多亏了此页面上的其他答案，我找到了一种实现方法。。。非常接近他们的建议，但是事实证明，使它起作用的唯一方法是重写“
getOutputStream”并查看此时的contentType。我已将此过滤器作为链中的第一个过滤器，它似乎工作正常。
import java.io.IOException;import javax.servlet.*;import javax.servlet.http.*;import javax.ws.rs.core.MediaType;public class EnsureJsonIsUtf8ResponseFilter implements Filter{ final String APPLICATION_JSON_WITH_UTF8_CHARSET = MediaType.APPLICATION_JSON + ";charset=" + java.nio.charset.StandardCharsets.UTF_8; @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { HttpServletResponse r = (HttpServletResponse) response; HttpServletResponse wrappedResponse = new HttpServletResponseWrapper(r) { @Override public ServletOutputStream getOutputStream() throws java.io.IOException { ServletResponse response = this.getResponse(); String ct = (response != null) ? response.getContentType() : null; if (ct != null && ct.toLowerCase().startsWith(MediaType.APPLICATION_JSON)) { response.setContentType(APPLICATION_JSON_WITH_UTF8_CHARSET); } return super.getOutputStream(); } }; chain.doFilter(request, wrappedResponse); } @Override public void init(FilterConfig filterConfig) throws ServletException { // This method intentionally left blank } @Override public void destroy() { // This method intentionally left blank }}
