HttpClient远程调用
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<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.5.6</version>
</dependency>
1 .案例代码
1.1 get请求
public class DoGET {
public static void main(String[] args) throws Exception {
// 创建Httpclient对象,相当于打开了浏览器
CloseableHttpClient httpclient = HttpClients.createDefault();
// 创建HttpGet请求，相当于在浏览器输入地址
HttpGet httpGet = new HttpGet("http://www.baidu.com/");
CloseableHttpResponse response = null;
try {
// 执行请求，相当于敲完地址后按下回车。获取响应
response = httpclient.execute(httpGet);
// 判断返回状态是否为200
if (response.getStatusLine().getStatusCode() == 200) {
// 解析响应，获取数据
String content = EntityUtils.toString(response.getEntity(), "UTF-8");
System.out.println(content);
}
} finally {
if (response != null) {
// 关闭资源
response.close();
}
// 关闭浏览器
httpclient.close();
}
}
}
1.2 带参数的get请求
public class DoGETParam {
public static void main(String[] args) throws Exception {
// 创建Httpclient对象
CloseableHttpClient httpclient = HttpClients.createDefault();
// 创建URI对象，并且设置请求参数
URI uri = new URIBuilder("http://www.baidu.com/s").setParameter("wd", "java").build();
// 创建http GET请求
HttpGet httpGet = new HttpGet(uri);
CloseableHttpResponse response = null;
try {
// 执行请求
response = httpclient.execute(httpGet);
// 判断返回状态是否为200
if (response.getStatusLine().getStatusCode() == 200) {
// 解析响应数据
String content = EntityUtils.toString(response.getEntity(), "UTF-8");
System.out.println(content);
}
} finally {
if (response != null) {
response.close();
}
httpclient.close();
}
}
}
1.3 POST请求
/*
* 演示：使用HttpClient发起POST请求
*/
public class DoPOST {
public static void main(String[] args) throws Exception {
// 创建Httpclient对象
CloseableHttpClient httpclient = HttpClients.createDefault();
// 创建http POST请求
HttpPost httpPost = new HttpPost("http://www.oschina.net/");
// 把自己伪装成浏览器。否则开源中国会拦截访问
httpPost.setHeader("User-Agent", "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36");
CloseableHttpResponse response = null;
try {
// 执行请求
response = httpclient.execute(httpPost);
// 判断返回状态是否为200
if (response.getStatusLine().getStatusCode() == 200) {
// 解析响应数据
String content = EntityUtils.toString(response.getEntity(), "UTF-8");
System.out.println(content);
}
} finally {
if (response != null) {
response.close();
}
// 关闭浏览器
httpclient.close();
}
}
}
1.4 带参数的POST请求
/*
* 演示：使用HttpClient发起带有参数的POST请求
*/
public class DoPOSTParam {
public static void main(String[] args) throws Exception {
// 创建Httpclient对象
CloseableHttpClient httpclient = HttpClients.createDefault();
// 创建http POST请求，访问开源中国
HttpPost httpPost = new HttpPost("http://www.oschina.net/search");
// 根据开源中国的请求需要，设置post请求参数
List<NameValuePair> parameters = new ArrayList<NameValuePair>(0);
parameters.add(new BasicNameValuePair("scope", "project"));
parameters.add(new BasicNameValuePair("q", "java"));
parameters.add(new BasicNameValuePair("fromerr", "8bDnUWwC"));
// 构造一个form表单式的实体
UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(parameters);
// 将请求实体设置到httpPost对象中
httpPost.setEntity(formEntity);
CloseableHttpResponse response = null;
try {
// 执行请求
response = httpclient.execute(httpPost);
// 判断返回状态是否为200
if (response.getStatusLine().getStatusCode() == 200) {
// 解析响应体
String content = EntityUtils.toString(response.getEntity(), "UTF-8");
System.out.println(content);
}
} finally {
if (response != null) {
response.close();
}
// 关闭浏览器
httpclient.close();
}
}
}
2.整合项目
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
</dependency>
2.1 在application.properties添加如下配置:
#The config for HttpClient
http.maxTotal=300
http.defaultMaxPerRoute=50
http.connectTimeout=1000
http.connectionRequestTimeout=500
http.socketTimeout=5000
http.staleConnectionCheckEnabled=true
2.2 config 配置类
package com.czxy.config;
import org.apache.http.client.HttpClient;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.conn.HttpClientConnectionManager;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.client.ClientHttpRequestFactory;
import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.web.client.RestTemplate;
import java.nio.charset.Charset;
import java.util.List;
/**
* HttpClient的配置类---类似工具类
* Configuration:标明这是一个配置类
* ConfigurationProperties：加载application.properties属性文件
* prefix：前缀
* ignoreUnknownFields：忽略找不到的属性
* 自动将属性文件中的值赋值该类中的属性
*
* 最终需要知道：
* 1 SpringBoot推荐使用RestTemplate操作RestFul API
* 2 RestTemplate底层需要借助HttpClient创建
*
*
*/
@Configuration
@ConfigurationProperties(prefix = "http", ignoreUnknownFields = true)
public class HttpClientConfig {
private Integer maxTotal;// 最大连接
private Integer defaultMaxPerRoute;// 每个host的最大连接
private Integer connectTimeout;// 连接超时时间
private Integer connectionRequestTimeout;// 请求超时时间
private Integer socketTimeout;// 响应超时时间
/**
* HttpClient连接池
* @return
*/
@Bean
public HttpClientConnectionManager httpClientConnectionManager() {
PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager();
connectionManager.setMaxTotal(maxTotal);
connectionManager.setDefaultMaxPerRoute(defaultMaxPerRoute);
return connectionManager;
}
/**
* 注册RequestConfig
* @return
*/
@Bean
public RequestConfig requestConfig() {
return RequestConfig.custom().setConnectTimeout(connectTimeout)
.setConnectionRequestTimeout(connectionRequestTimeout).setSocketTimeout(socketTimeout)
.build();
}
/**
* 注册HttpClient
* @param manager
* @param config
* @return
*/
@Bean
public HttpClient httpClient(HttpClientConnectionManager manager, RequestConfig config) {
return HttpClientBuilder.create().setConnectionManager(manager).setDefaultRequestConfig(config)
.build();
}
/**
* 使用连接池管理连接
* @param httpClient
* @return
*/
@Bean
public ClientHttpRequestFactory requestFactory(HttpClient httpClient) {
return new HttpComponentsClientHttpRequestFactory(httpClient);
}
/**
* 使用HttpClient来初始化一个RestTemplate
* @param requestFactory
* @return
*/
@Bean
public RestTemplate restTemplate(ClientHttpRequestFactory requestFactory) {
RestTemplate template = new RestTemplate(requestFactory);
List<HttpMessageConverter<?>> list = template.getMessageConverters();
for (HttpMessageConverter<?> mc : list) {
if (mc instanceof StringHttpMessageConverter) {
((StringHttpMessageConverter) mc).setDefaultCharset(Charset.forName("UTF-8"));
}
}
return template;
}
public Integer getMaxTotal() {
return maxTotal;
}
public void setMaxTotal(Integer maxTotal) {
this.maxTotal = maxTotal;
}
public Integer getDefaultMaxPerRoute() {
return defaultMaxPerRoute;
}
public void setDefaultMaxPerRoute(Integer defaultMaxPerRoute) {
this.defaultMaxPerRoute = defaultMaxPerRoute;
}
public Integer getConnectTimeout() {
return connectTimeout;
}
public void setConnectTimeout(Integer connectTimeout) {
this.connectTimeout = connectTimeout;
}
public Integer getConnectionRequestTimeout() {
return connectionRequestTimeout;
}
public void setConnectionRequestTimeout(Integer connectionRequestTimeout) {
this.connectionRequestTimeout = connectionRequestTimeout;
}
public Integer getSocketTimeout() {
return socketTimeout;
}
public void setSocketTimeout(Integer socketTimeout) {
this.socketTimeout = socketTimeout;
}
}
2.3.1 前端页面方法
2.3.2 调用（controller）
package com.czxy.web.product;
import com.alibaba.fastjson.JSON;
import com.czxy.pojo.DatagridResult;
import com.czxy.pojo.Product;
import org.apache.http.client.HttpClient;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpMethod;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.client.RestTemplate;
import java.util.LinkedHashMap;
import java.util.Map;
/**
* @author Fang
* @create 2018-10-25 16:20
* @desc 商品
**/
@RestController
@RequestMapping("/product")
public class ProductController {
@Autowired
private RestTemplate restTemplate;
/**
*@author Fang
*@create 2018/10/26 21:52
*@desc datagrid 分页查询
**/
@GetMapping("/findAll")
public ResponseEntity<DatagridResult> findAll(Integer page, Integer rows) {
String url = "http://127.0.0.1:8090/product02/findAll02?page=" + page + "&rows=" + rows;
ResponseEntity<String> entity = restTemplate.getForEntity(url, String.class);
String body = entity.getBody();
DatagridResult datagridResult = JSON.parseObject(body, DatagridResult.class);
return new ResponseEntity<DatagridResult>(datagridResult, HttpStatus.OK);
}
/**
* @author Fang
* @create 2018/10/25 18:10
* @desc 修改
**/
@PutMapping("/update")
public ResponseEntity<Void> update(Product product) {
String url = "http://127.0.0.1:8090/product02/update02";
restTemplate.put(url, product);
return new ResponseEntity(HttpStatus.OK);
}
/**
*@author Fang
*@create 2018/10/25 19:49
*@desc 删除
**/
@DeleteMapping("/deleteProduct/{ids}")
public ResponseEntity<Void> delete(@PathVariable("ids") String ids){
String url="http://127.0.0.1:8090/product02/deleteProduct02/"+ids;
restTemplate.delete(url);
return new ResponseEntity(HttpStatus.OK);
}
}
2.4 接收请求的（controller）
package com.czxy.web.product02;
import com.czxy.pojo.DatagridResult;
import com.czxy.pojo.Product;
import com.czxy.service.product.ProductService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import java.util.LinkedHashMap;
/**
* @author Fang
* @create 2018-10-25 16:20
* @desc 商品
**/
@RestController
@RequestMapping("/product02")
public class ProductController02 {
@Autowired
private ProductService productService;
/**
*@author Fang
*@create 2018/10/26 21:52
*@desc datagrid 分页查询
**/
@GetMapping("/findAll02")
public ResponseEntity<DatagridResult> findAll(Integer page, Integer rows) {
DatagridResult result = productService.findAll(page, rows);
return new ResponseEntity<DatagridResult>(result, HttpStatus.OK);
}
/**
* @author Fang
* @create 2018/10/25 18:10
* @desc 修改
**/
@PutMapping("/update02")
public ResponseEntity<Void> update(@RequestBody Product product) {
productService.update(product);
return new ResponseEntity(HttpStatus.OK);
}
/**
*@author Fang
*@create 2018/10/25 19:49
*@desc 删除
**/
@DeleteMapping("/deleteProduct02/{ids}")
public ResponseEntity<Void> delete(@PathVariable("ids") String ids){
productService.deleteProduct(ids);
return new ResponseEntity(HttpStatus.OK);
}
}
3 注意
发送post请求时 接受调用的方法要在参数上加一个@RequestBody注解
如图所示：
delete请求 注意参数注解
如图所示：