三种方法实现java调用Restful接口

1,基本介绍

Restful接口的调用，前端一般使用ajax调用，后端可以使用的方法比较多，

　　本次介绍三种：

　　　　1.HttpURLConnection实现

　　　　2.HttpClient实现

　　　　3.Spring的RestTemplate
　　　　

2，HttpURLConnection实现

@Controllerpublic class RestfulAction {    @Autowired    private UserService userService;    // 修改    @RequestMapping(value = "put/{param}", method = RequestMethod.PUT)    public @ResponseBody String put(@PathVariable String param) {        return "put:" + param;    }    // 新增    @RequestMapping(value = "post/{param}", method = RequestMethod.POST)    public @ResponseBody String post(@PathVariable String param,String id,String name) {        System.out.println("id:"+id);        System.out.println("name:"+name);        return "post:" + param;    }    // 删除    @RequestMapping(value = "delete/{param}", method = RequestMethod.DELETE)    public @ResponseBody String delete(@PathVariable String param) {        return "delete:" + param;    }    // 查找    @RequestMapping(value = "get/{param}", method = RequestMethod.GET)    public @ResponseBody String get(@PathVariable String param) {        return "get:" + param;    }    // HttpURLConnection 方式调用Restful接口    // 调用接口    @RequestMapping(value = "dealCon/{param}")    public @ResponseBody String dealCon(@PathVariable String param) {        try {            String url = "http://localhost:8080/tao-manager-web/";            url+=(param+"/xxx");            URL restServiceURL = new URL(url);            HttpURLConnection httpConnection = (HttpURLConnection) restServiceURL                    .openConnection();            //param 输入小写，转换成 GET POST DELETE PUT             httpConnection.setRequestMethod(param.toUpperCase());//            httpConnection.setRequestProperty("Accept", "application/json");            if("post".equals(param)){                //打开输出开关                httpConnection.setDoOutput(true);//                httpConnection.setDoInput(true);                //传递参数                String input = "&id="+ URLEncoder.encode("abc", "UTF-8");                input+="&name="+ URLEncoder.encode("啊啊啊", "UTF-8");                OutputStream outputStream = httpConnection.getOutputStream();                outputStream.write(input.getBytes());                outputStream.flush();            }            if (httpConnection.getResponseCode() != 200) {                throw new RuntimeException(                        "HTTP GET Request Failed with Error code : "                                + httpConnection.getResponseCode());            }            BufferedReader responseBuffer = new BufferedReader(                    new InputStreamReader((httpConnection.getInputStream())));            String output;            System.out.println("Output from Server:  \n");            while ((output = responseBuffer.readLine()) != null) {                System.out.println(output);            }            httpConnection.disconnect();        } catch (MalformedURLException e) {            e.printStackTrace();        } catch (IOException e) {            e.printStackTrace();        }        return "success";    }}

3.HttpClient实现

package com.taozhiye.controller;import org.apache.http.HttpEntity;import org.apache.http.HttpResponse;import org.apache.http.NameValuePair;import org.apache.http.client.HttpClient;import org.apache.http.client.entity.UrlEncodedFormEntity;import org.apache.http.client.methods.HttpDelete;import org.apache.http.client.methods.HttpGet;import org.apache.http.client.methods.HttpPost;import org.apache.http.client.methods.HttpPut;import org.apache.http.impl.client.HttpClients;import org.apache.http.message.BasicNameValuePair;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.PathVariable;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import org.springframework.web.bind.annotation.ResponseBody;import com.fasterxml.jackson.databind.ObjectMapper;import com.taozhiye.entity.User;import com.taozhiye.service.UserService;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.io.OutputStream;import java.net.HttpURLConnection;import java.net.MalformedURLException;import java.net.URL;import java.net.URLEncoder;import java.util.ArrayList;import java.util.List;@Controllerpublic class RestfulAction {      @Autowired    private UserService userService;    // 修改    @RequestMapping(value = "put/{param}", method = RequestMethod.PUT)    public @ResponseBody String put(@PathVariable String param) {        return "put:" + param;    }    // 新增    @RequestMapping(value = "post/{param}", method = RequestMethod.POST)    public @ResponseBody User post(@PathVariable String param,String id,String name) {        User u = new User();        System.out.println(id);        System.out.println(name);        u.setName(id);        u.setPassword(name);        u.setEmail(id);        u.setUsername(name);        return u;    }        // 删除    @RequestMapping(value = "delete/{param}", method = RequestMethod.DELETE)    public @ResponseBody String delete(@PathVariable String param) {        return "delete:" + param;    }    // 查找    @RequestMapping(value = "get/{param}", method = RequestMethod.GET)    public @ResponseBody User get(@PathVariable String param) {        User u = new User();        u.setName(param);        u.setPassword(param);        u.setEmail(param);        u.setUsername("爱爱啊");        return u;    }    @RequestMapping(value = "dealCon2/{param}")    public @ResponseBody User dealCon2(@PathVariable String param) {        User user = null;        try {            HttpClient client = HttpClients.createDefault();            if("get".equals(param)){                HttpGet request = new HttpGet("http://localhost:8080/tao-manager-web/get/"                        +"啊啊啊");                request.setHeader("Accept", "application/json");                HttpResponse response = client.execute(request);                HttpEntity entity = response.getEntity();                ObjectMapper mapper = new ObjectMapper();                user = mapper.readValue(entity.getContent(), User.class);            }else if("post".equals(param)){                HttpPost request2 = new HttpPost("http://localhost:8080/tao-manager-web/post/xxx");                List<NameValuePair> nvps = new ArrayList<NameValuePair>();                  nvps.add(new BasicNameValuePair("id", "啊啊啊"));                  nvps.add(new BasicNameValuePair("name", "secret"));                UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(nvps, "GBK");                request2.setEntity(formEntity);                HttpResponse response2 = client.execute(request2);                HttpEntity entity = response2.getEntity();                ObjectMapper mapper = new ObjectMapper();                user = mapper.readValue(entity.getContent(), User.class);            }else if("delete".equals(param)){            }else if("put".equals(param)){            }        } catch (Exception e) {            e.printStackTrace();        }        return user;    } }

4.Spring的RestTemplate

springmvc.xml增加

<!-- 配置RestTemplate -->    <!--Http client Factory -->    <bean id="httpClientFactory"        class="org.springframework.http.client.SimpleClientHttpRequestFactory">        <property name="connectTimeout" value="10000" />        <property name="readTimeout" value="10000" />    </bean>    <!--RestTemplate -->    <bean id="restTemplate" class="org.springframework.web.client.RestTemplate">        <constructor-arg ref="httpClientFactory" />    </bean>

controller

@Controllerpublic class RestTemplateAction {    @Autowired    private RestTemplate template;    @RequestMapping("RestTem")    public @ResponseBody User RestTem(String method) {        User user = null;        //查找        if ("get".equals(method)) {            user = template.getForObject(                    "http://localhost:8080/tao-manager-web/get/{id}",                    User.class, "呜呜呜呜");            //getForEntity与getForObject的区别是可以获取返回值和状态、头等信息            ResponseEntity<User> re = template.                    getForEntity("http://localhost:8080/tao-manager-web/get/{id}",                    User.class, "呜呜呜呜");            System.out.println(re.getStatusCode());            System.out.println(re.getBody().getUsername());        //新增        } else if ("post".equals(method)) {            HttpHeaders headers = new HttpHeaders();            headers.add("X-Auth-Token", UUID.randomUUID().toString());            MultiValueMap<String, String> postParameters = new LinkedMultiValueMap<String, String>();            postParameters.add("id", "啊啊啊");            postParameters.add("name", "部版本");            HttpEntity<MultiValueMap<String, String>> requestEntity = new HttpEntity<MultiValueMap<String, String>>(                    postParameters, headers);            user = template.postForObject(                    "http://localhost:8080/tao-manager-web/post/aaa", requestEntity,                    User.class);        //删除        } else if ("delete".equals(method)) {            template.delete("http://localhost:8080/tao-manager-web/delete/{id}","aaa");        //修改        } else if ("put".equals(method)) {            template.put("http://localhost:8080/tao-manager-web/put/{id}",null,"bbb");        }        return user;    }}

转载引用原地址