soul global plugin是做什么的呢？这个官方文档里面没有提及，其实是因为这个插件是个面向开发的这么一个插件。那么它具体有什么作用呢？
public class GlobalPlugin implements SoulPlugin {
private final SoulContextBuilder builder;
/**
* Instantiates a new Global plugin.
*
* @param builder the builder
*/
public GlobalPlugin(final SoulContextBuilder builder) {
this.builder = builder;
}
@Override
public Mono<Void> execute(final ServerWebExchange exchange, final SoulPluginChain chain) {
final ServerHttpRequest request = exchange.getRequest();
final HttpHeaders headers = request.getHeaders();
final String upgrade = headers.getFirst("Upgrade");
SoulContext soulContext;
if (StringUtils.isBlank(upgrade) || !"websocket".equals(upgrade)) {
soulContext = builder.build(exchange);
} else {
final MultiValueMap<String, String> queryParams = request.getQueryParams();
soulContext = transformMap(queryParams);
}
exchange.getAttributes().put(Constants.CONTEXT, soulContext);
return chain.execute(exchange);
}
@Override
public int getOrder() {
return 0;
}
private SoulContext transformMap(final MultiValueMap<String, String> queryParams) {
SoulContext soulContext = new SoulContext();
soulContext.setModule(queryParams.getFirst(Constants.MODULE));
soulContext.setMethod(queryParams.getFirst(Constants.METHOD));
soulContext.setRpcType(queryParams.getFirst(Constants.RPC_TYPE));
return soulContext;
}
@Override
public String named() {
return "global";
}
}从上面的代码可以看到，其实现了SoulPlugin接口，是个标准的插件，可以直接加到职责链中运行。做的事情就是构造一个上下文对象SoulContext。因为SoulContext的参数很多，所以使用了建造者模式，委托给了一个DefaultSoulContextBuilder去构造。
public class DefaultSoulContextBuilder implements SoulContextBuilder {
@Override
public SoulContext build(final ServerWebExchange exchange) {
final ServerHttpRequest request = exchange.getRequest();
String path = request.getURI().getPath();
MetaData metaData = MetaDataCache.getInstance().obtain(path);
if (Objects.nonNull(metaData) && metaData.getEnabled()) {
exchange.getAttributes().put(Constants.META_DATA, metaData);
}
return transform(request, metaData);
}
/**
* ServerHttpRequest transform RequestDTO .
*
* @param request {@linkplain ServerHttpRequest}
* @return RequestDTO request dto
*/
private SoulContext transform(final ServerHttpRequest request, final MetaData metaData) {
final String appKey = request.getHeaders().getFirst(Constants.APP_KEY);
final String sign = request.getHeaders().getFirst(Constants.SIGN);
final String timestamp = request.getHeaders().getFirst(Constants.TIMESTAMP);
SoulContext soulContext = new SoulContext();
String path = request.getURI().getPath();
soulContext.setPath(path);
if (Objects.nonNull(metaData) && metaData.getEnabled()) {
if (RpcTypeEnum.SPRING_CLOUD.getName().equals(metaData.getRpcType())) {
setSoulContextByHttp(soulContext, path);
soulContext.setRpcType(metaData.getRpcType());
} else if (RpcTypeEnum.DUBBO.getName().equals(metaData.getRpcType())) {
setSoulContextByDubbo(soulContext, metaData);
} else if (RpcTypeEnum.SOFA.getName().equals(metaData.getRpcType())) {
setSoulContextBySofa(soulContext, metaData);
} else if (RpcTypeEnum.TARS.getName().equals(metaData.getRpcType())) {
setSoulContextByTars(soulContext, metaData);
} else {
setSoulContextByHttp(soulContext, path);
soulContext.setRpcType(RpcTypeEnum.HTTP.getName());
}
} else {
setSoulContextByHttp(soulContext, path);
soulContext.setRpcType(RpcTypeEnum.HTTP.getName());
}
soulContext.setAppKey(appKey);
soulContext.setSign(sign);
soulContext.setTimestamp(timestamp);
soulContext.setStartDateTime(LocalDateTime.now());
Optional.ofNullable(request.getMethod()).ifPresent(httpMethod -> soulContext.setHttpMethod(httpMethod.name()));
return soulContext;
}
private void setSoulContextByDubbo(final SoulContext soulContext, final MetaData metaData) {
soulContext.setModule(metaData.getAppName());
soulContext.setMethod(metaData.getServiceName());
soulContext.setRpcType(metaData.getRpcType());
soulContext.setContextPath(metaData.getContextPath());
}
private void setSoulContextBySofa(final SoulContext soulContext, final MetaData metaData) {
soulContext.setModule(metaData.getAppName());
soulContext.setMethod(metaData.getServiceName());
soulContext.setRpcType(metaData.getRpcType());
soulContext.setContextPath(metaData.getContextPath());
}
private void setSoulContextByTars(final SoulContext soulContext, final MetaData metaData) {
soulContext.setModule(metaData.getServiceName());
soulContext.setMethod(metaData.getMethodName());
soulContext.setRpcType(metaData.getRpcType());
soulContext.setContextPath(metaData.getContextPath());
}
private void setSoulContextByHttp(final SoulContext soulContext, final String path) {
String contextPath = "/";
String[] splitList = StringUtils.split(path, "/");
if (splitList.length != 0) {
contextPath = contextPath.concat(splitList[0]);
}
String realUrl = path.substring(contextPath.length());
soulContext.setContextPath(contextPath);
soulContext.setModule(contextPath);
soulContext.setMethod(realUrl);
soulContext.setRealUrl(realUrl);
}
}Global插件作为第一个运行的插件，会从请求ServerWebExchange对象中取出SoulContext所需要的信息存入SoulContext中，如果有元数据也一应放入。最终放入到ServerWebExchange属性中取名为context，往下透传。这是一种上下文设计模式。spring中各种context都是如此。
关于Global插件代码一点思考
- 这段if-else逻辑可以优化掉
private SoulContext transform(final ServerHttpRequest request, final MetaData metaData) {
final String appKey = request.getHeaders().getFirst(Constants.APP_KEY);
final String sign = request.getHeaders().getFirst(Constants.SIGN);
final String timestamp = request.getHeaders().getFirst(Constants.TIMESTAMP);
SoulContext soulContext = new SoulContext();
String path = request.getURI().getPath();
soulContext.setPath(path);
if (Objects.nonNull(metaData) && metaData.getEnabled()) {
if (RpcTypeEnum.SPRING_CLOUD.getName().equals(metaData.getRpcType())) {
setSoulContextByHttp(soulContext, path);
soulContext.setRpcType(metaData.getRpcType());
} else if (RpcTypeEnum.DUBBO.getName().equals(metaData.getRpcType())) {
setSoulContextByDubbo(soulContext, metaData);
} else if (RpcTypeEnum.SOFA.getName().equals(metaData.getRpcType())) {
setSoulContextBySofa(soulContext, metaData);
} else if (RpcTypeEnum.TARS.getName().equals(metaData.getRpcType())) {
setSoulContextByTars(soulContext, metaData);
} else {
setSoulContextByHttp(soulContext, path);
soulContext.setRpcType(RpcTypeEnum.HTTP.getName());
}
} else {
setSoulContextByHttp(soulContext, path);
soulContext.setRpcType(RpcTypeEnum.HTTP.getName());
}
soulContext.setAppKey(appKey);
soulContext.setSign(sign);
soulContext.setTimestamp(timestamp);
soulContext.setStartDateTime(LocalDateTime.now());
Optional.ofNullable(request.getMethod()).ifPresent(httpMethod -> soulContext.setHttpMethod(httpMethod.name()));
return soulContext;
}- SoulContext构造有点分散，是否都放入建造者中处理会集中一些
