org.apache.ibatis.migration.operations.DownOperation Maven / Gradle / Ivy

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/**
 *    Copyright 2010-2019 the original author or authors.
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */
package org.apache.ibatis.migration.operations;

import java.io.PrintStream;
import java.sql.SQLException;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.ibatis.jdbc.ScriptRunner;
import org.apache.ibatis.jdbc.SqlRunner;
import org.apache.ibatis.migration.Change;
import org.apache.ibatis.migration.ConnectionProvider;
import org.apache.ibatis.migration.MigrationException;
import org.apache.ibatis.migration.MigrationLoader;
import org.apache.ibatis.migration.hook.HookContext;
import org.apache.ibatis.migration.hook.MigrationHook;
import org.apache.ibatis.migration.options.DatabaseOperationOption;
import org.apache.ibatis.migration.utils.Util;

public final class DownOperation extends DatabaseOperation {
  private Integer steps;

  public DownOperation() {
    this(null);
  }

  public DownOperation(Integer steps) {
    super();
    this.steps = steps;
  }

  public DownOperation operate(ConnectionProvider connectionProvider, MigrationLoader migrationsLoader,
      DatabaseOperationOption option, PrintStream printStream) {
    return operate(connectionProvider, migrationsLoader, option, printStream, null);
  }

  public DownOperation operate(ConnectionProvider connectionProvider, MigrationLoader migrationsLoader,
      DatabaseOperationOption option, PrintStream printStream, MigrationHook hook) {
    try {
      if (option == null) {
        option = new DatabaseOperationOption();
      }
      List changesInDb = Collections.emptyList();
      if (changelogExists(connectionProvider, option)) {
        changesInDb = getChangelog(connectionProvider, option);
      }
      if (changesInDb.isEmpty()) {
        println(printStream, "Changelog exist, but no migration found.");
      } else {
        List migrations = migrationsLoader.getMigrations();
        Collections.sort(migrations);
        String skippedOrMissing = checkSkippedOrMissing(changesInDb, migrations);
        Collections.reverse(migrations);
        int stepCount = 0;
        ScriptRunner runner = getScriptRunner(connectionProvider, option, printStream);

        Map hookBindings = new HashMap();

        try {
          for (Change change : migrations) {
            if (change.equals(changesInDb.get(changesInDb.size() - 1))) {
              if (stepCount == 0 && hook != null) {
                hookBindings.put(MigrationHook.HOOK_CONTEXT, new HookContext(connectionProvider, runner, null));
                hook.before(hookBindings);
              }
              if (hook != null) {
                hookBindings.put(MigrationHook.HOOK_CONTEXT,
                    new HookContext(connectionProvider, runner, change.clone()));
                hook.beforeEach(hookBindings);
              }
              println(printStream, Util.horizontalLine("Undoing: " + change.getFilename(), 80));
              runner.runScript(migrationsLoader.getScriptReader(change, true));
              if (changelogExists(connectionProvider, option)) {
                deleteChange(connectionProvider, change, option);
              } else {
                println(printStream,
                    "Changelog doesn't exist. No further migrations will be undone (normal for the last migration).");
                stepCount = steps;
              }
              println(printStream);
              if (hook != null) {
                hookBindings.put(MigrationHook.HOOK_CONTEXT,
                    new HookContext(connectionProvider, runner, change.clone()));
                hook.afterEach(hookBindings);
              }
              stepCount++;
              if (steps == null || stepCount >= steps) {
                break;
              }
              changesInDb.remove(changesInDb.size() - 1);
            }
          }
          if (stepCount > 0 && hook != null) {
            hookBindings.put(MigrationHook.HOOK_CONTEXT, new HookContext(connectionProvider, runner, null));
            hook.after(hookBindings);
          }
        } finally {
          runner.closeConnection();
        }
        println(printStream, skippedOrMissing);
      }
      return this;
    } catch (Throwable e) {
      while (e instanceof MigrationException) {
        e = e.getCause();
      }
      throw new MigrationException("Error undoing last migration.  Cause: " + e, e);
    }
  }

  protected void deleteChange(ConnectionProvider connectionProvider, Change change, DatabaseOperationOption option) {
    SqlRunner runner = getSqlRunner(connectionProvider);
    try {
      runner.delete("delete from " + option.getChangelogTable() + " where ID = ?", change.getId());
    } catch (SQLException e) {
      throw new MigrationException("Error querying last applied migration.  Cause: " + e, e);
    } finally {
      runner.closeConnection();
    }
  }
}