HashMap测试类

demo1/src/test/java/cn/freemud/demo/HashMapTest.java

 package cn.freemud.demo;
 
+import org.junit.Test;
+
+import java.util.HashMap;
+
+/**
+ *测试HashMap
+ * @author jingyuanyuan
+ */
 public class HashMapTest {
+    /**
+     * HashMap的键和值都可以存储为null
+     */
+    @Test
+    public void test(){
+        System.out.println("hello this is test");
+        HashMap map=new HashMap();
+        map.put(null,"你好");
+        map.put("key1",null);
+        System.out.println("map size:"+map.size());
+        System.out.println("key is null value:"+map.get(null));
+        System.out.println("value is null value:"+map.get("key1"));
+    }
+
+    /**
+     * clear 清空集合
+     */
+    @Test
+    public void clearTest(){
+        HashMap map=new HashMap();
+        map.put("key1","张三");
+        System.out.println("map size:"+map.size());
+        map.clear();
+        System.out.println("map size:"+map.size());
+    }
+
+    /**
+     * clone 克隆集合
+     */
+    @Test
+    public void cloneTest(){
+        HashMap map=new HashMap();
+        map.put("key1","张三");
+        map.put("key2","李四");
+        System.out.println("map size:"+map.size());
+        Object clone = map.clone();
+        System.out.println("clone map size:"+clone);
+    }
+
+    /**
+     * 测试集合中是否包含指定的key
+     */
+    @Test
+    public void containsKeyTest(){
+        HashMap map=new HashMap();
+        map.put("key1","张三");
+        map.put("key2","李四");
+        boolean key1 = map.containsKey("key1");
+        boolean key3 = map.containsKey("key3");
+        System.out.println("containsKey key1:"+key1);
+        System.out.println("containsKey key3:"+key3);
+    }
+
+    /**
+     * 测试集合中是否包含指定的value
+     */
+    @Test
+    public void containsValueTest(){
+        HashMap map=new HashMap();
+        map.put("key1","张三");
+        map.put("key2","李四");
+        boolean a = map.containsValue("张");
+        boolean b = map.containsValue("李四");
+        System.out.println("containsValue 张:"+a);
+        System.out.println("containsValue 李四:"+b);
+    }
+
+
 }