1.代碼示例
輸出打印
// 實(shí)際的邏輯是在這里
PrintWriter out = response.getWriter();
out.println("<h1>" + message + "</h1>");
out.println("<h1>" + username + "</h1>");
out.println("<h1>" + url + "</h1>");
配置文件 web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
version="4.0"
metadata-complete="true">
<context-param>
<param-name>url</param-name>
<param-value>jdc:mysql://localhost:3306/mybatis</param-value>
</context-param>
<!--session 配置 單位分鐘-->
<session-config>
<session-timeout>1</session-timeout>
</session-config>
<!--注冊(cè)servlet-->
<servlet>
<servlet-name>hellServlet</servlet-name>
<servlet-class>com.findcn.servlet.HelloServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>hellServlet</servlet-name>
<url-pattern>/kkk</url-pattern>
</servlet-mapping>
</web-app>
1.設(shè)置頭部
// 設(shè)置響應(yīng)內(nèi)容類型
response.setContentType("text/html");
response.setCharacterEncoding("utf-8");
//瀏覽器刷新 每三秒
response.setHeader("refresh","3");
response.setHeader("Content-Disposition","attachment;filenam="+ URLEncoder.encode(fileName,"UTF-8"));
response.setContentType("image/jpeg");//設(shè)置輸出為圖片
response.setDateHeader("expires",-1);//瀏覽器不去緩存
response.setHeader("Cache-Control","no-Cache");
response.setStatus(HttpServletResponse.SC_MOVED_TEMPORARILY);//設(shè)置請(qǐng)求狀態(tài)
2.使用 ServletContext
ServletContext context = this.getServletContext();
String uuname = "1223";
// 設(shè)置用戶名
context.setAttribute("username",uuname);
// 獲取設(shè)置用戶名
String username = (String) context.getAttribute("username");
// 獲取配置
String url = context.getInitParameter("url");
3.轉(zhuǎn)發(fā)
//請(qǐng)求轉(zhuǎn)發(fā) 鏈接不變
RequestDispatcher requestDispatcher=context.getRequestDispatcher("/pp");
requestDispatcher.forward(request,response);
//重定向鏈接跳轉(zhuǎn)
response.sendRedirect("/ddd");
4.下載文件
//1.獲取下載路徑
String realPath = "";
//2.獲取文件名
String fileName = realPath.substring(realPath.lastIndexOf("\\")+1);
//3.設(shè)置文件下載頭部
response.setHeader("Content-Disposition","attachment;filenam="+ URLEncoder.encode(fileName,"UTF-8"));
//4.獲取下載文件輸入流
FileInputStream in = new FileInputStream(realPath);
//5.創(chuàng)建緩沖區(qū)
int len = 0;
byte[] buffer = new byte[1024];
//6.獲取OutputStream對(duì)象
ServletOutputStream dout = response.getOutputStream();
//7.寫入緩沖區(qū)
while((len=in.read(buffer))>0){
dout.write(buffer,0,len);
}
in.close();
dout.close();
5.驗(yàn)證碼生成
// # 驗(yàn)證碼
BufferedImage image = new BufferedImage(80,20,BufferedImage.TYPE_INT_RGB);
Graphics2D g = (Graphics2D) image.getGraphics();
g.setColor(Color.WHITE);//設(shè)置背景
g.fillRect(0,0,80,20);
g.setColor(Color.BLUE);//設(shè)置文字顏色
g.setFont(new Font(null,Font.BOLD,20));
g.drawString(makeNum(),0,20);//寫入隨機(jī)數(shù)
response.setContentType("image/jpeg");//設(shè)置輸出為圖片
response.setDateHeader("expires",-1);//瀏覽器不去緩存
response.setHeader("Cache-Control","no-Cache");
ImageIO.write(image,"jpg",response.getOutputStream());//瀏覽器輸出
6.生成隨機(jī)數(shù)
private String makeNum(){
Random random = new Random();
String num = random.nextInt(9999999)+"";
StringBuffer sb = new StringBuffer();
for (int i = 0; i < 7-num.length(); i++) {
sb.append("0");
}
num = sb.toString()+num;
return num;
}
7.獲取request數(shù)據(jù)參數(shù)
String userName = request.getParameter("username");//獲取請(qǐng)求參數(shù)
String[] uArr = request.getParameterValues("ids");//獲取數(shù)組
8.Cookie 操作
//獲取cookie
Cookie[] cookies = request.getCookies();
for (int i = 0; i < cookies.length; i++) {
Cookie cookie = cookies[i];
cookie.getName();//獲取key
cookie.getValue();//獲取value
System.out.println(cookie.getName());
cookie.getName().equals("name");//判斷 是否等于
}
//寫入cookie
Cookie cookie = new Cookie("cname","到底是啥事");
cookie.setMaxAge(24*60*60);
response.addCookie(cookie);
9.Session
// 時(shí)間戳轉(zhuǎn)換
String nowTime = System.currentTimeMillis()+"";//時(shí)間戳字符串
Long longTime = Long.getLong(nowTime);//轉(zhuǎn)化為長(zhǎng)整型
Date longDate = new Date(longTime);//轉(zhuǎn)化時(shí)間日期
SpringBoot
1.簡(jiǎn)單示例
加載
@Component
// 加載主配置文件
@ConfigurationProperties(prefix = "dog")
// 加載指定配置文件
@PropertySource(value = "classpath:dog.properties")
@Value("阿黃") //賦值變量
// 數(shù)據(jù)校驗(yàn)
@Validated @Email()//校驗(yàn)數(shù)據(jù)
// 加載控制器
@RestController
// 路由設(shè)置
@RequestMapping("/hello")
測(cè)試控制器 Dog
@RestController // 加載控制器
public class HelloController {
@RequestMapping("/hello") //路由設(shè)置
public String hello() {
return "hhhha";
}
}
測(cè)試用例
@Autowired
private Dog dog; // 自動(dòng)加載測(cè)試類
@Test
void contextLoads() {
System.out.println(dog);
}
2.配置文件
// properties 格式
application.properties
//多環(huán)境配置（spring.profiles.active=test）
application-test.properties (server.port=8081)
application-dev.properties (server.port=8082)
//yaml 格式
application.yaml
//多環(huán)境配置 --- 分塊
spring:
profiles:
active: test
#debug: true
---
server:
port: 8081
spring:
profiles: test
dog:
name: 阿黃
age: 3
---
server:
port: 8082
spring:
profiles: dev
dog:
name: 阿黃
age: 3
3.簡(jiǎn)單類 示例
package com.lyb.api.pogo;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;
@Component
// 加載主配置文件
@ConfigurationProperties(prefix = "dog")
public class Dog {
private String name;
private Integer age;
public Dog() {}
public Dog(String name, Integer age) {
this.name = name;
this.age = age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
@Override
public String toString() {
return "Dog{" + "name='" + name + '\'' + ", age=" + age + '}';
}
}
