记使用JSTL时的一次愚蠢错误

今天使用jstl的foreach，平时没问题，今天出现如下错误：

javax.el.PropertyNotFoundException: Property 'id' not found on type java.lang.String
	javax.el.BeanELResolver$BeanProperties.get(BeanELResolver.java:193)
	javax.el.BeanELResolver$BeanProperties.access$400(BeanELResolver.java:170)
	javax.el.BeanELResolver.property(BeanELResolver.java:279)

明明有id属性，类型为int型，且get，set都有，怎么会报错呢？

于是打开tomcat解析后的代码：

private boolean _jspx_meth_c_005fforEach_005f0(PageContext _jspx_page_context)
          throws Throwable {
    PageContext pageContext = _jspx_page_context;
    JspWriter out = _jspx_page_context.getOut();
    //  c:forEach
    org.apache.taglibs.standard.tag.rt.core.ForEachTag _jspx_th_c_005fforEach_005f0 = (org.apache.taglibs.standard.tag.rt.core.ForEachTag) _005fjspx_005ftagPool_005fc_005fforEach_0026_005fvar_005fitems.get(org.apache.taglibs.standard.tag.rt.core.ForEachTag.class);
    _jspx_th_c_005fforEach_005f0.setPageContext(_jspx_page_context);
    _jspx_th_c_005fforEach_005f0.setParent(null);
    // /WEB-INF/view/body.jsp(33,0) name = items type = java.lang.Object reqTime = true required = false fragment = false deferredValue = false expectedTypeName = null deferredMethod = false methodSignature = null
    _jspx_th_c_005fforEach_005f0.setItems(new String("notices"));
    // /WEB-INF/view/body.jsp(33,0) name = var type = java.lang.String reqTime = false required = false fragment = false deferredValue = false expectedTypeName = null deferredMethod = false methodSignature = null
    _jspx_th_c_005fforEach_005f0.setVar("notice");
    int[] _jspx_push_body_count_c_005fforEach_005f0 = new int[] { 0 };
    try {
      int _jspx_eval_c_005fforEach_005f0 = _jspx_th_c_005fforEach_005f0.doStartTag();
      if (_jspx_eval_c_005fforEach_005f0 != javax.servlet.jsp.tagext.Tag.SKIP_BODY) {
        do {
          out.write("\r\n");
          out.write("<li><a href=\"");
          out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${pageContext.request.contextPath}", java.lang.String.class, (PageContext)_jspx_page_context, null, false));
          out.write("/news/detail?id=");
          out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${notice.id}", java.lang.String.class, (PageContext)_jspx_page_context, null, false)); //注意，此时notice解析类型为String，不是bean，肯定有问题
          out.write("\" title=\"");
          out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${notice.title}", java.lang.String.class, (PageContext)_jspx_page_context, null, false));
          out.write("\"><font style=color:green>");
          out.write((java.lang.String) org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate("${notice.title}", java.lang.String.class, (PageContext)_jspx_page_context, null, false));
          out.write("</font></a></li>\r\n");
          int evalDoAfterBody = _jspx_th_c_005fforEach_005f0.doAfterBody();
          if (evalDoAfterBody != javax.servlet.jsp.tagext.BodyTag.EVAL_BODY_AGAIN)
            break;
        } while (true);
      }
      if (_jspx_th_c_005fforEach_005f0.doEndTag() == javax.servlet.jsp.tagext.Tag.SKIP_PAGE) {
        return true;
      }
    } catch (Throwable _jspx_exception) {
      while (_jspx_push_body_count_c_005fforEach_005f0[0]-- > 0)
        out = _jspx_page_context.popBody();
      _jspx_th_c_005fforEach_005f0.doCatch(_jspx_exception);
    } finally {
      _jspx_th_c_005fforEach_005f0.doFinally();
      _005fjspx_005ftagPool_005fc_005fforEach_0026_005fvar_005fitems.reuse(_jspx_th_c_005fforEach_005f0);
    }
    return false;
  }

发现解析时notice变量被当做String了，不是Javabean对象，于是看代码，发现竟然少写了一个${}符号，stupid！！！

错误写法：

<c:forEach items="notices" var="notice">
<li><a href="${pageContext.request.contextPath}/news/detail/${notice.id}" title="${notice.title}"><font style=color:green>${notice.title}</font></a></li>
</c:forEach>

修正后：

<c:forEach items="${notices}" var="notice">
<li><a href="${pageContext.request.contextPath}/news/detail/${notice.id}" title="${notice.title}"><font style=color:green>${notice.title}</font></a></li>
</c:forEach>

谨以此警告自己，不能再犯此低级错误！