SpingMVC+MyBatis简单权限管理系统

package com.flf.plugin; import java.lang.reflect.Field; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.List; import java.util.Properties; import javax.xml.bind.PropertyException; import org.apache.ibatis.builder.xml.dynamic.ForEachSqlNode; import org.apache.ibatis.executor.ErrorContext; import org.apache.ibatis.executor.ExecutorException; import org.apache.ibatis.executor.statement.BaseStatementHandler; import org.apache.ibatis.executor.statement.RoutingStatementHandler; import org.apache.ibatis.executor.statement.StatementHandler; import org.apache.ibatis.mapping.BoundSql; import org.apache.ibatis.mapping.MappedStatement; import org.apache.ibatis.mapping.ParameterMapping; import org.apache.ibatis.mapping.ParameterMode; import org.apache.ibatis.plugin.Interceptor; import org.apache.ibatis.plugin.Intercepts; import org.apache.ibatis.plugin.Invocation; import org.apache.ibatis.plugin.Plugin; import org.apache.ibatis.plugin.Signature; import org.apache.ibatis.reflection.MetaObject; import org.apache.ibatis.reflection.property.PropertyTokenizer; import org.apache.ibatis.session.Configuration; import org.apache.ibatis.type.TypeHandler; import org.apache.ibatis.type.TypeHandlerRegistry; import com.flf.entity.Page; import com.flf.util.ReflectHelper; import com.flf.util.Tools; @Intercepts({@Signature(type=StatementHandler.class,method="prepare",args={Connection.class})}) public class PagePlugin implements Interceptor { private static String dialect = ""; //数据库方言 private static String pageSqlId = ""; //mapper.xml中需要拦截的ID(正则匹配) public Object intercept(Invocation ivk) throws Throwable { // TODO Auto-generated method stub if(ivk.getTarget() instanceof RoutingStatementHandler){ RoutingStatementHandler statementHandler = (RoutingStatementHandler)ivk.getTarget(); BaseStatementHandler delegate = (BaseStatementHandler) ReflectHelper.getValueByFieldName(statementHandler, "delegate"); MappedStatement mappedStatement = (MappedStatement) ReflectHelper.getValueByFieldName(delegate, "mappedStatement"); if(mappedStatement.getId().matches(pageSqlId)){ //拦截需要分页的SQL BoundSql boundSql = delegate.getBoundSql(); Object parameterObject = boundSql.getParameterObject();//分页SQL<select>中parameterType属性对应的实体参数，即Mapper接口中执行分页方法的参数,该参数不得为空 if(parameterObject==null){ throw new NullPointerException("parameterObject尚未实例化！"); }else{ Connection connection = (Connection) ivk.getArgs()[0]; String sql = boundSql.getSql(); String countSql = "select count(0) from (" + sql+ ") as tmp_count"; //记录统计 PreparedStatement countStmt = connection.prepareStatement(countSql); BoundSql countBS = new BoundSql(mappedStatement.getConfiguration(),countSql,boundSql.getParameterMappings(),parameterObject); setParameters(countStmt,mappedStatement,countBS,parameterObject); ResultSet rs = countStmt.executeQuery(); int count = 0; if (rs.next()) { count = rs.getInt(1); } rs.close(); countStmt.close(); //System.out.println(count); Page page = null; if(parameterObject instanceof Page){ //参数就是Page实体 page = (Page) parameterObject; page.setEntityOrField(true); //见com.flf.entity.Page.entityOrField 注释 page.setTotalResult(count); }else{ //参数为某个实体，该实体拥有Page属性 Field pageField = ReflectHelper.getFieldByFieldName(parameterObject,"page"); if(pageField!=null){ page = (Page) ReflectHelper.getValueByFieldName(parameterObject,"page"); if(page==null) page = new Page(); page.setEntityOrField(false); //见com.flf.entity.Page.entityOrField 注释 page.setTotalResult(count); ReflectHelper.setValueByFieldName(parameterObject,"page", page); //通过反射，对实体对象设置分页对象 }else{ throw new NoSuchFieldException(parameterObject.getClass().getName()+"不存在 page 属性！"); } } String pageSql = generatePageSql(sql,page); ReflectHelper.setValueByFieldName(boundSql, "sql", pageSql); //将分页sql语句反射回BoundSql. } } } return ivk.proceed(); } /** * 对SQL参数(?)设值,参考org.apache.ibatis.executor.parameter.DefaultParameterHandler * @param ps * @param mappedStatement * @param boundSql * @param parameterObject * @throws SQLException */ private void setParameters(PreparedStatement ps,MappedStatement mappedStatement,BoundSql boundSql,Object parameterObject) throws SQLException { ErrorContext.instance().activity("setting parameters").object(mappedStatement.getParameterMap().getId()); List<ParameterMapping> parameterMappings = boundSql.getParameterMappings(); if (parameterMappings != null) { Configuration configuration = mappedStatement.getConfiguration(); TypeHandlerRegistry typeHandlerRegistry = configuration.getTypeHandlerRegistry(); MetaObject metaObject = parameterObject == null ? null: configuration.newMetaObject(parameterObject); for (int i = 0; i < parameterMappings.size(); i++) { ParameterMapping parameterMapping = parameterMappings.get(i); if (parameterMapping.getMode() != ParameterMode.OUT) { Object value; String propertyName = parameterMapping.getProperty(); PropertyTokenizer prop = new PropertyTokenizer(propertyName); if (parameterObject == null) { value = null; } else if (typeHandlerRegistry.hasTypeHandler(parameterObject.getClass())) { value = parameterObject; } else if (boundSql.hasAdditionalParameter(propertyName)) { value = boundSql.getAdditionalParameter(propertyName); } else if (propertyName.startsWith(ForEachSqlNode.ITEM_PREFIX)&& boundSql.hasAdditionalParameter(prop.getName())) { value = boundSql.getAdditionalParameter(prop.getName()); if (value != null) { value = configuration.newMetaObject(value).getValue(propertyName.substring(prop.getName().length())); } } else { value = metaObject == null ? null : metaObject.getValue(propertyName); } TypeHandler typeHandler = parameterMapping.getTypeHandler(); if (typeHandler == null) { throw new ExecutorException("There was no TypeHandler found for parameter "+ propertyName + " of statement "+ mappedStatement.getId()); } typeHandler.setParameter(ps, i + 1, value, parameterMapping.getJdbcType()); } } } } /** * 根据数据库方言，生成特定的分页sql * @param sql * @param page * @return */ private String generatePageSql(String sql,Page page){ if(page!=null && Tools.notEmpty(dialect)){ StringBuffer pageSql = new StringBuffer(); if("mysql".equals(dialect)){ pageSql.append(sql); pageSql.append(" limit "+page.getCurrentResult()+","+page.getShowCount()); }else if("oracle".equals(dialect)){ pageSql.append("select * from (select tmp_tb.*,ROWNUM row_id from ("); pageSql.append(sql); pageSql.append(") as tmp_tb where ROWNUM<="); pageSql.append(page.getCurrentResult()+page.getShowCount()); pageSql.append(") where row_id>"); pageSql.append(page.getCurrentResult()); } return pageSql.toString(); }else{ return sql; } } public Object plugin(Object arg0) { // TODO Auto-generated method stub return Plugin.wrap(arg0, this); } public void setProperties(Properties p) { dialect = p.getProperty("dialect"); if (Tools.isEmpty(dialect)) { try { throw new PropertyException("dialect property is not found!"); } catch (PropertyException e) { // TODO Auto-generated catch block e.printStackTrace(); } } p