前言:
httpclient(4.5.x)默認是啟動連接池的, 其降低時耗(避免連接初3次握手, 以及關閉4次握手的消耗), 顯著提升高並發處理能力(大量減少time_wait), 確實扮演了重要的角色. 但是封裝httpclient, 需要了解不少細節, 還要根據業務合理配置參數.
這里結合這段時間深入httpclient(4.5.x)源碼分析, 結合網上的代碼案例, 以及線下測試的結果. 嘗試寫一個可用的的httpclient封裝類, 兼顧性能, 接口友好. 感謝cctv, ^_^.
相關文章:
1. HttpClient官方sample代碼的深入分析(連接池)
第一版本:
啥也不說了, 直接貼代碼了.
public class PooledHttpClientAdaptor {
private static final int DEFAULT_POOL_MAX_TOTAL = 200;
private static final int DEFAULT_POOL_MAX_PER_ROUTE = 200;
private static final int DEFAULT_CONNECT_TIMEOUT = 500;
private static final int DEFAULT_CONNECT_REQUEST_TIMEOUT = 500;
private static final int DEFAULT_SOCKET_TIMEOUT = 2000;
private PoolingHttpClientConnectionManager gcm = null;
private CloseableHttpClient httpClient = null;
// 連接池的最大連接數
private final int maxTotal;
// 連接池按route配置的最大連接數
private final int maxPerRoute;
// tcp connect的超時時間
private final int connectTimeout;
// 從連接池獲取連接的超時時間
private final int connectRequestTimeout;
// tcp io的讀寫超時時間
private final int socketTimeout;
public PooledHttpClientAdaptor() {
this(
PooledHttpClientAdaptor.DEFAULT_POOL_MAX_TOTAL,
PooledHttpClientAdaptor.DEFAULT_POOL_MAX_PER_ROUTE,
PooledHttpClientAdaptor.DEFAULT_CONNECT_TIMEOUT,
PooledHttpClientAdaptor.DEFAULT_CONNECT_REQUEST_TIMEOUT,
PooledHttpClientAdaptor.DEFAULT_SOCKET_TIMEOUT
);
}
public PooledHttpClientAdaptor(
int maxTotal,
int maxPerRoute,
int connectTimeout,
int connectRequestTimeout,
int socketTimeout
) {
this.maxTotal = maxTotal;
this.maxPerRoute = maxPerRoute;
this.connectTimeout = connectTimeout;
this.connectRequestTimeout = connectRequestTimeout;
this.socketTimeout = socketTimeout;
Registry<ConnectionSocketFactory> registry = RegistryBuilder.<ConnectionSocketFactory>create()
.register("http", PlainConnectionSocketFactory.getSocketFactory())
.register("https", SSLConnectionSocketFactory.getSocketFactory())
.build();
gcm = new PoolingHttpClientConnectionManager(registry);
gcm.setMaxTotal(this.maxTotal);
gcm.setDefaultMaxPerRoute(this.maxPerRoute);
RequestConfig requestConfig = RequestConfig.custom()
.setConnectTimeout(this.connectTimeout) // 設置連接超時
.setSocketTimeout(this.socketTimeout) // 設置讀取超時
.setConnectionRequestTimeout(this.connectRequestTimeout) // 設置從連接池獲取連接實例的超時
.build();
HttpClientBuilder httpClientBuilder = HttpClients.custom();
httpClient = httpClientBuilder
.setConnectionManager(gcm)
.setDefaultRequestConfig(requestConfig)
.build();
}
public String doGet(String url) {
return this.doGet(url, Collections.EMPTY_MAP, Collections.EMPTY_MAP);
}
public String doGet(String url, Map<String, Object> params) {
return this.doGet(url, Collections.EMPTY_MAP, params);
}
public String doGet(String url,
Map<String, String> headers,
Map<String, Object> params
) {
// *) 構建GET請求頭
String apiUrl = getUrlWithParams(url, params);
HttpGet httpGet = new HttpGet(apiUrl);
// *) 設置header信息
if ( headers != null && headers.size() > 0 ) {
for (Map.Entry<String, String> entry : headers.entrySet()) {
httpGet.addHeader(entry.getKey(), entry.getValue());
}
}
CloseableHttpResponse response = null;
try {
response = httpClient.execute(httpGet);
if (response == null || response.getStatusLine() == null) {
return null;
}
int statusCode = response.getStatusLine().getStatusCode();
if ( statusCode == HttpStatus.SC_OK ) {
HttpEntity entityRes = response.getEntity();
if (entityRes != null) {
return EntityUtils.toString(entityRes, "UTF-8");
}
}
return null;
} catch (IOException e) {
} finally {
if ( response != null ) {
try {
response.close();
} catch (IOException e) {
}
}
}
return null;
}
public String doPost(String apiUrl, Map<String, Object> params) {
return this.doPost(apiUrl, Collections.EMPTY_MAP, params);
}
public String doPost(String apiUrl,
Map<String, String> headers,
Map<String, Object> params
) {
HttpPost httpPost = new HttpPost(apiUrl);
// *) 配置請求headers
if ( headers != null && headers.size() > 0 ) {
for (Map.Entry<String, String> entry : headers.entrySet()) {
httpPost.addHeader(entry.getKey(), entry.getValue());
}
}
// *) 配置請求參數
if ( params != null && params.size() > 0 ) {
HttpEntity entityReq = getUrlEncodedFormEntity(params);
httpPost.setEntity(entityReq);
}
CloseableHttpResponse response = null;
try {
response = httpClient.execute(httpPost);
if (response == null || response.getStatusLine() == null) {
return null;
}
int statusCode = response.getStatusLine().getStatusCode();
if ( statusCode == HttpStatus.SC_OK ) {
HttpEntity entityRes = response.getEntity();
if ( entityRes != null ) {
return EntityUtils.toString(entityRes, "UTF-8");
}
}
return null;
} catch (IOException e) {
} finally {
if (response != null) {
try {
response.close();
} catch (IOException e) {
}
}
}
return null;
}
private HttpEntity getUrlEncodedFormEntity(Map<String, Object> params) {
List<NameValuePair> pairList = new ArrayList<NameValuePair>(params.size());
for (Map.Entry<String, Object> entry : params.entrySet()) {
NameValuePair pair = new BasicNameValuePair(entry.getKey(), entry
.getValue().toString());
pairList.add(pair);
}
return new UrlEncodedFormEntity(pairList, Charset.forName("UTF-8"));
}
private String getUrlWithParams(String url, Map<String, Object> params) {
boolean first = true;
StringBuilder sb = new StringBuilder(url);
for (String key : params.keySet()) {
char ch = '&';
if (first == true) {
ch = '?';
first = false;
}
String value = params.get(key).toString();
try {
String sval = URLEncoder.encode(value, "UTF-8");
sb.append(ch).append(key).append("=").append(sval);
} catch (UnsupportedEncodingException e) {
}
}
return sb.toString();
}
}
存在問題&解決方案
這個版本基本沒啥問題, 但是當流量為0時, 你會發現存在處於ClOSE_WAIT的連接. 究其原因是, httpclient清理過期/被動關閉的socket, 是采用懶惰清理的策略. 它是在連接從連接池取出使用的時候, 檢測狀態並做相應處理. 如果沒有流量, 那這些socket將一直處於CLOSE_WAIT(半連接的狀態), 系統資源被浪費.
不過解決方案也相當的簡單, 官方的建議引入一個清理線程, 定期主動處理過期/空閑連接, 這樣就OK了.
private class IdleConnectionMonitorThread extends Thread {
private final HttpClientConnectionManager connMgr;
private volatile boolean exitFlag = false;
public IdleConnectionMonitorThread(HttpClientConnectionManager connMgr) {
this.connMgr = connMgr;
setDaemon(true);
}
@Override
public void run() {
while (!this.exitFlag) {
synchronized (this) {
try {
this.wait(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
// 關閉失效的連接
connMgr.closeExpiredConnections();
// 可選的, 關閉30秒內不活動的連接
connMgr.closeIdleConnections(30, TimeUnit.SECONDS);
}
}
public void shutdown() {
this.exitFlag = true;
synchronized (this) {
notify();
}
}
}
最終版本
直接整合貼代碼, ^_^.
public class PooledHttpClientAdaptor {
private static final int DEFAULT_POOL_MAX_TOTAL = 200;
private static final int DEFAULT_POOL_MAX_PER_ROUTE = 200;
private static final int DEFAULT_CONNECT_TIMEOUT = 500;
private static final int DEFAULT_CONNECT_REQUEST_TIMEOUT = 500;
private static final int DEFAULT_SOCKET_TIMEOUT = 2000;
private PoolingHttpClientConnectionManager gcm = null;
private CloseableHttpClient httpClient = null;
private IdleConnectionMonitorThread idleThread = null;
// 連接池的最大連接數
private final int maxTotal;
// 連接池按route配置的最大連接數
private final int maxPerRoute;
// tcp connect的超時時間
private final int connectTimeout;
// 從連接池獲取連接的超時時間
private final int connectRequestTimeout;
// tcp io的讀寫超時時間
private final int socketTimeout;
public PooledHttpClientAdaptor() {
this(
PooledHttpClientAdaptor.DEFAULT_POOL_MAX_TOTAL,
PooledHttpClientAdaptor.DEFAULT_POOL_MAX_PER_ROUTE,
PooledHttpClientAdaptor.DEFAULT_CONNECT_TIMEOUT,
PooledHttpClientAdaptor.DEFAULT_CONNECT_REQUEST_TIMEOUT,
PooledHttpClientAdaptor.DEFAULT_SOCKET_TIMEOUT
);
}
public PooledHttpClientAdaptor(
int maxTotal,
int maxPerRoute,
int connectTimeout,
int connectRequestTimeout,
int socketTimeout
) {
this.maxTotal = maxTotal;
this.maxPerRoute = maxPerRoute;
this.connectTimeout = connectTimeout;
this.connectRequestTimeout = connectRequestTimeout;
this.socketTimeout = socketTimeout;
Registry<ConnectionSocketFactory> registry = RegistryBuilder.<ConnectionSocketFactory>create()
.register("http", PlainConnectionSocketFactory.getSocketFactory())
.register("https", SSLConnectionSocketFactory.getSocketFactory())
.build();
this.gcm = new PoolingHttpClientConnectionManager(registry);
this.gcm.setMaxTotal(this.maxTotal);
this.gcm.setDefaultMaxPerRoute(this.maxPerRoute);
RequestConfig requestConfig = RequestConfig.custom()
.setConnectTimeout(this.connectTimeout) // 設置連接超時
.setSocketTimeout(this.socketTimeout) // 設置讀取超時
.setConnectionRequestTimeout(this.connectRequestTimeout) // 設置從連接池獲取連接實例的超時
.build();
HttpClientBuilder httpClientBuilder = HttpClients.custom();
httpClient = httpClientBuilder
.setConnectionManager(this.gcm)
.setDefaultRequestConfig(requestConfig)
.build();
idleThread = new IdleConnectionMonitorThread(this.gcm);
idleThread.start();
}
public String doGet(String url) {
return this.doGet(url, Collections.EMPTY_MAP, Collections.EMPTY_MAP);
}
public String doGet(String url, Map<String, Object> params) {
return this.doGet(url, Collections.EMPTY_MAP, params);
}
public String doGet(String url,
Map<String, String> headers,
Map<String, Object> params
) {
// *) 構建GET請求頭
String apiUrl = getUrlWithParams(url, params);
HttpGet httpGet = new HttpGet(apiUrl);
// *) 設置header信息
if ( headers != null && headers.size() > 0 ) {
for (Map.Entry<String, String> entry : headers.entrySet()) {
httpGet.addHeader(entry.getKey(), entry.getValue());
}
}
CloseableHttpResponse response = null;
try {
response = httpClient.execute(httpGet);
if (response == null || response.getStatusLine() == null) {
return null;
}
int statusCode = response.getStatusLine().getStatusCode();
if ( statusCode == HttpStatus.SC_OK ) {
HttpEntity entityRes = response.getEntity();
if (entityRes != null) {
return EntityUtils.toString(entityRes, "UTF-8");
}
}
return null;
} catch (IOException e) {
} finally {
if ( response != null ) {
try {
response.close();
} catch (IOException e) {
}
}
}
return null;
}
public String doPost(String apiUrl, Map<String, Object> params) {
return this.doPost(apiUrl, Collections.EMPTY_MAP, params);
}
public String doPost(String apiUrl,
Map<String, String> headers,
Map<String, Object> params
) {
HttpPost httpPost = new HttpPost(apiUrl);
// *) 配置請求headers
if ( headers != null && headers.size() > 0 ) {
for (Map.Entry<String, String> entry : headers.entrySet()) {
httpPost.addHeader(entry.getKey(), entry.getValue());
}
}
// *) 配置請求參數
if ( params != null && params.size() > 0 ) {
HttpEntity entityReq = getUrlEncodedFormEntity(params);
httpPost.setEntity(entityReq);
}
CloseableHttpResponse response = null;
try {
response = httpClient.execute(httpPost);
if (response == null || response.getStatusLine() == null) {
return null;
}
int statusCode = response.getStatusLine().getStatusCode();
if ( statusCode == HttpStatus.SC_OK ) {
HttpEntity entityRes = response.getEntity();
if ( entityRes != null ) {
return EntityUtils.toString(entityRes, "UTF-8");
}
}
return null;
} catch (IOException e) {
} finally {
if (response != null) {
try {
response.close();
} catch (IOException e) {
}
}
}
return null;
}
private HttpEntity getUrlEncodedFormEntity(Map<String, Object> params) {
List<NameValuePair> pairList = new ArrayList<NameValuePair>(params.size());
for (Map.Entry<String, Object> entry : params.entrySet()) {
NameValuePair pair = new BasicNameValuePair(entry.getKey(), entry
.getValue().toString());
pairList.add(pair);
}
return new UrlEncodedFormEntity(pairList, Charset.forName("UTF-8"));
}
private String getUrlWithParams(String url, Map<String, Object> params) {
boolean first = true;
StringBuilder sb = new StringBuilder(url);
for (String key : params.keySet()) {
char ch = '&';
if (first == true) {
ch = '?';
first = false;
}
String value = params.get(key).toString();
try {
String sval = URLEncoder.encode(value, "UTF-8");
sb.append(ch).append(key).append("=").append(sval);
} catch (UnsupportedEncodingException e) {
}
}
return sb.toString();
}
public void shutdown() {
idleThread.shutdown();
}
// 監控有異常的鏈接
private class IdleConnectionMonitorThread extends Thread {
private final HttpClientConnectionManager connMgr;
private volatile boolean exitFlag = false;
public IdleConnectionMonitorThread(HttpClientConnectionManager connMgr) {
this.connMgr = connMgr;
setDaemon(true);
}
@Override
public void run() {
while (!this.exitFlag) {
synchronized (this) {
try {
this.wait(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
// 關閉失效的連接
connMgr.closeExpiredConnections();
// 可選的, 關閉30秒內不活動的連接
connMgr.closeIdleConnections(30, TimeUnit.SECONDS);
}
}
public void shutdown() {
this.exitFlag = true;
synchronized (this) {
notify();
}
}
}
}
總結:
其實沒啥難道, 主要就是買個安心, 這樣寫是安全的, 是經得起線上考驗的.