public class EasySqlInjector extends DefaultSqlInjector {
 
    @Override
    public List<AbstractMethod> getMethodList(Class<?> mapperClass) {
        // 注意：此SQL注入器繼承了DefaultSqlInjector(默認(rèn)注入器)，調(diào)用了DefaultSqlInjector的getMethodList方法，保留了mybatis-plus的自帶方法
        List<AbstractMethod> methodList = super.getMethodList(mapperClass);
        methodList.add(new InsertBatchSomeColumn(i -> i.getFieldFill() != FieldFill.UPDATE));
        return methodList;
    }
 
}

@EnableTransactionManagement(proxyTargetClass = true)
@Configuration
public class MybatisPlusConfig
{
    @Bean
    public PaginationInterceptor paginationInterceptor() {
        PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
        // 設(shè)置請(qǐng)求的頁(yè)面大于最大頁(yè)后操作， true調(diào)回到首頁(yè)，false 繼續(xù)請(qǐng)求 默認(rèn)false
        // paginationInterceptor.setOverflow(false);
        // 設(shè)置最大單頁(yè)限制數(shù)量，默認(rèn) 500 條，-1 不受限制
        // paginationInterceptor.setLimit(500);
        // 開(kāi)啟 count 的 join 優(yōu)化,只針對(duì)部分 left join
        paginationInterceptor.setLimit(-1);
//        paginationInterceptor.setCountSqlParser(new JsqlParserCountOptimize(true));
        return paginationInterceptor;
    }
 
    /**
     * 分頁(yè)插件，自動(dòng)識(shí)別數(shù)據(jù)庫(kù)類型 https://baomidou.com/guide/interceptor-pagination.html
     */
    public PaginationInnerInterceptor paginationInnerInterceptor()
    {
        PaginationInnerInterceptor paginationInnerInterceptor = new PaginationInnerInterceptor();
        // 設(shè)置數(shù)據(jù)庫(kù)類型為mysql
        paginationInnerInterceptor.setDbType(DbType.ORACLE);
        // 設(shè)置最大單頁(yè)限制數(shù)量，默認(rèn) 500 條，-1 不受限制
        paginationInnerInterceptor.setMaxLimit(-1L);
        return paginationInnerInterceptor;
    }
 
    /**
     * 樂(lè)觀鎖插件 https://baomidou.com/guide/interceptor-optimistic-locker.html
     */
    public OptimisticLockerInnerInterceptor optimisticLockerInnerInterceptor()
    {
        return new OptimisticLockerInnerInterceptor();
    }
 
    /**
     * 如果是對(duì)全表的刪除或更新操作，就會(huì)終止該操作 https://baomidou.com/guide/interceptor-block-attack.html
     */
    public BlockAttackInnerInterceptor blockAttackInnerInterceptor()
    {
        return new BlockAttackInnerInterceptor();
    }
 
    @Bean
    public EasySqlInjector sqlInjector() {
        return new EasySqlInjector();
    }
 
}

public interface  EasyBaseMapper<T> extends BaseMapper<T> {
    /**
     * @param entityList 實(shí)體列表
     */
    void insertBatchSomeColumn(Collection<T> entityList);
}

@Component
@Slf4j
@Order(1)
@Intercepts({@Signature(type = StatementHandler.class, method = "prepare", args = {Connection.class, Integer.class})})
public class OracleSqlInterceptor implements Interceptor {
 
 
    @Override
    public Object intercept(Invocation invocation) throws Throwable {
        //當(dāng)前業(yè)務(wù)，兼容pg 和 oracle，需要兼容oracle的批量插入語(yǔ)句
        StatementHandler statementHandler = (StatementHandler) invocation.getTarget();
 
        BoundSql boundSql = statementHandler.getBoundSql();
        String sql = boundSql.getSql();
        StatementHandler delegate = (StatementHandler) ReflectUtil.getFieldValue(statementHandler, "delegate");
        MappedStatement mappedStatement = (MappedStatement) ReflectUtil.getFieldValue(delegate, "mappedStatement");
        ReflectUtil.setFieldValue(mappedStatement,"keyGenerator", NoKeyGenerator.INSTANCE);
        String mName  = mappedStatement.getId().substring(mappedStatement.getId().lastIndexOf(".") + 1);
        if("insertBatchSomeColumn".equals(mName)){
            //開(kāi)始兼容批量插入語(yǔ)句,并設(shè)置boundSql
            Field declaredField = boundSql.getClass().getDeclaredField("sql");
            declaredField.setAccessible(true);
            declaredField.set(boundSql, convertOracleInsertSql(sql));
            log.info("---轉(zhuǎn)換后的sql為：{}", boundSql.getSql());
        }
        return invocation.proceed();
    }
 
    /**
     * Oracle Insert語(yǔ)句轉(zhuǎn)化
     *
     * @param sql 傳入的pg的sql
     * @return 轉(zhuǎn)化后的sql
     */
    public String convertOracleInsertSql(String sql) {
        //用oracle中的批量語(yǔ)句代替
        //查找values的位置，將后面全部括號(hào)里的東西取出，然后再用對(duì)應(yīng)的數(shù)據(jù)進(jìn)行封裝
        //獲取前面的sql，這段sql與Oracle的相同
        String prefix = sql.substring(0, getKeywordValueIndex(sql));
        //排除table中的括號(hào)，取后面的括號(hào)
        String subSql = sql.substring(getKeywordValueIndex(sql));
        String valueSql = subSql.substring(subSql.indexOf("("));
        List<String> valueList = getValues(valueSql);
 
        //拼接sql
        StringBuilder sqlBuilder = new StringBuilder().append(prefix);
        //sqlBuilder.append("SELECT A.* FROM (");
        String selectValue = "SELECT ";
        String endValue = " FROM DUAL ";
        String unionValue = "UNION ALL ";
        boolean start = true;
        for (String value : valueList) {
            if (!start) {
                sqlBuilder.append(unionValue);
            }
            else {
                start = false;
            }
            sqlBuilder.append(selectValue).append(value).append(endValue);
        }
        //sqlBuilder.append(") A");
        return sqlBuilder.toString();
    }
 
    /**
     * 使用棧實(shí)現(xiàn)獲取value中括號(hào)的值
     *
     */
    public List<String> getValues(String sql) {
        List<String> values = new ArrayList<>();
        Stack<Character> brackets = new Stack<>();
        StringBuilder splitValue = new StringBuilder();
        for (Character c : sql.toCharArray()) {
            if ('(' == c) {
                //左括號(hào)進(jìn)棧
                brackets.push(c);
            }
            else if (')' == c) {
                //右括號(hào)則將左括號(hào)出棧,清空builder
                brackets.pop();
                values.add(splitValue.toString());
                splitValue.delete(0, splitValue.length());
            }
            else if (!brackets.empty()) {
                //只有進(jìn)入括號(hào)中才將值放入，排除括號(hào)外的逗號(hào)
                splitValue.append(c);
            }
        }
        return values;
 
    }
 
    /**
     * 查找關(guān)鍵字value的位置
     */
    public  int getKeywordValueIndex(String sql) {
        //先找values，再找value
        if (sql.contains("values")) {
            return sql.indexOf("values");
        }
        else if (sql.contains("VALUES")) {
            return sql.indexOf("VALUES");
        }
        else if (sql.contains("value")) {
            return sql.indexOf("value");
        }
        else {
            return sql.indexOf("VALUE");
        }
    }
 
}