OGNL

Object-Graph Navigation Language ---- 对象视图导航语言

语法

User user = new User("李雷", 15);
User user1 = new User("韩梅梅", 15);

Map<String, User> userMap = new HashMap<>();
userMap.put("user1", new User("杰克", 15));
userMap.put("user1", new User("肉丝", 15));

OgnlContext ognlContext = new OgnlContext();

• 存入Root

  ognlContext.setRoot(user);
  ognlContext.setRoot(user1);
  

• 存入OgnlContext

  ognlContext.setValues(userMap);
  

• 取值

  //由Root取值 - - - - 属性名为name的值
  String name = (String) Ognl.getValue("name", ognlContext, ognlContext.getRoot());
  System.out.println("name:" + name);
  //由OgnlContext取值 - - - - #代表OgnlContext 即OgnlContext中key为user1的值的name属性
  String name1 = (String) Ognl.getValue("#user1.name", ognlContext,     ognlContext.getRoot());
  System.out.println("name:" + name1);
  
  /*name:韩梅梅
    name:肉丝*/
  

• 赋值

  //由Root赋值
  name = (String) Ognl.getValue("name='lilei'", ognlContext, ognlContext.getRoot());
  System.out.println("name:" + name);
  //由OgnlContext赋值
  name1 = (String) Ognl.getValue("#user1.name='jerry'", ognlContext, ognlContext.getRoot());
  System.out.println("name:" + name1);
  /*name:lilei
    name:jerry*/
  

• 调用方法

  //由Root调用方法
  Ognl.getValue("setName('韩梅梅')", ognlContext, ognlContext.getRoot());
  name = (String) Ognl.getValue("getName()", ognlContext, ognlContext.getRoot());
  System.out.println("name:" + name);
  //由OgnlContext调用方法
  Ognl.getValue("#user1.setName('肉丝')", ognlContext, ognlContext.getRoot());
  name1 = (String) Ognl.getValue("#user1.getName()", ognlContext, ognlContext.getRoot());
  System.out.println("name:" + name1);
  /*name:韩梅梅
  name:肉丝*/
  

• 调用静态方法 @的使用

  String s = (String) Ognl.getValue("@com.entity.Demo@same('你好')", ognlContext, ognlContext.getRoot());
  Double pi = (Double) Ognl.getValue("@@PI", ognlContext, ognlContext.getRoot());
  System.out.println("name:" + s);
  System.out.println("pi:" + pi);
  /*name:你好
  pi:3.141592653589793*/
  

• Ognl创建对象

  • list

    List<String> list = (List) Ognl.getValue("{'one','two','three'}", ognlContext, ognlContext.getRoot());
    for (String ss : list) {
        System.out.printf(ss + " ");
    }
    System.out.println();
    String s1 = (String) Ognl.getValue("{'one','two','three'}[0]", ognlContext, ognlContext.getRoot());
    String s2 = (String) Ognl.getValue("{'one','two','three'}.get(2)", ognlContext, ognlContext.getRoot());
    Integer number = (Integer) Ognl.getValue("{'one','two','three'}.size()", ognlContext, ognlContext.getRoot());
    System.out.println(s1 + " " + s2 + " " + number);
    /*one two three
    one three 3*/
    

  • map

    s1 = (String) Ognl.getValue("#{'name':'one','age':'12'}['name']", ognlContext, ognlContext.getRoot());
     s2 = (String) Ognl.getValue("#{'name':'one','age':'12'}.get('name')", ognlContext, ognlContext.getRoot());
    number = (Integer) Ognl.getValue("#{'name':'one','age':'12'}.size()", ognlContext, ognlContext.getRoot());
    System.out.println(s1 + " " + s2 + " " + number);
    /**
    * one one 2
    */