liquibase-core/src/main/java/liquibase/change/AbstractSQLChange.java
@Override
    public CheckSum generateCheckSum() {
        InputStream stream = null;
        try {
            stream = openSqlStream();

            String sql = this.sql;
            if ((stream == null) && (sql == null)) {
                sql = "";
            }

            if (sql != null) {
                stream = new ByteArrayInputStream(
                    sql.getBytes(
                        LiquibaseConfiguration.getInstance().getConfiguration(GlobalConfiguration.class)
                        .getOutputEncoding()
                    )
                );
            }

            return CheckSum.compute(new NormalizingStream(this.getEndDelimiter(), this.isSplitStatements(), this.isStripComments(), stream), false);
        } catch (IOException e) {
            throw new UnexpectedLiquibaseException(e);
        } finally {
            if (stream != null) {
                try {
                    stream.close();
                } catch (IOException e) {
                    Scope.getCurrentScope().getLog(getClass()).fine(LogType.LOG, "Error closing stream", e);
                }
            }
        }
    }
@Override
    public CheckSum generateCheckSum() {
        InputStream stream = null;
        try {
            stream = openSqlStream();

            String sql = this.sql;
            if ((stream == null) && (sql == null)) {
                sql = "";
            }

            if (sql != null) {
                stream = new ByteArrayInputStream(
                    sql.getBytes(
                        LiquibaseConfiguration.getInstance().getConfiguration(GlobalConfiguration.class)
                        .getOutputEncoding()
                    )
                );
            }

            return CheckSum.compute(new NormalizingStream(this.getEndDelimiter(), this.isSplitStatements(), this.isStripComments(), stream), false);
        } catch (IOException e) {
            throw new UnexpectedLiquibaseException(e);
        } finally {
            if (stream != null) {
                try {
                    stream.close();
                } catch (IOException e) {
                    Scope.getCurrentScope().getLog(getClass()).fine(LogType.LOG, "Error closing stream", e);
                }
            }
        }
    }
Calculates the checksum based on the contained SQL.

@see liquibase.change.AbstractChange#generateCheckSum()