[120] | 1 | /** |
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| 2 | * Licensed to the Apache Software Foundation (ASF) under one |
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| 3 | * or more contributor license agreements. See the NOTICE file |
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| 4 | * distributed with this work for additional information |
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| 5 | * regarding copyright ownership. The ASF licenses this file |
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| 6 | * to you under the Apache License, Version 2.0 (the |
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| 7 | * "License"); you may not use this file except in compliance |
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| 8 | * with the License. You may obtain a copy of the License at |
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| 9 | * |
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| 10 | * http://www.apache.org/licenses/LICENSE-2.0 |
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| 11 | * |
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| 12 | * Unless required by applicable law or agreed to in writing, software |
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| 13 | * distributed under the License is distributed on an "AS IS" BASIS, |
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| 14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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| 15 | * See the License for the specific language governing permissions and |
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| 16 | * limitations under the License. |
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| 17 | */ |
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| 18 | package org.apache.hadoop.fs; |
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| 19 | |
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| 20 | import java.net.URLStreamHandlerFactory; |
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| 21 | import java.util.HashMap; |
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| 22 | import java.util.Map; |
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| 23 | |
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| 24 | import org.apache.hadoop.conf.Configuration; |
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| 25 | |
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| 26 | /** |
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| 27 | * Factory for URL stream handlers. |
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| 28 | * |
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| 29 | * There is only one handler whose job is to create UrlConnections. A |
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| 30 | * FsUrlConnection relies on FileSystem to choose the appropriate FS |
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| 31 | * implementation. |
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| 32 | * |
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| 33 | * Before returning our handler, we make sure that FileSystem knows an |
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| 34 | * implementation for the requested scheme/protocol. |
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| 35 | */ |
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| 36 | public class FsUrlStreamHandlerFactory implements |
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| 37 | URLStreamHandlerFactory { |
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| 38 | |
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| 39 | // The configuration holds supported FS implementation class names. |
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| 40 | private Configuration conf; |
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| 41 | |
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| 42 | // This map stores whether a protocol is know or not by FileSystem |
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| 43 | private Map<String, Boolean> protocols = new HashMap<String, Boolean>(); |
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| 44 | |
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| 45 | // The URL Stream handler |
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| 46 | private java.net.URLStreamHandler handler; |
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| 47 | |
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| 48 | public FsUrlStreamHandlerFactory() { |
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| 49 | this.conf = new Configuration(); |
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| 50 | // force the resolution of the configuration files |
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| 51 | // this is required if we want the factory to be able to handle |
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| 52 | // file:// URLs |
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| 53 | this.conf.getClass("fs.file.impl", null); |
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| 54 | this.handler = new FsUrlStreamHandler(this.conf); |
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| 55 | } |
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| 56 | |
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| 57 | public FsUrlStreamHandlerFactory(Configuration conf) { |
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| 58 | this.conf = new Configuration(conf); |
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| 59 | // force the resolution of the configuration files |
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| 60 | this.conf.getClass("fs.file.impl", null); |
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| 61 | this.handler = new FsUrlStreamHandler(this.conf); |
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| 62 | } |
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| 63 | |
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| 64 | public java.net.URLStreamHandler createURLStreamHandler(String protocol) { |
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| 65 | if (!protocols.containsKey(protocol)) { |
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| 66 | boolean known = |
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| 67 | (conf.getClass("fs." + protocol + ".impl", null) != null); |
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| 68 | protocols.put(protocol, known); |
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| 69 | } |
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| 70 | if (protocols.get(protocol)) { |
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| 71 | return handler; |
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| 72 | } else { |
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| 73 | // FileSystem does not know the protocol, let the VM handle this |
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| 74 | return null; |
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| 75 | } |
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| 76 | } |
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| 77 | |
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| 78 | } |
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