Sample Java program to extract schema.object_name entries from migration scripts (Oracle)

ExtractDDL.java

// #!/usr/bin/java --source 11
// CC0 1.0 (public domain)

import java.util.Arrays;
import java.util.List;

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.FileSystems;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.PathMatcher;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.stream.Collectors;
import java.util.stream.Stream;


class ExtractDDL {
    private static final String START_TAG = "CREATE ";
    private static final String END_TAG = ";";
    private static final List<String> DB_OBJECTS = Arrays.asList("CLUSTER", "CONTEXT", "CONTROLFILE",
            "LINK", "DATABASE", "DIMENSION", "DIRECTORY", "FUNCTION", "INDEXTYPE", "INDEX", "JAVA",
            "LIBRARY", "LOG", "OPERATOR", "OUTLINE", "BODY", "PACKAGE", "PFILE", "PROCEDURE",
            "PROFILE", "SEGMENT", "SCHEMA", "SEQUENCE", "SNAPSHOT", "SPFILE", "SYNONYM",
            "TABLESPACE", "TABLE", "TRIGGER", "TYPE", "USER", "VIEW");

    public static void main(String... args) {
        if (args.length != 1) {
            System.out.println("Usage: ./script /path/to/migrations/directory");
			return;
        }
        PathMatcher pathMatcher = FileSystems.getDefault().getPathMatcher("glob:**/*.sql");
        try (Stream<Path> walk = Files.walk(Paths.get(args[0]))) {
            walk.filter(pathMatcher::matches)
                    .flatMap(path -> streamTagContents(START_TAG, END_TAG, path))
                    .map(statement -> statement.replaceAll("\\s+", " "))
                    .map(statement -> truncateToObjectName(DB_OBJECTS, statement))
                    .filter(statement -> !statement.isEmpty())
                    .forEach(System.out::println);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }


    private static String truncateToObjectName(List<String> objectNames, String statement) {
        return Stream.of(statement.split(" "))
                .limit(objectNames.stream()
                        .map(d -> Arrays.asList(statement.split(" ")).indexOf(d))
                        .filter(i -> i > 0).findFirst().orElse(-2) + 2)
                .collect(Collectors.joining(" "));
    }


    private static Stream<? extends String> streamTagContents(String startTag, String endTag, Path path) {
        List<String> results = new ArrayList<>();
        try {
            List<String> lines = Files.readAllLines(path, StandardCharsets.UTF_8);
            String fullString = String.join(" ", lines).toUpperCase();
            for (int createIndex = fullString.indexOf(startTag, 0),
                 endIndex = fullString.indexOf(endTag, createIndex);
                 createIndex != -1 && endIndex != -1;
                 createIndex = endIndex,
                         createIndex = fullString.indexOf(startTag, createIndex),
                         endIndex = fullString.indexOf(endTag, createIndex)) {
                results.add(fullString.substring(createIndex, endIndex));
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return results.stream();
    }

}

migration.sql

CREATE
TABLE
schema_name.table_name
(
    column_1 data_type column_constraint,
    column_2 data_type column_constraint,
    ...
    table_constraint
);


CREATE
TABLE
schema_name2.table_name2
(
    column_1 data_type column_constraint,
    column_2 data_type column_constraint,
    ...
    table_constraint
);

-- CREATE TABLE SCHEMA_NAME.TABLE_NAME
-- CREATE TABLE SCHEMA_NAME2.TABLE_NAME2