Java tutorial
/* * 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.ode.utils; import java.lang.reflect.InvocationHandler; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import java.lang.reflect.Proxy; import java.sql.Connection; import java.sql.Statement; import java.util.*; import javax.sql.DataSource; import org.apache.commons.logging.Log; public class LoggingInterceptor<T> implements InvocationHandler { private static final Set<String> PARAMSTYPES = new HashSet<String>(); static { PARAMSTYPES.add("setArray"); PARAMSTYPES.add("setBigDecimal"); PARAMSTYPES.add("setBoolean"); PARAMSTYPES.add("setByte"); PARAMSTYPES.add("setBytes"); PARAMSTYPES.add("setDate"); PARAMSTYPES.add("setDouble"); PARAMSTYPES.add("setFloat"); PARAMSTYPES.add("setInt"); PARAMSTYPES.add("setLong"); PARAMSTYPES.add("setObject"); PARAMSTYPES.add("setRef"); PARAMSTYPES.add("setShort"); PARAMSTYPES.add("setString"); PARAMSTYPES.add("setTime"); PARAMSTYPES.add("setTimestamp"); PARAMSTYPES.add("setURL"); } private Log _log; private T _delegate; private Map<String, Object> _paramsByName = new TreeMap<String, Object>(); private Map<Integer, Object> _paramsByIdx = new TreeMap<Integer, Object>(); public LoggingInterceptor(T delegate, Log log) { _log = log; _delegate = delegate; } public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { try { if (method.getDeclaringClass() == DataSource.class && "getConnection".equals(method.getName())) { Connection conn = (Connection) method.invoke(_delegate, args); print("getConnection (tx=" + conn.getTransactionIsolation() + ")"); return Proxy.newProxyInstance(_delegate.getClass().getClassLoader(), new Class[] { Connection.class }, new LoggingInterceptor<Connection>(conn, _log)); } else if (method.getDeclaringClass() == Connection.class && Statement.class.isAssignableFrom(method.getReturnType())) { Statement stmt = (Statement) method.invoke(_delegate, args); print(method, args); return Proxy.newProxyInstance(_delegate.getClass().getClassLoader(), new Class[] { method.getReturnType() }, new LoggingInterceptor<Statement>(stmt, _log)); } else { print(method, args); return method.invoke(_delegate, args); } } catch (InvocationTargetException e) { throw e.getTargetException(); } } private void print(Method method, Object[] args) { if (shouldPrint()) { // JDBC Connection if ("prepareStatement".equals(method.getName())) { print("prepareStatement: " + args[0]); } else if ("prepareCall".equals(method.getName())) { print("prepareCall: " + args[0]); } else if ("close".equals(method.getName())) { print("close()"); } else if ("commit".equals(method.getName())) { print("commit()"); } else if ("rollback".equals(method.getName())) { print("rollback()"); } else if ("setTransactionIsolation".equals(method.getName())) { print("Set isolation level to " + args[0]); } // JDBC Statement else if (method.getName().startsWith("execute") && args != null && args.length == 1 && args[0] instanceof String) { print(method.getName() + "(" + args[0] + "), " + getParams()); } else if (method.getName().startsWith("execute")) { print(method.getName() + ", " + getParams()); } else if ("clearParameters".equals(method.getName())) { _paramsByIdx.clear(); _paramsByName.clear(); } else if ("setNull".equals(method.getName())) { if (String.class.isAssignableFrom(args[0].getClass())) { _paramsByName.put((String) args[0], null); } else if (Integer.class.isAssignableFrom(args[0].getClass())) { _paramsByIdx.put((Integer) args[0], null); } } else if (PARAMSTYPES.contains(method.getName())) { if (String.class.isAssignableFrom(args[0].getClass())) { _paramsByName.put((String) args[0], args[1]); } else if (Integer.class.isAssignableFrom(args[0].getClass())) { _paramsByIdx.put((Integer) args[0], args[1]); } } } } private String getParams() { if (_paramsByIdx.size() > 0 || _paramsByName.size() > 0) { StringBuffer buf = new StringBuffer(); buf.append("bound "); for (Map.Entry<Integer, Object> entry : _paramsByIdx.entrySet()) { try { buf.append("(").append(entry.getKey()).append(",").append(entry.getValue()).append(") "); } catch (Throwable e) { // We don't want to mess with the connection just for logging return "[e]"; } } for (Map.Entry<String, Object> entry : _paramsByName.entrySet()) { try { buf.append("(").append(entry.getKey()).append(",").append(entry.getValue()).append(") "); } catch (Throwable e) { // We don't want to mess with the connection just for logging return "[e]"; } } return buf.toString(); } return "w/o params"; } private boolean shouldPrint() { if (_log != null) return _log.isDebugEnabled(); else return true; } private void print(String str) { if (_log != null) _log.debug(str); else System.out.println(str); } public static DataSource createLoggingDS(DataSource ds, Log log) { return (DataSource) Proxy.newProxyInstance(ds.getClass().getClassLoader(), new Class[] { DataSource.class }, new LoggingInterceptor<DataSource>(ds, log)); } }