页面上往往会传来各种参数，比如排序参数。怎样让这些参数参与到分页实现中去呢？！
mybatis查询方法接受RowBounds对象。只好继承该对象扩展一下了。
public class MyRowBounds extends RowBounds{
private String sidx; //排序参数
private String sord; //asc or desc
public MyRowBounds(int offset, int limit ){
super(offset,limit);
}
public MyRowBounds(int offset, int limit ,String sidx,String sord){
super(offset,limit);
if(StringUtils.isNotEmpty(sidx)){
this.sidx=sidx;
this.sord=sord;
}
}
public String getSidx() {
return sidx;
}
public void setSidx(String sidx) {
this.sidx = sidx;
}
public String getSord() {
return sord;
}
public void setSord(String sord) {
this.sord = sord;
}
}
参数封装好了，该找入口了
@Intercepts({@Signature(type=StatementHandler.class,method="prepare",args={Connection.class})})
public class PaginationInterceptor implements Interceptor{
private final static Logger log = Logger.getLogger(PaginationInterceptor.class);
private Dialect dialect;
public void setDialect(Dialect dialect) {
this.dialect = dialect;
}
@Override
public Object intercept(Invocation invocation) throws Throwable {
StatementHandler statementHandler = (StatementHandler)invocation.getTarget();
BoundSql boundSql = statementHandler.getBoundSql();
MetaObject metaStatementHandler = MetaObject.forObject(
statementHandler, new DefaultObjectFactory(),new DefaultObjectWrapperFactory());
RowBounds rowBounds = (RowBounds)metaStatementHandler.getValue("delegate.rowBounds");
if(rowBounds == null || rowBounds == RowBounds.DEFAULT){
return invocation.proceed();
}
if(this.dialect == null){
throw new RuntimeException("the value of the dialect property in configuration.xml is not defined : ");
}
String originalSql = (String) metaStatementHandler.getValue("delegate.boundSql.sql");
MyRowBounds myRowBounds =(MyRowBounds)rowBounds;
//支持排序
String pageSql=null;
if(StringUtils.isEmpty(myRowBounds.getSidx())){
pageSql=this.dialect.getLimitString(originalSql, rowBounds.getOffset(),rowBounds.getLimit());
} else {
pageSql = this.dialect.getLimitString(originalSql,
rowBounds.getOffset(), rowBounds.getLimit(),
myRowBounds.getSidx(), myRowBounds.getSord());
}
metaStatementHandler.setValue("delegate.boundSql.sql",pageSql);
metaStatementHandler.setValue("delegate.rowBounds.offset",
RowBounds.NO_ROW_OFFSET);
metaStatementHandler.setValue("delegate.rowBounds.limit", RowBounds.NO_ROW_LIMIT );
if(log.isDebugEnabled()){
log.debug("生成分页SQL : " + boundSql.getSql());
}
return invocation.proceed();
}
@Override
public Object plugin(Object target) {
return Plugin.wrap(target, this);
}
@Override
public void setProperties(Properties properties) {
}
}
入口告诉大家了，具体分页语句的拼接实现，我想就不用说了
记得注入给这个类注入
<!-- 定义mybatis -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="typeAliasesPackage" value="cn.com.ahsoft" />
<property name="configLocation" value="classpath:SqlMapConfig.xml"/>
<!-- 分页 -->
<property name="plugins">
<bean class="cn.com.ahsoft.framework.mybatis.page.PaginationInterceptor">
<property name="dialect">
<bean class="cn.com.xxxx.framework.jdbc.dialect.MySQLDialect"></bean>
</property>
</bean>
</property>
</bean>
dialect是分页实现，不同的数据库不同，这个由大家自己实现吧就不累赘了，网上也有很多