SpringBoot - 学习笔记 - RestTemplate

冷不防 2023-01-10 03:58 252阅读 0赞

### SpringBoot - 学习笔记 - RestTemplate ###

*  配置
 *   *  解决中文乱码问题
 *  Get 请求
 *   *  getForObject
     *   *  Get 传参：拼接url
         *  Get 传参：拼接url，占位符
         *  Get 传参：Map
         *  返回字符串
         *  返回对象
     *  getForEntity
     *   *  Get 传参 + 返回对象
         *  Get 传参 + 返回对象2
 *  Post 请求
 *   *  postForObject
     *   *  Post：请求头 + 请求体
     *  postForEntity
     *   *  Post：请求头 + 请求体
 *  exchange 请求
 *   *  Get 传参 + 带请求头
     *  Post：请求头 + 请求体
     *   *  请求，返回JSON对象
 *  参考资料

SpringBoot1.4之后不能自动注入RestTemplate了

# 配置 #

先添加配置

import org.springframework.boot.web.client.RestTemplateBuilder;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.web.client.RestTemplate;
    
    /** * @author jerryjin */
    @Configuration
    public class RestTemplateConfig { 
        @Bean
        public RestTemplate restTemplate(RestTemplateBuilder builder) { 
            return builder.build();
        }
    }

## 解决中文乱码问题 ##

//-----此处是 解决乱码 start-----
            List<HttpMessageConverter<?>> converterList = restTemplate.getMessageConverters();
            /** 移除StringHttpMessageConverter */
            converterList.remove(1);    
            HttpMessageConverter<?> converter = new StringHttpMessageConverter(Charset.forName("UTF-8"));
            /** convert顺序错误会导致失败 */
            converterList.add(1, converter);    
            restTemplate.setMessageConverters(converterList);
            //-----此处是 解决乱码 end----------

# Get 请求 #

## getForObject ##

### Get 传参：拼接url ###

public void update(){ 
        // 发起请求
        Result result = restTemplate.getForObject("https://www.baidu.com/s?wd=一壶泪,暗淡醇香味", Result.class, paramMap);
        // 输出结果
        System.out.println("响应结果：" + result.toString());
    }

### Get 传参：拼接url，占位符 ###

public void update(){ 
        // 发起请求
        String result = restTemplate.getForObject("http://localhost/hi?title={title}&level={level}&desc={desc}", String.class, "冷血杀手", "99", "我是一个杀手");
        // 输出结果
        System.out.println("响应结果：" + result);
    }

### Get 传参：Map ###

public void update() { 
        Map<String, Object> paramMap = new HashMap<String, Object>(1);
        paramMap.put("title", "冷血杀手");
        paramMap.put("level", "99");
        paramMap.put("desc", "我是一个杀手");
        
        // 发起请求
        String result = restTemplate.getForObject("http://localhost/hi", String.class, paramMap);
        // 输出结果
        System.out.println("响应结果：" + result);
    }

### 返回字符串 ###

import org.springframework.stereotype.Component;
    import org.springframework.web.client.RestTemplate;
    
    import javax.annotation.Resource;
    
    /** * @author jerryjin */
    @Component("newsTask")
    public class NewsTask { 
    	String url = "http://localhost/hi";
    	
        @Resource
        RestTemplate restTemplate;
    
        public void update(){ 
            String result =  restTemplate.getForObject(url , String.class);
            System.out.println(result);
        }
    }

### 返回对象 ###

public void update(){ 
            Npc result = restTemplate.getForObject(url, Npc.class);
            System.out.println(result);
        }

## getForEntity ##

### Get 传参 + 返回对象 ###

public void update() { 
            String url = "http://localhost/hi?title=冷血杀手&level=99&desc=我是一个杀手";
            RestTemplate restTemplate = new RestTemplate();
            // 发起请求
            ResponseEntity<Npc> result = restTemplate.getForEntity(url, Npc.class);
            Npc npc = result.getBody();
            // 输出结果
            System.out.println("响应结果：" + npc.toString());
        }

### Get 传参 + 返回对象2 ###

感觉这没什么意义啊

public void update() { 
            String url = "http://localhost/hi?title={title}&level={level}&desc={desc}";
            RestTemplate restTemplate = new RestTemplate();
    
            Map<String, String> map = new HashMap<>();
            map.put("title", "冷血杀手");
            map.put("level", "99");
            map.put("desc", "我是一个杀手");
            
            // 发起请求
            ResponseEntity<Npc> result = restTemplate.getForEntity(url, Npc.class, map);
            Npc npc = result.getBody();
            // 输出结果
            System.out.println("响应结果：" + npc.toString());
        }

# Post 请求 #

## postForObject ##

### Post：请求头 + 请求体 ###

public void update() { 
            String url = "http://localhost/hi?name={name}";
            // 创建请求头
            HttpHeaders headers = new HttpHeaders();
            headers.set("auth", "9527");
            // 构建请求参数
            Npc npc = new Npc("冷血杀手", 666, "我是一个杀手");
            // 构建请求体
            HttpEntity<Npc> entity = new HttpEntity<>(npc, headers);
            // 发起请求
            Npc result = restTemplate.postForObject(url, entity, Npc.class, "笨笨");
            // 输出结果
            System.out.println("响应结果：" + result.toString());
        }

## postForEntity ##

### Post：请求头 + 请求体 ###

public void update() { 
            String url = "http://localhost/hi?name={name}";
            // 创建请求头
            HttpHeaders headers = new HttpHeaders();
            headers.set("auth", "9527");
            // 构建请求参数
            Map<String, String> paramMap = new HashMap<>(4);
            paramMap.put("title", "冷血杀手");
            paramMap.put("level", "666");
            paramMap.put("desc", "我是一个杀手");
            // 构建请求体
            HttpEntity<Map<String, String>> entity = new HttpEntity<>(paramMap, headers);
            // 发起请求
            ResponseEntity<String> result = restTemplate.postForEntity(url, entity, String.class,"笨笨");
            // 输出结果
            System.out.println("响应结果：" + result.toString());
        }

Post：请求头 + 请求体 2

public void update() { 
            String url = "http://localhost/hi?name={name}";
            // 创建请求头
            HttpHeaders headers = new HttpHeaders();
            headers.set("auth", "9527");
            // 构建请求参数
            Npc npc = new Npc("冷血杀手", 666, "我是一个杀手");
            // 构建请求体
            HttpEntity<Npc> entity = new HttpEntity<>(npc, headers);
            // 发起请求
            ResponseEntity<Npc> result = restTemplate.postForEntity(url, entity, Npc.class, "笨笨");
            // 输出结果
            System.out.println("响应结果：" + result.toString());
        }

# exchange 请求 #

## Get 传参 + 带请求头 ##

拼参数

public void update() { 
            // 构建URL请求参数
            String url = "http://localhost/hi?title={title}&level={level}&desc={desc}";
            // 构建请求头
            HttpHeaders headers = new HttpHeaders();
            headers.add("auth", "333333333333333333333333333333");
            // 构建请求对象
            HttpEntity request = new HttpEntity(headers);
            // 发起请求
            ResponseEntity<String> result = restTemplate.exchange(url, HttpMethod.GET, request, String.class, "冷血杀手", "99", "我是一个杀手");
            // 输出结果
            System.out.println("响应结果：" + result);
        }

拼参数 + 占位符 + map

public void update() { 
            String url = "http://localhost/hi?title={title}&level={level}&desc={desc}";
            // 构建URL请求参数
            Map<String, String> paramMap = new HashMap<>(1);
            paramMap.put("title", "冷血杀手");
            paramMap.put("level", "99");
            paramMap.put("desc", "我是一个杀手");
            // 构建请求头
            HttpHeaders headers = new HttpHeaders();
            headers.add("auth", "333333333333333333333333333333");
            // 构建请求对象
            HttpEntity request = new HttpEntity(headers);
            // 发起请求
            ResponseEntity<String> result = restTemplate.exchange(url, HttpMethod.GET, request, String.class, paramMap);
            // 输出结果
            System.out.println("响应结果：" + result);
        }

## Post：请求头 + 请求体 ##

public void update() { 
            RestTemplate restTemplate = new RestTemplate();
            // 构建URL请求参数
            url = url + "?name=笨笨";
            // 构建请求头
            HttpHeaders headers = new HttpHeaders();
            headers.add("auth", "333333333333333333333333333333");
            // 构建请求体
            Npc npc = new Npc("冷血杀手", 99, "我是一个杀手");
            HttpEntity<Npc> request = new HttpEntity<>(npc, headers);
            // 发起请求
            ResponseEntity<String> result = restTemplate.exchange(url, HttpMethod.POST, request, String.class);
            // 输出结果
            System.out.println("响应结果：" + result);
        }

### 请求，返回JSON对象 ###

public void update() { 
            RestTemplate restTemplate = new RestTemplate();
            // 构建URL请求参数
            url = url + "?name=笨笨";
            // 构建请求头
            HttpHeaders headers = new HttpHeaders();
            headers.add("auth", "333333333333333333333333333333");
            // 构建请求体
            Npc npc = new Npc("冷血杀手", 99, "我是一个杀手");
            HttpEntity<Npc> request = new HttpEntity<>(npc, headers);
            // 发起请求
            ResponseEntity<Npc> result = restTemplate.exchange(url, HttpMethod.POST, request, Npc.class);
            Npc resultBody = result.getBody();
            // 输出结果
            System.out.println("响应结果：" + resultBody);
        }

响应结果：{ "title":"冷血杀手 - 笨笨","level":666,"desc":"我是一个杀手"}

# 参考资料 #

[REST in Spring 3: RestTemplate][REST in Spring 3_ RestTemplate]  
[Chapter 2. RestTemplate][]  
[RestTemplate][]  
[HttpEntity][]

[https://springbootdev.com/2017/11/21/spring-resttemplate-exchange-method/][https_springbootdev.com_2017_11_21_spring-resttemplate-exchange-method]  
[RestTemplate GET Request with Parameters and Headers][]  
[Spring RestTemplate.exchange()][Spring RestTemplate.exchange]

[REST in Spring 3_ RestTemplate]: https://spring.io/blog/2009/03/27/rest-in-spring-3-resttemplate/
[Chapter 2. RestTemplate]: http://www.springframework.net/rest/refdoc/resttemplate.html
[RestTemplate]: https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/web/client/RestTemplate.html
[HttpEntity]: https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/http/HttpEntity.html
[https_springbootdev.com_2017_11_21_spring-resttemplate-exchange-method]: https://springbootdev.com/2017/11/21/spring-resttemplate-exchange-method/
[RestTemplate GET Request with Parameters and Headers]: https://attacomsian.com/blog/spring-boot-resttemplate-get-request-parameters-headers
[Spring RestTemplate.exchange]: https://www.concretepage.com/spring-5/spring-resttemplate-exchange#Get