标签：com div ref query config parameter exce protected space
场景：在程序开发过程中经常需要跟踪程序中sql语句的执行过程，在控制台打印出sql语句和对应的参数传递就能够更快的定位错误！
原文出处：http://www.cnblogs.com/beiyeren/p/4196134.html
这里所采用的日志框架为logback
打印sql的时候只需要配置如下属性：
<logger name="java.sql.Connection" level="DEBUG" /> <logger name="java.sql.Statement" level="DEBUG" /> <logger name="java.sql.PreparedStatement" level="DEBUG" />
源码解析：
PreparedStatementLogger里面看这个log.isDebugEnabled()
public Object invoke(Object proxy, Method method, Object[] params) throws Throwable { try { if (EXECUTE_METHODS.contains(method.getName())) { if (log.isDebugEnabled()) { log.debug("==> Executing: " + removeBreakingWhitespace(sql)); log.debug("==> Parameters: " + getParameterValueString()); } clearColumnInfo(); if ("executeQuery".equals(method.getName())) { ResultSet rs = (ResultSet) method.invoke(statement, params); if (rs != null) { return ResultSetLogger.newInstance(rs); } else { return null; } } else { return method.invoke(statement, params); } }
这个log定义的是PreparedStatement
private static final Log log = LogFactory.getLog(PreparedStatement.class);
只需要简单的两步即可！
更改了打印Sql的模式，它将sql打印细化到了每一个mapperStatement的每一个方法上。
如果你打算有一个全局配置打印所有的sql，则需要如下配置
在mybatis的configuration中增加setting配置
<settings>
<setting name="logPrefix" value="dao."/>
</settings>
然后增加配置
<logger name="dao" level="DEBUG"/>
源码解析：
ConnectionLogger
public Object invoke(Object proxy, Method method, Object[] params) throws Throwable { try { if (Object.class.equals(method.getDeclaringClass())) { return method.invoke(this, params); } if ("prepareStatement".equals(method.getName())) { if (isDebugEnabled()) { debug(" Preparing: " + removeBreakingWhitespace((String) params[0]), true); } PreparedStatement stmt = (PreparedStatement) method.invoke(connection, params); stmt = PreparedStatementLogger.newInstance(stmt, statementLog, queryStack); return stmt; }
其中的isDebugEnabled()指的是
protected boolean isDebugEnabled() { return statementLog.isDebugEnabled(); }
注意这里的statementLog，看SimpleExecutor的prepareStatement(handler, ms.getStatementLog());
public <E> List<E> doQuery(MappedStatement ms, Object parameter, RowBounds rowBounds, ResultHandler resultHandler, BoundSql boundSql) throws SQLException { Statement stmt = null; try { Configuration configuration = ms.getConfiguration(); StatementHandler handler = configuration.newStatementHandler(wrapper, ms, parameter, rowBounds, resultHandler, boundSql); stmt = prepareStatement(handler, ms.getStatementLog()); return handler.<E>query(stmt, resultHandler); } finally { closeStatement(stmt); } }
这个statementLog是ms.getStatementLog()而来的。而MappedStatement的StatementLog
String logId = id; if (configuration.getLogPrefix() != null) logId = configuration.getLogPrefix() + id; mappedStatement.statementLog = LogFactory.getLog(logId);
这里可以看到，logPrefix决定了所有log前缀，所以只需要配置logPrefix就行了
标签：com div ref query config parameter exce protected space
原文地址：http://www.cnblogs.com/lixuwu/p/6323739.html
