Java Http下载文件到本地

package com.proxy.util;import java.io.BufferedOutputStream;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.io.UnsupportedEncodingException;import java.net.URLEncoder;import java.util.ArrayList;import java.util.List;import java.util.Map;import org.apache.http.Header;import org.apache.http.HttpResponse;import org.apache.http.HttpStatus;import org.apache.http.NameValuePair;import org.apache.http.client.ClientProtocolException;import org.apache.http.client.HttpClient;import org.apache.http.client.entity.UrlEncodedFormEntity;import org.apache.http.client.methods.HttpGet;import org.apache.http.client.methods.HttpPost;import org.apache.http.client.methods.HttpUriRequest;import org.apache.http.impl.client.DefaultHttpClient;import org.apache.http.message.BasicNameValuePair;import org.apache.http.params.CoreConnectionPNames;import org.apache.http.util.EntityUtils;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import com.anxin.common.util.SSLUtil;/** * HTTP工具类. *  * @author David.Huang */public class HttpUtil {private static Logger log = LoggerFactory.getLogger(HttpUtil.class);/** 默认编码方式 -UTF8 */private static final String DEFAULT_ENCODE = "utf-8";// 信任所有站点static {SSLUtil.trustAllHostnames();SSLUtil.trustAllHttpsCertificates();}/** * 构造方法 */public HttpUtil() {// empty constructor for some tools that need an instance object of the// class}/** * GET请求, 结果以字符串形式返回. *  * @param url *            请求地址 * @return 内容字符串 */public static String getUrlAsString(String url) throws Exception {return getUrlAsString(url, null, DEFAULT_ENCODE);}/** * GET请求, 结果以字符串形式返回. *  * @param url *            请求地址 * @param params *            请求参数 * @return 内容字符串 */public static String getUrlAsString(String url, Map<String, String> params)throws Exception {return getUrlAsString(url, params, DEFAULT_ENCODE);}/** * GET请求, 结果以字符串形式返回. *  * @param url *            请求地址 * @param params *            请求参数 * @param encode *            编码方式 * @return 内容字符串 */public static String getUrlAsString(String url, Map<String, String> params,String encode) throws Exception {// 开始时间long t1 = System.currentTimeMillis();// 获得HttpGet对象HttpGet httpGet = getHttpGet(url, params, encode);// 调试信息log.debug("url:" + url);log.debug("params:" + params.toString());log.debug("encode:" + encode);// 发送请求String result = executeHttpRequest(httpGet, null);// 结束时间long t2 = System.currentTimeMillis();// 调试信息log.debug("result:" + result);log.debug("consume time:" + ((t2 - t1)));// 返回结果return result;}/** * POST请求, 结果以字符串形式返回. *  * @param url *            请求地址 * @return 内容字符串 */public static String postUrlAsString(String url) throws Exception {return postUrlAsString(url, null, null, null);}/** * POST请求, 结果以字符串形式返回. *  * @param url *            请求地址 * @param params *            请求参数 * @return 内容字符串 */public static String postUrlAsString(String url, Map<String, String> params)throws Exception {return postUrlAsString(url, params, null, null);}/** * POST请求, 结果以字符串形式返回. *  * @param url *            请求地址 * @param params *            请求参数 * @param reqHeader *            请求头内容 * @return 内容字符串 * @throws Exception */public static String postUrlAsString(String url,Map<String, String> params, Map<String, String> reqHeader)throws Exception {return postUrlAsString(url, params, reqHeader, null);}/** * POST请求, 结果以字符串形式返回. *  * @param url *            请求地址 * @param params *            请求参数 * @param reqHeader *            请求头内容 * @param encode *            编码方式 * @return 内容字符串 * @throws Exception */public static String postUrlAsString(String url,Map<String, String> params, Map<String, String> reqHeader,String encode) throws Exception {// 开始时间long t1 = System.currentTimeMillis();// 获得HttpPost对象HttpPost httpPost = getHttpPost(url, params, encode);// 发送请求String result = executeHttpRequest(httpPost, reqHeader);// 结束时间long t2 = System.currentTimeMillis();// 调试信息log.debug("url:" + url);log.debug("params:" + params.toString());log.debug("reqHeader:" + reqHeader);log.debug("encode:" + encode);log.debug("result:" + result);log.debug("consume time:" + ((t2 - t1)));// 返回结果return result;}/** * 获得HttpGet对象 *  * @param url *            请求地址 * @param params *            请求参数 * @param encode *            编码方式 * @return HttpGet对象 */private static HttpGet getHttpGet(String url, Map<String, String> params,String encode) {StringBuffer buf = new StringBuffer(url);if (params != null) {// 地址增加?或者&String flag = (url.indexOf('?') == -1) ? "?" : "&";// 添加参数for (String name : params.keySet()) {buf.append(flag);buf.append(name);buf.append("=");try {String param = params.get(name);if (param == null) {param = "";}buf.append(URLEncoder.encode(param, encode));} catch (UnsupportedEncodingException e) {log.error("URLEncoder Error,encode=" + encode + ",param="+ params.get(name), e);}flag = "&";}}HttpGet httpGet = new HttpGet(buf.toString());return httpGet;}/** * 获得HttpPost对象 *  * @param url *            请求地址 * @param params *            请求参数 * @param encode *            编码方式 * @return HttpPost对象 */private static HttpPost getHttpPost(String url, Map<String, String> params,String encode) {HttpPost httpPost = new HttpPost(url);if (params != null) {List<NameValuePair> form = new ArrayList<NameValuePair>();for (String name : params.keySet()) {form.add(new BasicNameValuePair(name, params.get(name)));}try {UrlEncodedFormEntity entity = new UrlEncodedFormEntity(form,encode);httpPost.setEntity(entity);} catch (UnsupportedEncodingException e) {log.error("UrlEncodedFormEntity Error,encode=" + encode+ ",form=" + form, e);}}return httpPost;}/** * 执行HTTP请求 *  * @param request *            请求对象 * @param reqHeader *            请求头信息 * @return 内容字符串 */private static String executeHttpRequest(HttpUriRequest request,Map<String, String> reqHeader) throws Exception {HttpClient client = null;String result = null;try {// 创建HttpClient对象client = new DefaultHttpClient();// 设置连接超时时间client.getParams().setParameter(CoreConnectionPNames.CONNECTION_TIMEOUT, 60);// 设置Socket超时时间client.getParams().setParameter(CoreConnectionPNames.SO_TIMEOUT,36600);// 设置请求头信息if (reqHeader != null) {for (String name : reqHeader.keySet()) {request.addHeader(name, reqHeader.get(name));}}// 获得返回结果HttpResponse response = client.execute(request);// 如果成功if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {result = EntityUtils.toString(response.getEntity());}// 如果失败else {StringBuffer errorMsg = new StringBuffer();errorMsg.append("httpStatus:");errorMsg.append(response.getStatusLine().getStatusCode());errorMsg.append(response.getStatusLine().getReasonPhrase());errorMsg.append(", Header: ");Header[] headers = response.getAllHeaders();for (Header header : headers) {errorMsg.append(header.getName());errorMsg.append(":");errorMsg.append(header.getValue());}log.error("HttpResonse Error:" + errorMsg);}} catch (Exception e) {log.error("http连接异常", e);throw new Exception("http连接异常");} finally {try {client.getConnectionManager().shutdown();} catch (Exception e) {log.error("finally HttpClient shutdown error", e);}}return result;}/** * 下载文件保存到本地 *  * @param path *            文件保存位置 * @param url *            文件地址 * @throws IOException */public static void downloadFile(String path, String url) throws IOException {log.debug("path:" + path);log.debug("url:" + url);HttpClient client = null;try {// 创建HttpClient对象client = new DefaultHttpClient();// 获得HttpGet对象HttpGet httpGet = getHttpGet(url, null, null);// 发送请求获得返回结果HttpResponse response = client.execute(httpGet);// 如果成功if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {byte[] result = EntityUtils.toByteArray(response.getEntity());BufferedOutputStream bw = null;try {// 创建文件对象File f = new File(path);// 创建文件路径if (!f.getParentFile().exists())f.getParentFile().mkdirs();// 写入文件bw = new BufferedOutputStream(new FileOutputStream(path));bw.write(result);} catch (Exception e) {log.error("保存文件错误,path=" + path + ",url=" + url, e);} finally {try {if (bw != null)bw.close();} catch (Exception e) {log.error("finally BufferedOutputStream shutdown close",e);}}}// 如果失败else {StringBuffer errorMsg = new StringBuffer();errorMsg.append("httpStatus:");errorMsg.append(response.getStatusLine().getStatusCode());errorMsg.append(response.getStatusLine().getReasonPhrase());errorMsg.append(", Header: ");Header[] headers = response.getAllHeaders();for (Header header : headers) {errorMsg.append(header.getName());errorMsg.append(":");errorMsg.append(header.getValue());}log.error("HttpResonse Error:" + errorMsg);}} catch (ClientProtocolException e) {log.error("下载文件保存到本地,http连接异常,path=" + path + ",url=" + url, e);throw e;} catch (IOException e) {log.error("下载文件保存到本地,文件操作异常,path=" + path + ",url=" + url, e);throw e;} finally {try {client.getConnectionManager().shutdown();} catch (Exception e) {log.error("finally HttpClient shutdown error", e);}}}public static void main(String[] args) throws IOException {// String result = getUrlAsString("http://www.gewara.com/");// System.out.println(result);downloadFile("F:/logo3w.png","http://www.google.com.hk/images/srpr/logo3w.png");}}