Android中HttpClient网络请求
HttpClient是Apache对Java提供方法的一些封装, 在Android2.2版本之前，建议使用。
特点：上传文件很便利, 不过须要导入apache-mime4j-0.6.jar和httpmime-4.0.jar。注意默认不带gzip压缩。
public class HttpClientUtil {
public static final int READ_TIMEOUT = 30*1000;
public static final int CONNECT_TIMEOUT = 10*1000;
public static final int EXCEPTION_ERR = 888;
// 文件下载的状态
public static final int DOWNLOAD_FAIL = -1; //下载失败
public static final int DOWNLOAD_PART = 0; //下载了一部分
public static final int DOWNLOAD_COMPLETE = 1; //完全下载
/**
* 采用POST方式提交数据流
* @param handler
* 用消息发送机制返回HTTP Response结果
* @param urlStr
* 链接
* @param params
* 提交到服务器的参数
* @param files
* 提交到服务器的文件
* */
public static void postWithHttpClient(Handler handler, String urlStr,
Map<String, String> params, Map<String, File> files){
Message msg = handler.obtainMessage();
HttpPost post = null;
try{
post = new HttpPost(urlStr);
HttpParams http_param = new BasicHttpParams();
HttpConnectionParams.setConnectionTimeout(http_param, CONNECT_TIMEOUT);//socket建立链接的超时时间。
HttpConnectionParams.setSoTimeout(http_param, CONNECT_TIMEOUT);//建立链接成功后，获取response的返回等待时间。
ConnManagerParams.setTimeout(http_param, CONNECT_TIMEOUT);//从连接池中取连接的超时时间
post.setParams(http_param);
MultipartEntity entity = new MultipartEntity();
if (params != null) { //添加参数
for (Map.Entry<String, String> entry : params.entrySet()) {
entity.addPart(entry.getKey(), new StringBody(entry.getValue(), Charset.forName("UTF-8")));
}
}
if (files != null) { //添加文件
for (Map.Entry<String, File> entry : files.entrySet()) {
entity.addPart(entry.getKey(), new FileBody(entry.getValue(), entry.getValue().getName()));
}
}
post.setEntity(entity);
HttpClient client = new DefaultHttpClient();
HttpResponse response = client.execute(post);
int statuscode = response.getStatusLine().getStatusCode();
msg.what = statuscode;
HttpEntity e = response.getEntity();
if ( e!=null ) {
msg.obj = EntityUtils.toString(e);
} else {
msg.obj = "";
}
} catch (Exception e) {
msg.what = EXCEPTION_ERR;
msg.obj = e.getMessage();
} finally {
msg.sendToTarget();
if( post != null ){
post.abort();
}
}
}
/**
* 采用GET方式获取数据流
* @param handler
* 用消息发送机制返回HTTP Response结果
* @param urlStr
* 链接
* */
public static void getWithHttpClient(String url, Handler handler) {
Message msg = handler.obtainMessage();
HttpGet httpGet = null;
try {
httpGet= new HttpGet(url);
HttpParams httpParams = new BasicHttpParams();
HttpConnectionParams.setConnectionTimeout(httpParams, CONNECT_TIMEOUT);
HttpConnectionParams.setSoTimeout(httpParams, CONNECT_TIMEOUT);
httpGet.setParams(httpParams);
HttpClient httpClient = new DefaultHttpClient();
HttpResponse response = httpClient.execute(httpGet);
int statusCode = response.getStatusLine().getStatusCode();
msg.what = statusCode;
HttpEntity entity = response.getEntity();
if (entity!=null) {
msg.obj = EntityUtils.toString(entity);
} else {
msg.obj = "";
}
} catch (Exception e) {
msg.what = EXCEPTION_ERR;
msg.obj = e.getMessage();
} finally {
msg.sendToTarget();
if( httpGet!=null ){
httpGet.abort();
}
}
}
/**
* 一次性全部下载
* 1. 使用GET方法下载
* 2. 不要设置SoTimeout，如果要设置，最好时间长一些，因为大文件的下载本来就耗时
* 3. 下载过程采用一边读输入流，一边写入文件的方法，节约内存
* 4. 如果只下载了一部分就被中断，但是服务器不支持断点续传的话，必须重新下载
*/
public static int downloadWithHttpClient(DownloadFileInfo fileInfo) {
HttpGet httpGet = null;
InputStream is = null;
RandomAccessFile savedfile = null;
try {
httpGet = new HttpGet(fileInfo.mURL);
HttpParams httpParams = new BasicHttpParams();
HttpConnectionParams.setConnectionTimeout(httpParams, CONNECT_TIMEOUT);
httpGet.setParams(httpParams);
HttpClient httpClient = new DefaultHttpClient();
HttpResponse response = httpClient.execute(httpGet);
//保存文件的标示
Header[] headers = response.getAllHeaders();
int headerSize = headers.length;
for( int i = 0; i < headerSize; ++i ) {
if (headers[i].getName().equalsIgnoreCase("ETag")){
String etag = headers[i].getValue();
fileInfo.mEtag = etag;
break;
}
}
//新建需要写入的RandomAccessFile
File dir = new File(fileInfo.mFilePath);
if(!dir.exists()){
dir.mkdirs();
}
File file = new File(fileInfo.mFilePath+File.separator+fileInfo.mFileName);
if(!file.exists()){
file.createNewFile();
}
savedfile = new RandomAccessFile(file,"rwd");
int responseCode = response.getStatusLine().getStatusCode();
if ( responseCode == 200 ) {//用来表示请求成功.
long len = response.getEntity().getContentLength();
if( len <= 0 ) {
return DOWNLOAD_FAIL;
}
fileInfo.mCompleteFileLength = len;
int readSize = 0;
byte[] buffer = new byte[1024];//1k内存
is = response.getEntity().getContent();
while( ( readSize = is.read(buffer) ) != -1 ) {
// 循环从输入流中读1k数据，写入文件
savedfile.write(buffer, 0, readSize);
fileInfo.mCurrentFileLength += readSize;
}
} else {
return DOWNLOAD_FAIL;
}
int status = DOWNLOAD_FAIL;
if( fileInfo.mCurrentFileLength > 0 ) {
if( fileInfo.mCurrentFileLength == fileInfo.mCompleteFileLength ) {
status = DOWNLOAD_COMPLETE;
} else {
status = DOWNLOAD_PART;
}
}
return status;
} catch (Exception e) {
e.printStackTrace();
int status = DOWNLOAD_FAIL;
if( fileInfo.mCurrentFileLength > 0 ) {
status = DOWNLOAD_PART;
}
return status;
} finally {
if( httpGet != null ) {
httpGet.abort();
}
if( is != null ) {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if( savedfile != null ) {
try {
savedfile.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
/**
* 断点续传下载
**/
public static int downloadRangeWithHttpClient(DownloadFileInfo fileInfo) {
HttpGet httpGet = null;
InputStream is = null;
RandomAccessFile savedfile = null;
try {
httpGet = new HttpGet(fileInfo.mURL);
HttpParams httpParams = new BasicHttpParams();
HttpConnectionParams.setConnectionTimeout(httpParams, CONNECT_TIMEOUT);
httpGet.setParams(httpParams);
long startPos = fileInfo.mCurrentFileLength;//开始位置
httpGet.addHeader("Range", "bytes=" + startPos + "-"); //设置获取实体数据的范围
//新建需要写入的RandomAccessFile
File file = new File(fileInfo.mFilePath+File.separator+fileInfo.mFileName);
savedfile = new RandomAccessFile(file,"rwd");
savedfile.seek(startPos);
HttpClient httpClient = new DefaultHttpClient();
HttpResponse response = httpClient.execute(httpGet);
int responseCode = response.getStatusLine().getStatusCode();
if ( responseCode == 206 ) {//断点续传成功的反馈值是206，不是200
long len = response.getEntity().getContentLength();
if( len <= 0 ) {
return DOWNLOAD_FAIL;
}
byte[] buffer = new byte[1024];
int readSize = 0;
is = response.getEntity().getContent();
while( (readSize=is.read(buffer)) != -1 ) {
savedfile.write(buffer, 0, readSize);
fileInfo.mCurrentFileLength += readSize;
}
} else {
return DOWNLOAD_FAIL;
}
int status = DOWNLOAD_FAIL;
if( fileInfo.mCurrentFileLength > 0 ) {
if( fileInfo.mCurrentFileLength == fileInfo.mCompleteFileLength ) {
status = DOWNLOAD_COMPLETE;
} else {
status = DOWNLOAD_PART;
}
}
return status;
} catch (Exception e) {
e.printStackTrace();
int status = DOWNLOAD_FAIL;
if( fileInfo.mCurrentFileLength > 0 ) {
status = DOWNLOAD_PART;
}
return status;
} finally {
if (httpGet!=null){
httpGet.abort();
}
if(is!=null){
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if(savedfile!=null){
try {
savedfile.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
/**
* 判断是否可以断点续传
*
* @param DownloadFileInfo 保存下载信息：
* mURL：下载链接
* mFilePath：指定下载文件保存路径
* mFileName：下载文件的文件名
* mCompleteFileLength：待下载文件的Size
* mCurrentFileLength：已经下载的文件的Size，用于断点续传
* mEtag：服务器为某个文件生产的唯一标识值，每次文件有更新该值就会变化。
* */
public static boolean shouldRangeDownload(DownloadFileInfo fileInfo){
File file = new File(fileInfo.mFilePath+File.separator+fileInfo.mFileName);
if(!file.exists()){
// 原来下载的文件已经被删除了，重新下载
fileInfo.clearFileSizeRecord();
return false;
}
HttpGet httpGet = null;
try {
httpGet = new HttpGet(fileInfo.mURL);
HttpClient httpClient = new DefaultHttpClient();
HttpResponse response = httpClient.execute(httpGet);
Header[] headers = response.getAllHeaders();
boolean acceptRangesIsBytes = false;
boolean eTagChanged = true;
int headerSize = headers.length;
for( int i = 0; i < headerSize; ++i ) {
if(headers[i].getName().equalsIgnoreCase("Accept-Ranges")){
if(headers[i].getValue().equalsIgnoreCase("bytes")){
acceptRangesIsBytes = true;
}
} else if (headers[i].getName().equalsIgnoreCase("ETag")){
if(fileInfo.mEtag!=null && headers[i].getValue().equalsIgnoreCase(fileInfo.mEtag)){
eTagChanged = false;
}
}
}
if( acceptRangesIsBytes == true && eTagChanged == false ) {
return true;
} else {
// 1. 服务器不支持断点续传
// 2. ETag改变了
// 应该重新下载整个文件
return false;
}
} catch (Exception e) {
return false;
} finally {
if( httpGet!=null ){
httpGet.abort();
}
}
}
}