add testcase

src/test/java/com/alibaba/druid/bvt/utils/DruidWebUtilsTest.java

@@ -0,0 +1,32 @@
+package com.alibaba.druid.bvt.utils;
+
+import junit.framework.TestCase;
+
+import org.junit.Assert;
+import org.springframework.mock.web.MockServletContext;
+
+import com.alibaba.druid.util.DruidWebUtils;
+
+public class DruidWebUtilsTest extends TestCase {
+
+    public void test_getContextPath_2_5() throws Exception {
+        new DruidWebUtils(); //
+
+        MockServletContext context = new MockServletContext() {
+
+            public int getMajorVersion() {
+                return 2;
+            }
+
+            public int getMinorVersion() {
+                return 4;
+            }
+
+            public String getContextPath() {
+                throw new NoSuchMethodError();
+            }
+        };
+
+        Assert.assertNull(DruidWebUtils.getContextPath(context));
+    }
+}

src/test/java/com/alibaba/druid/bvt/utils/HistogramTest.java

@@ -0,0 +1,45 @@
+package com.alibaba.druid.bvt.utils;
+
+import junit.framework.Assert;
+import junit.framework.TestCase;
+
+import com.alibaba.druid.util.Histogram;
+
+public class HistogramTest extends TestCase {
+
+    public void test_histo() throws Exception {
+        Histogram histo = Histogram.makeHistogram(4);
+        
+        Assert.assertEquals(4, histo.getRanges().length);
+
+        histo.record(0);
+        
+        histo.record(1);
+        histo.record(2);
+        
+        histo.record(11);
+        histo.record(12);
+        histo.record(13);
+        
+        histo.record(101);
+        histo.record(102);
+        histo.record(103);
+        histo.record(104);
+        
+        histo.record(1001);
+        histo.record(1002);
+        histo.record(1003);
+        histo.record(1004);
+        histo.record(1005);
+        
+        histo.record(10001);
+        
+        Assert.assertEquals(1, histo.get(0));
+        Assert.assertEquals(2, histo.get(1));
+        Assert.assertEquals(3, histo.get(2));
+        Assert.assertEquals(4, histo.get(3));
+        Assert.assertEquals(6, histo.get(4));
+        
+        histo.toString();
+    }
+}