该问题是怎么引起的？

beetl的这个自动获取属性的方法很不错。但是返回值被限定成为Object类本身，任何Object的子类都不行，不够灵活。其实返回值只要不为void就行。

重现步骤

1.测试用例java类：
@test
public void testJsonParse() throws Exception {
//上面的代码省略...
//rootNode是一个com.fasterxml.jackson.databind.node.ObjectNode对象，由"{a:{name:'hello',age:18},b:[1,2,3]}"解析生成。

	Template t = gt.getTemplate("/jsonparse.html");
	this.bind(t, "b", rootNode);
	String str = t.render();
	System.out.println(str);
}

2.jsonparse.html文件：
${b["a"]["age"]}
${b["b"][0]}
${b.a.age}
${b.b[0]}

报错信息

java.lang.NoSuchMethodError: com.fasterxml.jackson.databind.node.ObjectNode.get(Ljava/lang/String;)Ljava/lang/Object;
at com.fasterxml.jackson.databind.node.ObjectNode$AttributeAccess.value(Unknown Source)
at org.beetl.core.statement.VarSquareAttribute.evaluate(VarSquareAttribute.java:59)
at org.beetl.core.statement.VarRef.evaluate(VarRef.java:99)
at org.beetl.core.statement.PlaceholderST.execute(PlaceholderST.java:30)
at org.beetl.core.statement.Program.run(Program.java:69)
at org.beetl.core.statement.Program.execute(Program.java:61)
at org.beetl.core.Template.renderTo(Template.java:130)
at org.beetl.core.Template.renderTo(Template.java:90)
at org.beetl.core.Template.render(Template.java:78)
at org.beetl.core.exp.JsonTest.testJsonParse(JsonTest.java:69)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at junit.framework.TestCase.runTest(TestCase.java:154)
at junit.framework.TestCase.runBare(TestCase.java:127)
at junit.framework.TestResult$1.protect(TestResult.java:106)
at junit.framework.TestResult.runProtected(TestResult.java:124)
at junit.framework.TestResult.run(TestResult.java:109)
at junit.framework.TestCase.run(TestCase.java:118)
at org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestReference.run(JUnit3TestReference.java:121)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:538)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:760)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:460)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:206)