Http发送get、post、delete、put请求
1、GET请求会向数据库发索取数据的请求，从而来获取信息，该请求就像数据库的select操作一样，只是用来查询一下数据，不会修改、增加数据，不会影响资源的内容，即该请求不会产生副作用。无论进行多少次操作，结果都是一样的。
2、与GET不同的是，PUT请求是向服务器端发送数据的，从而改变信息，该请求就像数据库的update操作一样，用来修改数据的内容，但是不会增加数据的种类等，也就是说无论进行多少次PUT操作，其结果并没有不同。
3、POST请求同PUT请求类似，都是向服务器端发送数据的，但是该请求会改变数据的种类等资源，就像数据库的insert操作一样，会创建新的内容。几乎目前所有的提交操作都是用POST请求的。
4、DELETE请求顾名思义，就是用来删除某一个资源的，该请求就像数据库的delete操作。
package mon.tool;import com.alibaba.fastjson.JSONObject;import mons.lang3.StringUtils;import org.apache.http.HttpEntity;import org.apache.http.client.methods.CloseableHttpResponse;import org.apache.http.entity.StringEntity;import org.apache.http.impl.client.CloseableHttpClient;import org.apache.http.impl.client.HttpClients;import org.apache.http.util.EntityUtils;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import java.io.*;import .HttpURLConnection;import .URL;import .URLConnection;import java.nio.charset.Charset;import java.util.List;import java.util.Map;/*** @author wjw*/public class HttpURLConnectionUtil {private static final Logger logger = LoggerFactory.getLogger(HttpURLConnectionUtil.class);/*** 向指定URL发送GET方法的请求** @param url* 发送请求的URL* @param param* 请求参数，请求参数应该是 name1=value1&name2=value2 的形式。* @return URL 所代表远程资源的响应结果*/public static String sendGet(String url, String param) {String result = "";BufferedReader in = null;try {String urlNameString = url + "?" + param;URL realUrl = new URL(urlNameString);// 打开和URL之间的连接URLConnection connection = realUrl.openConnection();// 设置通用的请求属性connection.setRequestProperty("accept", "*/*");connection.setRequestProperty("connection", "Keep-Alive");connection.setRequestProperty("user-agent","Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");// 建立实际的连接connection.connect();// 获取所有响应头字段Map<String, List<String>> map = connection.getHeaderFields();// 遍历所有的响应头字段for (String key : map.keySet()) {System.out.println(key + "--->" + map.get(key));}// 定义 BufferedReader输入流来读取URL的响应in = new BufferedReader(new InputStreamReader(connection.getInputStream()));String line;while ((line = in.readLine()) != null) {result += line;}} catch (Exception e) {System.out.println("发送GET请求出现异常！" + e);e.printStackTrace();}// 使用finally块来关闭输入流finally {try {if (in != null) {in.close();}} catch (Exception e2) {e2.printStackTrace();}}return result;}/*** 向指定 URL 发送POST方法的请求** @param url* 发送请求的 URL* @param param* 请求参数，请求参数应该是 name1=value1&name2=value2 的形式。* @return 所代表远程资源的响应结果*/public static String sendPost(String url, String param,String token) {PrintWriter out = null;BufferedReader in = null;String result = "";try {URL realUrl = new URL(url);// 打开和URL之间的连接URLConnection conn = realUrl.openConnection();// 设置通用的请求属性conn.setRequestProperty("accept", "*/*");conn.setRequestProperty("connection", "Keep-Alive");conn.setRequestProperty("user-agent","Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");conn.setRequestProperty("Content-Type", "application/json; charset=utf-8");if(token!=null){conn.setRequestProperty("Authorization",token);}// 发送POST请求必须设置如下两行conn.setDoOutput(true);conn.setDoInput(true);// 获取URLConnection对象对应的输出流out = new PrintWriter(conn.getOutputStream());// 发送请求参数out.print(param);// flush输出流的缓冲out.flush();// 定义BufferedReader输入流来读取URL的响应in = new BufferedReader(new InputStreamReader(conn.getInputStream()));String line;while ((line = in.readLine()) != null) {result += line;}} catch (Exception e) {System.out.println("发送 POST 请求出现异常！"+e);e.printStackTrace();}//使用finally块来关闭输出流、输入流finally{try{if(out!=null){out.close();}if(in!=null){in.close();}}catch(IOException ex){ex.printStackTrace();}}return result;}/*** delete请求* @param data* @param url* @param token* @return* @throws IOException*/public static String sendDelete(String data, String url, String token) throws IOException {logger.info("请求参数:{}", data);logger.info("请求url:{}", url);CloseableHttpClient client = null;HttpDeleteWithBody httpDelete = null;String result = null;try {client = HttpClients.createDefault();httpDelete = new HttpDeleteWithBody(url);httpDelete.addHeader("Content-type", "application/json; charset=utf-8");httpDelete.setHeader("Accept", "application/json; charset=utf-8");httpDelete.setHeader("Authorization", token);httpDelete.setEntity(new StringEntity(data));CloseableHttpResponse response = client.execute(httpDelete);HttpEntity entity = response.getEntity();result = EntityUtils.toString(entity);logger.info("请求结果:{}", result);if (200 == response.getStatusLine().getStatusCode()) {logger.info("DELETE方式请求远程调用成功.msg={}", result);}} catch (Exception e) {logger.error("DELETE方式请求远程调用失败,errorMsg={}", e.getMessage());} finally {client.close();}return result;}/*** put请求* @param urlPath* @param data* @param token* @return*/public static String sendPut(String data, String urlPath, String token) {logger.info("请求参数:{}", data);logger.info("请求url:{}", urlPath);String result = null;URL url = null;HttpURLConnection httpurlconnection = null;try {url = new URL(urlPath);httpurlconnection = (HttpURLConnection) url.openConnection();httpurlconnection.setDoInput(true);httpurlconnection.setDoOutput(true);// 设置通用的请求属性httpurlconnection.setRequestProperty("accept", "*/*");httpurlconnection.setRequestProperty("connection", "Keep-Alive");httpurlconnection.setRequestProperty("user-agent","Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");httpurlconnection.setRequestProperty("Content-Type", "application/json; charset=utf-8");if (token != null) {httpurlconnection.setRequestProperty("Authorization", token);}httpurlconnection.setRequestMethod("PUT");httpurlconnection.setRequestProperty("Content-Type", "application/json;charset=utf-8");if (StringUtils.isNotBlank(data)) {httpurlconnection.getOutputStream().write(data.getBytes("UTF-8"));}httpurlconnection.getOutputStream().flush();httpurlconnection.getOutputStream().close();int code = httpurlconnection.getResponseCode();if (code == 200) {DataInputStream in = new DataInputStream(httpurlconnection.getInputStream());int len = in.available();byte[] by = new byte[len];in.readFully(by);result = new String(by, Charset.forName("UTF-8"));logger.info("请求结果:{}", result);in.close();} else {logger.error("请求地址：" + urlPath + "返回状态异常，异常号为：" + code);}} catch (Exception e) {logger.error("访问url地址：" + urlPath + "发生异常", e);} finally {url = null;if (httpurlconnection != null) {httpurlconnection.disconnect();}}return result;}public static void main(String[] args) {//发送 GET 请求/*String s=HttpURLConnectionUtil.sendGet("http://localhost:6144/Home/RequestString", "key=123&v=456");System.out.println(s);*///发送 POST 请求 http://61.55.158.220:54778/handle-paas-api/login/v1String param="{\n" +"\"username\":\"nuode@nuodwl\",\n" +"\"password\":\"3e856379df63de7c19be0f6580f9726c4ad5905303f9779f9be984d5eae207ee\",\n" +"\"developUsername\":\"hljjcsundi\",\n" +"\"developPassword\":\"6493f5041ed91a81e0e629d0770e4bed6a5c90f58e50682ffaf17333280f37ff\"\n" +"}";String sr=HttpURLConnectionUtil.sendPost("http://61.55.158.220:54778/handle-paas-api/login/v1", param,null);System.out.println(sr);JSONObject result = (JSONObject) JSONObject.parse(sr);JSONObject data =(JSONObject) result.get("data");String token = data.get("token").toString();System.out.println(token);}}
HttpDelete的方法中本身并没有setEntity方法，所以需要自定义一个HttpDeleteWithBody类
package mon.tool;import org.apache.http.client.methods.HttpEntityEnclosingRequestBase;import .URI;/*** @author wjw*/public class HttpDeleteWithBody extends HttpEntityEnclosingRequestBase {public static final String METHOD_NAME = "DELETE";@Overridepublic String getMethod(){return METHOD_NAME;}public HttpDeleteWithBody(final String uri){super();setURI(URI.create(uri));}public HttpDeleteWithBody(final URI uri){super();setURI(uri);}public HttpDeleteWithBody(){super();}}
需要引入的包如下:
<dependency><groupId>org.apache.httpcomponents</groupId><artifactId>httpclient</artifactId><version>4.5</version></dependency><dependency><groupId>org.apache.httpcomponents</groupId><artifactId>httpcore</artifactId><version>4.4.1</version></dependency>
