前言:
最新Servlet 3.0拦截器的使用
1.pom.xml添加需要使用的依赖
<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>top.ytheng</groupId>
<artifactId>springboot-demo</artifactId>
<version>0.0.1</version>
<packaging>jar</packaging> <parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.5.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent> <properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties> <dependencies>
<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>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency> <dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<optional>true</optional>
<scope>true</scope>
</dependency>
</dependencies> <build>
<!-- 打包的名称 -->
<finalName>myspringboot</finalName>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
</build>
</project>
2.添加Filter拦截器
package top.ytheng.demo.filter; import java.io.IOException; import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse; //Servlet3.0特性
//urlPatterns:拦截的url地址
//filterName:拦截器名称
@WebFilter(urlPatterns="/api/*", filterName="loginFilter")
public class LoginFilter implements Filter{ /*
* 容器加载完成调用
* */
@Override
public void init(FilterConfig filterConfig) throws ServletException {
// TODO Auto-generated method stub
System.out.println("filter init...");
} /*
* 请求被拦截的时候调用
* */
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
// TODO Auto-generated method stub
System.out.println("doFilter..."); HttpServletRequest req = (HttpServletRequest)request;
HttpServletResponse resp = (HttpServletResponse)response; String username = req.getParameter("username");
if(username.equals("theng")) {
chain.doFilter(request, response);
} else {
//重定向
resp.sendRedirect("/filter.html");
return;
} } /*
* 容器被销毁的时候调用
* */
@Override
public void destroy() {
// TODO Auto-generated method stub
System.out.println("filter destroy...");
} }
3.添加测试控制器
package top.ytheng.demo.controller; import java.util.HashMap;
import java.util.Map; import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController; @RestController
@RequestMapping("/api/v1/filter")
public class FilterController { @RequestMapping("/test")
public Object testFilter() {
Map<String, Object> map = new HashMap<>();
map.put("name", "theng");
map.put("pwd", "123456");
return map;
}
}
4.添加启动类
package top.ytheng.demo; import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletComponentScan; @SpringBootApplication //等于下面3个
//@SpringBootConfiguration
//@EnableAutoConfiguration
//@ComponentScan
//拦截器用到
@ServletComponentScan
public class DemoApplication { public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
} }
5.添加拦截后调整的页面filter.html
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<h4>hello theng</h4>
<h3>filter success</h3>
</body>
</html>
6.右键项目Run As启动项目,测试地址
http://localhost:8080/api/v1/filter/test?username=theng
http://localhost:8080/api/v1/filter/test?username=ytheng
另附: