📄 jdbcappender.java
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/* * Copyright (C) The Apache Software Foundation. All rights reserved.*/package com.klopotek.utils.log;import java.sql.*;import java.util.*;import org.apache.log4j.*;import org.apache.log4j.helpers.*;import org.apache.log4j.spi.*;/**The JDBCAppender, writes messages into a database<p><b>The JDBCAppender is configurable at runtime by setting options in two alternatives : </b></p><dir> <p><b>1. Use a configuration-file</b></p> <p>Define the options in a file (<A HREF="configfile_example.txt">example</A>) and call a <code>PropertyConfigurator.configure(filename)</code> in your code.</p> <p><b>2. Use the methods of JDBCAppender to do it</b></p> <p>Call <code>JDBCAppender::setOption(JDBCAppender.xxx_OPTION, String value)</code> to do it analogically without a configuration-file (<A HREF="code_example2.java">example</A>)</p></dir><p>All available options are defined as static String-constants in JDBCAppender named xxx_OPTION.</p><p><b>Here is a description of all available options :</b></p><dir> <p><b>1. Database-options to connect to the database</b></p> <p>- <b>URL_OPTION</b> : a database url of the form jdbc:subprotocol:subname</p> <p>- <b>USERNAME_OPTION</b> : the database user on whose behalf the connection is being made</p> <p>- <b>PASSWORD_OPTION</b> : the user's password</p> <p><b>2. Connector-option to specify your own JDBCConnectionHandler</b></p> <p>- <b>CONNECTOR_OPTION</b> : a classname which is implementing the JDBCConnectionHandler-interface</p> <p>This interface is used to get a customized connection.</p> <p>If in addition the database-options are given, these options will be used as arguments for the JDBCConnectionHandler-interface to get a connection.</p> <p>Else if no database-options are given, the JDBCConnectionHandler-interface is called without them.</p> <p>Else if this option is not defined, the database-options are required to open a connection by the JDBCAppender.</p> <p><b>3. SQL-option to specify a static sql-statement which will be performed with every occuring message-event</b></p> <p>- <b>SQL_OPTION</b> : a sql-statement which will be used to write to the database</p> <p>Use the variable <b>@MSG@</b> on a location in the statement, which has to be dynamically replaced by the message-text.</p> <p>If you give this option, the table-option and columns-option will be ignored !</p> <p><b>4. Table-option to specify a table contained by the database</b></p> <p>- <b>TABLE_OPTION</b> : the table in which the logging will be done</p> <p><b>5. Columns-option to describe the important columns of the table (Not nullable columns are mandatory to describe!)</b></p> <p>- <b>COLUMNS_OPTION</b> : a formatted list of column-descriptions</p> <p>Each column description consists of</p> <dir> <p>- the <b><i>name</i></b> of the column (required)</p> <p>- a <b><i>logtype</i></b> which is a static constant of class LogType (required)</p> <p>- and a <b><i>value</i></b> which depends by the LogType (optional/required, depending by logtype)</p> </dir> <p>Here is a description of the available logtypes of class <b>{@link LogType}</b> and how to handle the <b><i>value</i></b>:</p> <dir> <p>o <b>MSG</b> = a value will be ignored, the column will get the message. (One columns need to be of this type!)</p> <p>o <b>STATIC</b> = the value will be filled into the column with every logged message. (Ensure that the type of value can be casted into the sql-type of the column!)</p> <p>o <b>ID</b> = value must be a classname, which implements the JDBCIDHandler-interface.</p> <p>o <b>TIMESTAMP</b> = a value will be ignored, the column will be filled with a actually timestamp with every logged message.</p> <p>o <b>EMPTY</b> = a value will be ignored, the column will be ignored when writing to the database (Ensure to fill not nullable columns by a database trigger!)</p> </dir> <p>If there are more than one column to describe, the columns must be separated by a Tabulator-delimiter (unicode0008) !</p> <p>The arguments of a column-description must be separated by the delimiter '~' !</p> <p><i>(Example : name1~logtype1~value1 name2~logtype2~value2...)</i></p> <p><b>6. Layout-options to define the layout of the messages (optional)</b></p> <p>- <b>_</b> : the layout wont be set by a xxx_OPTION</p> <p>See the configuration-file and code examples below...</p> <p>The default is a layout of the class {@link org.apache.log4j.PatternLayout} with the pattern=%m which representate only the message.</p> <p><b>7. Buffer-option to define the size of the message-event-buffer (optional)</b></p> <p>- <b>BUFFER_OPTION</b> : define how many messages will be buffered until they will be updated to the database.</p> <p>The default is buffer=1, which will do a update with every happened message-event.</p> <p><b>8. Commit-option to define a auto-commitment</b></p> <p>- <b>COMMIT_OPTION</b> : define whether updated messages should be committed to the database (Y) or not (N).</p> <p>The default is commit=Y.</p></dir><p><b>The sequence of some options is important :</b></p><dir> <p><b>1. Connector-option OR/AND Database-options</b></p> <p>Any database connection is required !</p> <p><b>2. (Table-option AND Columns-option) OR SQL-option</b></p> <p>Anything of that is required ! Whether where to write something OR what to write somewhere...;-)</p> <p><b>3. All other options can be set at any time...</b></p> <p>The other options are optional and have a default initialization, which can be customized.</p></dir><p><b>Here is a <b>configuration-file example</b>, which can be used as argument for the <b>PropertyConfigurator</b> : </b><A HREF="configfile_example.txt"> configfile_example.txt</A></p><p><b>Here is a <b>code-example</b> to configure the JDBCAppender <b>with a configuration-file</b> : </b><A HREF="code_example1.java"> code_example1.java</A></p><p><b>Here is a <b>another code-example</b> to configure the JDBCAppender <b>without a configuration-file</b> : </b><A HREF="code_example2.java"> code_example2.java</A></p><p><b>Author : </b><A HREF="mailto:t.fenner@klopotek.de">Thomas Fenner</A></p>@since 1.0*/public class JDBCAppender extends AppenderSkeleton{ /** A database-option to to set a database url of the form jdbc:subprotocol:subname. */ public static final String URL_OPTION = "url"; /** A database-option to set the database user on whose behalf the connection is being made. */ public static final String USERNAME_OPTION = "username"; /** A database-option to set the user's password. */ public static final String PASSWORD_OPTION = "password"; /** A table-option to specify a table contained by the database */ public static final String TABLE_OPTION = "table"; /** A connector-option to specify your own JDBCConnectionHandler */ public static final String CONNECTOR_OPTION = "connector"; /** A columns-option to describe the important columns of the table */ public static final String COLUMNS_OPTION = "columns"; /** A sql-option to specify a static sql-statement which will be performed with every occuring message-event */ public static final String SQL_OPTION = "sql"; /** A buffer-option to define the size of the message-event-buffer */ public static final String BUFFER_OPTION = "buffer"; /** A commit-option to define a auto-commitment */ public static final String COMMIT_OPTION = "commit"; //Variables to store the options values setted by setOption() : private String url = null; private String username = null; private String password = null; private String table = null; private String connection_class = null; private String sql = null; private boolean docommit = true; private int buffer_size = 1; private JDBCConnectionHandler connectionHandler = null; //This buffer stores message-events. //When the buffer_size is reached, the buffer will be flushed and the messages will updated to the database. private ArrayList buffer = new ArrayList(); //Database-connection private Connection con = null; //This class encapsulate the logic which is necessary to log into a table private JDBCLogger jlogger = new JDBCLogger(); //Flags : //A flag to indicate a established database connection private boolean connected = false; //A flag to indicate configuration status private boolean configured = false; //A flag to indicate that everything is ready to get append()-commands. private boolean ready = false; /** If program terminates close the database-connection and flush the buffer */ public void finalize() { close(); super.finalize(); } /** Internal method. Returns a array of strings containing the available options which can be set with method setOption() */ public String[] getOptionStrings() { // The sequence of options in this string is important, because setOption() is called this way ... return new String[]{CONNECTOR_OPTION, URL_OPTION, USERNAME_OPTION, PASSWORD_OPTION, SQL_OPTION, TABLE_OPTION, COLUMNS_OPTION, BUFFER_OPTION, COMMIT_OPTION}; } /** Sets all necessary options */ public void setOption(String _option, String _value) { _option = _option.trim(); _value = _value.trim(); if(_option == null || _value == null) return; if(_option.length() == 0 || _value.length() == 0) return; _value = _value.trim(); if(_option.equals(CONNECTOR_OPTION)) { if(!connected) connection_class = _value; } else if(_option.equals(URL_OPTION)) { if(!connected) url = _value; } else if(_option.equals(USERNAME_OPTION)) { if(!connected) username = _value; } else if(_option.equals(PASSWORD_OPTION)) { if(!connected) password = _value; } else if(_option.equals(SQL_OPTION)) { sql = _value; } else if(_option.equals(TABLE_OPTION)) { if(sql != null) return; table = _value; } else if(_option.equals(COLUMNS_OPTION)) { if(sql != null) return; String name = null; int logtype = -1; String value = null; String column = null; String arg = null; int num_args = 0; int num_columns = 0; StringTokenizer st_col; StringTokenizer st_arg; //Columns are TAB-separated st_col = new StringTokenizer(_value, " "); num_columns = st_col.countTokens(); if(num_columns < 1) { errorHandler.error("JDBCAppender::setOption(), Invalid COLUMN_OPTION value : " + _value + " !"); return; } for(int i=1; i<=num_columns; i++) { column = st_col.nextToken(); //Arguments are ~-separated st_arg = new StringTokenizer(column, "~"); num_args = st_arg.countTokens(); if(num_args < 2) { errorHandler.error("JDBCAppender::setOption(), Invalid COLUMN_OPTION value : " + _value + " !"); return; } for(int j=1; j<=num_args; j++) { arg = st_arg.nextToken(); if(j == 1) name = arg; else if(j == 2) { try { logtype = Integer.parseInt(arg); } catch(Exception e) { logtype = LogType.parseLogType(arg); } if(!LogType.isLogType(logtype))
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