Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.iflytek.spider.protocol; import java.io.DataInput; import java.io.DataOutput; import java.io.IOException; import java.util.HashMap; import org.apache.hadoop.io.VersionMismatchException; import org.apache.hadoop.io.Writable; import org.apache.hadoop.io.WritableUtils; /** * @author Andrzej Bialecki */ public class ProtocolStatus implements Writable { private final static byte VERSION = 2; /** Content was retrieved without errors. */ public static final int SUCCESS = 1; /** Content was not retrieved. Any further errors may be indicated in args. */ public static final int FAILED = 2; /** This protocol was not found. Application may attempt to retry later. */ public static final int PROTO_NOT_FOUND = 10; /** Resource is gone. */ public static final int GONE = 11; /** Resource has moved permanently. New url should be found in args. */ public static final int MOVED = 12; /** Resource has moved temporarily. New url should be found in args. */ public static final int TEMP_MOVED = 13; /** Resource was not found. */ public static final int NOTFOUND = 14; /** Temporary failure. Application may retry immediately. */ public static final int RETRY = 15; /** Unspecified exception occured. Further information may be provided in args. */ public static final int EXCEPTION = 16; /** Access denied - authorization required, but missing/incorrect. */ public static final int ACCESS_DENIED = 17; /** Access denied by robots.txt rules. */ public static final int ROBOTS_DENIED = 18; /** Too many redirects. */ public static final int REDIR_EXCEEDED = 19; /** Not fetching. */ public static final int NOTFETCHING = 20; /** Unchanged since the last fetch. */ public static final int NOTMODIFIED = 21; /** Request was refused by protocol plugins, because it would block. * The expected number of milliseconds to wait before retry may be provided * in args. */ public static final int WOULDBLOCK = 22; /** Thread was blocked http.max.delays times during fetching. */ public static final int BLOCKED = 23; // Useful static instances for status codes that don't usually require any // additional arguments. public static final ProtocolStatus STATUS_SUCCESS = new ProtocolStatus(SUCCESS); public static final ProtocolStatus STATUS_FAILED = new ProtocolStatus(FAILED); public static final ProtocolStatus STATUS_GONE = new ProtocolStatus(GONE); public static final ProtocolStatus STATUS_NOTFOUND = new ProtocolStatus(NOTFOUND); public static final ProtocolStatus STATUS_RETRY = new ProtocolStatus(RETRY); public static final ProtocolStatus STATUS_ROBOTS_DENIED = new ProtocolStatus(ROBOTS_DENIED); public static final ProtocolStatus STATUS_REDIR_EXCEEDED = new ProtocolStatus(REDIR_EXCEEDED); public static final ProtocolStatus STATUS_NOTFETCHING = new ProtocolStatus(NOTFETCHING); public static final ProtocolStatus STATUS_NOTMODIFIED = new ProtocolStatus(NOTMODIFIED); public static final ProtocolStatus STATUS_WOULDBLOCK = new ProtocolStatus(WOULDBLOCK); public static final ProtocolStatus STATUS_BLOCKED = new ProtocolStatus(BLOCKED); private int code; private long lastModified; private String[] args; private static final HashMap<Integer, String> codeToName = new HashMap<Integer, String>(); static { codeToName.put(new Integer(SUCCESS), "success"); codeToName.put(new Integer(FAILED), "failed"); codeToName.put(new Integer(PROTO_NOT_FOUND), "proto_not_found"); codeToName.put(new Integer(GONE), "gone"); codeToName.put(new Integer(MOVED), "moved"); codeToName.put(new Integer(TEMP_MOVED), "temp_moved"); codeToName.put(new Integer(NOTFOUND), "notfound"); codeToName.put(new Integer(RETRY), "retry"); codeToName.put(new Integer(EXCEPTION), "exception"); codeToName.put(new Integer(ACCESS_DENIED), "access_denied"); codeToName.put(new Integer(ROBOTS_DENIED), "robots_denied"); codeToName.put(new Integer(REDIR_EXCEEDED), "redir_exceeded"); codeToName.put(new Integer(NOTFETCHING), "notfetching"); codeToName.put(new Integer(NOTMODIFIED), "notmodified"); codeToName.put(new Integer(WOULDBLOCK), "wouldblock"); codeToName.put(new Integer(BLOCKED), "blocked"); } public ProtocolStatus() { } public ProtocolStatus(int code, String[] args) { this.code = code; this.args = args; } public ProtocolStatus(int code, String[] args, long lastModified) { this.code = code; this.args = args; this.lastModified = lastModified; } public ProtocolStatus(int code) { this(code, null); } public ProtocolStatus(int code, long lastModified) { this(code, null, lastModified); } public ProtocolStatus(int code, Object message) { this(code, message, 0L); } public ProtocolStatus(int code, Object message, long lastModified) { this.code = code; this.lastModified = lastModified; if (message != null) this.args = new String[] { String.valueOf(message) }; } public ProtocolStatus(Throwable t) { this(EXCEPTION, t); } public static ProtocolStatus read(DataInput in) throws IOException { ProtocolStatus res = new ProtocolStatus(); res.readFields(in); return res; } public void readFields(DataInput in) throws IOException { byte version = in.readByte(); switch (version) { case 1: code = in.readByte(); lastModified = in.readLong(); args = WritableUtils.readCompressedStringArray(in); break; case VERSION: code = in.readByte(); lastModified = in.readLong(); args = WritableUtils.readStringArray(in); break; default: throw new VersionMismatchException(VERSION, version); } } public void write(DataOutput out) throws IOException { out.writeByte(VERSION); out.writeByte((byte) code); out.writeLong(lastModified); if (args == null) { out.writeInt(-1); } else { WritableUtils.writeStringArray(out, args); } } public void setArgs(String[] args) { this.args = args; } public String[] getArgs() { return args; } public int getCode() { return code; } public String getName() { return codeToName.get(this.code); } public void setCode(int code) { this.code = code; } public boolean isSuccess() { return code == SUCCESS; } public boolean isTransientFailure() { return code == ACCESS_DENIED || code == EXCEPTION || code == REDIR_EXCEEDED || code == RETRY || code == TEMP_MOVED || code == WOULDBLOCK || code == PROTO_NOT_FOUND; } public boolean isPermanentFailure() { return code == FAILED || code == GONE || code == MOVED || code == NOTFOUND || code == ROBOTS_DENIED; } public String getMessage() { if (args != null && args.length > 0) return args[0]; return null; } public void setMessage(String msg) { if (args != null && args.length > 0) args[0] = msg; else args = new String[] { msg }; } public long getLastModified() { return lastModified; } public void setLastModified(long lastModified) { this.lastModified = lastModified; } public boolean equals(Object o) { if (o == null) return false; if (!(o instanceof ProtocolStatus)) return false; ProtocolStatus other = (ProtocolStatus) o; if (this.code != other.code || this.lastModified != other.lastModified) return false; if (this.args == null) { if (other.args == null) return true; else return false; } else { if (other.args == null) return false; if (other.args.length != this.args.length) return false; for (int i = 0; i < this.args.length; i++) { if (!this.args[i].equals(other.args[i])) return false; } } return true; } public String toString() { StringBuffer res = new StringBuffer(); res.append(codeToName.get(new Integer(code)) + "(" + code + "), lastModified=" + lastModified); if (args != null) { if (args.length == 1) { res.append(": " + String.valueOf(args[0])); } else { for (int i = 0; i < args.length; i++) { if (args[i] != null) res.append(", args[" + i + "]=" + String.valueOf(args[i])); } } } return res.toString(); } }