首先我想直接回答这个问题，对于 Java 人来说：
这是您可以使用过滤器在请求标头触及控制器之前对其进行操作的方法：
class TracingFilterAction extends Action<TracingFilter> {
@Override
public Promise<SimpleResult> call(Context ctx) throws Throwable {
ctx.request().headers().put(key, value)
自从你问了一个关于“跟踪”请求的问题，我有分享我的 LoggingFilter 的冲动。
对于 Play Framework Java 社区，我开发了一个出色的 LoggingFilter，它将记录完整的请求、标头和负载。
对于 Scala 社区，它应该仍然适合您，但您将不得不在您的 Scala 项目中使用一些额外的 Java 代码:(
用法
这将启用类级别的请求日志记录
@LoggingFilter
public final class MyController extends Controller {
}
这将在方法级别启用请求日志记录
@LoggingFilter
public Result index() {
...
}
这是 2.2.x（可能还有 2.2.3）的实现
import java.io.UnsupportedEncodingException;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import java.net.URLEncoder;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;
import org.apache.commons.lang3.StringUtils;
import play.Logger;
import play.Logger.ALogger;
import play.libs.F.Function0;
import play.libs.F.Promise;
import play.mvc.Action;
import play.mvc.Http.Context;
import play.mvc.Http.Request;
import play.mvc.SimpleResult;
import play.mvc.With;
@With(LoggingFilterAction.class)
@Target({ ElementType.TYPE, ElementType.METHOD })
@Retention(RetentionPolicy.RUNTIME)
public @interface LoggingFilter {
}
class LoggingFilterAction extends Action<LoggingFilter> {
private static final String NOTIFICATION_PREFIX = "* ";
private static final String REQUEST_PREFIX = "> ";
private static final String RESPONSE_PREFIX = "< ";
private final ALogger logger = Logger.of(getClass());
private final AtomicLong _id = new AtomicLong(0);
private final String newLine = System.getProperty("line.separator");
@Override
public Promise<SimpleResult> call(Context ctx) throws Throwable {
long id = _id.incrementAndGet();
StringBuilder b = new StringBuilder();
printRequestLine(b, id, ctx.request().method(), ctx.request().uri());
printRequestHeaders(b, id, REQUEST_PREFIX, ctx.request().headers());
String requestContent = contentAsString(ctx.request(), b);
if (!StringUtils.isEmpty(requestContent)) {
b.append(requestContent);
}
b.append(newLine);
final SimpleResult result = delegate.call(ctx).get(5, TimeUnit.SECONDS);
printResponseLine(b, id, getStatus(result));
printResponseHeaders(b, id, RESPONSE_PREFIX, headers(result));
String responseContent = contentAsString(result);
if (!StringUtils.isEmpty(responseContent)) {
b.append(responseContent);
}
b.append(newLine);
logger.debug(b.toString());
return Promise.promise(new Function0<SimpleResult>() {
public SimpleResult apply() throws Throwable {
return result;
}
});
}
private String header(String header, SimpleResult result) {
return play.core.j.JavaResultExtractor.getHeaders(result).get(header);
}
private String charset(SimpleResult result) {
String h = header("Content-Type", result);
if (h == null) return null;
if (h.contains("; charset=")) {
return h.substring(h.indexOf("; charset=") + 10, h.length()).trim();
}
else {
return null;
}
}
private byte[] contentAsBytes(SimpleResult result) {
return play.core.j.JavaResultExtractor.getBody(result);
}
private String contentAsString(Request request, StringBuilder b) {
try {
if (request.body() == null) {
return "request has no body";
}
} catch (ClassCastException e) {
return "request has no body";
}
if (request.body().asText() != null) {
logger.debug("getting request body as text");
return request.body().asText();
}
if (request.body().asRaw() != null) {
logger.debug("getting request body as raw");
try {
return new String(request.body().asRaw().asBytes(), "utf-8");
}
catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
}
}
if (request.body().asJson() != null) {
logger.debug("getting request body as json");
return request.body().asJson().toString();
}
if (request.body().asFormUrlEncoded() != null) {
logger.debug("getting request body as as formUrlEncoded");
return toString(request.body().asFormUrlEncoded());
}
if (request.body().asMultipartFormData() != null) {
logger.debug("getting request body as multipartFormData");
return request.body().asMultipartFormData().toString();
}
if (request.body().asXml() != null) {
logger.debug("getting request body as xml");
return request.body().asXml().toString();
}
logger.debug("getting request body as default");
return request.body().toString();
}
private String toString(Map<String, String[]> data) {
StringBuilder sb = new StringBuilder();
for (Map.Entry<String, String[]> e : data.entrySet()) {
String[] val = e.getValue();
String key = e.getKey();
if (sb.length() > 0) {
sb.append("&");
}
try {
sb.append(key).append("=").append(URLEncoder.encode(val[0], "utf-8"));
}
catch (UnsupportedEncodingException e1) {
throw new RuntimeException(e1);
}
}
return sb.toString();
}
private String contentAsString(SimpleResult result) {
try {
String charset = charset(result);
if (charset == null) {
charset = "utf-8";
}
return new String(contentAsBytes(result), charset);
}
catch (RuntimeException e) {
throw e;
}
catch (Throwable t) {
throw new RuntimeException(t);
}
}
private Map<String, String> headers(SimpleResult result) {
return play.core.j.JavaResultExtractor.getHeaders(result);
}
private int getStatus(SimpleResult result) {
return result.getWrappedSimpleResult().header().status();
}
private StringBuilder prefixId(StringBuilder b, long id) {
b.append(Long.toString(id)).append(" ");
return b;
}
private void printRequestLine(StringBuilder b, long id, String method, String uri) {
prefixId(b, id).append(NOTIFICATION_PREFIX)
.append("LoggingFilter - Request received on thread ")
.append(Thread.currentThread().getName()).append("\n");
prefixId(b, id).append(REQUEST_PREFIX).append(method).append(" ").append(uri).append("\n");
}
private void printResponseLine(StringBuilder b, long id, int status) {
prefixId(b, id).append(NOTIFICATION_PREFIX)
.append("LoggingFilter - Response received on thread ")
.append(Thread.currentThread().getName()).append("\n");
prefixId(b, id).append(RESPONSE_PREFIX).append(Integer.toString(status)).append("\n");
}
private void printResponseHeaders(StringBuilder b, long id, final String prefix,
Map<String, String> headers) {
for (Map.Entry<String, String> e : headers.entrySet()) {
String val = e.getValue();
String header = e.getKey();
printPrefixedHeader(b, id, prefix, header, new String[] { val });
}
}
private void printRequestHeaders(StringBuilder b, long id, final String prefix,
Map<String, String[]> headers) {
for (Map.Entry<String, String[]> e : headers.entrySet()) {
String[] val = e.getValue();
String header = e.getKey();
printPrefixedHeader(b, id, prefix, header, val);
}
}
private void printPrefixedHeader(StringBuilder b, long id, final String prefix, String header,
String[] val) {
if (val.length == 1) {
prefixId(b, id).append(prefix).append(header).append(": ").append(val[0]).append("\n");
}
else {
StringBuilder sb = new StringBuilder();
boolean add = false;
for (Object s : val) {
if (add) {
sb.append(',');
}
add = true;
sb.append(s);
}
prefixId(b, id).append(prefix).append(header).append(": ").append(sb.toString())
.append("\n");
}
}
}
添加基于读取布尔配置属性来禁用日志记录的功能应该是一个简单的练习。
然后在生产/登台/任何模式下，您可以轻松禁用 LoggingFilter。
干杯！