org.apache.ibatis.migration.MigrationReader Maven / Gradle / Ivy

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package org.apache.ibatis.migration;

import org.apache.ibatis.parsing.PropertyParser;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Properties;
import java.util.Set;

public class MigrationReader extends Reader {

  private static final String LINE_SEPARATOR = System.getProperty("line.separator", "\n");

  private Reader target;

  public MigrationReader(Reader source, boolean undo, Properties properties) throws IOException {
    final Properties variables = filterVariables(properties);
    try {
      BufferedReader reader = new BufferedReader(source);
      StringBuilder doBuilder = new StringBuilder();
      StringBuilder undoBuilder = new StringBuilder();
      StringBuilder currentBuilder = doBuilder;
      String line;
      while ((line = reader.readLine()) != null) {
        if (line != null) {
          if (line.trim().startsWith("--//")) {
            if (line.contains("@UNDO")) {
              currentBuilder = undoBuilder;
            }
            line = line.replace("--//", "-- ");
          }
          currentBuilder.append(line);
          currentBuilder.append(LINE_SEPARATOR);
        }
      }
      if (undo) {
        target = new StringReader(PropertyParser.parse(undoBuilder.toString(), variables));
      } else {
        target = new StringReader(PropertyParser.parse(doBuilder.toString(), variables));
      }
    } finally {
      source.close();
    }
  }

  public int read(char[] cbuf, int off, int len) throws IOException {
    return target.read(cbuf, off, len);
  }

  public void close() throws IOException {
    target.close();
  }


  private Properties filterVariables(final Properties properties) {
    final Set KNOWN_PROPERTIES_TO_IGNORE = new HashSet() {{
      addAll(Arrays.asList(
          "time_zone", "script_char_set",
          "driver", "url", "username", "password",
          "send_full_script", "delimiter", "full_line_delimiter",
          "auto_commit", "driver_path"));
    }};
    return new Properties() {
      @Override
      public synchronized boolean containsKey(Object o) {
        return KNOWN_PROPERTIES_TO_IGNORE.contains(o) ? false : properties.containsKey(o);
      }

      @Override
      public String getProperty(String key) {
        return KNOWN_PROPERTIES_TO_IGNORE.contains(key) ? null : properties.getProperty(key);
      }
    };
  }


}