javax.script.ScriptEngineManager#put ( )源码实例Demo

@Test
public void testScopes() throws Exception {
    ScriptEngineManager manager = new ScriptEngineManager();
    Assert.assertNotNull("Manager should not be null", manager);
    ScriptEngine engine = manager.getEngineByName("JEXL");
    Assert.assertNotNull("Engine should not be null (JEXL)", engine);
    manager.put("global", 1);
    engine.put("local", 10);
    manager.put("both", 7);
    engine.put("both", 7);
    engine.eval("local=local+1");
    engine.eval("global=global+1");
    engine.eval("both=both+1"); // should update engine value only
    engine.eval("newvar=42;");
    Assert.assertEquals(2,manager.get("global"));
    Assert.assertEquals(11,engine.get("local"));
    Assert.assertEquals(7,manager.get("both"));
    Assert.assertEquals(8,engine.get("both"));
    Assert.assertEquals(42,engine.get("newvar"));
    Assert.assertNull(manager.get("newvar"));
}
 

public static Object executeScript(String resourcePath, Map<String, Object> params,
                                   List<String> attributesToRemove) {
  ScriptEngineManager manager = new ScriptEngineManager();
  ScriptEngine engine = manager.getEngineByName("ruby");
  InputStream resource = GrokIngestMapper.class.getClassLoader().getResourceAsStream(resourcePath);

  for (String toRemove : attributesToRemove) {
    engine.getContext().setAttribute(toRemove, params.get(toRemove),
        ScriptContext.ENGINE_SCOPE);// necessary limit the scope to just engine
  }

  for (Map.Entry<String, Object> entry : params.entrySet()) {
    manager.put(entry.getKey(), entry.getValue());
  }

  if (resource == null) {
    throw new RuntimeException("Resource not found " + resourcePath);
  }
  if (engine == null) {
    throw new RuntimeException("Script engine can not be created");
  }
  InputStreamReader is = new InputStreamReader(resource);

  try {
    Object response = engine.eval(is);
    return response;
  } catch (Exception e) {
    log.error("Error executing script: " + e.getMessage(), e);
    throw new RuntimeException("Error executing ruby script", e);
  }
}