001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hdfs.web.resources;
019
020import java.util.Arrays;
021import java.util.Collections;
022import java.util.List;
023
024import javax.ws.rs.core.Response;
025
026
027/** Http operation parameter. */
028public abstract class HttpOpParam<E extends Enum<E> & HttpOpParam.Op>
029    extends EnumParam<E> {
030  /** Parameter name. */
031  public static final String NAME = "op";
032
033  /** Default parameter value. */
034  public static final String DEFAULT = NULL;
035
036  /** Http operation types */
037  public static enum Type {
038    GET, PUT, POST, DELETE;
039  }
040
041  /** Http operation interface. */
042  public static interface Op {
043    /** @return the Http operation type. */
044    public Type getType();
045
046    /** @return true if the operation will do output. */
047    public boolean getDoOutput();
048
049    /** @return true if the operation will be redirected. */
050    public boolean getRedirect();
051
052    /** @return true the expected http response code. */
053    public int getExpectedHttpResponseCode();
054
055    /** @return a URI query string. */
056    public String toQueryString();
057  }
058
059  /** Expects HTTP response 307 "Temporary Redirect". */
060  public static class TemporaryRedirectOp implements Op {
061    static final TemporaryRedirectOp CREATE = new TemporaryRedirectOp(
062        PutOpParam.Op.CREATE);
063    static final TemporaryRedirectOp APPEND = new TemporaryRedirectOp(
064        PostOpParam.Op.APPEND);
065    static final TemporaryRedirectOp OPEN = new TemporaryRedirectOp(
066        GetOpParam.Op.OPEN);
067    static final TemporaryRedirectOp GETFILECHECKSUM = new TemporaryRedirectOp(
068        GetOpParam.Op.GETFILECHECKSUM);
069    
070    static final List<TemporaryRedirectOp> values
071        = Collections.unmodifiableList(Arrays.asList(
072            new TemporaryRedirectOp[]{CREATE, APPEND, OPEN, GETFILECHECKSUM}));
073
074    /** Get an object for the given op. */
075    public static TemporaryRedirectOp valueOf(final Op op) {
076      for(TemporaryRedirectOp t : values) {
077        if (op == t.op) {
078          return t;
079        }
080      }
081      throw new IllegalArgumentException(op + " not found.");
082    }
083
084    private final Op op;
085
086    private TemporaryRedirectOp(final Op op) {
087      this.op = op;
088    }
089
090    @Override
091    public Type getType() {
092      return op.getType();
093    }
094
095    @Override
096    public boolean getDoOutput() {
097      return op.getDoOutput();
098    }
099
100    @Override
101    public boolean getRedirect() {
102      return false;
103    }
104
105    /** Override the original expected response with "Temporary Redirect". */
106    @Override
107    public int getExpectedHttpResponseCode() {
108      return Response.Status.TEMPORARY_REDIRECT.getStatusCode();
109    }
110
111    @Override
112    public String toQueryString() {
113      return op.toQueryString();
114    }
115  }
116
117  /** @return the parameter value as a string */
118  @Override
119  public String getValueString() {
120    return value.toString();
121  }
122
123  HttpOpParam(final Domain<E> domain, final E value) {
124    super(domain, value);
125  }
126}