OGNL取值范围分两部分,root、Context两部分
可以放置任何对象作为ROOT,CONTEXT中必须是Map键值对
示例:
准备工作:
public void fun1() throws Exception { // 准备ONGLContext // 准备Root User rootUser = new User("tom", 18); // 准备Context Map<String, User> context = new HashMap<String, User>(); context.put("user1", new User("jack", 18)); context.put("user2", new User("rose", 22)); OgnlContext oc = new OgnlContext(); // 将rootUser作为root部分 oc.setRoot(rootUser); // 将context这个Map作为Context部分 oc.setValues(context); // 书写OGNL Ognl.getValue("", oc, oc.getRoot()); //在""中书写OGNL表达式即可 }
User类:
package bean; public class User { private String name; private Integer age; public User() { super(); // TODO Auto-generated constructor stub } public User(String name, Integer age) { super(); this.name = name; this.age = age; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Integer getAge() { return age; } public void setAge(Integer age) { this.age = age; } }
语法:
从root中取出对象:
// 取出root中user对象的name属性 String name = (String) Ognl.getValue("name", oc, oc.getRoot()); Integer age = (Integer) Ognl.getValue("age", oc, oc.getRoot());
从Context中取出对象:
// 取出context中键为user1对象的name属性 String name1 = (String) Ognl.getValue("#user1.name", oc, oc.getRoot()); String name2 = (String) Ognl.getValue("#user2.name", oc, oc.getRoot()); Integer age = (Integer) Ognl.getValue("#user2.age", oc, oc.getRoot());
为属性赋值:
// 将root中的user对象的name属性赋值 Ognl.getValue("name=‘jerry‘", oc, oc.getRoot());
给context赋值:
String name2 = (String) Ognl.getValue("#user1.name=‘张三‘", oc, oc.getRoot());
调用对象的方法:
// 调用root中user对象的setName方法 Ognl.getValue("setName(‘张三‘)", oc, oc.getRoot()); String name1 = (String) Ognl.getValue("getName()", oc, oc.getRoot()); String name2 = (String) Ognl.getValue("#user1.setName(‘lucy‘),#user1.getName()", oc, oc.getRoot());
(注意:可以将两条语句写在一起,逗号分隔,返回值是最后一个语句)
调用静态方法:
Double pi = (Double) Ognl.getValue("@java.lang.Math@PI", oc,oc.getRoot());
创建对象:
// 创建list对象 Integer size = (Integer) Ognl.getValue("{‘tom‘,‘jerry‘,‘jack‘,‘rose‘}.size()", oc, oc.getRoot()); String name1 = (String) Ognl.getValue("{‘tom‘,‘jerry‘,‘jack‘,‘rose‘}[0]", oc, oc.getRoot()); String name2 = (String) Ognl.getValue("{‘tom‘,‘jerry‘,‘jack‘,‘rose‘}.get(1)", oc, oc.getRoot()); // 创建Map对象 Integer size2 = (Integer) Ognl.getValue("#{‘name‘:‘tom‘,‘age‘:18}.size()", oc, oc.getRoot()); String name3 = (String) Ognl.getValue("#{‘name‘:‘tom‘,‘age‘:18}[‘name‘]", oc, oc.getRoot()); Integer age = (Integer) Ognl.getValue("#{‘name‘:‘tom‘,‘age‘:18}.get(‘age‘)", oc, oc.getRoot());