接口、定时、异步
1 远程接口
1.1 URL与HttpUrlConnection
//接口路径
String path = "";
//创建URL
URL url = new URL(path);
//连接
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
//开始连接
urlConnection.connect();
//获取字节流
InputStream inputStream = urlConnection.getInputStream();
//把数据转换为字符串
byte[] bytes = new byte[inputStream.available()];
inputStream.read(bytes);
String s = new String(bytes);
System.out.println(s);
//json字符串转对象
JSONObject jsonObject = JSON.parseObject(s);
Object code = jsonObject.get("code");
if (code.equals(200)) {
JSONObject result = jsonObject.getJSONObject("result");
Object content = result.get("content");
System.out.println(content);
}
//JSON转对象需要的依赖
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.83</version>
</dependency>
1.2 apache的HttpClient
//apache的HttpClient要用的依赖
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.5.6</version>
</dependency>
1.2.1 GET请求
//接口路径
String path = "";
//创建发送请求的客户端
CloseableHttpClient hc = HttpClients.createDefault();
HttpGet httpGet = new HttpGet(path);
//设置请求头(防止TCP状态一直保持在CLOSE_WAIT，在请求头中进行Connection配置)
httpGet.setHeader("connection", "close");
//获取返回结果
HttpResponse response = hc.execute(httpGet);
int statusCode = response.getStatusLine().getStatusCode();
if (statusCode == HttpStatus.SC_OK) {
HttpEntity entity = response.getEntity();
String s = EntityUtils.toString(entity);
System.out.println(s);
//关闭资源
EntityUtils.consume(entity);
}
//关闭资源
httpGet.abort();
hc.close();
1.2.2 POST请求
//接口路径
String path = "";
CloseableHttpClient hc = HttpClients.createDefault();
HttpPost httpPost = new HttpPost(path);
//设置请求头
httpPost.setHeader("Content-type", "application/json");
httpPost.setHeader("Connection", "close");
//post请求的参数
HashMap<String, String> map = new HashMap<>();
map.put("phone", "13213785063");
map.put("code", "123456");
// 设置请求体内容
String s = JSON.toJSONString(map);
httpPost.setEntity(new StringEntity(s));
// 执行
HttpResponse response = hc.execute(httpPost);
System.out.println(response);
if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
HttpEntity entity = response.getEntity();
String data = EntityUtils.toString(entity);
System.out.println(data);
EntityUtils.consume(entity);
}
httpPost.abort();
hc.close();
1.2.3 PUT请求
参考 1.2.2 POST请求
1.2.4 DELETE请求
参考 1.2.1 GET请求
1.3 spring的RestTemplate
1.3.1 GET请求
RestTemplate restTemplate = new RestTemplate();
//接口路径
String path="";
//所有响应信息
ResponseEntity<String> forEntity = restTemplate.getForEntity(path, String.class);
System.out.println(forEntity);
//响应体信息
String forObject = restTemplate.getForObject(path, String.class);
System.out.println(forObject);
1.3.2 POST请求
RestTemplate restTemplate = new RestTemplate();
//接口路径
String path="";
User user = new User("张三", 18);
//所有响应信息
ResponseEntity<String> stringResponseEntity = restTemplate.postForEntity(path, user, String.class);
System.out.println(stringResponseEntity);
1.3.3 PUT请求
RestTemplate restTemplate = new RestTemplate();
//接口路径
String path="";
HashMap<String, Object> map = new HashMap<>();
map.put("userName","张三");
map.put("age",18);
restTemplate.put(path,map);
1.3.4 DELETE请求
RestTemplate restTemplate = new RestTemplate();
//接口路径
String path="http://localhost:8080/delete/{0}";
restTemplate.delete(path,"1,2,3,4");
1.3.5 复杂请求
RestTemplate restTemplate = new RestTemplate();
String path="http://localhost:8080/delete/{0}";
//设置请求头
HttpHeaders headers = new HttpHeaders();
//设置token
headers.add("token","");
HttpEntity httpEntity = new HttpEntity(headers);
ResponseEntity<String> exchange = restTemplate.exchange(path, HttpMethod.DELETE, httpEntity, String.class, "1,3.5");
System.out.println(exchange.getStatusCode());
System.out.println(exchange.getHeaders());
System.out.println(exchange.getBody());
2 定时
2.1 Timer
- 定义类继承TimerTask类，重写run方法
2.2 spring-task
<!-- 开启定时任务注解驱动-->
<task:annotation-driven/>
在方法上添加注解@Scheduled(cron = "0/5 * * * * ?")
@Scheduled(cron = "0/5 * * * * ?")
public void test(){
System.out.println("123465");
}
-
springtask默认多个任务之间使用的是同一个线程，是同步的。一个任务如果有耗时操作，会影响另一个任务。
-
@Async注解可以保证任务每次都是按照cron表达式的时间执行，因为每次都是开启新的线程。
-
也可以使用配置的方式，让一个任务分配一条线程去执行。
<!-- size默认1个 -->
<task:scheduler id="taskScheduler" pool-size="2"></task:scheduler>
<!-- 指定通过taskScheduler任务调度线程池来对指定的任务按照各自的cron表达式执行 -->
<task:scheduled-tasks scheduler="taskScheduler">
<task:scheduled ref="Test" method="test1" cron="0/5 * * * * ?"/>
<task:scheduled ref="Test" method="test2" cron="0/10 * * * * ?"/>
</task:scheduled-tasks>
2.3 quartz组件
- 可百度配置xml
3 异步任务
<!-- 配置线程池对象-->
<bean class="org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor">
<!-- 核心线程数-->
<property name="corePoolSize" value="10"></property>
<!-- 最大线程数量-->
<property name="maxPoolSize" value="100"></property>
<!-- 空闲线程的闲置时间-->
<property name="keepAliveSeconds" value="20"></property>
<!-- 等待队列的容量-->
<property name="queueCapacity" value="100"></property>
<!-- 拒绝策略(等待队列满了，直接在主线程上执行)-->
<property name="rejectedExecutionHandler">
<bean class="java.util.concurrent.ThreadPoolExecutor$CallerRunsPolicy"></bean>
</property>
</bean>
- 定义一个类提供异步任务的方法
public static Runnable test(String name, String age) {
return new Runnable() {
@Override
public void run() {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println(Thread.currentThread().getName() + "----邮件");
}
};
}
- 提供任务管理类，执行异步任务
@Component
public class TestManger {
@Autowired
private ThreadPoolTaskExecutor threadPoolTaskExecutor;
public void execute (Runnable a){
threadPoolTaskExecutor.execute(a);
}
}
- 测试
@GetMapping("test")
@ResponseBody
public String sendEmail(){
asyncManger.execute(TestFactory.test("111",222));
System.out.println("主线程");
return "success";
}
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