com.wsun.seap.dao.interceptor.PaginationInterceptor.java Source code

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Here is the source code for com.wsun.seap.dao.interceptor.PaginationInterceptor.java

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/**
 * Copyright &copy; 2012-2013 <a href="https://github.com/thinkgem/jeesite">JeeSite</a> All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 */
package com.wsun.seap.dao.interceptor;

import com.wsun.seap.common.context.QueryParam;
import org.apache.commons.lang3.StringUtils;
import org.apache.ibatis.executor.Executor;
import org.apache.ibatis.mapping.BoundSql;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.mapping.SqlSource;
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.session.ResultHandler;
import org.apache.ibatis.session.RowBounds;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.HashMap;
import java.util.Map;
import java.util.Properties;

/**
 * ????.
 *
 * @author wshuang
 * @version 2013-8-28
 */
@Intercepts({ @Signature(type = Executor.class, method = "query", args = { MappedStatement.class, Object.class,
        RowBounds.class, ResultHandler.class }) })
public class PaginationInterceptor extends BaseInterceptor {

    private static Logger logger = LoggerFactory.getLogger(PaginationInterceptor.class);

    private static final long serialVersionUID = 1L;

    @Override
    public Object intercept(Invocation invocation) throws Throwable {
        // ??
        final MappedStatement mappedStatement = (MappedStatement) invocation.getArgs()[MAPPED_STATEMENT_INDEX];
        // ?SQL
        // ??
        Object parameterObj = invocation.getArgs()[PARAMETER_INDEX];
        // ??QueryParam
        Object parameter;
        if (parameterObj instanceof QueryParam) {
            // ?QueryParam,??Map
            parameter = ((QueryParam) parameterObj).getAllParam();
            invocation.getArgs()[PARAMETER_INDEX] = parameter;
        } else {
            parameter = parameterObj;
        }

        BoundSql boundSql = mappedStatement.getBoundSql(parameter);
        if (StringUtils.isBlank(boundSql.getSql())) {
            return null;
        }
        // ??RowBounds
        RowBounds rowBounds = (RowBounds) invocation.getArgs()[ROWBOUNDS_INDEX];
        // 
        if (rowBounds != null && rowBounds != RowBounds.DEFAULT) {
            String originalSql = boundSql.getSql().trim();
            // ??sql
            String pageSql = dialect.getLimitString(originalSql, rowBounds.getOffset(), rowBounds.getLimit());
            invocation.getArgs()[ROWBOUNDS_INDEX] = new RowBounds(RowBounds.NO_ROW_OFFSET, RowBounds.NO_ROW_LIMIT);
            BoundSql newBoundSql = new BoundSql(mappedStatement.getConfiguration(), pageSql,
                    boundSql.getParameterMappings(), boundSql.getParameterObject());
            MappedStatement newMs = copyFromMappedStatement(mappedStatement, new BoundSqlSqlSource(newBoundSql));
            invocation.getArgs()[MAPPED_STATEMENT_INDEX] = newMs;
        }
        return invocation.proceed();
    }

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

    @Override
    public void setProperties(Properties properties) {
        super.initProperties(properties);
    }

    private MappedStatement copyFromMappedStatement(MappedStatement ms, SqlSource newSqlSource) {
        MappedStatement.Builder builder = new MappedStatement.Builder(ms.getConfiguration(), ms.getId(),
                newSqlSource, ms.getSqlCommandType());
        builder.resource(ms.getResource());
        builder.fetchSize(ms.getFetchSize());
        builder.statementType(ms.getStatementType());
        builder.keyGenerator(ms.getKeyGenerator());
        if (ms.getKeyProperties() != null) {
            for (String keyProperty : ms.getKeyProperties()) {
                builder.keyProperty(keyProperty);
            }
        }
        builder.timeout(ms.getTimeout());
        builder.parameterMap(ms.getParameterMap());
        builder.resultMaps(ms.getResultMaps());
        builder.cache(ms.getCache());
        return builder.build();
    }

    public static class BoundSqlSqlSource implements SqlSource {
        BoundSql boundSql;

        public BoundSqlSqlSource(BoundSql boundSql) {
            this.boundSql = boundSql;
        }

        public BoundSql getBoundSql(Object parameterObject) {
            return boundSql;
        }
    }
}