Java 調(diào)用第三方接口示范
不點(diǎn)藍(lán)字關(guān)注,我們哪來故事?
?正文如下?
來源:blog.csdn.net/qq_35860138/article/details/82967727
在項(xiàng)目開發(fā)中經(jīng)常會遇到調(diào)用第三方接口的情況,比如說調(diào)用第三方的天氣預(yù)報(bào)接口。
# 使用流程
1、準(zhǔn)備工作:在項(xiàng)目的工具包下導(dǎo)入HttpClientUtil這個工具類,或者也可以使用Spring框架的restTemplate來調(diào)用,上面有調(diào)用接口的方法【分為Get和Post方式的有參和無參調(diào)用】:
package com.njsc.credit.util;import java.io.IOException;import java.net.URI;import java.util.ArrayList;import java.util.List;import java.util.Map;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.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.impl.client.HttpClients;import org.apache.http.message.BasicNameValuePair;import org.apache.http.util.EntityUtils;public class HttpClientUtil {/*** 帶參數(shù)的get請求* @param url* @param param* @return String*/public static String doGet(String url, Map<String, String> param) {// 創(chuàng)建Httpclient對象CloseableHttpClient httpclient = HttpClients.createDefault();String resultString = "";CloseableHttpResponse response = null;try {// 創(chuàng)建uriURIBuilder builder = new URIBuilder(url);if (param != null) {for (String key : param.keySet()) {builder.addParameter(key, param.get(key));}}URI uri = builder.build();// 創(chuàng)建http GET請求HttpGet httpGet = new HttpGet(uri);// 執(zhí)行請求response = httpclient.execute(httpGet);// 判斷返回狀態(tài)是否為200if (response.getStatusLine().getStatusCode() == 200) {resultString = EntityUtils.toString(response.getEntity(), "UTF-8");}} catch (Exception e) {e.printStackTrace();} finally {try {if (response != null) {response.close();}httpclient.close();} catch (IOException e) {e.printStackTrace();}}return resultString;}/*** 不帶參數(shù)的get請求* @param url* @return String*/public static String doGet(String url) {return doGet(url, null);}/*** 帶參數(shù)的post請求* @param url* @param param* @return String*/public static String doPost(String url, Map<String, String> param) {// 創(chuàng)建Httpclient對象CloseableHttpClient httpClient = HttpClients.createDefault();CloseableHttpResponse response = null;String resultString = "";try {// 創(chuàng)建Http Post請求HttpPost httpPost = new HttpPost(url);// 創(chuàng)建參數(shù)列表if (param != null) {ListparamList = new ArrayList<>(); for (String key : param.keySet()) {paramList.add(new BasicNameValuePair(key, param.get(key)));}// 模擬表單UrlEncodedFormEntity entity = new UrlEncodedFormEntity(paramList);httpPost.setEntity(entity);}// 執(zhí)行http請求response = httpClient.execute(httpPost);resultString = EntityUtils.toString(response.getEntity(), "utf-8");} catch (Exception e) {e.printStackTrace();} finally {try {response.close();} catch (IOException e) {e.printStackTrace();}}return resultString;}/*** 不帶參數(shù)的post請求* @param url* @return String*/public static String doPost(String url) {return doPost(url, null);}/*** 傳送json類型的post請求* @param url* @param json* @return String*/public static String doPostJson(String url, String json) {// 創(chuàng)建Httpclient對象CloseableHttpClient httpClient = HttpClients.createDefault();CloseableHttpResponse response = null;String resultString = "";try {// 創(chuàng)建Http Post請求HttpPost httpPost = new HttpPost(url);// 創(chuàng)建請求內(nèi)容StringEntity entity = new StringEntity(json, ContentType.APPLICATION_JSON);httpPost.setEntity(entity);// 執(zhí)行http請求response = httpClient.execute(httpPost);resultString = EntityUtils.toString(response.getEntity(), "utf-8");} catch (Exception e) {e.printStackTrace();} finally {try {response.close();} catch (IOException e) {e.printStackTrace();}}return resultString;}}
2、創(chuàng)建url和訪問key 以及參數(shù)等:
代碼如下:
/*** 聚合接口校驗(yàn)身份證* @param idCard* @param realName* @return boolean*/public boolean identityCheck(String idCard, String realName){logger.info("-----------------調(diào)用聚合數(shù)據(jù) 身份證驗(yàn)證API BEGIN--------------->");String key = "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX";String url = "http://op.juhe.cn/idcard/query" + "?key=" + key + "&idcard=" + idCard + "&realname=" + realName;logger.info("請求url:" + url);boolean match = false; //是否匹配try {String result = HttpClientUtil.doGet(url);System.out.println("請求結(jié)果:" + result);IdentityCheckResult identityCheckResult = JsonUtils.parse(result, IdentityCheckResult.class);IdentityCheck identityCheck = JsonUtils.parse(result, "result", IdentityCheck.class);logger.info(identityCheckResult);logger.info(identityCheck.toString());if(identityCheckResult.correct() && identityCheck.getRes() == 1){match = true;}} catch (Exception e) {e.printStackTrace();}logger.info("<-----------------調(diào)用聚合數(shù)據(jù) 身份證驗(yàn)證API END---------------");return match;}
3、請求這個第三方接口:
使用HttpClientUtil工具類中的doGet方法來請求URL,得到結(jié)果,現(xiàn)在大多數(shù)是一個json字符串,類型為String
4、根據(jù)接口返回?cái)?shù)據(jù)格式來解析數(shù)據(jù):

可以看到,返回參數(shù)有六個,所以在項(xiàng)目中新建一個bean,包含以上六個字段,用來接住返回?cái)?shù)據(jù),如下:

因?yàn)榻涌诜祷氐臄?shù)據(jù)是一個json的字符串,類型實(shí)際上是一個String字符串,要解析數(shù)據(jù),用工具類JsonUtils的parse方法將字符串轉(zhuǎn)換為Java對象,JsonUtils的代碼如下:
package com.eqianxian.commons.utils.json;import java.util.List;import java.util.Map;import com.alibaba.fastjson.JSON;import com.alibaba.fastjson.JSONObject;import com.alibaba.fastjson.serializer.PropertyFilter;import com.alibaba.fastjson.serializer.SerializerFeature;/*** 在系統(tǒng)中統(tǒng)一使用這個,以方便將來切換不同的JSON生成工具** @author KelvinZ**/public class JsonUtils {public static final int TYPE_FASTJSON = 0;public static final int TYPE_GSON = 1;/**** 對象轉(zhuǎn)化為json字符串** @param obj 待轉(zhuǎn)化對象* @return 代表該對象的Json字符串*/public static final String toJson(final Object obj) {return JSON.toJSONString(obj);// return gson.toJson(obj);}/**** 對象轉(zhuǎn)化為json字符串** @param obj 待轉(zhuǎn)化對象* @return 代表該對象的Json字符串*/public static final String toJson(final Object obj, SerializerFeature... features) {return JSON.toJSONString(obj, features);// return gson.toJson(obj);}/*** 對象轉(zhuǎn)化為json字符串并格式化** @param obj* @param format 是否要格式化* @return*/public static final String toJson(final Object obj, final boolean format) {return JSON.toJSONString(obj, format);}/*** 對象對指定字段進(jìn)行過濾處理,生成json字符串** @param obj* @param fields 過濾處理字段* @param ignore true做忽略處理,false做包含處理* @param features json特征,為null忽略* @return*/public static final String toJson(final Object obj, final String[] fields, final boolean ignore,SerializerFeature... features) {if (fields == null || fields.length < 1) {return toJson(obj);}if (features == null)features = new SerializerFeature[] { SerializerFeature.QuoteFieldNames };return JSON.toJSONString(obj, new PropertyFilter() {public boolean apply(Object object, String name, Object value) {for (int i = 0; i < fields.length; i++) {if (name.equals(fields[i])) {return !ignore;}}return ignore;}}, features);}/**** 解析json字符串中某路徑的值** @param json* @param path* @return*/("unchecked")public static finalE parse(final String json, final String path) { String[] keys = path.split(",");JSONObject obj = JSON.parseObject(json);for (int i = 0; i < keys.length - 1; i++) {obj = obj.getJSONObject(keys[i]);}return (E) obj.get(keys[keys.length - 1]);}/**** json字符串解析為對象** @param json 代表一個對象的Json字符串* @param clazz 指定目標(biāo)對象的類型,即返回對象的類型* @return 從json字符串解析出來的對象*/public static finalT parse(final String json, final Class clazz) {return JSON.parseObject(json, clazz);}/**** json字符串解析為對象** @param json json字符串* @param path 逗號分隔的json層次結(jié)構(gòu)* @param clazz 目標(biāo)類*/public static finalT parse(final String json, final String path, final Class clazz) {String[] keys = path.split(",");JSONObject obj = JSON.parseObject(json);for (int i = 0; i < keys.length - 1; i++) {obj = obj.getJSONObject(keys[i]);}String inner = obj.getString(keys[keys.length - 1]);return parse(inner, clazz);}/*** 將制定的對象經(jīng)過字段過濾處理后,解析成為json集合** @param obj* @param fields* @param ignore* @param clazz* @param features* @return*/public static finalList parseArray(final Object obj, final String[] fields, boolean ignore, final Classclazz, final SerializerFeature... features) {String json = toJson(obj, fields, ignore, features);return parseArray(json, clazz);}/**** 從json字符串中解析出一個對象的集合,被解析字符串要求是合法的集合類型* (形如:["k1":"v1","k2":"v2",..."kn":"vn"])** @param json - [key-value-pair...]* @param clazz* @return*/public static finalList parseArray(final String json, final Class {clazz) return JSON.parseArray(json, clazz);}/**** 從json字符串中按照路徑尋找,并解析出一個對象的集合,例如:* 類Person有一個屬性name,要從以下json中解析出其集合:* {* "page_info":{* "items":{* "item":[{"name":"KelvinZ"},{"name":"Jobs"},...{"name":"Gates"}]* }* }* 使用方法:parseArray(json, "page_info,items,item", Person.class),* 將根據(jù)指定路徑,正確的解析出所需集合,排除外層干擾** @param json json字符串* @param path 逗號分隔的json層次結(jié)構(gòu)* @param clazz 目標(biāo)類* @return*/public static finalList parseArray(final String json, final String path, final Class {clazz) String[] keys = path.split(",");JSONObject obj = JSON.parseObject(json);for (int i = 0; i < keys.length - 1; i++) {obj = obj.getJSONObject(keys[i]);}String inner = obj.getString(keys[keys.length - 1]);Listret = parseArray(inner, clazz); return ret;}/**** 有些json的常見格式錯誤這里可以處理,以便給后續(xù)的方法處理* 常見錯誤:使用了\" 或者 "{ 或者 }",騰訊的頁面中常見這種格式** @param invalidJson 包含非法格式的json字符串* @return*/public static final String correctJson(final String invalidJson) {String content = invalidJson.replace("\\\"", "\"").replace("\"{", "{").replace("}\"", "}");return content;}/*** 格式化Json** @param json* @return*/public static final String formatJson(String json) {Map, ?> map = (Map, ?>) JSON.parse(json);return JSON.toJSONString(map, true);}/*** 獲取json串中的子json** @param json* @param path* @return*/public static final String getSubJson(String json, String path) {String[] keys = path.split(",");JSONObject obj = JSON.parseObject(json);for (int i = 0; i < keys.length - 1; i++) {obj = obj.getJSONObject(keys[i]);System.out.println(obj.toJSONString());}return obj != null ? obj.getString(keys[keys.length - 1]) : null;}}
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