PageInterceptor.java

package com.github.ouyangbob.mybatis;

import java.sql.Connection;
import java.util.Properties;

import org.apache.ibatis.executor.statement.StatementHandler;
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.SystemMetaObject;
import org.apache.ibatis.session.RowBounds;

@Intercepts({@Signature(type =StatementHandler.class, method = "prepare", args ={Connection.class})})
public class PageInterceptor implements Interceptor {

	public Object intercept(Invocation invocation) throws Throwable {
		StatementHandler statementHandler = (StatementHandler)invocation.getTarget(); 
        MetaObject metaStatementHandler = SystemMetaObject.forObject(statementHandler);  

        RowBounds rowBounds = (RowBounds)metaStatementHandler.getValue("delegate.rowBounds");    
        if(rowBounds == null || rowBounds == RowBounds.DEFAULT){
            return invocation.proceed();
        }

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

	public Object plugin(Object target) {
		return Plugin.wrap(target, this);
	}

	public void setProperties(Properties arg0) {
	}

	
	private String getLimitString(String sql, int skipResults, int maxResults) {
		if (skipResults > 0) {
			return sql + " limit " + skipResults + "," + maxResults;
		}
		return sql + " limit " + maxResults;
	}
}