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【注】本文译自:https://www.tutorialspoint.co…_boot/spring_boot_servlet_filter.htm
过滤器是一种拦挡利用中 HTTP 申请和响应的对象,应用过滤器,你能够执行以下两种情景下的两种操作:
- 在发送申请到到控制器之前
- 在发送响应到客户端之前
上面的示例代码是以 @Component 注解的类来实现 Servlet 过滤器:
public class SimpleFilter implements Filter {
@Override
public void destroy() {}
@Override
public void doFilter
(ServletRequest request, ServletResponse response, FilterChain filterchain)
throws IOException, ServletException {}
@Override
public void init(FilterConfig filterconfig) throws ServletException {}}
上面的示例代码展现了在发送申请到控制器之前,从 ServletRequest 对象读取近程主机和地址:
在 doFilter() 办法中,咱们加了 System.out.println 语句打印近程主机和地址:
package com.tutorialspoint.demo;
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 org.springframework.stereotype.Component;
@Component
public class SimpleFilter implements Filter {
@Override
public void destroy() {}
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterchain)
throws IOException, ServletException {System.out.println("Remote Host:"+request.getRemoteHost());
System.out.println("Remote Address:"+request.getRemoteAddr());
filterchain.doFilter(request, response);
}
@Override
public void init(FilterConfig filterconfig) throws ServletException {}}
在 Spring Boot 主利用类文件中,咱们加了简略 REST 端点返回“Hello World”字串:
package com.tutorialspoint.demo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@SpringBootApplication
@RestController
public class DemoApplication {public static void main(String\[\] args) {SpringApplication.run(DemoApplication.class, args);
}
@RequestMapping(value = "/")
public String hello() {return "Hello World";}
}
Maven build – pom.xml 代码如下:
<?xml version = "1.0" encoding = "UTF-8"?>
<project xmlns = "[http://maven.apache.org/POM/4.0.0](http://maven.apache.org/POM/4.0.0)" xmlns:xsi = "[http://www.w3.org/2001/XMLSchema-instance](http://www.w3.org/2001/XMLSchema-instance)"
xsi:schemaLocation = "[http://maven.apache.org/POM/4.0.0](http://maven.apache.org/POM/4.0.0)
[http://maven.apache.org/xsd/maven-4.0.0.xsd](http://maven.apache.org/xsd/maven-4.0.0.xsd)"\>
<modelVersion\>4.0.0</modelVersion\>
<groupId\>com.tutorialspoint</groupId\>
<artifactId\>demo</artifactId\>
<version\>0.0.1-SNAPSHOT</version\>
<packaging\>jar</packaging\>
<name\>demo</name\>
<description\>Demo project for Spring Boot</description\>
<parent\>
<groupId\>org.springframework.boot</groupId\>
<artifactId\>spring-boot-starter-parent</artifactId\>
<version\>1.5.8.RELEASE</version\>
<relativePath/>
</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\>
</dependencies\>
<build\>
<plugins\>
<plugin\>
<groupId\>org.springframework.boot</groupId\>
<artifactId\>spring-boot-maven-plugin</artifactId\>
</plugin\>
</plugins\>
</build\>
</project\>
Gradle Build – build.gradle 代码如下:
buildscript {
ext {springBootVersion = '1.5.8.RELEASE'}
repositories {mavenCentral()
}
dependencies {classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
}
}
apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'org.springframework.boot'
group = 'com.tutorialspoint'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = 1.8
repositories {mavenCentral()
}
dependencies {compile('org.springframework.boot:spring-boot-starter-web')
testCompile('org.springframework.boot:spring-boot-starter-test')
}
你能够应用以下 Maven 或 Gradle 命令来创立可执行 JAR 文件,运行 Spring Boot 利用:
Maven 命令如下:
mvn clean install
在 BUILD SUCCESS 之后,你能够在 target 目录下找到 JAR 文件。
Gradle 命令如下:
gradle clean build
在 BUILD SUCCESSFUL 之后,你能够在 build/libs 目录下找到 JAR 文件。
当初,应用上面的命令运行 JAR 文件:
java –jar <JARFILE>
你能够看到利用曾经在 Tomcat 端口号 8080 启动了。
当初单击 URL http://localhost:8080/ 能够看到输入了 Hello World。看起来该当是上面的样子:
而后你能够看到如下所示的控制台日志:
正文完
发表至: springboot
2020-08-31