用 MCP 连接工具，保留应用控制权

URI endpoint = URI.create(configuredEndpoint); // 只解析结构，不发起网络连接。
String scheme = endpoint.getScheme();
String host = endpoint.getHost(); // 解析出的主机也不等于已获授权目标。
// Host仍需按受信配置限制协议、主机及重定向；不要把工具返回URL直接注册为新服务。

import java.util.*;
public class Main {
    record Server(String id,List<String> tools){} record Key(String server,String tool){}
    static Map<Key,String> catalog(List<Server> servers){
        Map<Key,String> routes=new HashMap<>();Set<String> ids=new HashSet<>();
        for(Server server:servers){
            if(server.id()==null||server.id().isBlank()||!ids.add(server.id()))throw new IllegalArgumentException("server id");
            for(String tool:server.tools()){
                if(tool==null||tool.isBlank())throw new IllegalArgumentException("tool name");
                Key key=new Key(server.id(),tool); // 结构化二元组，避免分隔符拼接碰撞。
                if(routes.putIfAbsent(key,server.id())!=null)throw new IllegalArgumentException("duplicate tool");
            }
        }
        return Map.copyOf(routes); // 目录作为不可变快照交付。
    }
    static String resolve(Map<Key,String> routes,Key key){
        String route=routes.get(key);if(route==null)throw new IllegalArgumentException("unknown route");return route; // 不做模糊回退。
    }
    static void eq(Object e,Object a){if(!e.equals(a))throw new AssertionError(a);}
    public static void main(String[] args){
        var map=catalog(List.of(new Server("A",List.of("search")),new Server("B",List.of("search"))));
        eq(2,map.size());eq("B",resolve(map,new Key("B","search")));
        eq(0,catalog(List.of()).size());
        eq(2,catalog(List.of(new Server("a:b",List.of("c")),new Server("a",List.of("b:c")))).size());
        try{catalog(List.of(new Server("A",List.of("x","x"))));throw new AssertionError();}catch(IllegalArgumentException expected){}
        try{resolve(map,new Key("C","search"));throw new AssertionError();}catch(IllegalArgumentException expected){}
        try{map.clear();throw new AssertionError();}catch(UnsupportedOperationException expected){}
        System.out.println("PASS 7 tests");
    }
}