如何使最简单的servlet过滤器尊重设置的字符编码 [英] How to make simplest servlet filter respect setted character encoding
问题描述
我正在尝试编写最简单的servlet过滤器（并将其部署到tomcat）。这是一个常规代码，但实际上我在这里大量使用java方法，所以它几乎是复制粘贴，这也是我添加java标记的原因。
我的问题是 - 如何插入UTF-8字符串来过滤？
这里是代码：
public class SimpleFilter implements javax.servlet.Filter
{
...
public void doFilter（ServletRequest请求，ServletResponse响应，
FilterChain链）
抛出java.io.IOException，javax.servlet.ServletException
{
PrintWriter out = response.getWriter（）
chain.doFilter（request，wrapResponse（（HttpServletResponse）response））
response.setCharacterEncoding（'UTF-8'）
response.setContentType（'text / plain'）
def saw ='АБВГДЕЙКАЭТОНЕПРОСТАЯПЕРЕДАЧАABCDEFGHIJKLMNOP !!!'
def bytes = saw.getBytes（'UTF-8'）
def content = new String（bytes，'UTF-8'）
response.setContentLength（content.length（））
out.write（content）;
out.close（）;
}
private static HttpServletResponse wrapResponse（HttpServletResponse响应）{
返回新的HttpServletResponseWrapper（响应）{
@Override
public PrintWriter getWriter（）{
def writer = new OutputStreamWriter（new ByteArrayOutputStream（），'UTF-8'）
return new PrintWriter（writer）
}
}
}
}
过滤页面的内容类型为 text / plain; charset = ISO -8859-1 。
因此，内容类型已经改变，但字符集被忽略。
正如你所看到的，我已经采取了一些措施肯定的内容是UTF-8，但这些步骤实际上都没有帮助。
我也尝试添加 URIEncoding =UTF-8 或 useBodyEncodingForUri =true属性到
tomcat conf / server.xml中的连接器
如果有人向我解释我做错了什么，那将会很好。
UPD：只是一些解释 - 我正在编写XSLT应用过滤器，这是我试图放弃整个请求的真正原因。
<$ p $ '
def bytes = saw.getBytes（'UTF-8'）
def content = new String（bytes， 'UTF-8'）
不会改变锯和内容之间的东西。你想要做什么（使用 outputstream 和不是作者，这就是为什么字符集重置为ISO-8859-1 查看tomcat文档）：
out.write（saw.getBytes（UTF-8）;
你的代码看起来可以将字符集设置为UTF-8。
我不明白你在用HttpResponseWrapper 。
为了说清楚，这将起作用：
public void doFilter（ServletRequest请求，ServletResponse响应，
FilterChain链）
抛出java.io.IOException，javax.servlet.ServletException
{
OutputStream out = response.getOutputStream（）
response.setCharacterEncoding（'UTF-8'）
response.setContentType（'text / plain'）
def saw ='АБВГДЕЙКАУТ НЕПРОСТАЯПЕРЕДАЧАABCDEFGHIJKLMNOP !!!
response.setContentLength（saw.length（））
out.write（content.getBytes（ UTF-8））;
}
It feels like I'm stuck. I'm trying to write the simplest servlet Filter (and deploy it to tomcat). It's a groovy code, but actually I'm heavily using java approaches here, so it is almost copy-paste, that's the reason I've added java tag as well.
My question is - how can I insert UTF-8 string to filter? Here is the code:
public class SimpleFilter implements javax.servlet.Filter
{
...
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain)
throws java.io.IOException, javax.servlet.ServletException
{
PrintWriter out = response.getWriter()
chain.doFilter(request, wrapResponse((HttpServletResponse) response))
response.setCharacterEncoding('UTF-8')
response.setContentType('text/plain')
def saw = 'АБВГДЕЙКА ЭТО НЕПРОСТАЯ ПЕРЕДАЧА ABCDEFGHIJKLMNOP!!!'
def bytes = saw.getBytes('UTF-8')
def content = new String(bytes, 'UTF-8')
response.setContentLength(content.length())
out.write(content);
out.close();
}
private static HttpServletResponse wrapResponse(HttpServletResponse response) {
return new HttpServletResponseWrapper(response) {
@Override
public PrintWriter getWriter() {
def writer = new OutputStreamWriter(new ByteArrayOutputStream(), 'UTF-8')
return new PrintWriter(writer)
}
}
}
}
Content-Type of the filtered page is text/plain;charset=ISO-8859-1.
So, content type have changed, but charset is ignored.
As you can see, I've take some measures (I guess quite naive) to make sure content is UTF-8, but none of these steps actually was helpful.
I've also tried to add URIEncoding="UTF-8" or useBodyEncodingForUri="true" attributes to
Connector in tomcat conf/server.xml
It would be nice if somebody explained me what I'm doing wrong.
UPD: just a bit of explanation - I'm writing XSLT-applying filter, that is the real reason I'm trying to discard whole request.
def saw = 'АБВГДЕЙКА ЭТО НЕПРОСТАЯ ПЕРЕДАЧА ABCDEFGHIJKLMNOP!!!'
def bytes = saw.getBytes('UTF-8')
def content = new String(bytes, 'UTF-8')
Does not change a thing between saw and content. What you want is to do (using the outputstream and not the writer, this is why the charset is reset to ISO-8859-1 See tomcat doc):
out.write(saw.getBytes("UTF-8);
Your code looks okay to set the charset as UTF-8.
I don't understand what you are doing with HttpResponseWrapper.
To make it clear, this will work:
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain)
throws java.io.IOException, javax.servlet.ServletException
{
OutputStream out = response.getOutputStream()
response.setCharacterEncoding('UTF-8')
response.setContentType('text/plain')
def saw = 'АБВГДЕЙКА ЭТО НЕПРОСТАЯ ПЕРЕДАЧА ABCDEFGHIJKLMNOP!!!'
response.setContentLength(saw.length())
out.write(content.getBytes("UTF-8"));
}
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