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java/org/apache/tomcat/dbcp/dbcp2/DelegatingStatement.java

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+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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.tomcat.dbcp.dbcp2;
+
+import java.sql.Connection;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.SQLWarning;
+import java.sql.Statement;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A base delegating implementation of {@link Statement}.
+ * <p>
+ * All of the methods from the {@link Statement} interface simply check to see that the {@link Statement} is active, and
+ * call the corresponding method on the "delegate" provided in my constructor.
+ * <p>
+ * Extends AbandonedTrace to implement Statement tracking and logging of code which created the Statement. Tracking the
+ * Statement ensures that the Connection which created it can close any open Statement's on Connection close.
+ *
+ * @since 2.0
+ */
+public class DelegatingStatement extends AbandonedTrace implements Statement {
+
+    /** My delegate. */
+    private Statement statement;
+
+    /** The connection that created me. **/
+    private DelegatingConnection<?> connection;
+
+    private boolean closed = false;
+
+    /**
+     * Create a wrapper for the Statement which traces this Statement to the Connection which created it and the code
+     * which created it.
+     *
+     * @param statement
+     *            the {@link Statement} to delegate all calls to.
+     * @param connection
+     *            the {@link DelegatingConnection} that created this statement.
+     */
+    public DelegatingStatement(final DelegatingConnection<?> connection, final Statement statement) {
+        super(connection);
+        this.statement = statement;
+        this.connection = connection;
+    }
+
+    /**
+     *
+     * @throws SQLException
+     *             thrown by the delegating statement.
+     * @since 2.4.0 made public, was protected in 2.3.0.
+     */
+    public void activate() throws SQLException {
+        if (statement instanceof DelegatingStatement) {
+            ((DelegatingStatement) statement).activate();
+        }
+    }
+
+    @Override
+    public void addBatch(final String sql) throws SQLException {
+        checkOpen();
+        try {
+            statement.addBatch(sql);
+        } catch (final SQLException e) {
+            handleException(e);
+        }
+    }
+
+    @Override
+    public void cancel() throws SQLException {
+        checkOpen();
+        try {
+            statement.cancel();
+        } catch (final SQLException e) {
+            handleException(e);
+        }
+    }
+
+    protected void checkOpen() throws SQLException {
+        if (isClosed()) {
+            throw new SQLException(this.getClass().getName() + " with address: \"" + this.toString() + "\" is closed.");
+        }
+    }
+
+    @Override
+    public void clearBatch() throws SQLException {
+        checkOpen();
+        try {
+            statement.clearBatch();
+        } catch (final SQLException e) {
+            handleException(e);
+        }
+    }
+
+    @Override
+    public void clearWarnings() throws SQLException {
+        checkOpen();
+        try {
+            statement.clearWarnings();
+        } catch (final SQLException e) {
+            handleException(e);
+        }
+    }
+
+    /**
+     * Close this DelegatingStatement, and close any ResultSets that were not explicitly closed.
+     */
+    @Override
+    public void close() throws SQLException {
+        if (isClosed()) {
+            return;
+        }
+        final List<Exception> thrownList = new ArrayList<>();
+        try {
+            if (connection != null) {
+                connection.removeTrace(this);
+                connection = null;
+            }
+
+            // The JDBC spec requires that a statement close any open
+            // ResultSet's when it is closed.
+            // FIXME The PreparedStatement we're wrapping should handle this for us.
+            // See bug 17301 for what could happen when ResultSets are closed twice.
+            final List<AbandonedTrace> resultSetList = getTrace();
+            if (resultSetList != null) {
+                final int size = resultSetList.size();
+                final ResultSet[] resultSets = resultSetList.toArray(new ResultSet[size]);
+                for (final ResultSet resultSet : resultSets) {
+                    if (resultSet != null) {
+                        try {
+                            resultSet.close();
+                        } catch (Exception e) {
+                            if (connection != null) {
+                                // Does not rethrow e.
+                                connection.handleExceptionNoThrow(e);
+                            }
+                            thrownList.add(e);
+                        }
+                    }
+                }
+                clearTrace();
+            }
+            if (statement != null) {
+                try {
+                    statement.close();
+                } catch (Exception e) {
+                    if (connection != null) {
+                        // Does not rethrow e.
+                        connection.handleExceptionNoThrow(e);
+                    }
+                    thrownList.add(e);
+                }
+            }
+        } finally {
+            closed = true;
+            statement = null;
+            if (!thrownList.isEmpty()) {
+                throw new SQLExceptionList(thrownList);
+            }
+        }
+    }
+
+    @Override
+    public void closeOnCompletion() throws SQLException {
+        checkOpen();
+        try {
+            Jdbc41Bridge.closeOnCompletion(statement);
+        } catch (final SQLException e) {
+            handleException(e);
+        }
+    }
+
+    @Override
+    public boolean execute(final String sql) throws SQLException {
+        checkOpen();
+        setLastUsedInParent();
+        try {
+            return statement.execute(sql);
+        } catch (final SQLException e) {
+            handleException(e);
+            return false;
+        }
+    }
+
+    @Override
+    public boolean execute(final String sql, final int autoGeneratedKeys) throws SQLException {
+        checkOpen();
+        setLastUsedInParent();
+        try {
+            return statement.execute(sql, autoGeneratedKeys);
+        } catch (final SQLException e) {
+            handleException(e);
+            return false;
+        }
+    }
+
+    @Override
+    public boolean execute(final String sql, final int columnIndexes[]) throws SQLException {
+        checkOpen();
+        setLastUsedInParent();
+        try {
+            return statement.execute(sql, columnIndexes);
+        } catch (final SQLException e) {
+            handleException(e);
+            return false;
+        }
+    }
+
+    @Override
+    public boolean execute(final String sql, final String columnNames[]) throws SQLException {
+        checkOpen();
+        setLastUsedInParent();
+        try {
+            return statement.execute(sql, columnNames);
+        } catch (final SQLException e) {
+            handleException(e);
+            return false;
+        }
+    }
+
+    @Override
+    public int[] executeBatch() throws SQLException {
+        checkOpen();
+        setLastUsedInParent();
+        try {
+            return statement.executeBatch();
+        } catch (final SQLException e) {
+            handleException(e);
+            throw new AssertionError();
+        }
+    }
+
+    @Override
+    public ResultSet executeQuery(final String sql) throws SQLException {
+        checkOpen();
+        setLastUsedInParent();
+        try {
+            return DelegatingResultSet.wrapResultSet(this, statement.executeQuery(sql));
+        } catch (final SQLException e) {
+            handleException(e);
+            throw new AssertionError();
+        }
+    }
+
+    @Override
+    public int executeUpdate(final String sql) throws SQLException {
+        checkOpen();
+        setLastUsedInParent();
+        try {
+            return statement.executeUpdate(sql);
+        } catch (final SQLException e) {
+            handleException(e);
+            return 0;
+        }
+    }
+
+    @Override
+    public int executeUpdate(final String sql, final int autoGeneratedKeys) throws SQLException {
+        checkOpen();
+        setLastUsedInParent();
+        try {
+            return statement.executeUpdate(sql, autoGeneratedKeys);
+        } catch (final SQLException e) {
+            handleException(e);
+            return 0;
+        }
+    }
+
+    @Override
+    public int executeUpdate(final String sql, final int columnIndexes[]) throws SQLException {
+        checkOpen();
+        setLastUsedInParent();
+        try {
+            return statement.executeUpdate(sql, columnIndexes);
+        } catch (final SQLException e) {
+            handleException(e);
+            return 0;
+        }
+    }
+
+    @Override
+    public int executeUpdate(final String sql, final String columnNames[]) throws SQLException {
+        checkOpen();
+        setLastUsedInParent();
+        try {
+            return statement.executeUpdate(sql, columnNames);
+        } catch (final SQLException e) {
+            handleException(e);
+            return 0;
+        }
+    }
+
+    @Override
+    protected void finalize() throws Throwable {
+        // This is required because of statement pooling. The poolable
+        // statements will always be strongly held by the statement pool. If the
+        // delegating statements that wrap the poolable statement are not
+        // strongly held they will be garbage collected but at that point the
+        // poolable statements need to be returned to the pool else there will
+        // be a leak of statements from the pool. Closing this statement will
+        // close all the wrapped statements and return any poolable statements
+        // to the pool.
+        close();
+        super.finalize();
+    }
+
+    @Override
+    public Connection getConnection() throws SQLException {
+        checkOpen();
+        return getConnectionInternal(); // return the delegating connection that created this
+    }
+
+    protected DelegatingConnection<?> getConnectionInternal() {
+        return connection;
+    }
+
+    /**
+     * Returns my underlying {@link Statement}.
+     *
+     * @return my underlying {@link Statement}.
+     * @see #getInnermostDelegate
+     */
+    public Statement getDelegate() {
+        return statement;
+    }
+
+    @Override
+    public int getFetchDirection() throws SQLException {
+        checkOpen();
+        try {
+            return statement.getFetchDirection();
+        } catch (final SQLException e) {
+            handleException(e);
+            return 0;
+        }
+    }
+
+    @Override
+    public int getFetchSize() throws SQLException {
+        checkOpen();
+        try {
+            return statement.getFetchSize();
+        } catch (final SQLException e) {
+            handleException(e);
+            return 0;
+        }
+    }
+
+    @Override
+    public ResultSet getGeneratedKeys() throws SQLException {
+        checkOpen();
+        try {
+            return DelegatingResultSet.wrapResultSet(this, statement.getGeneratedKeys());
+        } catch (final SQLException e) {
+            handleException(e);
+            throw new AssertionError();
+        }
+    }
+
+    /**
+     * If my underlying {@link Statement} is not a {@code DelegatingStatement}, returns it, otherwise recursively
+     * invokes this method on my delegate.
+     * <p>
+     * Hence this method will return the first delegate that is not a {@code DelegatingStatement} or {@code null} when
+     * no non-{@code DelegatingStatement} delegate can be found by traversing this chain.
+     * </p>
+     * <p>
+     * This method is useful when you may have nested {@code DelegatingStatement}s, and you want to make sure to obtain
+     * a "genuine" {@link Statement}.
+     * </p>
+     *
+     * @return The innermost delegate.
+     *
+     * @see #getDelegate
+     */
+    @SuppressWarnings("resource")
+    public Statement getInnermostDelegate() {
+        Statement s = statement;
+        while (s != null && s instanceof DelegatingStatement) {
+            s = ((DelegatingStatement) s).getDelegate();
+            if (this == s) {
+                return null;
+            }
+        }
+        return s;
+    }
+
+    @Override
+    public int getMaxFieldSize() throws SQLException {
+        checkOpen();
+        try {
+            return statement.getMaxFieldSize();
+        } catch (final SQLException e) {
+            handleException(e);
+            return 0;
+        }
+    }
+
+    @Override
+    public int getMaxRows() throws SQLException {
+        checkOpen();
+        try {
+            return statement.getMaxRows();
+        } catch (final SQLException e) {
+            handleException(e);
+            return 0;
+        }
+    }
+
+    @Override
+    public boolean getMoreResults() throws SQLException {
+        checkOpen();
+        try {
+            return statement.getMoreResults();
+        } catch (final SQLException e) {
+            handleException(e);
+            return false;
+        }
+    }
+
+    @Override
+    public boolean getMoreResults(final int current) throws SQLException {
+        checkOpen();
+        try {
+            return statement.getMoreResults(current);
+        } catch (final SQLException e) {
+            handleException(e);
+            return false;
+        }
+    }
+
+    @Override
+    public int getQueryTimeout() throws SQLException {
+        checkOpen();
+        try {
+            return statement.getQueryTimeout();
+        } catch (final SQLException e) {
+            handleException(e);
+            return 0;
+        }
+    }
+
+    @Override
+    public ResultSet getResultSet() throws SQLException {
+        checkOpen();
+        try {
+            return DelegatingResultSet.wrapResultSet(this, statement.getResultSet());
+        } catch (final SQLException e) {
+            handleException(e);
+            throw new AssertionError();
+        }
+    }
+
+    @Override
+    public int getResultSetConcurrency() throws SQLException {
+        checkOpen();
+        try {
+            return statement.getResultSetConcurrency();
+        } catch (final SQLException e) {
+            handleException(e);
+            return 0;
+        }
+    }
+
+    @Override
+    public int getResultSetHoldability() throws SQLException {
+        checkOpen();
+        try {
+            return statement.getResultSetHoldability();
+        } catch (final SQLException e) {
+            handleException(e);
+            return 0;
+        }
+    }
+
+    @Override
+    public int getResultSetType() throws SQLException {
+        checkOpen();
+        try {
+            return statement.getResultSetType();
+        } catch (final SQLException e) {
+            handleException(e);
+            return 0;
+        }
+    }
+
+    @Override
+    public int getUpdateCount() throws SQLException {
+        checkOpen();
+        try {
+            return statement.getUpdateCount();
+        } catch (final SQLException e) {
+            handleException(e);
+            return 0;
+        }
+    }
+
+    @Override
+    public SQLWarning getWarnings() throws SQLException {
+        checkOpen();
+        try {
+            return statement.getWarnings();
+        } catch (final SQLException e) {
+            handleException(e);
+            throw new AssertionError();
+        }
+    }
+
+    protected void handleException(final SQLException e) throws SQLException {
+        if (connection != null) {
+            connection.handleException(e);
+        } else {
+            throw e;
+        }
+    }
+
+    /*
+     * Note: This method was protected prior to JDBC 4.
+     */
+    @Override
+    public boolean isClosed() throws SQLException {
+        return closed;
+    }
+
+    protected boolean isClosedInternal() {
+        return closed;
+    }
+
+    @Override
+    public boolean isCloseOnCompletion() throws SQLException {
+        checkOpen();
+        try {
+            return Jdbc41Bridge.isCloseOnCompletion(statement);
+        } catch (final SQLException e) {
+            handleException(e);
+            return false;
+        }
+    }
+
+    @Override
+    public boolean isPoolable() throws SQLException {
+        checkOpen();
+        try {
+            return statement.isPoolable();
+        } catch (final SQLException e) {
+            handleException(e);
+            return false;
+        }
+    }
+
+    @Override
+    public boolean isWrapperFor(final Class<?> iface) throws SQLException {
+        if (iface.isAssignableFrom(getClass())) {
+            return true;
+        } else if (iface.isAssignableFrom(statement.getClass())) {
+            return true;
+        } else {
+            return statement.isWrapperFor(iface);
+        }
+    }
+
+    /**
+     *
+     * @throws SQLException
+     *             thrown by the delegating statement.
+     * @since 2.4.0 made public, was protected in 2.3.0.
+     */
+    public void passivate() throws SQLException {
+        if (statement instanceof DelegatingStatement) {
+            ((DelegatingStatement) statement).passivate();
+        }
+    }
+
+    protected void setClosedInternal(final boolean closed) {
+        this.closed = closed;
+    }
+
+    @Override
+    public void setCursorName(final String name) throws SQLException {
+        checkOpen();
+        try {
+            statement.setCursorName(name);
+        } catch (final SQLException e) {
+            handleException(e);
+        }
+    }
+
+    /**
+     * Sets my delegate.
+     *
+     * @param statement
+     *            my delegate.
+     */
+    public void setDelegate(final Statement statement) {
+        this.statement = statement;
+    }
+
+    @Override
+    public void setEscapeProcessing(final boolean enable) throws SQLException {
+        checkOpen();
+        try {
+            statement.setEscapeProcessing(enable);
+        } catch (final SQLException e) {
+            handleException(e);
+        }
+    }
+
+    @Override
+    public void setFetchDirection(final int direction) throws SQLException {
+        checkOpen();
+        try {
+            statement.setFetchDirection(direction);
+        } catch (final SQLException e) {
+            handleException(e);
+        }
+    }
+
+    @Override
+    public void setFetchSize(final int rows) throws SQLException {
+        checkOpen();
+        try {
+            statement.setFetchSize(rows);
+        } catch (final SQLException e) {
+            handleException(e);
+        }
+    }
+
+    private void setLastUsedInParent() {
+        if (connection != null) {
+            connection.setLastUsed();
+        }
+    }
+
+    @Override
+    public void setMaxFieldSize(final int max) throws SQLException {
+        checkOpen();
+        try {
+            statement.setMaxFieldSize(max);
+        } catch (final SQLException e) {
+            handleException(e);
+        }
+    }
+
+    @Override
+    public void setMaxRows(final int max) throws SQLException {
+        checkOpen();
+        try {
+            statement.setMaxRows(max);
+        } catch (final SQLException e) {
+            handleException(e);
+        }
+    }
+
+    @Override
+    public void setPoolable(final boolean poolable) throws SQLException {
+        checkOpen();
+        try {
+            statement.setPoolable(poolable);
+        } catch (final SQLException e) {
+            handleException(e);
+        }
+    }
+
+    @Override
+    public void setQueryTimeout(final int seconds) throws SQLException {
+        checkOpen();
+        try {
+            statement.setQueryTimeout(seconds);
+        } catch (final SQLException e) {
+            handleException(e);
+        }
+    }
+
+    /**
+     * Returns a String representation of this object.
+     *
+     * @return String
+     */
+    @Override
+    public synchronized String toString() {
+        return statement == null ? "NULL" : statement.toString();
+    }
+
+    @Override
+    public <T> T unwrap(final Class<T> iface) throws SQLException {
+        if (iface.isAssignableFrom(getClass())) {
+            return iface.cast(this);
+        } else if (iface.isAssignableFrom(statement.getClass())) {
+            return iface.cast(statement);
+        } else {
+            return statement.unwrap(iface);
+        }
+    }
+}