Java: Use HttpClient for POST and GET requests and file download, httpclientpost

Java: Use HttpClient for POST and GET requests and file download, httpclientpost

1. HttpClient

You can take a look at the introduction of HttpClient, this blog is not bad: http://blog.csdn.net/wangpeng047/article/details/19624529

Of course, for detailed documentation, you can go to the official website to view and download: http://hc.apache.org/httpclient-3.x/

2. This blog briefly introduces POST, GET, and object download applications.

The Code is as follows:

Package net. mobctrl; import java. io. byteArrayOutputStream; import java. io. fileOutputStream; import java. io. IOException; import java. io. inputStream; import java. util. arrayList; import java. util. list; import java. util. map; import java. util. set; import java. util. concurrent. executorService; import java. util. concurrent. executors; import org. apache. http. httpEntity; import org. apache. http. nameValuePair; import org. apa Che. http. client. entity. urlEncodedFormEntity; import org. apache. http. client. methods. closeableHttpResponse; import org. apache. http. client. methods. httpGet; import org. apache. http. client. methods. httpPost; import org. apache. http. impl. client. closeableHttpClient; import org. apache. http. impl. client. httpClients; import org. apache. http. message. basicNameValuePair; import org. apache. http. util. entityUtils;/*** @ web Http://www.mobctrl.net * @ author Zheng Haibo * @ Description: File Download post get */public class HttpClientUtils {/*** maximum thread pool */public static final int THREAD_POOL_SIZE = 5; public interface HttpClientDownLoadProgress {public void onProgress (int progress);} private static HttpClientUtils httpClientDownload; private ExecutorService downloadExcutorService; private HttpClientUtils () {downloadExcutorService = Ex Ecutors. newFixedThreadPool (THREAD_POOL_SIZE);} public static HttpClientUtils getInstance () {if (httpClientDownload = null) {httpClientDownload = new HttpClientUtils ();} return httpClientDownload ;} /*** download file ** @ param url * @ param filePath */public void download (final String url, final String filePath) implements downloadexcutorservice.exe cute (new Runnable () {@ Overridepublic void run () {httpDownloadFile (url, FilePath, null, null );}});} /*** download file ** @ param url * @ param filePath * @ param progress * progress callback */public void download (final String url, final String filePath, final HttpClientDownLoadProgress progress) unzip downloadexcutorservice.exe cute (new Runnable () {@ Overridepublic void run () {httpDownloadFile (url, filePath, progress, null );}});} /***** download file ** @ param url * @ param filePath */private void httpDownloa DFile (String url, String filePath, HttpClientDownLoadProgress progress, Map <String, String> headMap) {CloseableHttpClient httpclient = HttpClients. createDefault (); try {HttpGet httpGet = new HttpGet (url); setGetHead (httpGet, headMap); CloseableHttpResponse response1 = httpclient.exe cute (httpGet); try {System. out. println (response1.getStatusLine (); HttpEntity httpEntity = response1.getEntity (); long conte NtLength = httpEntity. getContentLength (); InputStream is = httpEntity. getContent (); // download the ByteArrayOutputStream output = new ByteArrayOutputStream (); byte [] buffer = new byte [4096]; int r = 0; long totalRead = 0; while (r = is. read (buffer)> 0) {output. write (buffer, 0, r); totalRead + = r; if (progress! = Null) {// callback progress SS. onProgress (int) (totalRead * 100/contentLength) ;}} FileOutputStream fos = new FileOutputStream (filePath); output. writeTo (fos); output. flush (); output. close (); fos. close (); EntityUtils. consume (httpEntity) ;}finally {response1.close () ;}} catch (Exception e) {e. printStackTrace ();} finally {try {httpclient. close ();} catch (IOException e) {e. printStackTrace () ;}}/ *** get request ** @ p Aram url * @ return */public String httpGet (String url) {return httpGet (url, null );} /*** http get request ** @ param url * @ return */public String httpGet (String url, Map <String, String> headMap) {String responseContent = null; closeableHttpClient httpclient = HttpClients. createDefault (); try {HttpGet httpGet = new HttpGet (url); CloseableHttpResponse response1 = httpclient.exe cute (httpGet); setGetHead (httpG Et, headMap); try {System. out. println (response1.getStatusLine (); HttpEntity entity = response1.getEntity (); InputStream is = entity. getContent (); StringBuffer strBuf = new StringBuffer (); byte [] buffer = new byte [4096]; int r = 0; while (r = is. read (buffer)> 0) {strBuf. append (new String (buffer, 0, r, "UTF-8");} responseContent = strBuf. toString (); System. out. println ("debug:" + responseContent); EntityU Tils. consume (entity) ;}finally {response1.close () ;}} catch (Exception e) {e. printStackTrace ();} finally {try {httpclient. close ();} catch (IOException e) {e. printStackTrace () ;}} return responseContent;} public String httpPost (String url, Map <String, String> paramsMap) {return httpPost (url, paramsMap, null );} /*** http post request ** @ param url * @ param paramsMap * @ return */public String httpPost (String Url, Map <String, String> paramsMap, Map <String, String> headMap) {String responseContent = null; CloseableHttpClient httpclient = HttpClients. createDefault (); try {HttpPost httpPost = new HttpPost (url); setPostHead (httpPost, headMap); setPostParams (httpPost, paramsMap); CloseableHttpResponse response = httpclient.exe cute (httpPost ); try {System. out. println (response. getStatusLine (); HttpEntity entity = res Ponse. getEntity (); InputStream is = entity. getContent (); StringBuffer strBuf = new StringBuffer (); byte [] buffer = new byte [4096]; int r = 0; while (r = is. read (buffer)> 0) {strBuf. append (new String (buffer, 0, r, "UTF-8");} responseContent = strBuf. toString (); EntityUtils. consume (entity);} finally {response. close () ;}} catch (Exception e) {e. printStackTrace ();} finally {try {httpclient. close ();} catch (IOException e) {e. printStackTrace () ;}} System. out. println ("responseContent =" + responseContent); return responseContent ;} /*** set the POST parameter ** @ param httpPost * @ param paramsMap * @ throws Exception */private void setPostParams (HttpPost httpPost, Map <String, String> paramsMap) throws Exception {if (paramsMap! = Null & paramsMap. size ()> 0) {List <NameValuePair> nvps = new ArrayList <NameValuePair> (); Set <String> keySet = paramsMap. keySet (); for (String key: keySet) {nvps. add (new BasicNameValuePair (key, paramsMap. get (key);} httpPost. setEntity (new UrlEncodedFormEntity (nvps);}/*** set the http HEAD ** @ param httpPost * @ param headMap */private void setPostHead (HttpPost httpPost, map <String, String> headMap ){ If (headMap! = Null & headMap. size ()> 0) {Set <String> keySet = headMap. keySet (); for (String key: keySet) {httpPost. addHeader (key, headMap. get (key) ;}}/ *** set http HEAD ** @ param httpGet * @ param headMap */private void setGetHead (HttpGet httpGet, Map <String, string> headMap) {if (headMap! = Null & headMap. size ()> 0) {Set <String> keySet = headMap. keySet (); for (String key: keySet) {httpGet. addHeader (key, headMap. get (key ));}}}}

We can use the following code for testing:

Import java. util. hashMap; import java. util. map; import net. mobctrl. httpClientUtils; import net. mobctrl. httpClientUtils. httpClientDownLoadProgress;/*** @ date 1:49:50 on January 1, January 14, 2015 * @ author Zheng Haibo * @ Description: test */public class Main {public static void main (String [] args) {/*** test asynchronous download of the downloaded file */HttpClientUtils. getInstance (). download ("http://newbbs.qiniudn.com/phone.png", "test.png", new HttpClient DownLoadProgress () {@ Overridepublic void onProgress (int progress) {System. out. println ("download progress =" + progress) ;}}); // Map <String, String> params = new HashMap <String, String> (); params. put ("username", "admin"); params. put ("password", "admin"); HttpClientUtils. getInstance (). httpPost ("http: // localhost: 8080/sshmysql/register", params); // GET synchronization method HttpClientUtils. getInstance (). httpGet (" Http://wthrcdn.etouch.cn/weather_mini? City = Beijing ");}}

The running result is:

HTTP/1.1 200 OKresponseContent = {"id": "-2", "msg": "failed to add! The user name already exists! "} HTTP/1.1 200 OKdebug: {" desc ":" OK "," status ": 1000," data ": {" wendu ":"-1 ", "ganmao": "The weather turns cooler, the air humidity is high, and it is easy to catch a cold. If you are physically weak, please pay attention to proper protection. "," Forecast ": [{" fengxiang ":" No sustained wind direction "," fengli ":" Breeze level "," high ":" high temperature 2 ℃ ", "type": "Xiao Xue", "low": "low Temperature-5 ℃", "date": "Wednesday 14" },{ "fengxiang ": "No sustained wind direction", "fengli": "Breeze level", "high": "high temperature 3 ℃", "type": "Haze", "low ": "Low Temperature-3 ℃", "date": "Thursday 15" },{ "fengxiang": "beifeng", "fengli": "4-5", "high ": "High Temperature 5 ℃", "type": "clear", "low": "low Temperature-6 ℃", "date": "Friday 16 "}, {"fengxiang": "No sustained wind direction", "fengli": "Breeze level", "high": "high Temperature 4 ℃", "type": "multi cloud ", "low": "low Temperature-5 ℃", "date": "Saturday 17" },{ "fengxiang": "No sustained wind direction", "fengli ": "Breeze level", "high": "high Temperature 6 ℃", "type": "multi cloud", "low": "low Temperature-4 ℃", "date ": "Sunday 18"}], "yesterday": {"fl": "Breeze", "fx": "No sustained wind direction", "high ": "High Temperature 4℃", "type": "Haze", "low": "low Temperature-4℃", "date": "Tuesday 13"}, "aqi ": & quot; 309 & quot;, & quot; city & quot ": "Beijing"} HTTP/1.1 200 OKdownload progress = 2 download progress = 6 download progress = 8 download progress = 10 download progress = 12 download progress = 15 download progress = 17 download progress = 20 download progress = 22 download progress = 27 download progress = 29 download progress = 31 download progress = 33 download progress = 36 download progress = 38 download progress = 40 download progress = 45 download progress = 47 download progress = 49 download progress = 51 download progress = 54 download progress = 56 download progress = 58 download progress = 60 download progress = 62 download progress = 69 download progress = 75 download progress = 81 download progress = 87 download progress = 89 download progress = 91 download progress = 93 download progress = 96 download progress = 100

The download process has a progress callback.

The related libs package can be downloaded in the following link: http://download.csdn.net/detail/nuptboyzhb/8362801

The above code can be used in J2SE and J2EE, or in Android. Related permissions are required when used in android.

Not for commercial purposes without permission