sql.java

来自「Groovy动态语言 运行在JVM中的动态语言 可以方便的处理业务逻辑变化大的业」· Java 代码 · 共 1,263 行 · 第 1/4 页

    public DataSource getDataSource() {
        return dataSource;
    }


    public void commit() {
        try {
            this.useConnection.commit();
        }
        catch (SQLException e) {
            log.log(Level.SEVERE, "Caught exception commiting connection: " + e, e);
        }
    }

    public void rollback() {
        try {
            this.useConnection.rollback();
        }
        catch (SQLException e) {
            log.log(Level.SEVERE, "Caught exception rollbacking connection: " + e, e);
        }
    }

    /**
     * @return Returns the updateCount.
     */
    public int getUpdateCount() {
        return updateCount;
    }

    /**
     * If this instance was created with a single Connection then the connection
     * is returned. Otherwise if this instance was created with a DataSource
     * then this method returns null
     *
     * @return the connection wired into this object, or null if this object
     *         uses a DataSource
     */
    public Connection getConnection() {
        return useConnection;
    }


    /**
     * Allows a closure to be passed in to configure the JDBC statements before they are executed
     * to do things like set the query size etc.
     *
     * @param configureStatement
     */
    public void withStatement(Closure configureStatement) {
        this.configureStatement = configureStatement;
    }

    // Implementation methods
    //-------------------------------------------------------------------------

    /**
     * @return the SQL version of the given query using ? instead of any
     *         parameter
     */
    protected String asSql(GString gstring, List values) {
        String[] strings = gstring.getStrings();
        if (strings.length <= 0) {
            throw new IllegalArgumentException("No SQL specified in GString: " + gstring);
        }
        boolean nulls = false;
        StringBuffer buffer = new StringBuffer();
        boolean warned = false;
        Iterator iter = values.iterator();
        for (int i = 0; i < strings.length; i++) {
            String text = strings[i];
            if (text != null) {
                buffer.append(text);
            }
            if (iter.hasNext()) {
                Object value = iter.next();
                if (value != null) {
                    if(value instanceof ExpandedVariable){
                        buffer.append(((ExpandedVariable)value).getObject());
                        iter.remove();
                    }else{
                        boolean validBinding = true;
                        if (i < strings.length - 1) {
                            String nextText = strings[i + 1];
                            if ((text.endsWith("\"") || text.endsWith("'")) && (nextText.startsWith("'") || nextText.startsWith("\""))) {
                                if (!warned) {
                                    log.warning("In Groovy SQL please do not use quotes around dynamic expressions " +
                                            "(which start with $) as this means we cannot use a JDBC PreparedStatement " +
                                            "and so is a security hole. Groovy has worked around your mistake but the security hole is still there. " +
                                            "The expression so far is: " + buffer.toString() + "?" + nextText);
                                    warned = true;
                                }
                                buffer.append(value);
                                iter.remove();
                                validBinding = false;
                            }
                        }
                        if (validBinding) {
                            buffer.append("?");
                        }
                    }
                }
                else {
                    nulls = true;
                    buffer.append("?'\"?"); // will replace these with nullish
                    // values
                }
            }
        }
        String sql = buffer.toString();
        if (nulls) {
            sql = nullify(sql);
        }
        return sql;
    }

    /**
     * replace ?'"? references with NULLish
     * 
     * @param sql
     */
    protected String nullify(String sql) {
        /*
         * Some drivers (Oracle classes12.zip) have difficulty resolving data
         * type if setObject(null). We will modify the query to pass 'null', 'is
         * null', and 'is not null'
         */
        //could be more efficient by compiling expressions in advance.
        int firstWhere = findWhereKeyword(sql);
        if (firstWhere >= 0) {
            Pattern[] patterns = { Pattern.compile("(?is)^(.{" + firstWhere + "}.*?)!=\\s{0,1}(\\s*)\\?'\"\\?(.*)"),
                    Pattern.compile("(?is)^(.{" + firstWhere + "}.*?)<>\\s{0,1}(\\s*)\\?'\"\\?(.*)"),
                    Pattern.compile("(?is)^(.{" + firstWhere + "}.*?[^<>])=\\s{0,1}(\\s*)\\?'\"\\?(.*)"), };
            String[] replacements = { "$1 is not $2null$3", "$1 is not $2null$3", "$1 is $2null$3", };
            for (int i = 0; i < patterns.length; i++) {
                Matcher matcher = patterns[i].matcher(sql);
                while (matcher.matches()) {
                    sql = matcher.replaceAll(replacements[i]);
                    matcher = patterns[i].matcher(sql);
                }
            }
        }
        return sql.replaceAll("\\?'\"\\?", "null");
    }

    /**
     * Find the first 'where' keyword in the sql.
     * 
     * @param sql
     */
    protected int findWhereKeyword(String sql) {
        char[] chars = sql.toLowerCase().toCharArray();
        char[] whereChars = "where".toCharArray();
        int i = 0;
        boolean inString = false; //TODO: Cater for comments?
        boolean noWhere = true;
        int inWhere = 0;
        while (i < chars.length && noWhere) {
            switch (chars[i]) {
                case '\'':
                    if (inString) {
                        inString = false;
                    }
                    else {
                        inString = true;
                    }
                    break;
                default:
                    if (!inString && chars[i] == whereChars[inWhere]) {
                        inWhere++;
                        if (inWhere == whereChars.length) {
                            return i;
                        }
                    }
            }
            i++;
        }
        return -1;
    }

    /**
     * @return extracts the parameters from the expression as a List
     */
    protected List getParameters(GString gstring) {
        Object[] values = gstring.getValues();
        List answer = new ArrayList(values.length);
        for (int i = 0; i < values.length; i++) {
            if (values[i] != null) {
                answer.add(values[i]);
            }
        }
        return answer;
    }

    /**
     * Appends the parameters to the given statement
     */
    protected void setParameters(List params, PreparedStatement statement) throws SQLException {
        int i = 1;
        for (Iterator iter = params.iterator(); iter.hasNext();) {
            Object value = iter.next();
            setObject(statement, i++, value);
        }
    }

    /**
     * Strategy method allowing derived classes to handle types differently
     * such as for CLOBs etc.
     */
    protected void setObject(PreparedStatement statement, int i, Object value)
        throws SQLException {
        if (value instanceof InParameter  || value instanceof OutParameter) {
            if(value instanceof InParameter){
                InParameter in = (InParameter) value;
                Object val = in.getValue();
                if (null == val) {
                    statement.setNull(i, in.getType());
                } else {
                    statement.setObject(i, val, in.getType());
                }
            }
            if(value instanceof OutParameter){
                try{
                    OutParameter out = (OutParameter)value;
                    ((CallableStatement)statement).registerOutParameter(i,out.getType());
                }catch(ClassCastException e){
                    throw new SQLException("Cannot register out parameter.");
                }
            }
        } else {
            statement.setObject(i, value);
        }
    }

    protected Connection createConnection() throws SQLException {
        if (dataSource != null) {
            //Use a doPrivileged here as many different properties need to be
            // read, and the policy
            //shouldn't have to list them all.
            Connection con = null;
            try {
                con = (Connection) AccessController.doPrivileged(new PrivilegedExceptionAction() {
                    public Object run() throws SQLException {
                        return dataSource.getConnection();
                    }
                });
            }
            catch (PrivilegedActionException pae) {
                Exception e = pae.getException();
                if (e instanceof SQLException) {
                    throw (SQLException) e;
                }
                else {
                    throw (RuntimeException) e;
                }
            }
            return con;
        }
        else {
            //System.out.println("createConnection returning: " +
            // useConnection);
            return useConnection;
        }
    }

    protected void closeResources(Connection connection, Statement statement, ResultSet results) {
        if (results != null) {
            try {
                results.close();
            }
            catch (SQLException e) {
                log.log(Level.SEVERE, "Caught exception closing resultSet: " + e, e);
            }
        }
        closeResources(connection, statement);
    }

    protected void closeResources(Connection connection, Statement statement) {
        if (statement != null) {
            try {
                statement.close();
            }
            catch (SQLException e) {
                log.log(Level.SEVERE, "Caught exception closing statement: " + e, e);
            }
        }
        if (dataSource != null) {
            try {
                connection.close();
            }
            catch (SQLException e) {
                log.log(Level.SEVERE, "Caught exception closing connection: " + e, e);
            }
        }
    }

    private void warnDeprecated() {
        if (!warned) {
            warned = true;
            log.warning("queryEach() is deprecated, please use eachRow() instead");
        }
    }

    /**
     * Provides a hook to be able to configure JDBC statements, such as to configure
     *
     * @param statement
     */
    protected void configure(Statement statement) {
        if (configureStatement != null) {
            configureStatement.call(statement);
        }
    }
}