What I found to be the solution was something very very simple that I think you should try before tinkering with the preferences. In my case I had this problem in a strings file that had as a base tag "resources" ...all I did was delete the tag from the top and the bottom, clean the project, save the file and reinsert the tag. The problem has since disappeared and never gave me any warnings. It may sound to simple to be true but hey, sometimes it's the simplest things that solve the problems. Cheers

下面是这个问题的有效解决方案:

步骤1:右键单击项目并进入属性

步骤2:转到“libraries”，删除项目的“JRE系统库”

步骤3:点击“添加库”——>“JRE系统库”——>选择“工作区默认JRE”

步骤3:转到“订购和导出”，并标记新添加的“JRE系统库”

步骤4:刷新和清理项目

尤里卡!它正在工作:)

在Eclipse 3.5.2中解决了此问题。两个完全相同的布局，其中一个有警告。关闭所有标签，重新打开时，警告已经消失。

What I found to be the solution was something very very simple that I think you should try before tinkering with the preferences. In my case I had this problem in a strings file that had as a base tag "resources" ...all I did was delete the tag from the top and the bottom, clean the project, save the file and reinsert the tag. The problem has since disappeared and never gave me any warnings. It may sound to simple to be true but hey, sometimes it's the simplest things that solve the problems. Cheers

答:

下面每个DTD部分的注释。更多信息请参考官方规范。

  <!
  DOCTYPE ----------------------------------------- correct
  templates --------------------------------------- correct  Name matches root element.
  PUBLIC ------------------------------------------ correct  Accessing external subset via URL.
  "//UNKNOWN/" ------------------------------------ invalid? Seems useless, wrong, out-of-place.
                                                             Safely replaceable by DTD URL in next line.
  "http://fast-code.sourceforge.net/template.dtd" - invalid  URL is currently broken.
  >

简单的解释:

一个非常基本的DTD看起来就像这里的第二行:

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE nameOfYourRootElement>
<nameOfYourRootElement>
</nameOfYourRootElement>

详细解释:

dtd用于建立商定的数据格式并验证此类数据的接收。它们定义了XML文档的结构，包括:

法律要素清单 特殊字符 字符串 还有更多

E.g.

<!DOCTYPE nameOfYourRootElement
[
<!ELEMENT nameOfYourRootElement (nameOfChildElement1,nameOfChildElement2)>
<!ELEMENT nameOfChildElement1 (#PCDATA)>
<!ELEMENT nameOfChildElement2 (#PCDATA)>
<!ENTITY nbsp "&#xA0;"> 
<!ENTITY author "Your Author Name">
]>

Meaning of above lines... Line 1) Root element defined as "nameOfYourRootElement" Line 2) Start of element definitions Line 3) Root element children defined as "nameOfYourRootElement1" and "nameOfYourRootElement2" Line 4) Child element, which is defined as data type #PCDATA Line 5) Child element, which is defined as data type #PCDATA Line 6) Expand instances of   to   when document is parsed by XML parser Line 7) Expand instances of &author; to Your Author Name when document is parsed by XML parser Line 8) End of definitions

一种新的干净的方法可能是这样写xml:

<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE rootElement>

<rootElement>
 ....
</rootElement>

以上内容适用于Eclipse Juno+