这篇文章主要讲解了Java http请求封装工具类的方法，内容清晰明了，对此有兴趣的小伙伴可以学习一下，相信大家阅读完之后会有帮助。
java实现http请求的方法常用有两种，一种则是通过java自带的标准类HttpURLConnection去实现，另一种是通过apache的httpclient去实现。
本文用httpclient去实现，需要导入httpclient和httpcore两个jar包，测试时用的httpclient-4.5.1和httpcore-4.4.3。
HttpMethod.java
package demo;
public enum HttpMethod {
GET, POST;
}HttpHeader.java
package demo;
import java.util.HashMap;
import java.util.Map;
/**
* 请求头
*/
public class HttpHeader {
private Map<String, String> params = new HashMap<String, String>();
public HttpHeader addParam(String name, String value) {
this.params.put(name, value);
return this;
}
public Map<String, String> getParams() {
return this.params;
}
}HttpParamers.java
package demo;
import java.io.IOException;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import com.alibaba.fastjson.JSON;
/**
* 请求参数
*/
public class HttpParamers {
private Map<String, String> params = new HashMap<String, String>();
private HttpMethod httpMethod;
private String jsonParamer = "";
public HttpParamers(HttpMethod httpMethod) {
this.httpMethod = httpMethod;
}
public static HttpParamers httpPostParamers() {
return new HttpParamers(HttpMethod.POST);
}
public static HttpParamers httpGetParamers() {
return new HttpParamers(HttpMethod.GET);
}
public HttpParamers addParam(String name, String value) {
this.params.put(name, value);
return this;
}
public HttpMethod getHttpMethod() {
return this.httpMethod;
}
public String getQueryString(String charset) throws IOException {
if ((this.params == null) || (this.params.isEmpty())) {
return null;
}
StringBuilder query = new StringBuilder();
Set<Map.Entry<String, String>> entries = this.params.entrySet();
for (Map.Entry<String, String> entry : entries) {
String name = entry.getKey();
String value = entry.getValue();
query.append("&").append(name).append("=").append(URLEncoder.encode(value, charset));
}
return query.substring(1);
}
public boolean isJson() {
return !isEmpty(this.jsonParamer);
}
public Map<String, String> getParams() {
return this.params;
}
public String toString() {
return "HttpParamers " + JSON.toJSONString(this);
}
public String getJsonParamer() {
return this.jsonParamer;
}
public void setJsonParamer() {
this.jsonParamer = JSON.toJSONString(this.params);
}
private static boolean isEmpty(CharSequence cs) {
return (cs == null) || (cs.length() == 0);
}
}HttpClient.java
package demo;
import java.io.IOException;
import java.util.Map;
import java.util.Set;
import org.apache.http.HttpEntity;
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.methods.HttpRequestBase;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.protocol.HTTP;
import org.apache.http.util.EntityUtils;
public class HttpClient {
public static final String DEFAULT_CHARSET = "UTF-8";
public static final String JSON_CONTENT_FORM = "application/json;charset=UTF-8";
public static final String CONTENT_FORM = "application/x-www-form-urlencoded;charset=UTF-8";
public static String doService(String url, HttpParamers paramers, HttpHeader header, int connectTimeout, int readTimeout) throws Exception {
HttpMethod httpMethod = paramers.getHttpMethod();
switch (httpMethod) {
case GET:
return doGet(url, paramers, header, connectTimeout, readTimeout);
case POST:
return doPost(url, paramers, header, connectTimeout, readTimeout);
}
return null;
}
/**
* post方法
* @param url
* @param paramers
* @param header
* @param connectTimeout
* @param readTimeout
* @return
* @throws IOException
*/
public static String doPost(String url, HttpParamers paramers, HttpHeader header, int connectTimeout, int readTimeout) throws IOException {
String responseData = "";
CloseableHttpClient httpClient = null;
CloseableHttpResponse httpResponse = null;
try{
String query = null;
HttpPost httpPost = new HttpPost(url);
setHeader(httpPost, header);
if (paramers.isJson()) {
//json数据
httpPost.setHeader(HTTP.CONTENT_TYPE, JSON_CONTENT_FORM);
query = paramers.getJsonParamer();
} else {
//表单数据
httpPost.setHeader(HTTP.CONTENT_TYPE, CONTENT_FORM);
query = paramers.getQueryString(DEFAULT_CHARSET);
}
if(query != null){
HttpEntity reqEntity = new StringEntity(query);
httpPost.setEntity(reqEntity);
}
httpClient = HttpClients.createDefault();
httpResponse = httpClient.execute(httpPost);
HttpEntity resEntity = httpResponse.getEntity();
responseData = EntityUtils.toString(resEntity);
} catch (Exception e){
e.printStackTrace();
} finally{
httpResponse.close();
httpClient.close();
}
return responseData;
}
/**
* get方法
* @param url
* @param params
* @param header
* @param connectTimeout
* @param readTimeout
* @return
* @throws IOException
*/
public static String doGet(String url, HttpParamers params, HttpHeader header, int connectTimeout, int readTimeout) throws IOException {
String responseData = "";
CloseableHttpClient httpClient = null;
CloseableHttpResponse httpResponse = null;
try{
String query = params.getQueryString(DEFAULT_CHARSET);
url = buildGetUrl(url, query);
HttpGet httpGet = new HttpGet(url);
setHeader(httpGet, header);
httpClient = HttpClients.createDefault();
httpResponse = httpClient.execute(httpGet);
HttpEntity resEntity = httpResponse.getEntity();
responseData = EntityUtils.toString(resEntity);
} catch (Exception e){
e.printStackTrace();
} finally{
httpResponse.close();
httpClient.close();
}
return responseData;
}
private static void setHeader(HttpRequestBase httpRequestBase, HttpHeader header){
if(header != null){
Map<String,String> headerMap = header.getParams();
if (headerMap != null && !headerMap.isEmpty()) {
Set<Map.Entry<String, String>> entries = headerMap.entrySet();
for (Map.Entry<String, String> entry : entries) {
String name = entry.getKey();
String value = entry.getValue();
httpRequestBase.setHeader(name, value);
}
}
}
}
private static String buildGetUrl(String url, String query) throws IOException {
if (query == null || query.equals("")) {
return url;
}
StringBuilder newUrl = new StringBuilder(url);
boolean hasQuery = url.contains("?");
boolean hasPrepend = (url.endsWith("?")) || (url.endsWith("&"));
if (!hasPrepend) {
if (hasQuery) {
newUrl.append("&");
} else {
newUrl.append("?");
hasQuery = true;
}
}
newUrl.append(query);
hasPrepend = false;
return newUrl.toString();
}
}HttpService.java
package demo;
import java.util.Map;
import com.alibaba.fastjson.JSONObject;
import com.alibaba.fastjson.TypeReference;
public class HttpService {
private String serverUrl;
private int connectTimeout = 15000;
private int readTimeout = 30000;
public HttpService(String serverUrl) {
this.serverUrl = serverUrl.trim();
}
public Map<String, Object> commonService(String serviceUrl, HttpParamers paramers) throws Exception{
return commonService(serviceUrl, paramers, null);
}
public Map<String, Object> commonService(String serviceUrl, HttpParamers paramers, HttpHeader header) throws Exception{
String response = service(serviceUrl, paramers, header);
try {
Map<String, Object> result = JSONObject.parseObject(response, new TypeReference<Map<String, Object>>() {});
if ((result == null) || (result.isEmpty())) {
throw new Exception("远程服务返回的数据无法解析");
}
Integer code = (Integer) result.get("code");
if ((code == null) || (code.intValue() != 0)) {
throw new Exception((String) result.get("message"));
}
return result;
} catch (Exception e) {
throw new Exception("返回结果异常,response:" + response, e);
}
}
public String service(String serviceUrl, HttpParamers paramers) throws Exception {
return service(serviceUrl, paramers, null);
}
public String service(String serviceUrl, HttpParamers paramers, HttpHeader header) throws Exception {
String url = this.serverUrl + serviceUrl;
String responseData = "";
try {
responseData = HttpClient.doService(url, paramers, header, this.connectTimeout, this.readTimeout);
} catch (Exception e) {
throw new Exception(e.getMessage(), e);
}
return responseData;
}
public String getServerUrl() {
return this.serverUrl;
}
public int getConnectTimeout() {
return this.connectTimeout;
}
public int getReadTimeout() {
return this.readTimeout;
}
public void setConnectTimeout(int connectTimeout) {
this.connectTimeout = connectTimeout;
}
public void setReadTimeout(int readTimeout) {
this.readTimeout = readTimeout;
}
}测试例子Test1.java
package demo;
import org.junit.Ignore;
import org.junit.Test;
public class Test1 {
//免费的在线REST服务, 提供测试用的HTTP请求假数据
//接口信息说明可见：http://www.hangge.com/blog/cache/detail_2020.html
String uri = "http://jsonplaceholder.typicode.com";
//get方式请求数据
//请求地址：http://jsonplaceholder.typicode.com/posts
@Ignore("暂时忽略")
@Test
public void test1() {
System.out.print("\n" + "test1---------------------------"+ "\n");
HttpParamers paramers = HttpParamers.httpGetParamers();
String response = "";
try {
HttpService httpService = new HttpService(uri);
response = httpService.service("/posts", paramers);
} catch (Exception e) {
e.printStackTrace();
}
System.out.print(response);
}
//get方式请求数据
//请求地址：http://jsonplaceholder.typicode.com/posts?userId=5
@Ignore("暂时忽略")
@Test
public void test2() {
System.out.print("\n" + "test2---------------------------"+ "\n");
HttpParamers paramers = HttpParamers.httpGetParamers();
paramers.addParam("userId", "5");
String response = "";
try {
HttpService httpService = new HttpService(uri);
response = httpService.service("/posts", paramers);
} catch (Exception e) {
e.printStackTrace();
}
System.out.print(response);
}
//post方式请求数据
//请求地址：http://jsonplaceholder.typicode.com/posts
@Test
public void test3() {
System.out.print("\n" + "test3---------------------------"+ "\n");
HttpParamers paramers = HttpParamers.httpPostParamers();
paramers.addParam("time", String.valueOf(System.currentTimeMillis()));
String response = "";
try {
HttpService httpService = new HttpService(uri);
response = httpService.service("/posts", paramers);
} catch (Exception e) {
e.printStackTrace();
}
System.out.print(response);
}
}看完上述内容，是不是对Java http请求封装工具类的方法有进一步的了解，如果还想学习更多内容，欢迎关注亿速云行业资讯频道。
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