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| 1 | +package com.linkedin.hoptimator.mcp.server; |
| 2 | + |
| 3 | +import java.sql.Connection; |
| 4 | +import java.sql.DriverManager; |
| 5 | +import java.sql.ResultSet; |
| 6 | +import java.sql.ResultSetMetaData; |
| 7 | +import java.sql.Statement; |
| 8 | +import java.sql.SQLException; |
| 9 | +import java.util.ArrayList; |
| 10 | +import java.util.HashMap; |
| 11 | +import java.util.Map; |
| 12 | +import java.util.List; |
| 13 | + |
| 14 | +import com.google.gson.Gson; |
| 15 | +import io.modelcontextprotocol.server.McpServer; |
| 16 | +import io.modelcontextprotocol.server.McpSyncServer; |
| 17 | +import io.modelcontextprotocol.server.transport.StdioServerTransportProvider; |
| 18 | + |
| 19 | +import static io.modelcontextprotocol.server.McpServerFeatures.SyncToolSpecification; |
| 20 | +import static io.modelcontextprotocol.spec.McpSchema.CallToolResult; |
| 21 | +import static io.modelcontextprotocol.spec.McpSchema.ServerCapabilities; |
| 22 | +import static io.modelcontextprotocol.spec.McpSchema.Tool; |
| 23 | + |
| 24 | + |
| 25 | +public final class HoptimatorMcpServer { |
| 26 | + |
| 27 | + private HoptimatorMcpServer() { |
| 28 | + } |
| 29 | + |
| 30 | + public static void main(String[] args) throws Exception { |
| 31 | + Connection conn = DriverManager.getConnection("jdbc:hoptimator://fun=mysql"); |
| 32 | + Gson gson = new Gson(); |
| 33 | + |
| 34 | + String sqlSchema = "{\"type\" : \"object\", \"id\" : \"urn:jsonschema:Sql\"," |
| 35 | + + "\"properties\" : {\"sql\" : {\"type\" : \"string\"}}}"; |
| 36 | + StdioServerTransportProvider transportProvider = new StdioServerTransportProvider(); |
| 37 | + SyncToolSpecification query = new SyncToolSpecification( |
| 38 | + new Tool("query", "SQL Query", sqlSchema), (x, args2) -> { |
| 39 | + try (Statement stmt = conn.createStatement()) { |
| 40 | + String sql = rewriteCommands((String) args2.get("sql")); |
| 41 | + ResultSet rs = stmt.executeQuery(sql); |
| 42 | + return new CallToolResult(gson.toJson(collect(rs)), false); |
| 43 | + } catch (Exception e) { |
| 44 | + return new CallToolResult("ERROR: " + e.toString(), true); |
| 45 | + } |
| 46 | + }); |
| 47 | + |
| 48 | + McpSyncServer server = McpServer.sync(transportProvider) |
| 49 | + .serverInfo("hoptimator", "0.0.0") |
| 50 | + .capabilities(ServerCapabilities.builder() |
| 51 | + .tools(true) // Enable tool support |
| 52 | + .build()) |
| 53 | + .build(); |
| 54 | + |
| 55 | + server.addTool(query); |
| 56 | + while (true) { |
| 57 | + Thread.sleep(1000L); |
| 58 | + } |
| 59 | + } |
| 60 | + |
| 61 | + private static String rewriteCommands(String sql) { |
| 62 | + if ("show tables".equalsIgnoreCase(sql)) { |
| 63 | + return "select * from \"metadata\".tables"; |
| 64 | + } |
| 65 | + if ("show databases".equalsIgnoreCase(sql)) { |
| 66 | + return "select * from \"k8s\".databases"; |
| 67 | + } |
| 68 | + if ("show pipelines".equalsIgnoreCase(sql)) { |
| 69 | + return "select * from \"k8s\".pipelines"; |
| 70 | + } |
| 71 | + return sql; |
| 72 | + } |
| 73 | + |
| 74 | + private static List<Map<String, String>> collect(ResultSet rs) throws SQLException { |
| 75 | + ResultSetMetaData meta = rs.getMetaData(); |
| 76 | + int n = meta.getColumnCount(); |
| 77 | + List<Map<String, String>> results = new ArrayList<>(); |
| 78 | + while (rs.next()) { |
| 79 | + Map<String, String> row = new HashMap<>(); |
| 80 | + for (int j = 1; j <= n; j++) { |
| 81 | + row.put(meta.getColumnName(j), rs.getString(j)); |
| 82 | + } |
| 83 | + results.add(row); |
| 84 | + } |
| 85 | + return results; |
| 86 | + } |
| 87 | +} |
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