如何使用ActionExpression将动作分配给jsf中的动态CommandButton？

Question

这是我的示例代码

CommandButton save = new CommandButton();
        save.setValue("Save");
        save.setActionExpression(createActionExpression("#{controller.saveData}", String.class));



private MethodExpression createActionExpression(String actionExpression, Class<?> returnType) {

     FacesContext facesContext = FacesContext.getCurrentInstance();
        return facesContext.getApplication().getExpressionFactory().createMethodExpression(
            facesContext.getELContext(), actionExpression, returnType, new Class[0]);
}

public void saveData(){

  }

我的问题是如何将参数传递给此函数 喜欢？

save.setActionExpression(createActionExpression("#{controller.saveData('str')}", String.class));


 public void saveData(String str){

  }

我有这个错误

javax.el.ELException: Error Parsing: #{controller.saveData('str')}

非常感谢