num);
+                    try {
+                        Thread.sleep(((Double) (Math.random() * 10)).intValue());
+                    } catch (Exception e) {
+                    }
+                }
+            }).start();
+        }
+    }
+}
+
+class Bank {
+    /**
+     * 10个资金账户
+     */
+    public int[] accounts = new int[10];
+
+    private ReentrantLock lock = new ReentrantLock();
+//    private Condition condition = lock.newCondition();
+
+    public Bank() {
+        Arrays.fill(accounts, 1000);
+    }
+
+    synchronized public void transfer(int from, int to, int num) {
+        try {
+//            lock.lock();
+            while (accounts[from] < num) {
+                //进入阻塞状态
+//                condition.await();
+                this.wait();
+            }
+            accounts[from] -= num;
+            accounts[to] += num;
+            //计算和
+            int sum = 0;
+            for (int j = 0; j < 10; j++) {
+                sum += accounts[j];
+            }
+            System.out.println(sum);
+            //通知解除阻塞
+//            condition.signalAll();
+            this.notifyAll();
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+//        finally {
+//            lock.unlock();
+//        }
+    }
+}