output: #fixed code
                                  public void index() {
  
  
  
  
          renderText("hello " + serviceTest.getName("aaa"));
  
  
  
  
      }
input: #vulnerable code 
                                  public void index() {
  
  
  
          List<Record> records = Db.find("select * from `user`");
  
          System.out.println("index .... ");
  
          LogKit.error("xxxxxxx");
  
          Jboot.getCache().put("test","test","valueeeeeeeeee");
          String value = Jboot.getCache().get("test","test");
  
          System.out.println("value:"+value);
  
  
          renderText("hello " + serviceTest.getName());
  
  //        render();
  
  
  
  
      } 
                              #location 11 
                              #vulnerability type NULL_DEREFERENCE