fix code analysis bug (#56)

core/src/main/java/com/usthe/sureness/provider/ducument/DocumentResourceAccess.java

@@ -41,7 +41,9 @@ public class DocumentResourceAccess {
      */
     public static DocumentResourceEntity loadConfig(String yamlFileName) throws IOException {
         Yaml yaml = new Yaml();
-        InputStream inputStream = DocumentResourceAccess.class.getClassLoader().getResourceAsStream(yamlFileName);
+        InputStream inputStream = null;
+        try {
+            inputStream = DocumentResourceAccess.class.getClassLoader().getResourceAsStream(yamlFileName);
             if (inputStream == null) {
                 inputStream = Thread.currentThread().getContextClassLoader().getResourceAsStream(yamlFileName);
             }
@@ -60,6 +62,11 @@ public class DocumentResourceAccess {
                         "please create the file if you need config resource");
             }
             return yaml.loadAs(inputStream, DocumentResourceEntity.class);
+        } finally {
+            if (inputStream != null) {
+                inputStream.close();
+            }
+        }
     }
 
     /**

core/src/main/java/com/usthe/sureness/util/ClassScanner.java

@@ -240,7 +240,7 @@ public enum ClassScanner {
     private static List<Class<?>> recursiveScan4Jar(String pkg, String jarPath) throws IOException {
         List<Class<?>> classList = new LinkedList<>();
 
-        JarInputStream jin = new JarInputStream(new FileInputStream(jarPath));
+        try (JarInputStream jin = new JarInputStream(new FileInputStream(jarPath))) {
             JarEntry entry = jin.getNextJarEntry();
             while (entry != null) {
                 String name = entry.getName();
@@ -263,7 +263,7 @@ public enum ClassScanner {
                     }
                 }
             }
-
+        }
         return classList;
     }
 

core/src/main/java/com/usthe/sureness/util/SurenessCommonUtil.java

@@ -21,6 +21,7 @@ public class SurenessCommonUtil {
     private static final String PATH_SPLIT = "/";
 
     private static final String RANDOM_CHAR = "abcdefghijklmnopqrstuvwxyz0123456789";
+    private static final Random RANDOM = new Random();
 
     /**
      * match the userAgent
@@ -58,10 +59,9 @@ public class SurenessCommonUtil {
         if (length < 1) {
             length = 6;
         }
-        Random random = new Random();
         StringBuilder sb = new StringBuilder();
         for (int i = 0; i < length; i++) {
-            int number = random.nextInt(RANDOM_CHAR.length());
+            int number = RANDOM.nextInt(RANDOM_CHAR.length());
             sb.append(RANDOM_CHAR.charAt(number));
         }
         return sb.toString();