Refine some code

Author: zhangt2333

src/main/java/org/apache/ibatis/builder/xml/XMLMapperBuilder.java

@@ -108,7 +108,7 @@ public XNode getSqlFragment(String refid) {
   private void configurationElement(XNode context) {
     try {
       String namespace = context.getStringAttribute("namespace");
-      if (namespace == null || namespace.equals("")) {
+      if (namespace == null || namespace.isEmpty()) {
         throw new BuilderException("Mapper's namespace cannot be empty");
       }
       builderAssistant.setCurrentNamespace(namespace);

src/main/java/org/apache/ibatis/executor/ReuseExecutor.java

@@ -95,7 +95,7 @@ private Statement prepareStatement(StatementHandler handler, Log statementLog) t
 
   private boolean hasStatementFor(String sql) {
     try {
-      return statementMap.keySet().contains(sql) && !statementMap.get(sql).getConnection().isClosed();
+      return statementMap.containsKey(sql) && !statementMap.get(sql).getConnection().isClosed();
     } catch (SQLException e) {
       return false;
     }

src/main/java/org/apache/ibatis/jdbc/ScriptRunner.java

@@ -208,7 +208,7 @@ private void handleLine(StringBuilder command, String line) throws SQLException
       }
       println(trimmedLine);
     } else if (commandReadyToExecute(trimmedLine)) {
-      command.append(line.substring(0, line.lastIndexOf(delimiter)));
+      command.append(line, 0, line.lastIndexOf(delimiter));
       command.append(LINE_SEPARATOR);
       println(command);
       executeStatement(command.toString());

src/main/java/org/apache/ibatis/reflection/Reflector.java

@@ -149,8 +149,9 @@ private void addMethodConflict(Map<String, List<Method>> conflictingMethods, Str
   }
 
   private void resolveSetterConflicts(Map<String, List<Method>> conflictingSetters) {
-    for (String propName : conflictingSetters.keySet()) {
-      List<Method> setters = conflictingSetters.get(propName);
+    for (Entry<String, List<Method>> entry : conflictingSetters.entrySet()) {
+      String propName = entry.getKey();
+      List<Method> setters = entry.getValue();
       Class<?> getterType = getTypes.get(propName);
       boolean isGetterAmbiguous = getMethods.get(propName) instanceof AmbiguousMethodInvoker;
       boolean isSetterAmbiguous = false;
@@ -428,7 +429,7 @@ public String[] getSetablePropertyNames() {
    * @return True if the object has a writable property by the name
    */
   public boolean hasSetter(String propertyName) {
-    return setMethods.keySet().contains(propertyName);
+    return setMethods.containsKey(propertyName);
   }
 
   /**
@@ -438,7 +439,7 @@ public boolean hasSetter(String propertyName) {
    * @return True if the object has a readable property by the name
    */
   public boolean hasGetter(String propertyName) {
-    return getMethods.keySet().contains(propertyName);
+    return getMethods.containsKey(propertyName);
   }
 
   public String findPropertyName(String name) {

src/test/java/org/apache/ibatis/submitted/blocking_cache/Person.java

@@ -59,9 +59,9 @@ public void setLastname(String lastname) {
   @Override
   public String toString() {
     StringBuilder sb = new StringBuilder();
-    sb.append("id=" + id);
-    sb.append(", lastname=" + lastname);
-    sb.append(", firstname=" + firstname);
+    sb.append("id=").append(id);
+    sb.append(", lastname=").append(lastname);
+    sb.append(", firstname=").append(firstname);
     return sb.toString();
   }
 

src/test/java/org/apache/ibatis/submitted/cache/Person.java

@@ -59,9 +59,9 @@ public void setLastname(String lastname) {
   @Override
   public String toString() {
     StringBuilder sb = new StringBuilder();
-    sb.append("id=" + id);
-    sb.append(", lastname=" + lastname);
-    sb.append(", firstname=" + firstname);
+    sb.append("id=").append(id);
+    sb.append(", lastname=").append(lastname);
+    sb.append(", firstname=").append(firstname);
     return sb.toString();
   }
 

src/test/java/org/apache/ibatis/submitted/mapper_type_parameter/BaseMapper.java

@@ -73,7 +73,7 @@ public String provideInsert(Map<String, Object> map) {
         } else {
           sql.append(",");
         }
-        sql.append(" (#{list[" + i + "].id}, #{list[" + i + "].name})");
+        sql.append(" (#{list[").append(i).append("].id}, #{list[").append(i).append("].name})");
       }
       return sql == null ? "" : sql.toString();
     }