【SSM分散式架構電商專案-15】Httpclient訪問介面服務
對外的介面服務
package com.taotao.manage.controller.api;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation .RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import com.taotao.common.bean.EasyUIResult;
import com.taotao.manage.service.ContentService;
@RequestMapping("api/content")
@Controller
public class ApiContentController {
@Autowired
private ContentService contentService;
/**
* 根據內容分類id查詢分類列表
*
* @param categoryId
* @param page
* @param rows
* @return
*/
@RequestMapping(method = RequestMethod.GET)
public ResponseEntity<EasyUIResult> queryListByCategoryId(@RequestParam("categoryId") Long categoryId,
@RequestParam(value = "page" , defaultValue = "1") Integer page,
@RequestParam(value = "rows", defaultValue = "10") Integer rows) {
try {
EasyUIResult easyUIResult = this.contentService.queryListByCategoryId(categoryId, page, rows);
return ResponseEntity.ok(easyUIResult);
} catch (Exception e) {
e.printStackTrace();
}
return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(null);
}
}
測試:
訪問介面服務的方式
方式有2種:
1、 js訪問
a) 有跨域 – jsonp解決
b) 無跨域 – ajax解決
2、 Java程式碼訪問
a) Httpclient
Httpclient
匯入依賴
DoGET
package cn.itcast.httpclient;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
public class DoGET {
public static void main(String[] args) throws Exception {
// 建立Httpclient物件
CloseableHttpClient httpclient = HttpClients.createDefault();
// 建立http GET請求
HttpGet httpGet = new HttpGet("http://www.baidu.com/s?wd=java");
CloseableHttpResponse response = null;
try {
// 執行請求
response = httpclient.execute(httpGet);
// 判斷返回狀態是否為200
if (response.getStatusLine().getStatusCode() == 200) {
String content = EntityUtils.toString(response.getEntity(), "UTF-8");
System.out.println("內容:"+content);
}
} finally {
if (response != null) {
response.close();
}
httpclient.close();
}
}
}
帶有引數的GET請求
package cn.itcast.httpclient;
import java.net.URI;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
public class DoGETParam {
public static void main(String[] args) throws Exception {
// 建立Httpclient物件
CloseableHttpClient httpclient = HttpClients.createDefault();
// 定義請求的引數
URI uri = new URIBuilder("http://manage.taotao.com/rest/api/content").setParameter("categoryId", "33")
.setParameter("page", "1").setParameter("rows", "1").build();
System.out.println(uri);
// 建立http GET請求
HttpGet httpGet = new HttpGet(uri);
CloseableHttpResponse response = null;
try {
// 執行請求
response = httpclient.execute(httpGet);
// 判斷返回狀態是否為200
if (response.getStatusLine().getStatusCode() == 200) {
String content = EntityUtils.toString(response.getEntity(), "UTF-8");
System.out.println(content);
}
} finally {
if (response != null) {
response.close();
}
httpclient.close();
}
}
}
DoPOST
package cn.itcast.httpclient;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
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;
public class DoPOSTParam {
public static void main(String[] args) throws Exception {
// 建立Httpclient物件
CloseableHttpClient httpclient = HttpClients.createDefault();
// 建立http POST請求
HttpPost httpPost = new HttpPost("http://www.oschina.net/search");
// 偽裝成瀏覽器
httpPost.setHeader(
"User-Agent",
"Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.94 Safari/537.36");
// 設定2個post引數,一個是scope、一個是q
List<NameValuePair> parameters = new ArrayList<NameValuePair>(0);
parameters.add(new BasicNameValuePair("scope", "project"));
parameters.add(new BasicNameValuePair("q", "java"));
parameters.add(new BasicNameValuePair("fromerr", "7nXH76r7"));
// 構造一個form表單式的實體
UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(parameters);
// 將請求實體設定到httpPost物件中
httpPost.setEntity(formEntity);
CloseableHttpResponse response = null;
try {
// 執行請求
response = httpclient.execute(httpPost);
// 判斷返回狀態是否為200
if (response.getStatusLine().getStatusCode() == 200) {
String content = EntityUtils.toString(response.getEntity(), "UTF-8");
System.out.println(content);
}
} finally {
if (response != null) {
response.close();
}
httpclient.close();
}
}
}
帶有引數的POST請求
public static void main(String[] args) throws Exception {
// 建立Httpclient物件
CloseableHttpClient httpclient = HttpClients.createDefault();
// 建立http POST請求
HttpPost httpPost = new HttpPost("http://www.oschina.net/search");
// 偽裝成瀏覽器
httpPost.setHeader("User-Agent", "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.94 Safari/537.36");
// 設定2個post引數,一個是scope、一個是q
List<NameValuePair> parameters = new ArrayList<NameValuePair>(0);
parameters.add(new BasicNameValuePair("scope", "project"));
parameters.add(new BasicNameValuePair("q", "java"));
parameters.add(new BasicNameValuePair("fromerr", "7nXH76r7"));
// 構造一個form表單式的實體
UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(parameters);
// 將請求實體設定到httpPost物件中
httpPost.setEntity(formEntity);
CloseableHttpResponse response = null;
try {
// 執行請求
response = httpclient.execute(httpPost);
// 判斷返回狀態是否為200
if (response.getStatusLine().getStatusCode() == 200) {
String content = EntityUtils.toString(response.getEntity(), "UTF-8");
System.out.println(content);
}
} finally {
if (response != null) {
response.close();
}
httpclient.close();
}
}
連線管理器
注意:
package cn.itcast.httpclient;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.conn.HttpClientConnectionManager;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.util.EntityUtils;
public class HttpConnectManager {
public static void main(String[] args) throws Exception {
PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager();
// 設定最大連線數
cm.setMaxTotal(200);
// 設定每個主機地址的併發數
cm.setDefaultMaxPerRoute(20);
doGet(cm);
doGet(cm);
}
public static void doGet(HttpClientConnectionManager cm) throws Exception {
CloseableHttpClient httpClient = HttpClients.custom().setConnectionManager(cm).build();
// 建立http GET請求
HttpGet httpGet = new HttpGet("http://www.baidu.com/");
CloseableHttpResponse response = null;
try {
// 執行請求
response = httpClient.execute(httpGet);
// 判斷返回狀態是否為200
if (response.getStatusLine().getStatusCode() == 200) {
String content = EntityUtils.toString(response.getEntity(), "UTF-8");
System.out.println("內容長度:" + content.length());
}
} finally {
if (response != null) {
response.close();
}
// 此處不能關閉httpClient,如果關閉httpClient,連線池也會銷燬
// httpClient.close();
}
}
}
定期關閉無效連線
public class ClientEvictExpiredConnections {
public static void main(String[] args) throws Exception {
PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager();
// 設定最大連線數
cm.setMaxTotal(200);
// 設定每個主機地址的併發數
cm.setDefaultMaxPerRoute(20);
new IdleConnectionEvictor(cm).start();
}
public static class IdleConnectionEvictor extends Thread {
private final HttpClientConnectionManager connMgr;
private volatile boolean shutdown;
public IdleConnectionEvictor(HttpClientConnectionManager connMgr) {
this.connMgr = connMgr;
}
@Override
public void run() {
try {
while (!shutdown) {
synchronized (this) {
wait(5000);
// 關閉失效的連線
connMgr.closeExpiredConnections();
}
}
} catch (InterruptedException ex) {
// 結束
}
}
public void shutdown() {
shutdown = true;
synchronized (this) {
notifyAll();
}
}
}
}
設定請求引數
Httpclient和Spring的整合
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p"
xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.0.xsd">
<bean id="connectionManager"
class="org.apache.http.impl.conn.PoolingHttpClientConnectionManager">
<!-- 最大連線數 -->
<property name="maxTotal" value="${http.maxTotal}" />
<!-- 設定每個主機地址的併發數 -->
<property name="defaultMaxPerRoute" value="${http.defaultMaxPerRoute}" />
</bean>
<!-- Httpclient物件的構建器 -->
<bean id="httpClientBuilder" class="org.apache.http.impl.client.HttpClientBuilder">
<property name="connectionManager" ref="connectionManager" />
</bean>
<!-- Httpclient物件 -->
<!-- 注意:該物件為多例 -->
<bean class="org.apache.http.impl.client.CloseableHttpClient"
factory-bean="httpClientBuilder" factory-method="build" scope="prototype">
</bean>
<!-- 請求配置的構建器 -->
<bean id="requestConfigBuilder" class="org.apache.http.client.config.RequestConfig.Builder">
<!-- 建立連線的最長時間 -->
<property name="connectTimeout" value="${http.connectTimeout}" />
<!-- 從連線池中獲取到連線的最長時間 -->
<property name="connectionRequestTimeout" value="${http.connectionRequestTimeout}" />
<!-- 資料傳輸的最長時間 -->
<property name="socketTimeout" value="${http.socketTimeout}" />
<!-- 提交請求前測試連線是否可用 -->
<property name="staleConnectionCheckEnabled" value="${http.staleConnectionCheckEnabled}" />
</bean>
<!-- 請求配置物件 -->
<bean class="org.apache.http.client.config.RequestConfig"
factory-bean="requestConfigBuilder" factory-method="build" />
<!-- 定期清理無效連線 -->
<bean class="com.taotao.common.httpclient.IdleConnectionEvictor">
<constructor-arg index="0" ref="connectionManager"/>
</bean>
</beans>
分析:
我們先配置連線管理器:PoolingHttpClientConnectionManager
之後我們需要拿到CloseableHttpClient:
CloseableHttpClient httpClient = HttpClients.custom().setConnectionManager(cm).build();
這裡分兩步,先是HttpClients.custom()
,然後並設定setConnectionManager(cm)。
第二步使用build()方法生成CloseableHttpClient 物件。
第一步:
我們可以看到在第一步HttpClients.custom().setConnectionManager(cm)
最後返回的是HttpClientBuilder物件,所以我們先來配置HttpClientBuilder的bean
第二步:使用build()方法:
接下來我們要配置請求引數:
// 構建請求配置資訊
RequestConfig config = RequestConfig.custom().setConnectTimeout(1000) // 建立連線的最長時間
.setConnectionRequestTimeout(500) // 從連線池中獲取到連線的最長時間
.setSocketTimeout(10 * 1000) // 資料傳輸的最長時間
.setStaleConnectionCheckEnabled(true) // 提交請求前測試連線是否可用
.build();
這裡我們也分兩步:第一步先是RequestConfig.custom()得到org.apache.http.client.config.RequestConfig.Builder,並且設定其屬性,第二步通過build()方法得到RequestConfig 物件。
所以我們先配置 org.apache.http.client.config.RequestConfig.Builder
之後我們在給它設定屬性:
第二步:通過build方法得到RequestConfig
接下來我們還要配置定期清理無用連線,我們在common中加入:
package com.taotao.common.httpclient;
import org.apache.http.conn.HttpClientConnectionManager;
public class IdleConnectionEvictor extends Thread {
private final HttpClientConnectionManager connMgr;
private volatile boolean shutdown;
public IdleConnectionEvictor(HttpClientConnectionManager connMgr) {
this.connMgr = connMgr;
// 啟動當前執行緒
this.start();
}
@Override
public void run() {
try {
while (!shutdown) {
synchronized (this) {
wait(5000);
// 關閉失效的連線
connMgr.closeExpiredConnections();
}
}
} catch (InterruptedException ex) {
// 結束
}
}
public void shutdown() {
shutdown = true;
synchronized (this) {
notifyAll();
}
}
}
然後我們在配置檔案中配置:
然後我們要加入外部配置檔案:
在Spring配置中,載入外部配置檔案:
封裝ApiService
我們來封裝使用HttpClient的通用Service,我們把它放在common中。
package com.taotao.common.service;
import java.io.IOException;
import java.net.URISyntaxException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.config.RequestConfig;
import org.apache.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.client.utils.URIBuilder;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import com.taotao.common.httpclient.HttpResult;
@Service
public class ApiService implements BeanFactoryAware {
@Autowired(required = false)
private RequestConfig requestConfig;
private BeanFactory beanFactory;
/**
* GET請求地址,響應200,返回響應的內容,響應為404、500返回null
*
* @param url
* @return
* @throws ClientProtocolException
* @throws IOException
*/
public String doGet(String url) throws ClientProtocolException, IOException {
// 建立http GET請求
HttpGet httpGet = new HttpGet(url);
httpGet.setConfig(this.requestConfig);
CloseableHttpResponse response = null;
try {
// 執行請求
response = getHttpclient().execute(httpGet);
// 判斷返回狀態是否為200
if (response.getStatusLine().getStatusCode() == 200) {
return EntityUtils.toString(response.getEntity(), "UTF-8");
}
} finally {
if (response != null) {
response.close();
}
}
return null;
}
/**
* 帶有引數的GET請求
*
* @param url
* @param params
* @return
* @throws ClientProtocolException
* @throws IOException
* @throws URISyntaxException
*/
public String doGet(String url, Map<String, String> params) throws ClientProtocolException, IOException,
URISyntaxException {
// 定義請求的引數
URIBuilder builder = new URIBuilder(url);
for (Map.Entry<String, String> entry : params.entrySet()) {
builder.setParameter(entry.getKey(), entry.getValue());
}
return this.doGet(builder.build().toString());
}
/**
* 帶有引數的POST請求
*
* @param url
* @param params
* @return
* @throws ClientProtocolException
* @throws IOException
*/
public HttpResult doPost(String url, Map<String, String> params) throws ClientProtocolException,
IOException {
// 建立http POST請求
HttpPost httpPost = new HttpPost(url);
httpPost.setConfig(this.requestConfig);
if (null != params) {
List<NameValuePair> parameters = new ArrayList<NameValuePair>(0);
for (Map.Entry<String, String> entry : params.entrySet()) {
parameters.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
}
// 構造一個form表單式的實體
UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(parameters);
// 將請求實體設定到httpPost物件中
httpPost.setEntity(formEntity);
}
CloseableHttpResponse response = null;
try {
// 執行請求
response = getHttpclient().execute(httpPost);
HttpEntity entity = response.getEntity();
if (null == entity) {
return new HttpResult(response.getStatusLine().getStatusCode(), null);
}
return new HttpResult(response.getStatusLine().getStatusCode(), EntityUtils.toString(
response.getEntity(), "UTF-8"));
} finally {
if (response != null) {
response.close();
}
}
}
/**
* 帶有json引數的POST請求
*
* @param url
* @param params
* @return
* @throws ClientProtocolException
* @throws IOException
*/
public HttpResult doPostJson(String url, String json) throws ClientProtocolException,
IOException {
// 建立http POST請求
HttpPost httpPost = new HttpPost(url);
httpPost.setConfig(this.requestConfig);
if (null != json) {
StringEntity stringEntity = new StringEntity(json, ContentType.APPLICATION_JSON);
// 將請求實體設定到httpPost物件中
httpPost.setEntity(stringEntity);
}
CloseableHttpResponse response = null;
try {
// 執行請求
response = getHttpclient().execute(httpPost);
HttpEntity entity = response.getEntity();
if (null == entity) {
return new HttpResult(response.getStatusLine().getStatusCode(), null);
}
return new HttpResult(response.getStatusLine().getStatusCode(), EntityUtils.toString(
response.getEntity(), "UTF-8"));
} finally {
if (response != null) {
response.close();
}
}
}
/**
* 沒有引數的POST請求
*
* @param url
* @return
* @throws ClientProtocolException
* @throws IOException
*/
public HttpResult doPost(String url) throws ClientProtocolException, IOException {
return this.doPost(url, null);
}
private CloseableHttpClient getHttpclient() {
return this.beanFactory.getBean(CloseableHttpClient.class);
}
@Override
public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
// 該方法是在Spring容器初始化時會呼叫該方法,傳入beanFactory
this.beanFactory = beanFactory;
}
}
異常處理:
get返回值是根據狀態碼為200則返回資料,狀態碼不為200則返回null。post的返回值必須返回響應狀態碼和內容,比如返回狀態碼為201的時候同時也會返回內容,所以我們構造一個物件來返回:
package com.taotao.common.httpclient;
public class HttpResult {
private Integer code;
private String body;
public HttpResult() {
}
public HttpResult(Integer code, String body) {
this.code = code;
this.body = body;
}
public Integer getCode() {
return code;
}
public void setCode(Integer code) {
this.code = code;
}
public String getBody() {
return body;
}
public void setBody(String body) {
this.body = body;
}
}
然後我們再來看一個單例物件中如何使用多例的物件的問題:
原本我們應該這樣寫:
然後我們通過注入的httpclient使用httpclient.execute(httpGet);
得到CloseableHttpResponse物件。但是因為我們註解@Service的ApiService是單例的,只會例項化一次,例項化一次的時候只會注入一次httpclient,那麼我們的httpclient就變成單例的了。然而我們的httpclient必須是個多例物件。那我們可能會想把ApiService變成多例的,加@Scope(“prototype”)就可以了。那麼如果有其他的Service或者Controller要呼叫這個ApiService是不是也是同樣的情況,也是在單例物件中使用多例物件。所以這個方法不可行。那麼我們如何在單例物件中使用多例物件?
解決方法就是:httpclient這個物件不能注入,而是每次使用的時候,通過容器裡面去獲取,因為在容器裡面指定httpclient是多例的。
所以主要的程式碼截圖下:
通過以上步驟就可以達到在單例物件中使用多例物件。