Authentication Codes 305: Fill & Download for Free

I added this question, because i have been asked by in one interview.Successful Responses:Successful response code: code lies between 200 to 399.200→If response contain message body(i.e object) + with status message as OK204→if response doesn’t contain message body + No Content is returned .Error Responses:Error response code lies between 400 to 599400→when the request is not understood by server(BAD Request).401→can be used for unauthenticated user (UnAuthorised).403→authenticated user with insufficient permission(Forbidden)404→ when the typed url in the domain is wrong(Page Not Found).405→when requested HTTP method is not mapped(Method Not Found)406→when requested input is (text/html), and allowed is (application/json) (Not Accepted)500→server encountered condition, which prevent it from processing a request (Internal Server Error)501→ Not Implemented502→ Bad Gateway503→ Service Unavailable504→ Gateway Timeout505→ Http Version not supportedIf you want to study from code, then you can look at servlet interface javax.servlet.http.HttpServletResponse. /**  * Status code (100) indicating the client can continue.  */  public static final int SC_CONTINUE = 100;  /**  * Status code (101) indicating the server is switching protocols  * according to Upgrade header.  */  public static final int SC_SWITCHING_PROTOCOLS = 101;  /**  * Status code (200) indicating the request succeeded normally.  */  public static final int SC_OK = 200;  /**  * Status code (201) indicating the request succeeded and created  * a new resource on the server.  */  public static final int SC_CREATED = 201;  /**  * Status code (202) indicating that a request was accepted for  * processing, but was not completed.  */  public static final int SC_ACCEPTED = 202;  /**  * Status code (203) indicating that the meta information presented  * by the client did not originate from the server.  */  public static final int SC_NON_AUTHORITATIVE_INFORMATION = 203;  /**  * Status code (204) indicating that the request succeeded but that  * there was no new information to return.  */  public static final int SC_NO_CONTENT = 204;  /**  * Status code (205) indicating that the agent <em>SHOULD</em> reset  * the document view which caused the request to be sent.  */  public static final int SC_RESET_CONTENT = 205;  /**  * Status code (206) indicating that the server has fulfilled  * the partial GET request for the resource.  */  public static final int SC_PARTIAL_CONTENT = 206;  /**  * Status code (300) indicating that the requested resource  * corresponds to any one of a set of representations, each with  * its own specific location.  */  public static final int SC_MULTIPLE_CHOICES = 300;  /**  * Status code (301) indicating that the resource has permanently  * moved to a new location, and that future references should use a  * new URI with their requests.  */  public static final int SC_MOVED_PERMANENTLY = 301;  /**  * Status code (302) indicating that the resource has temporarily  * moved to another location, but that future references should  * still use the original URI to access the resource.  *  * This definition is being retained for backwards compatibility.  * SC_FOUND is now the preferred definition.  */  public static final int SC_MOVED_TEMPORARILY = 302;  /**  * Status code (302) indicating that the resource reside  * temporarily under a different URI. Since the redirection might  * be altered on occasion, the client should continue to use the  * Request-URI for future requests.(HTTP/1.1) To represent the  * status code (302), it is recommended to use this variable.  */  public static final int SC_FOUND = 302;  /**  * Status code (303) indicating that the response to the request  * can be found under a different URI.  */  public static final int SC_SEE_OTHER = 303;  /**  * Status code (304) indicating that a conditional GET operation  * found that the resource was available and not modified.  */  public static final int SC_NOT_MODIFIED = 304;  /**  * Status code (305) indicating that the requested resource  * <em>MUST</em> be accessed through the proxy given by the  * <code><em>Location</em></code> field.  */  public static final int SC_USE_PROXY = 305;  /**  * Status code (307) indicating that the requested resource   * resides temporarily under a different URI. The temporary URI  * <em>SHOULD</em> be given by the <code><em>Location</em></code>   * field in the response.  */  public static final int SC_TEMPORARY_REDIRECT = 307;  /**  * Status code (400) indicating the request sent by the client was  * syntactically incorrect.  */  public static final int SC_BAD_REQUEST = 400;  /**  * Status code (401) indicating that the request requires HTTP  * authentication.  */  public static final int SC_UNAUTHORIZED = 401;  /**  * Status code (402) reserved for future use.  */  public static final int SC_PAYMENT_REQUIRED = 402;  /**  * Status code (403) indicating the server understood the request  * but refused to fulfill it.  */  public static final int SC_FORBIDDEN = 403;  /**  * Status code (404) indicating that the requested resource is not  * available.  */  public static final int SC_NOT_FOUND = 404;  /**  * Status code (405) indicating that the method specified in the  * <code><em>Request-Line</em></code> is not allowed for the resource  * identified by the <code><em>Request-URI</em></code>.  */  public static final int SC_METHOD_NOT_ALLOWED = 405;  /**  * Status code (406) indicating that the resource identified by the  * request is only capable of generating response entities which have  * content characteristics not acceptable according to the accept  * headers sent in the request.  */  public static final int SC_NOT_ACCEPTABLE = 406;  /**  * Status code (407) indicating that the client <em>MUST</em> first  * authenticate itself with the proxy.  */  public static final int SC_PROXY_AUTHENTICATION_REQUIRED = 407;  /**  * Status code (408) indicating that the client did not produce a  * request within the time that the server was prepared to wait.  */  public static final int SC_REQUEST_TIMEOUT = 408;  /**  * Status code (409) indicating that the request could not be  * completed due to a conflict with the current state of the  * resource.  */  public static final int SC_CONFLICT = 409;  /**  * Status code (410) indicating that the resource is no longer  * available at the server and no forwarding address is known.  * This condition <em>SHOULD</em> be considered permanent.  */  public static final int SC_GONE = 410;  /**  * Status code (411) indicating that the request cannot be handled  * without a defined <code><em>Content-Length</em></code>.  */  public static final int SC_LENGTH_REQUIRED = 411;  /**  * Status code (412) indicating that the precondition given in one  * or more of the request-header fields evaluated to false when it  * was tested on the server.  */  public static final int SC_PRECONDITION_FAILED = 412;  /**  * Status code (413) indicating that the server is refusing to process  * the request because the request entity is larger than the server is  * willing or able to process.  */  public static final int SC_REQUEST_ENTITY_TOO_LARGE = 413;  /**  * Status code (414) indicating that the server is refusing to service  * the request because the <code><em>Request-URI</em></code> is longer  * than the server is willing to interpret.  */  public static final int SC_REQUEST_URI_TOO_LONG = 414;  /**  * Status code (415) indicating that the server is refusing to service  * the request because the entity of the request is in a format not  * supported by the requested resource for the requested method.  */  public static final int SC_UNSUPPORTED_MEDIA_TYPE = 415;  /**  * Status code (416) indicating that the server cannot serve the  * requested byte range.  */  public static final int SC_REQUESTED_RANGE_NOT_SATISFIABLE = 416;  /**  * Status code (417) indicating that the server could not meet the  * expectation given in the Expect request header.  */  public static final int SC_EXPECTATION_FAILED = 417;  /**  * Status code (500) indicating an error inside the HTTP server  * which prevented it from fulfilling the request.  */  public static final int SC_INTERNAL_SERVER_ERROR = 500;  /**  * Status code (501) indicating the HTTP server does not support  * the functionality needed to fulfill the request.  */  public static final int SC_NOT_IMPLEMENTED = 501;  /**  * Status code (502) indicating that the HTTP server received an  * invalid response from a server it consulted when acting as a  * proxy or gateway.  */  public static final int SC_BAD_GATEWAY = 502;  /**  * Status code (503) indicating that the HTTP server is  * temporarily overloaded, and unable to handle the request.  */  public static final int SC_SERVICE_UNAVAILABLE = 503;  /**  * Status code (504) indicating that the server did not receive  * a timely response from the upstream server while acting as  * a gateway or proxy.  */  public static final int SC_GATEWAY_TIMEOUT = 504;  /**  * Status code (505) indicating that the server does not support  * or refuses to support the HTTP protocol version that was used  * in the request message.  */  public static final int SC_HTTP_VERSION_NOT_SUPPORTED = 505; 

The Roman Empire lasted a rather long time (27 BC – 1453 AD) and produced many capable emperors. Those included people like Leo VI and Constantine VII, great scholar-emperors, brilliant administrators/fiscal reformists like Anastasius and the enlightened rulers of the Antonine dynasty that presided over a golden age (in Gibbon’s words: If a man were called to fix the period in the history of the world during which the condition of the human race was most happy and prosperous, he would, without hesitation, name that which elapsed from the death of Domitian to the accession of Commodus. The vast extent of the Roman Empire was governed by absolute power, under the guidance of virtue and wisdom. The armies were restrained by the firm but gentle hand of four successive emperors, whose characters and authority commanded respect). As such, choosing the three more effective rulers of Rome is a rather hard task and opinions will naturally differ. In my personal opinion, the three most effective were:3. Justinian (527 – 565)Usually, we focus on Justinian’s reconquest of the West (or, at least, part of it). Yet, his most enduring legacy wasn’t his reconquest but his legal reform. From 529 to 534, Justinian collected and codified Roman law (from Hadrian’s time) in his Codex Justinianus (Code of Justinian). This not only formed the basis of Roman law for the next thousand years, but it also became the basis for much of the European law codes. The extend of its influence cannot be overstated. It was the crowning achievement of Justinian’s reign. Justinian was also able to keep a tight leash on his generals (including the brilliant Belisarius and the eunuch Narses) and squash any opposition; when there was a revolt by the populace of Constantinople (Nika Revolt, 532), he brutally crushed it, massacring more than 30,000 people and asserting imperial control. Justinian also simplified provincial administration by delegating more powers to prefectures and provinces while reducing the powers of the dioceses. Whatever one may think about his reconquest of the West, he was one of the more competent and effective administrators of Rome.2. Diocletian (284 – 305)While Constantine the Great was the more influential emperor of the time (due to his support for Christianity and construction of Constantinople), it was Diocletian that was the most effective administrator and in many ways a second ‘founder’ of the empire. He made widespread reforms that changed the nature of the Roman Empire. He expanded the army in order to oppose the barbarian incursions while also expanding the bureaucracy in order to collect more taxes to finance the expanded state machinery (he introduced a new system of taxation based on heads (capita) and land (iugera) while he also issued better quality coinage to stabilize the monetary system). He also reformed the administration by bringing the number of provinces up from fifty to about a hundred; he did so by splitting larger provinces (such as Egypt) into smaller ones. This ensured better local administration and reduced the risk of provincial revolt. Diocletian also divorced civil and military responsibilities, with governors assuming the former and duces the later. His longest-lasting reform though was his twofold administrative division of the empire.1. Augustus (27 BC – 14 AD)By far the most effective ruler Rome had was its first emperor, Octavian Augustus. He was the man that laid the foundations of the Roman Empire. He defeated his rivals and ensured his supremacy in the Roman world by 31 BC (with the victory of his forces at the naval battle of Actium). Augustus did not present himself as the founder of an empire but rather as the restorer of the Roman Republic. He did not alter the republican institutions; assemblies continued to be held as before and Augustus even distributed bribes to make elections look authentic. Nevertheless, he took for himself the position of princeps and was the effective ruler of Rome, being granted tribunal powers (to convene the Senate and people, veto the actions of assemblies and Senate, preside over elections and speak first at meetings), purging his enemies in the Senate in 29 BC, ensuring direct control of the provinces in which legions were stationed and forming the Praetorian Guards. His military supremacy allowed him to be the supreme ruler of the Roman world, even if officially the state was still a republic. Augustus also reformed revenue collection, bringing large parts of Rome’s empire under consistent direct taxation instead of asking for intermittent tributes. Taxation was determined by population census and private tax farming was abolished in favor for civil service tax collectors. This made provincial administration far more tolerable, decreased corruption and oppression and increased revenues.

Here only 3XX HTTPS codes are a redirection, 4XX codes are Client Error and 5XX codes are Server Errors.3XX Redirections300: Multiple Choices: A link list. The user can select a link and go to that location. Maximum five addresses.301: Moved Permanently: The requested page has moved to a new URL.302: Found: The requested page has moved temporarily to a new URL.303: See Other: The requested page can be found under a different URL.304: Not Modified: This is the response code to an If-Modified-Since or If-None-Match header, where the URL has not been modified since the specified date.305: Use Proxy: The requested URL must be accessed through the proxy mentioned in the Location header.306: Unused: This code was used in a previous version. It is no longer used, but the code is reserved.307: Temporary Redirect: The requested page has moved temporarily to a new URL.4XX Error Codes (Client Error Codes)400: Bad Request: The server did not understand the request.401: Unauthorized: The requested page needs a username and a password.402: Payment Required: You can not use this code yet.403: Forbidden: Access is forbidden to the requested page.404: Not Found: The server can not find the requested page.405: Method Not Allowed: The method specified in the request is not allowed.406: Not Acceptable: The server can only generate a response that is not accepted by the client.407: Proxy Authentication Required: You must authenticate with a proxy server before this request can be served.408: Request Timeout: The request took longer than the server was prepared to wait.409: Conflict: The request could not be completed because of a conflict.410: Gone: The requested page is no longer available.411: Length Required: "Content-Length" is not defined. The server will not accept the request without it.412: Precondition Failed: The precondition given in the request evaluated to false by the server.413: Request Entity Too Large: The server will not accept the request, because the request entity is too large.414: Request-URL Too Long: The server will not accept the request, because the URL is too long. Occurs when you convert a "post" request to a "get" request with long query information.415: Unsupported Media Type: The server will not accept the request because the media type is not supported.416: Requested Range Not Satisfiable: The requested byte range is not available and is out of bounds.417: Expectation Failed: The expectation given in an Expect request-header field could not be met by this server.5XX Error Codes (Server Error Codes)500: Internal Server Error: The request was not completed. The server met an unexpected condition.501: Not Implemented: The request was not completed. The server did not support the functionality required.502: Bad Gateway: The request was not completed. The server received an invalid response from the upstream server.503: Service Unavailable: The request was not completed. The server is temporarily overloading or down.504: Gateway Timeout: The gateway has timed out.505: HTTP Version Not Supported: The server does not support the "HTTP protocol" version.