SpringCloud系列之自定义GatewayFilterFactory
学习目的：
- 知道创建一个网关sample
- 知道网关的基本配置
- 知道自定义GatewayFilterFactory类
环境准备：
- JDK 1.8
- SpringBoot2.2.3
- SpringCloud(Hoxton.SR7)
- Maven 3.2
- 开发工具
- IntelliJ IDEA
- smartGit
新增SpringBoot Initializer项目：New Module->Spring Initializer，选择jdk版本，至少jdk8
packaging选择jar，java version选择jdk8的，然后点next
选择Gateway的依赖，选择之后会自动加上对应pom配置
新建项目之后，检查pom是否有spring-cloud-starter-gateway
代码语言：javascript复制<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-gateway</artifactId>
</dependency>如果不通过idea的Spring Initializer新建项目的，需要自己加上：
代码语言：javascript复制<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>网关配置，业务场景，一个第三方的接口，经过网关路由之后需要在request header里加上一些校验参数
代码语言：javascript复制spring:
application:
name: api-gateway # 指定application name
cloud:
gateway:
routes:
- id: get_user_info
uri: http://127.0.0.1:8083
predicates:
- Path=/api/findUser
filters:
- AddRequestHeader=passToken,a68f3eac-5b9c-4fc1-a900-98ee18574576
# FilterFactory名为自定义类名前几个
- name: Custom
args:
passid: 7a11600c-403c-4260-9165-659e138ada9c
serviceId: d8c6ce4c-1b2c-4826-9044-4197d17aad87自定义一个GatewayFilterFactory，命名后面统一加上GatewayFilterFactory，自定义的字段配在yml的filters.name
代码语言：javascript复制package com.example.springcloud.gateway.filter.factories;
import com.example.springcloud.gateway.util.EncryptUtils;
import lombok.Data;
import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.gateway.filter.GatewayFilter;
import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;
import org.springframework.core.Ordered;
import org.springframework.http.server.reactive.ServerHttpRequest;
import java.util.Date;
/**
* <pre>
* 自定义网关过滤器
* </pre>
*
* <pre>
* @author mazq
* 修改记录
* 修改后版本: 修改人： 修改日期: 2021/12/14 09:59 修改内容:
* </pre>
*/
@Slf4j
public class CustomGatewayFilterFactory extends AbstractGatewayFilterFactory<CustomGatewayFilterFactory.Config>
implements Ordered {
public CustomGatewayFilterFactory() {
super(Config.class);
}
@Override
public GatewayFilter apply(Config config) {
return ((exchange, chain) -> {
String passToken = exchange.getRequest().getHeaders().getFirst("passToken");
log.info("passToken:{}" , passToken);
long now = new Date().getTime();
String timestamp = Long.toString((long)Math.floor(now/1000));
String signature = "";
try {
signature = EncryptUtils.toSHA256(timestamp passToken timestamp);
} catch (Exception e) {
e.printStackTrace();
}
log.info("signature:{}" , signature);
ServerHttpRequest request = exchange.getRequest().mutate()
.header("passid", config.getPassid())
.header("serviceId", config.getServiceId())
.header("signature", signature)
.build();
log.info("passid:{}" , config.getPassid());
log.info("serviceId:{}" , config.getServiceId());
return chain.filter(exchange.mutate().request(request).build());
});
}
@Override
public int getOrder() {
return Ordered.HIGHEST_PRECEDENCE;
}
@Data
public static class Config {
private String passid;
private String serviceId;
}
}过滤器将在较早的阶段执行其“pre”逻辑，但稍后会调用它的“post”实现：
官网的图例：首先客户端请求都会先经过Gateway Handler Mapping，匹配上就通过Gateway Web Handler转给过滤器处理，过滤器分为PreFilter（前置过滤器）、PostFilter（后置过滤器）。过滤器由虚线分隔的原因是，筛选器可以在发送代理请求之前和之后运行逻辑。所有“前置”过滤器逻辑均被执行。然后发出代理请求。发出代理请求后，将运行“后置”过滤器逻辑
import java.security.MessageDigest;
/**
* <pre>
* 加密工具类
* </pre>
*/
public class EncryptUtils {
/**
* sha256签名算法
*/
public static String toSHA256(String str) throws Exception {
MessageDigest messageDigest;
String encodeStr = "";
try {
messageDigest = MessageDigest.getInstance("SHA-256");
messageDigest.update(str.getBytes("UTF-8"));
encodeStr = byte2Hex(messageDigest.digest());
} catch (Exception e) {
throw e;
}
return encodeStr;
}
/**
* byte转换成16进制
*/
protected static String byte2Hex(byte[] bytes) {
StringBuffer stringBuffer = new StringBuffer();
String temp = null;
for (int i = 0; i < bytes.length; i ) {
temp = Integer.toHexString(bytes[i] & 0xFF);
if (temp.length() == 1) {
stringBuffer.append("0");
}
stringBuffer.append(temp);
}
return stringBuffer.toString();
}
}控制台打印：
代码语言：javascript复制signature:72bdd60d2fc6f115eabda1ced766c0c0aa7397521d653977b2fd15d6c6978587
passid:7a11600c-403c-4260-9165-659e138ada9c
serviceId:d8c6ce4c-1b2c-4826-9044-4197d17aad87然后去第三方接口看请求header参数，可以带过来
注意：如果网关配置不起效，可以尝试设置ordered确定优先级，有多个配置，可以将配置位置适当挪前点
