jfcloud-gene/jfcloud-gene-biz/src/main/java/com/github/jfcloud/gene/handler/LongTextHandler.java

package com.github.jfcloud.gene.handler;

import cn.hutool.core.io.IoUtil;
import cn.hutool.core.util.StrUtil;
import cn.hutool.crypto.digest.DigestUtil;
import com.github.jfcloud.common.core.util.SpringContextHolder;
import com.github.jfcloud.gene.file.service.FileInfoService;
import com.github.jfcloud.gene.file.vo.FileVo;
import lombok.extern.slf4j.Slf4j;
import org.apache.ibatis.type.JdbcType;
import org.apache.ibatis.type.StringTypeHandler;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.sql.CallableStatement;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

/**
 * 自定义长文本类型处理器，将长文本存储在minIO上
 */
@Slf4j
public class LongTextHandler extends StringTypeHandler {

    /**
     * 长文本字段前缀
     */
    public static final String LONG_TEXT_FIELD_PREFIX = "@SampleLongText@";
    public static final String FILE_PREFIX = "SampleLongText_Md5_";
    /**
     * 长文本字段最大长度，过短的文本没必要使用minIO
     */
    public static final int MAX_TEXT_LENGTH = 200;

    @Override
    public void setNonNullParameter(PreparedStatement ps, int i, String parameter, JdbcType jdbcType) throws SQLException {
        ps.setString(i, saveLongText(parameter));
    }

    @Override
    public String getNullableResult(ResultSet rs, String columnName) throws SQLException {
        String textKey = super.getNullableResult(rs, columnName);
        return getLongText(textKey);
    }

    @Override
    public String getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
        String textKey = super.getNullableResult(rs, columnIndex);
        return getLongText(textKey);
    }

    @Override
    public String getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
        String textKey = super.getNullableResult(cs, columnIndex);
        return getLongText(textKey);
    }

    /**
     * 保存长文本
     *
     * @param text 长文本字符串
     * @return 长文本key
     */
    private String saveLongText(String text) {
        if (StrUtil.isBlank(text) || text.length() <= MAX_TEXT_LENGTH) {
            return text;
        }

        try (ByteArrayInputStream bytesArrayInputStream = new ByteArrayInputStream(text.getBytes(StandardCharsets.UTF_8))) {

            FileInfoService fileService = SpringContextHolder.getBean(FileInfoService.class);
            FileVo fileVo = fileService.uploadFileWithFileName(bytesArrayInputStream,
                    FILE_PREFIX + DigestUtil.md5Hex(text) + ".txt");
            return LONG_TEXT_FIELD_PREFIX + fileVo.getBucketUrl();
        } catch (IOException e) {
            log.error("保存长文本失败", e);
        }
        return "";
    }

    /**
     * 获取长文本
     *
     * @param textKey 长文本key
     * @return 长文本字符串
     */
    public String getLongText(String textKey) {
        if (StrUtil.isBlank(textKey) || !textKey.startsWith(LONG_TEXT_FIELD_PREFIX)) {
            return textKey;
        }

        FileInfoService fileService = SpringContextHolder.getBean(FileInfoService.class);
        InputStream inputStream = fileService.getStreamByUrl(textKey.substring(LONG_TEXT_FIELD_PREFIX.length() + 1));
        if (inputStream == null) {
            log.warn("获取长文本失败，文件不存在：{}", textKey);
            return null;
        }
        return IoUtil.read(inputStream, StandardCharsets.UTF_8);
    }
}