java执行JavaScript代码

学习资料http://jnotnull./blog/262384

Java代码  

1. import java.util.ArrayList;  
2. import java.util.HashMap;  
3. import java.util.List;  
4. import java.util.Map;  
5. import java.util.Set;  
6. import java.util.Map.Entry;  
7.   
8. import javax.script.Invocable;  
9. import javax.script.ScriptEngine;  
10. import javax.script.ScriptEngineManager;  
11. import javax.script.ScriptException;  
12.   
13. import sun.org.mozilla.javascript.internal.NativeArray;  
14. import sun.org.mozilla.javascript.internal.NativeObject;  
15.   
16. public class TestScript {  
17.     public static void main(String[] args) throws Exception {  
18.         ScriptEngineManager factory = new ScriptEngineManager();  
19.         ScriptEngine engine = factory.getEngineByName("JavaScript");  
20.         // engine.eval("print('hello')");  
21.         // testScriptVariables(engine);// 演示如何暴露Java对象为脚本语言的全局变量  
22.         // testInvokeScriptMethod(engine);// 演示如何在Java中调用脚本语言的方法  
23.         // testScriptInterface(engine);// 演示脚本语言如何实现Java的接口  
24.         // testUsingJDKClasses(engine);// 演示脚本语言如何使用JDK平台下的类  
25.   
26.         test(engine);  
27.     }  
28.   
29.     public static void testScriptVariables(ScriptEngine engine)  
30.             throws ScriptException {  
31.         Map<String, Object> map = new HashMap<String, Object>();  
32.   
33.         engine.put("map", map);  
34.         engine.eval("map.put('s',new Date);");  
35.         System.out.println(map.get("s").getClass());  
36.     }  
37.   
38.     public static void testInvokeScriptMethod(ScriptEngine engine)  
39.             throws Exception {  
40.         String script = "function hello(name) { return 'Hello,' + name;}";  
41.         engine.eval(script);  
42.         Invocable inv = (Invocable) engine;  
43.         String res = (String) inv.invokeFunction("hello", "Scripting");  
44.         System.out.println("res:" + res);  
45.     }  
46.   
47.     public static void testScriptInterface(ScriptEngine engine)  
48.             throws ScriptException {  
49.         String script = "var obj = new Object();obj.run = function() { println('run method called');}";  
50.         engine.eval(script);  
51.         Object obj = engine.get("obj");  
52.         Invocable inv = (Invocable) engine;  
53.         Runnable r = inv.getInterface(obj, Runnable.class);  
54.         Thread th = new Thread(r);  
55.         th.start();  
56.     }  
57.   
58.     public static void testUsingJDKClasses(ScriptEngine engine)  
59.             throws Exception {  
60.         // Packages是脚本语言里的一个全局变量,专用于访问JDK的package  
61.         // String js = "function doSwing(t){var f=new  
62.         // Packages.javax.swing.JFrame(t);f.setSize(400,300);f.setVisible(true);}";  
63.         String js = "function doSwing(t){var f=Packages.java.util.UUID.randomUUID();print(f)}";  
64.         engine.eval(js);  
65.         Invocable inv = (Invocable) engine;  
66.         inv.invokeFunction("doSwing", "Scripting Swing");  
67.     }  
68.   
69.     /** 
70.      * 我能想到的应用场景，将前台传过来的json数组构造成java的List<Map<String, 
71.      * Object>>,然后就可以随心所欲的使用该list了 当然可以使用第三方jar采用json to 
72.      * bean的方式，而且这种方案更优雅，但是需要引入第三方库 
73.      *  
74.      * @throws NoSuchMethodException 
75.      * @throws ScriptException 
76.      */  
77.   
78.     public static void test(ScriptEngine engine) throws ScriptException,  
79.             NoSuchMethodException {  
80.   
81.         // String json =  
82.         // "{'key1':'a','son':{'dd':'dd','a':8},'ran':Math.random()},{'key3':'xor'}";  
83.         String json = "{'key1':'a','son':[{'dd':'dd'},{'dd1':'dd1'}],'ran':Math.random()},{'key3':'xor'}";  
84.         NativeArray json2array = json2array(engine, "[" + json + "]");  
85.         List<Map<String, Object>> list = array2list(engine, json2array);  
86.         System.out.println(list);  
87.   
88.     }  
89.   
90.     public static NativeArray json2array(ScriptEngine engine, String json)  
91.             throws ScriptException, NoSuchMethodException {  
92.   
93.         String script = "function hello() { return " + json + ";}";  
94.         engine.eval(script);  
95.         Invocable inv = (Invocable) engine;  
96.         Object obj = inv.invokeFunction("hello");  
97.   
98.         // System.out.println(obj);  
99.         return (NativeArray) obj;  
100.   
101.     }  
102.   
103.     public static List<Map<String, Object>> array2list(ScriptEngine engine,  
104.             NativeArray nativeArray) throws ScriptException,  
105.             NoSuchMethodException {  
106.         List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();  
107.         engine.put("list", list);  
108.         engine.put("arr", nativeArray);  
109.         String script = "   function dosomething(){                                     "  
110.                 + "                                                                             "  
111.                 + "                     for (n=0; n< arr.length; n++){                           "  
112.                 + "                         var map=new Packages.java.util.HashMap();           "  
113.                 + "                         for (i in arr[n]){                                  "  
114.                 + "                             map.put(i,arr[n][i]);                           "  
115.                 + "                         }                                                   " + "                           list.add(map);                                      "  
116.                 + "                     }                                                       " + "                   }                                                           ";  
117.         engine.eval(script);  
118.   
119.         Invocable inv = (Invocable) engine;  
120.         inv.invokeFunction("dosomething");  
121.         for (Map<String, Object> map : list) {  
122.             Set<Entry<String, Object>> entrySet = map.entrySet();  
123.             for (Entry<String, Object> entry : entrySet) {  
124.                 Object object = entry.getValue();  
125.                 if (object instanceof NativeArray) {  
126.   
127.                     map.put(entry.getKey(), array2list(engine,  
128.                             (NativeArray) object));  
129.                 } else if (object instanceof NativeObject) {  
130.                     map.put(entry.getKey(), obj2map(engine,  
131.                             (NativeObject) object));  
132.                 }  
133.             }  
134.   
135.         }  
136.   
137.         return list;  
138.   
139.     }  
140.   
141.     public static Map<String, Object> obj2map(ScriptEngine engine,  
142.             Object nativeObject) throws ScriptException, NoSuchMethodException {  
143.         Map<String, Object> map = new HashMap<String, Object>();  
144.   
145.         engine.put("map", map);  
146.         engine.put("obj", nativeObject);  
147.         String script = "   function dosomething(){                                         "  
148.                 + "                         for (i in obj){                                         "  
149.                 + "                             map.put(i,obj[i]);                                  "  
150.                 + "                         }                                                       " + "                   }                                                               ";  
151.         engine.eval(script);  
152.   
153.         Invocable inv = (Invocable) engine;  
154.         inv.invokeFunction("dosomething");  
155.         return map;  
156.   
157.     }  
158.   
159. }