SpringBoot使用RestTemplate

1. SpringBoot使用RestTempate
2. SpringBoot使用RestTemplate摘要认证
3. SpringBoot使用RestTemplate基础认证

设置pom引用

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.itstudy</groupId>
    <artifactId>demo</artifactId>
    <version>1.0.0-SNAPSHOT</version>

    <name>demo</name>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.9.RELEASE</version>
    </parent>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.30</version>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <executions>
                    <execution>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

2.增加配置类

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.client.ClientHttpRequestFactory;
import org.springframework.http.client.SimpleClientHttpRequestFactory;
import org.springframework.web.client.RestTemplate;
import org.springframework.http.converter.StringHttpMessageConverter;
import java.nio.charset.Charset;

@Configuration
public class RestTemplateConfig {

    @Bean
    public RestTemplate restTemplate(ClientHttpRequestFactory factory){
        RestTemplate restTemplate= new RestTemplate(factory);
        // 支持中文编码
        restTemplate.getMessageConverters().set(1,
                new StringHttpMessageConverter(Charset.forName("UTF-8")));
        return restTemplate;

    }

    @Bean
    public ClientHttpRequestFactory simpleClientHttpRequestFactory(){
        SimpleClientHttpRequestFactory factory = new SimpleClientHttpRequestFactory();
        factory.setReadTimeout(5000);//单位为ms
        factory.setConnectTimeout(5000);//单位为ms
        return factory;
    }
}

3.在service中使用

import com.alibaba.fastjson.JSONObject;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.web.client.RestTemplate;

public class RestTestService {

    @Autowired
    private RestTemplate restTemplate;

    public void test(){

        String paras = "data";
        String url="http://127.0.0.1";

        HttpHeaders headers = new HttpHeaders();
        MediaType type = MediaType.parseMediaType("application/json; charset=UTF-8");
        headers.setContentType(type);
        headers.add("Accept", MediaType.APPLICATION_JSON.toString());
        JSONObject jsonObj = JSONObject.parseObject(paras);
        HttpEntity<String> formEntity = new HttpEntity<String>(jsonObj.toString(), headers);
        String result = restTemplate.postForObject(url, formEntity, String.class);
    }

    public void testExchage(){

        String url="";

        HttpHeaders httpHeaders = new HttpHeaders();
        httpHeaders.setAccept(Collections.singletonList(MediaType.APPLICATION_JSON_UTF8));

        Map<String,String> postData = new HashMap<String,String>();
        postData.put("param1","");
        postData.put("param2","abc");

        //发送json字符串
        String content = JSON.toJSONString(postData);

        HttpEntity<String> httpEntity = new HttpEntity<String>(content, httpHeaders);

        try {

            ResponseEntity<String> responseEntity =
                    restTemplate.exchange(url, HttpMethod.POST, httpEntity, String.class);

            Map<String,String> mapResponse = JSON.parseObject(responseEntity.getBody(),HashMap.class);

        }catch (Exception ex){
            //进行错误处理
        }
    }

    public void testExchage2(){

        String url="";

        HttpHeaders httpHeaders = new HttpHeaders();
        httpHeaders.setAccept(Collections.singletonList(MediaType.APPLICATION_JSON_UTF8));

        //参数放入一个map中，restTemplate不能用hashMap
        MultiValueMap<String,String> param = new LinkedMultiValueMap<String, String>();
        //将请求参数放入map中
        param.add("param1","abc");
        param.add("param2","");

        //将参数和header组成一个请求
        HttpEntity<MultiValueMap<String,String>> httpEntity = new HttpEntity<MultiValueMap<String,String>>(param,headers);

        try {
            ResponseEntity<String> responseEntity =
                    restTemplate.exchange(url, HttpMethod.POST, httpEntity, String.class);    

            //responseEntity.getBody()进行其它处理

        }catch (Exception ex){
            //进行错误处理
        }
    }
}

4.应用启动

import org.springframework.boot.Banner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class App {

    public static void main(String[] args) {

        SpringApplication app = new SpringApplication(App.class);
        //关闭banner
        app.setBannerMode(Banner.Mode.OFF);
        app.run(args);
    }

}

另外注意RestTemplate默认 如果返回状态不是200则会报错，因此这个要进行捕获

/判断接口返回是否为200
    public static Boolean ping(){
        String url = domain + "/it/ping";
        try{
            ResponseEntity<String> responseEntity = template.getForEntity(url,String.class);
            HttpStatus status = responseEntity.getStatusCode();//获取返回状态
            return status.is2xxSuccessful();//判断状态码是否为2开头的
        }catch(Exception e){
            return false; //502 ,500是不能正常返回结果的，需要catch住，返回一个false
        }
    }

或者进行自定义处理

import java.io.IOException;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.client.ClientHttpRequestFactory;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.http.client.SimpleClientHttpRequestFactory;
import org.springframework.web.client.ResponseErrorHandler;
import org.springframework.web.client.RestTemplate;

@Configuration
public class RestTemplateConfig {
    
    @Bean
    public RestTemplate restTemplate(ClientHttpRequestFactory factory) throws Exception {
        RestTemplate restTemplate = new RestTemplate(factory);
        ResponseErrorHandler responseErrorHandler = new ResponseErrorHandler() {
            @Override
            public boolean hasError(ClientHttpResponse clientHttpResponse) throws IOException {
                return true;
            }
            @Override
            public void handleError(ClientHttpResponse clientHttpResponse) throws IOException {

            }
        };
        restTemplate.setErrorHandler(responseErrorHandler);
        return restTemplate;
    }
    
    @Bean
    public ClientHttpRequestFactory simpleClientHttpRequestFactory(){
        SimpleClientHttpRequestFactory factory = new SimpleClientHttpRequestFactory();
        //读取超时5秒
        factory.setReadTimeout();
        //连接超时15秒
        factory.setConnectTimeout();
        return factory;
    }
}