WebClient类

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#string #encoding #header #exception #cookies #redirect

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本文介绍了一个基于HttpClient封装的WebClient类，该类提供post和get方法来发送HTTP请求，并能够处理重定向。此外，还实现了详细的日志记录功能，便于调试。

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利用HttpClient封装了一个WebClient类，主要实现的方法是post和get方法，并提供了详细的日志信息打印，利于调试。可以用于提交表单或得到网页内容。

WebClient.java

public class WebClient { private static final Log logger = LogFactory.getLog(WebClient.class); private static final String DEFAULT_ENCODING = "UTF-8"; private HttpClient httpClient; protected String encoding; protected int bufferLength = 4096; protected String lastVisitUrl; public WebClient() { this(DEFAULT_ENCODING); } public WebClient(String encoding) { this.encoding = encoding; httpClient = new HttpClient(); httpClient.getParams().setCookiePolicy(CookiePolicy.BROWSER_COMPATIBILITY); httpClient.getParams().setParameter(HttpMethodParams.HTTP_CONTENT_CHARSET, encoding); httpClient.getParams().setParameter(HttpMethodParams.SINGLE_COOKIE_HEADER, true); } //----------- callable methods -------------// public WebResponse doGet(String url) throws WebBrowserException, WebServerException { return doGet(url, ""); } public WebResponse doGet(String url, String referer) throws WebBrowserException, WebServerException { try { GetMethod getMethod = new GetMethod(url); setHttpRequestHeader(getMethod); if (referer != null && referer.trim().length() != 0) { getMethod.setRequestHeader("Referer", referer); } logHttpGetRequest(getMethod); int status =httpClient.executeMethod(getMethod); String strResp = getMethod.getResponseBodyAsString(); byte[] byteResp = getMethod.getResponseBody(); String respEnc = getResponseEncoding(getMethod); logHttpResponse(getMethod, strResp); getMethod.releaseConnection(); //http:301,302,303,307 if (status == HttpStatus.SC_MOVED_PERMANENTLY || status == HttpStatus.SC_MOVED_TEMPORARILY || status == HttpStatus.SC_SEE_OTHER || status == HttpStatus.SC_TEMPORARY_REDIRECT) { Header locationHeader = getMethod.getResponseHeader("Location"); String location = locationHeader.getValue(); if (logger.isDebugEnabled()) { logger.debug("Redirect To Location = " + location); } if (location.startsWith("http")) { return doGet(location); } else { return doGet("http://" + getResponseHost(getMethod) + location); } } else if (status == HttpStatus.SC_OK) { //http:200 return new WebResponse(getMethod.getURI().toString(), byteResp, respEnc); } else { throw new WebServerException("Server Exception[code=" + status + "]"); } } catch (HttpException e) { throw new WebBrowserException(e); } catch (IOException e) { throw new WebBrowserException(e); } } public WebResponse doPost(String url, NameValuePair[] params) throws WebBrowserException, WebServerException { return doPost(url, params, ""); } public WebResponse doPost(String url, NameValuePair[] params, String referer) throws WebBrowserException, WebServerException { try { PostMethod postMethod = new PostMethod(url); setHttpRequestHeader(postMethod); if (referer != null && referer.trim().length() != 0) { postMethod.setRequestHeader("Referer", referer); } postMethod.setRequestHeader("Content-Type", "application/x-www-form-urlencoded"); postMethod.setRequestBody(params); logHttpPostRequest(postMethod); int status = httpClient.executeMethod(postMethod); String strResp = postMethod.getResponseBodyAsString(); byte[] byteResp = postMethod.getResponseBody(); String respEnc = getResponseEncoding(postMethod); logHttpResponse(postMethod, strResp); postMethod.releaseConnection(); //http:301,302,303,307 if (status == HttpStatus.SC_MOVED_PERMANENTLY || status == HttpStatus.SC_MOVED_TEMPORARILY || status == HttpStatus.SC_SEE_OTHER || status == HttpStatus.SC_TEMPORARY_REDIRECT) { Header locationHeader = postMethod.getResponseHeader("Location"); String location = locationHeader.getValue(); if (logger.isDebugEnabled()) { logger.debug("Redirect To Location = " + location); } if (location.startsWith("http")) { return doGet(location); } else { return doGet("http://" + getResponseHost(postMethod) + location); } } else if (status == HttpStatus.SC_OK) { //http:200 return new WebResponse(postMethod.getURI().toString(), byteResp, respEnc); } else { throw new WebServerException("Server Exception[code=" + status + "]"); } } catch (HttpException e) { throw new WebBrowserException(e); } catch (IOException e) { throw new WebBrowserException(e); } } public Cookie[] getCurrentCookies() { Cookie[] cookies = httpClient.getState().getCookies(); return cookies; } protected void setHttpRequestHeader(HttpMethod method) { method.setRequestHeader("Accept", "text/html,application/xhtml+xml,application/xml,application/json,image/jpeg,image/gif,*/*"); method.setRequestHeader("Accept-Language", "zh-cn"); method.setRequestHeader( "User-Agent", "Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN; rv:1.9.0.3) Gecko/2008092417 Firefox/3.0.3"); method.setRequestHeader("Accept-Charset", encoding); method.setRequestHeader("Keep-Alive", "300"); method.setRequestHeader("Connection", "Keep-Alive"); method.setRequestHeader("Cache-Control", "no-cache"); } //------------- log methods ----------------// private void logHttpGetRequest(HttpMethod method) { try { if (logger.isDebugEnabled()) { logger.debug("/n/n============= HTTP Request Start ============="); logger.debug("HTTP Get Request URL ==>/n" + method.getURI().toString()); logger.debug("HTTP Get Request Headers ==>/n" + getHttpRequestHeader(method)); logger.debug("HTTP Get Request Cookies ==>/n" + getHttpCookie()); logger.debug("HTTP Get Request QueryString ==>/n" + method.getQueryString()); logger.debug("============= HTTP Request End =============/n/n"); } } catch (URIException e) { logger.error(e); } } private void logHttpPostRequest(PostMethod method) { try { if (logger.isDebugEnabled()) { logger.debug("/n/n============= HTTP Request Start ============="); logger.debug("HTTP Post Request URL ==>/n" + method.getURI().toString()); logger.debug("HTTP Post Request Headers ==>/n" + getHttpRequestHeader(method)); logger.debug("HTTP Post Request Cookies ==>/n" + getHttpCookie()); logger.debug("HTTP Post Request QueryString ==>/n" + method.getQueryString()); logger.debug("HTTP Post Request Body ==>/n" + getHttpRequestBody(method)); logger.debug("============= HTTP Request End =============/n/n"); } } catch (URIException e) { logger.error("URIException", e); } } private void logHttpResponse(HttpMethod method, String strResp) { try { if (logger.isDebugEnabled()) { logger.debug("/n/n============= HTTP Response Start ============="); logger.debug("HTTP Response URL ==>/n" + method.getURI().toString()); logger.debug("HTTP Response Headers ==>/n" + getHttpResponseHeader(method)); logger.debug("HTTP Response Cookies ==>/n" + getHttpCookie()); logger.debug("HTTP Response Body ==>/n" + strResp); logger.debug("============= HTTP Response End =============/n/n"); } } catch (URIException e) { logger.error("URIException", e); } } //---------- util methods -------------// private String getResponseEncoding(HttpMethod method) { Header header = method.getResponseHeader("Content-Type"); String encoding = DEFAULT_ENCODING; if (header != null) { if (logger.isDebugEnabled()) { logger.debug("Content-Type=" + header.getValue()); } if (header != null) { String value = header.getValue(); int idx1 = value.indexOf("charset="); if (idx1 > -1) { encoding = value.substring(idx1 + 8); if (logger.isDebugEnabled()) { logger.debug("Response Encoding=" + encoding); } } } } return encoding; } private String getResponseHost(HttpMethod method) { try { String hostRegexp = "http://([^/]+)/.*"; Pattern p = Pattern.compile(hostRegexp); String url = method.getURI().toString(); Matcher matcher = p.matcher(url); if (!matcher.find()) { String msg = ExceptionMessage.PROTOCOL_MSG + "[Type=ResponseHost,Regexp=" + p.pattern() + "]"; logger.error(msg); } if (logger.isDebugEnabled()) { logger.debug("Host=" + matcher.group(1)); } return matcher.group(1); } catch (Exception e) { logger.error(e); } return ""; } private String getHttpRequestBody(PostMethod method) { StringBuilder strBody = new StringBuilder(); NameValuePair[] pairs = method.getParameters(); for (NameValuePair pair : pairs) { String name = pair.getName(); String value = pair.getValue(); strBody.append(name + "=" + value + ";"); } return strBody.toString(); } private String getHttpCookie() { StringBuilder strHeader = new StringBuilder(); Cookie[] cookies = httpClient.getState().getCookies(); for (Cookie cookie : cookies) { String domain = cookie.getDomain(); String path = cookie.getPath(); String name = cookie.getName(); String value = cookie.getValue(); Date expired = cookie.getExpiryDate(); boolean isSecure = cookie.getSecure(); strHeader.append("domain=" + domain + ";"); strHeader.append("path=" + path + ";"); strHeader.append(name + "=" + value + ";"); if (expired != null) { strHeader.append("expired=" + expired.toGMTString() + ";"); } strHeader.append("isSecure=" + isSecure+ "/n"); } return strHeader.toString(); } private String getHttpRequestHeader(HttpMethod method) { StringBuilder strHeader = new StringBuilder(); Header[] headers = method.getRequestHeaders(); for (Header header : headers) { String name = header.getName(); String value = header.getValue(); strHeader.append(name + "=" + value + ";"); } return strHeader.toString(); } private String getHttpResponseHeader(HttpMethod method) { StringBuilder strHeader = new StringBuilder(); Header[] headers = method.getResponseHeaders(); for (Header header : headers) { String name = header.getName(); String value = header.getValue(); strHeader.append(name + "=" + value + ";"); } return strHeader.toString(); } }

WebResponse.java

public class WebResponse { private static final Log logger = LogFactory.getLog(WebResponse.class); private static final String DEFAULT_ENCODING = "UTF-8"; private final String responseUrl; private final byte[] bodyAsBytes; private final String encoding; public WebResponse(String responseUrl, byte[] bodyAsBytes) { this(responseUrl, bodyAsBytes, DEFAULT_ENCODING); } public WebResponse(String responseUrl, byte[] bodyAsBytes, String encoding) { this.responseUrl = responseUrl; this.bodyAsBytes = bodyAsBytes; this.encoding = encoding; } public String getResponseUrl() { return responseUrl; } public String getEncoding() { return encoding; } public String getBodyAsString() { try { if (logger.isDebugEnabled()) { logger.debug("Convert Encoding=" + encoding); } return new String(bodyAsBytes, encoding); } catch (UnsupportedEncodingException e) { logger.error("Encoding Error[encoding=" + encoding + "]", e); try { return new String(bodyAsBytes, DEFAULT_ENCODING); } catch (UnsupportedEncodingException e1) { logger.error("Encoding Error[encoding=" + DEFAULT_ENCODING + "]", e); return new String(bodyAsBytes); } } } public byte[] getBodyAsBytes() { return bodyAsBytes; } public InputStream getBodyAsStream() { return new ByteArrayInputStream(bodyAsBytes); }

WebServerException.java

public class WebServerException extends Exception { public WebServerException() { super(); } public WebServerException(String error) { super(error); } public WebServerException(Throwable t) { super(t); } public WebServerException(String error, Throwable t) { super(error, t); } }

WebBrowserException.java

public class WebBrowserException extends Exception { public WebBrowserException() { super(); } public WebBrowserException(String error) { super(error); } public WebBrowserException(Throwable t) { super(t); } public WebBrowserException(String error, Throwable t) { super(error, t); } }