com.github.dreamroute.pager.starter.interceptor.PagerInterceptor Maven / Gradle / Ivy

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package com.github.dreamroute.pager.starter.interceptor;

import cn.hutool.core.annotation.AnnotationUtil;
import com.github.dreamroute.pager.starter.anno.Pager;
import com.github.dreamroute.pager.starter.anno.PagerContainer;
import com.github.dreamroute.pager.starter.api.PageRequest;
import com.github.dreamroute.pager.starter.exception.PaggerException;
import net.sf.jsqlparser.parser.CCJSqlParserUtil;
import net.sf.jsqlparser.statement.select.OrderByElement;
import net.sf.jsqlparser.statement.select.PlainSelect;
import net.sf.jsqlparser.statement.select.Select;
import net.sf.jsqlparser.util.TablesNamesFinder;
import org.apache.commons.lang3.StringUtils;
import org.apache.ibatis.cache.CacheKey;
import org.apache.ibatis.executor.Executor;
import org.apache.ibatis.executor.parameter.ParameterHandler;
import org.apache.ibatis.mapping.BoundSql;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.mapping.ParameterMapping;
import org.apache.ibatis.plugin.Interceptor;
import org.apache.ibatis.plugin.Intercepts;
import org.apache.ibatis.plugin.Invocation;
import org.apache.ibatis.plugin.Signature;
import org.apache.ibatis.reflection.MetaObject;
import org.apache.ibatis.session.Configuration;
import org.apache.ibatis.session.ResultHandler;
import org.apache.ibatis.session.RowBounds;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.transaction.Transaction;
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.util.CollectionUtils;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Objects;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;

import static com.github.dreamroute.pager.starter.anno.PagerContainer.ID;
import static com.github.dreamroute.pager.starter.interceptor.ProxyUtil.getOriginObj;
import static java.util.Arrays.stream;
import static java.util.Optional.ofNullable;
import static java.util.stream.Collectors.joining;
import static java.util.stream.Collectors.toSet;

/**
 * 分页插件
 *
 * @author w.dehi
 */
@Intercepts({
        @Signature(type = Executor.class, method = "query", args = {MappedStatement.class, Object.class, RowBounds.class, ResultHandler.class}),
        @Signature(type = Executor.class, method = "query", args = {MappedStatement.class, Object.class, RowBounds.class, ResultHandler.class, CacheKey.class, BoundSql.class})
})
public class PagerInterceptor implements Interceptor, ApplicationListener {

    private ConcurrentHashMap pagerContainer;

    /**
     * 单表
     */
    private static final int SINGLE = 1;
    private static final String COUNT_NAME = "_$count$_";
    private static final String WHERE = " WHERE ";
    private static final String FROM = " FROM ";

    @Override
    public void onApplicationEvent(ContextRefreshedEvent event) {
        SqlSessionFactory sqlSessionFactory = event.getApplicationContext().getBean(SqlSessionFactory.class);
        // 将此方法移动到Spring容器初始化之后执行的原因是：如果放在下方的intercept方法中来执行，
        // 那么就会有并发问题（获取ms的sqlSource然后修改sqlSource），那么就需要对该方法加锁，影响性能
        parsePagerContainer(sqlSessionFactory.getConfiguration());
    }

    @Override
    public Object intercept(Invocation invocation) throws Throwable {
        Object[] args = invocation.getArgs();
        MappedStatement ms = (MappedStatement) args[0];
        Object param = args[1];
        Configuration config = ms.getConfiguration();

        PagerContainer pc = pagerContainer.get(ms.getId());
        // 拦截请求的条件：1. @Page标记接口，2.参数是：PageRequest
        if (pc == null || !(param instanceof PageRequest)) {
            return invocation.proceed();
        }

        Executor executor = (Executor) (getOriginObj(invocation.getTarget()));
        Transaction transaction = executor.getTransaction();
        Connection conn = transaction.getConnection();
        String count = pc.getCount();
        PreparedStatement ps = conn.prepareStatement(count);
        BoundSql countBoundSql = new BoundSql(config, count, pc.getOriginPmList(), param);
        ParameterHandler parameterHandler = config.newParameterHandler(ms, param, countBoundSql);
        parameterHandler.setParameters(ps);
        ResultSet rs = ps.executeQuery();
        PageContainer