goto — Fri, 16 May 2008 03:00:00 GMT

getOutputStream() has already been called for this response问题的解�?br />
在jsp向页面输出图片的时�?使用response.getOutputStream()会有�q�样的提�C�：java.lang.IllegalStateException:getOutputStream() has already been called for this response,会抛出Exception
原因一:
JSP 默认的输出流为PrintWriter ,�?lt;% %>以外的东西所默认的输出方�?如果你尝试在JSP中��用ServletOutputStream��׃��引�v错误.要嘛直接改用Servlet输出 (复写service�Ҏ��),要嘛删除�?><%中的��M��东西(包括HTML标签,�I�格,回�R�{�东�?应该��可以�?br /> 对于�q�样的情况应该这��h��解决�Q�删�?><%之间的所有内容包括空格和换行�W�，最后也要消除空格和换行�W�，最好再加上一句response.reset()�?br /> 原因�?

在J2EE的API参考里有这么个:

ServletResponse的getWriter()�Ҏ��里会抛出�q�个异常,

IllegalStateException - if the getOutputStream method has already been called
for this response object

而它的getOutputStream()�Ҏ��里会抛出�q�个异常.

IllegalStateException - if the getOutputStream method has already been called for this response object

�q�且两者的函数��x��里都有这么样的一�?br /> Either this method or getOutputStream() may be called to write the body, not both.
Either this method or getWriter() may be called to write the body, not both.

以上说明也解释了��Z��么在往��面中写入图片的时候要使用如下循环格式
OutputStream output=response.getOutputStream();
while((len=in.read(b)) >0)
{
output.write(b,0,len);

}
output.flush();
而不是把response.getOutputStream().write()攑ֈ�循环体内

goto 2008-05-16 11:00 发表评论

tomcat 无法调试当前J2EE工程问题报souce not found

goto — Fri, 16 May 2008 03:00:00 GMT

在Eclipse 下调试Servlet 出现了Source not found for XxxAction.execute�Q?..�Q�的问题�Q�猜��x��没有��Servlet代码加入到debug 路径下以致在调试的时候找不到Source�Q�虽知道原因�Q�却不知道怎么解决�?br /> 只能在Eclipse 里�ؕ逛，东点西击�Q�最后终于发��C��问题所在�?br /> �q? 入Window > Preferences > Tomcat > Source Path�Q�在Source Path 标签下有行文字：Add java projects to source path�Q�Eclipse debugger will search for source files in these projects�Q�。将要调试的project 选中然后再调试，果然不再出现Source not found for...了！�Q?/p>

�q�不行再从新部��v一�?重启一下tomcat。就�?/p>

goto 2008-05-16 11:00 发表评论

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tomcat 无法调试当前J2EE工程问题 报souce not found

tomcat 无法调试当前J2EE工程问题报souce not found