Spring3.1.1+MyBatis3.1.1的增、删、查、改以及分页和事务管理

Spring3.1.1+MyBatis3.1.1的增、删、查、改以及分页和事务管理

1. [代码]Mybatis全局配置文件

< plugin interceptor = "com.has.core.page.PaginationInterceptor" />

2. [文件] PaginationInterceptor.java

@Intercepts ({ @Signature (type = StatementHandler. class , method = "http://prepare" , args = { Connection. class }) })

public class PaginationInterceptor implements Interceptor {

@Override

public Object intercept(Invocation invocation) throws Throwable {

StatementHandler statementHandler = (StatementHandler) invocation.getTarget();

BoundSql boundSql = statementHandler.getBoundSql();

MetaObject metaStatementHandler = MetaObject.forObject(statementHandler);

RowBounds rowBounds = (RowBounds) metaStatementHandler.getValue( "delegate.rowBounds" );

if (rowBounds == null || rowBounds == RowBounds.DEFAULT) {

return invocation.proceed();

}

Configuration configuration = (Configuration) metaStatementHandler.getValue( "delegate.configuration" );

Dialect.Type databaseType = null ;

try {

databaseType = Dialect.Type.valueOf(configuration.getVariables().getProperty( "dialect" ).toUpperCase());

} catch (Exception e) {

}

if (databaseType == null ) {

throw new RuntimeException( "the value of the dialect property in configuration.xml is not defined : "

+ configuration.getVariables().getProperty( "dialect" ));

}

Dialect dialect = null ;

switch (databaseType) {

case mysql:

dialect = new MySql5Dialect();

break ;

case ORACLE:

dialect = new OracleDialect();

break ;

}

String originalSql = (String) metaStatementHandler.getValue( "delegate.boundSql.sql" );

metaStatementHandler.setValue( "delegate.boundSql.sql" ,

dialect.getLimitString(originalSql, rowBounds.getOffset(), rowBounds.getLimit()));

metaStatementHandler.setValue( "delegate.rowBounds.offset" , RowBounds.NO_ROW_OFFSET);

metaStatementHandler.setValue( "delegate.rowBounds.limit" , RowBounds.NO_ROW_LIMIT);

return invocation.proceed();

}

@Override

public Object plugin(Object target) {

return Plugin.wrap(target, this );

}

@Override

public void setProperties(Properties properties) {

}

}

3. [文件] Dialect.java

/**

* 数据库方言定义

*

*/

public abstract class Dialect {

public static enum Type {

MYSQL, ORACLE

}

public abstract String getLimitString(String sql, int skipResults, int maxResults);

}

4. [文件] MySql5Dialect.java

/**

* mysql方言分页类

*/

public class MySql5Dialect extends Dialect {

protected static final String SQL_END_DELIMITER = ";" ;

public String getLimitString(String sql, boolean hasOffset) {

return MySxsYJoPgpadql5PageHepler.getLimitString(sql, - 1 , - 1 );

}

public String getLimitString(String sql, int offset, int limit) {

return MySql5PageHepler.getLimitString(sql, offset, limit);

}

public boolean supportsLimit() {

return true ;

}

}

5. [文件] OracleDialect.java

package com.chyjr.has.core.page.dialect;

/**

* oracel方言分页

*

*/

public class OracleDialect extends Dialect {

public String getLimitString(String sql, int offset, int limit) {

// TODO 未实现

return "";

}

}

6. [文件] MySql5PageHepler.java

import java.util.regex.Matcher;

import java.util.regex.Pattern;

/**

* mysql分页工具类

*/

public class MySql5PageHepler {

/**

* 得到查询总数的sql

*/

public static String getCountString(String querySelect) {

querySelect = getLineSql(querySelect);

int orderIndex = getLastOrderInsertPoint(querySelect);

int formIndex = getAfterFormInsertPoint(querySelect);

String select = querySelect.substring( 0 , formIndex);

// 如果SELECT 中包含 DISTINCT 只能在外层包含COUNT

if (select.toLowerCase().indexOf( "select distinct" ) != - 1

|| querySelect.toLowerCase().indexOf( "group by" ) != - 1 ) {

return new StringBuffer(querySelect.length()).append( "select count(1) count from (" )

.append(querySelect.substring( 0 , orderIndex)).append( " ) t" ).toString();

} else {

return new StringBuffer(querySelect.length()).append( "select count(1) count " )

.append(querySelect.substring(formIndex, orderIndex)).toString();

}

}

/**

* 得到最后一个Order By的插入点位置

*

* @return 返回最后一个Order By插入点的位置

*/

private static int getLastOrderInsertPoint(String querySelect) {

int orderIndex = querySelect.toLowerCase().lastIndexOf( "order by" );

if (orderIndex == - 1 || !isBracketCanPartnership(querySelect.substring(orderIndex, querySelect.length()))) {

throw new RuntimeException( "My SQL 分页必须要有Order by 语句!" );

}

return orderIndex;

}

/**

* 得到分页的SQL

*

* @param offset

* 偏移量

* @param limit

* 位置

* @return 分页SQL

*/

public static String getLimitString(String querySelect, int offset, int limit) {

querySelect = getLineSql(querySelect);

// String sql = querySelect.replaceAll("[^\\s,]+\\.", "") + " limit " +

// offset + " ," + limit;

String sql = querySelect + " limit " + offset + " ," + limit;

return sql;

}

/**

* 将SQL语句变成一条语句，并且每个单词的间隔都是1个空格

*

* @param sql

* SQL语句

* @return 如果sql是NULL返回空，否则返回转化后的SQL

*/

private static String getLineSql(String sql) {

return sql.replaceAll( "[\r\n]" , " " ).replaceAll( "\\s{2,}" , " " );

}

/**

* 得到SQL第一个正确的FROM的的插入点

*/

private static int getAfterFormInsertPoint(String querySelect) {

String regex = "\\s+FROM\\s+" ;

Pattern pattern = Pattern.compile(regex, Pattern.CASE_INSENSITIVE);

Matcher matcher = pattern.matcher(querySelect);

while (matcher.find()) {

int fromStartIndex = matcher.start( 0 );

String text = querySelect.substring( 0 , fromStartIndex);

if (isBracketCanPartnership(text)) {

return fromStartIndex;

}

}

return 0 ;

}

/**

* 判断括号"()"是否匹配,并不会判断排列顺序是否正确

*

* @param text

* 要判断的文本

* @return 如果匹配返回TRUE,否则返回FALSE

*/

private xsYJoPgpadstatic boolean isBracketCanPartnership(String text) {

if (text == null || (getIndexOfCount(text, '(' ) != getIndexOfCount(text, ')' ))) {

return false ;

}

return true ;

}

/**

* 得到一个字符在另一个字符串中出现的次数

*

* @param text

* 文本

* @param ch

* 字符

*/

private static int getIndexOfCount(String text, char ch) {

int count = 0 ;

for ( int i = 0 ; i < text.length(); i++) {

count = (text.charAt(i) == ch) ? count + 1 : count;

}

return count;

}

}

2. [图片] Mybatis.jpg

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