001// ***************************************************************************************************************************
002// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements.  See the NOTICE file *
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004// * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance            *
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006// *                                                                                                                         *
007// *  http://www.apache.org/licenses/LICENSE-2.0                                                                             *
008// *                                                                                                                         *
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011// * specific language governing permissions and limitations under the License.                                              *
012// ***************************************************************************************************************************
013package org.apache.juneau.rest.arg;
014
015import static org.apache.juneau.http.annotation.HeaderAnnotation.*;
016import java.lang.reflect.*;
017
018import org.apache.juneau.*;
019import org.apache.juneau.http.annotation.*;
020import org.apache.juneau.http.header.*;
021import org.apache.juneau.httppart.*;
022import org.apache.juneau.reflect.*;
023import org.apache.juneau.rest.*;
024import org.apache.juneau.rest.annotation.*;
025import org.apache.juneau.rest.httppart.*;
026
027/**
028 * Resolves method parameters annotated with {@link Header} of type {@link Value} representing response headers
029 * on {@link RestOp}-annotated Java methods.
030 *
031 * <p>
032 * The parameter value must be of type {@link Value} that accepts a value that is then set via:
033 * <p class='bjava'>
034 *    <jv>opSession</jv>
035 *       .{@link RestOpSession#getResponse() getResponse}()
036 *       .{@link RestResponse#setHeader(String,String) setOutput}(<jv>name</jv>,<jv>value</jv>);
037 * </p>
038 *
039 * <h5 class='section'>See Also:</h5><ul>
040 *    <li class='link'><a class="doclink" href="../../../../../index.html#jrs.JavaMethodParameters">Java Method Parameters</a>
041 * </ul>
042 */
043public class ResponseHeaderArg implements RestOpArg {
044   final ResponsePartMeta meta;
045   final String name;
046   private final Type type;
047
048   /**
049    * Static creator.
050    *
051    * @param paramInfo The Java method parameter being resolved.
052    * @param annotations The annotations to apply to any new part parsers.
053    * @return A new {@link ResponseHeaderArg}, or <jk>null</jk> if the parameter is not annotated with {@link Header}.
054    */
055   public static ResponseHeaderArg create(ParamInfo paramInfo, AnnotationWorkList annotations) {
056      if (paramInfo.getParameterType().is(Value.class) && (paramInfo.hasAnnotation(Header.class) || paramInfo.getParameterType().hasAnnotation(Header.class)))
057         return new ResponseHeaderArg(paramInfo, annotations);
058      return null;
059   }
060
061   /**
062    * Constructor.
063    *
064    * @param pi The Java method parameter being resolved.
065    * @param annotations The annotations to apply to any new part parsers.
066    */
067   protected ResponseHeaderArg(ParamInfo pi, AnnotationWorkList annotations) {
068      this.name = findName(pi).orElseThrow(() -> new ArgException(pi, "@Header used without name or value"));
069      this.type = pi.getParameterType().innerType();
070      HttpPartSchema schema = HttpPartSchema.create(Header.class, pi);
071
072      Class<? extends HttpPartSerializer> ps = schema.getSerializer();
073      this.meta = new ResponsePartMeta(HttpPartType.HEADER, schema, ps != null ? HttpPartSerializer.creator().type(ps).apply(annotations).create() : null);
074
075      Class<?> c = type instanceof Class ? (Class<?>)type : type instanceof ParameterizedType ? (Class<?>)((ParameterizedType)type).getRawType() : null;
076      if (c != Value.class)
077         throw new ArgException(pi, "Type must be Value<?> on parameter annotated with @Header annotation");
078   }
079
080   @SuppressWarnings({ "unchecked", "rawtypes" })
081   @Override /* RestOpArg */
082   public Object resolve(final RestOpSession opSession) throws Exception {
083      Value<Object> v = new Value();
084      v.listener(new ValueListener() {
085         @Override
086         public void onSet(Object o) {
087            RestRequest req = opSession.getRequest();
088            RestResponse res = opSession.getResponse();
089            ResponsePartMeta rpm = req.getOpContext().getResponseHeaderMeta(o);
090            if (rpm == null)
091               rpm = ResponseHeaderArg.this.meta;
092            HttpPartSerializerSession pss = rpm.getSerializer() == null ? req.getPartSerializerSession() : rpm.getSerializer().getPartSession();
093            res.setHeader(new SerializedHeader(name, o, pss, rpm.getSchema(), false));
094         }
095      });
096      return v;
097   }
098}